Welcome to OLGA 7 User ManualThis is the OLGA 7 User Manual. The user manual includes both information about the OLGA 7 engine and the OLGA 7 graphical user interface (GUI). The complete program documentation includes - Release Notes for OLGA 7 - OLGA 7 User Manual (this document) - Wells GUI User Manual - FEMTherm GUI Manual - OLGA OPCServer Guide - Installation Guide All documents listed above are available from the Start Menu (Start - All Programs - SPT Group - OLGA 7 - Documentation). The OLGA User Manual is also available from the Help menu in the GUI). OLGA is equipped with a context sensitive help document which can be opened directly from the user interface. The help can be reached in several ways: • Click the Properties view and press F1 -> leads to the information on the relevant model • Select Help from the File menu User Manuals for other tools included with the OLGA 7 installation (e.g. FEMTherm, Rocx, etc) are available from the Help menus in the tools. Release Information Please refer to the Release Notes for detailed release information for OLGA 7. The Release Notes describes changes in OLGA 7 relative to OLGA 6.3, and should be read by all users of the program. The complete program documentation consists of the OLGA User Manual, Wells GUI User Manual, FEMTherm GUI Manual, OLGA OPCServer Guide, Installation Guide, and the Release Notes. The program is available on PC’s with Microsoft Windows operating systems (Windows XP, Windows Vista and Windows 7). Several versions of OLGA may be installed in parallel. Note that you may also run several versions of the engine from one version of the GUI - please refer to the Installation Guide to learn how to configure the GUI for several engines. The support center provides useful information about frequently asked questions and known issues. The support centre is available from the SPT Group Support Centre Please contact SPT Group if problems or missing functionality are encountered when using OLGA or any of the related tools included in the OLGA software package. E-mail:
[email protected] Telephone: +47 6484 4550 Fax: +47 6484 4500 Address: SPT Group AS, P.O. Box 113, N-2027 Kjeller Introduction OLGA is the industry standard tool for transient simulation of multiphase petroleum production. The purpose of this manual is to assist the user in the preparation of the input data for an OLGA simulation. In this manual you can find a general introduction to OLGA an overview of the required and the optional input to OLGA. It also describes in some detail different simulation options such as wax deposition, corrosion etc. a detailed description of all input data and the required fluid property tables a description of the output The sample cases presented with the installation of OLGA are intended to illustrate important program options and typical simulation output. A description of the sample cases are also included in this manual. OLGA comes in a basic version with a number of optional modules;FEMTherm, Multiphase Pumps, Corrosion, Wells, Slug Tracking, Wax Deposition, Inhibitor Tracking, Compositional Tracking, Single Component Tuning, Hydrate Kinetics and Complex Fluid. In addition there is a number of additional programs like the OLGA GUI and the FEMThermViewer for preparation of input data and visualisation of results. These optional modules and additional programs are available to the user according to the user's licensing agreement with SPT Group. See also: Background OLGA as a strategic tool OLGA Model Basics How to use in general Graphical User Interface Simulation model Input files Applications Threaded Execution Background OLGA 7 is the latest version in a continuous development which was started by the Institute for Energy Research (IFE) in 1980. The oil industry started using OLGA in 1984 when Statoil had supported its development for 3 years. Data from the large scale flow loop at SINTEF, and later from the medium scale loop at IFE, were essential for the development of the multiphase flow correlations and also for the validation of OLGA. Oil companies have since then supported the development and provided field data to help manage uncertainty, predominantly within the OLGA Verification and Improvement Project (OVIP). OLGA has been commercially available since the SPT Group started marketing it in 1990. OLGA is used for networks of wells, flowlines and pipelines and process equipment, covering the production system from bottom hole into the production system. OLGA comes with a steady state pre-processor included which is intended for calculating initial values to the transient simulations, but which also is useful for traditional steady state parameter variations. However, the transient capabilities of OLGA dramatically increase the range of applicability compared with steady state simulators. OLGA as a strategic tool OLGA is applied for engineering throughout field life from conceptual studies to support of operations. However the application has been extended to be an integral part of operator training simulators, used for making operating procedures, training of operators and check out of control systems. Further, OLGA is frequently embedded in on-line systems for monitoring of pipeline conditions and forecasting and planning of operations. OLGA can dynamically interface with all major dynamic process simulators, such as Hysys, DynSim, UniSim, D-SPICE, INDISS and ASSETT. This allows for making integrated engineering simulators and operator training simulators studying the process from bottom hole all the way through the process facility in a single high fidelity model. Note that the OLGA flow correlation has been implemented in all major steady state simulators providing consistent results moving between different simulators. Applications When the resources become more scarce and complicated to get to careful design and optimisation of the entire production system is vital for investments and revenues. The dimensions and layout of wells and pipelines must be optimised for variable operational windows defined by changing reservoir properties and limitations given by environment and processing facilities. OLGA is being used for design and engineering, mapping of operational limits and to establish operational procedures. OLGA is also used for safety analysis to assess the consequences of equipment malfunctions and operational failures. REFERENCES contains a list of papers describing the OLGA model and its applications. Design and Engineering OLGA is a powerful instrument for the design engineer when considering different concepts for hydrocarbon production and transport - whether it is new developments or modifications of existing installations. OLGA should be used in the various design phases i.e. Conceptual, FEED [2] and detailed design and the following issues should be addressed: • Design Sizes of tubing and pipes Insulation and coverage Inhibitors for hydrate / wax Liquid inventory management / pigging Slug mitigation Processing capacity (Integrated simulation) • Focus on maximizing the production window during field life Initial Mid-life Tail • Accuracy / Uncertainty management Input accuracy Parameter sensitivity • Risk and Safety Normally the engineering challenge becomes more severe when accounting for tail-end production with reduced pressure, increasing water-cut and gas-oil ratio. This increase the slugging potential while fluid temperature reduces which in turn increase the need for inhibitors and the operational window is generally reduced. Operation OLGA should be used to establish Operational procedures and limitations Emergency procedures Contingency plans OLGA is also a very useful tool for operator training Training in flow assurance in general Practicing operational procedures Initial start up preparations Some typical operational events suitable for OLGA simulations are discussed below. Pipeline shut-down If the flow in a pipeline for some reason has to be shut down, different procedures may be investigated. The dynamics during the shut-down can be studied as well as the final conditions in the pipe. The liquid content is of interest as well as the temperature evolution in the fluid at rest since the walls may cool the fluid below a critical temperature where hydrates may start to form. Pipeline blow-down One of the primary strategies for hydrate prevention in case of a pipeline shut-down is to blow down. The primary aim to reduce the pipeline pressure below the pressure where hydrates can form. The main effects that can be studied are the liquid and gas rates during the blow-down, the time required and the final pressure. Pipeline start-up The initial conditions of a pipeline to be started is either specified by the user or defined by a restart from a shut-down case. The start-up simulation can determine the evolution of any accumulated liquid slugs in the system. A start-up procedure is often sought whereby any terrain slugging is minimised or altogether avoided. The slug tracking module is very useful in this regard. In a network case a strategy for the start-up procedure of several merging flow lines could be particularly important. Change in production Sometimes the production level or type of fluid will change during the lifetime of a reservoir. The modification of the liquid properties due to the presence of water, is one of the important effects accounted for in OLGA. A controlled change in the production rate or an injection of another fluid are important cases to be simulated. Of particular interest is the dynamics of network interactions e.g. how the transport line operation is affected by flow rate changes in one of several merging flow lines. Process equipment Process equipment can be used to regulate or control the varying flow conditions in a multi-phase flow line. This is of special interest in cases where slugging is to be avoided. The process equipment simulated in OLGA includes critical- and sub-critical chokes with fixed or controlled openings, check-valves, compressors with speed and anti- surge controllers, separators, heat exchangers, pumps and mass sources and sinks. Pipeline pigging OLGA can simulate the pigging of a pipeline. A user specified pig may be inserted in the pipeline in OLGA at any time and place. Any liquid slugs that are created by the pig along the pipeline can be followed in time. Of special interest is the determination of the size and velocity of a liquid slug leaving the system ahead of a pig that has been inserted into a shutdown flow line. Hydrate control Hydrate prevention and control are important for flow assurance. Passive and active control strategies can be investigated: Passive control is mainly achieved by proper insulation while there are several options for active control which can be simulated with OLGA: Bundles, electrical heating, inhibition by additives like MEG. Wax deposition In many production systems wax would tend to deposit on the pipe wall during production. The wax deposition depends on the fluid composition and temperature. OLGA can model wax deposition as function of time and location along the pipeline. Tuning Even if the OLGA models are sophisticated models made for conceptual studies and engineering will be based on input and assumptions which are not 100% relevant for operations. Therefore OLGA is equipped with a tuning module which can be used on-line and off-line to modify input parameters and also critical model parameters to match field data. Wells - Flow stability e.g. permanent or temporary slugging, rate changes - Artificial lift for production optimization - Shut-in/start-up - water cut limit for natural flow - Cross flow between layers under static conditions - WAG injection - Horizontal wells / Smart wells - Well Clean-up and Kick-off - Well Testing - Well control and Work-over Solutions Safety Analysis Safety analysis is an important field of application of OLGA. OLGA is capable of describing propagation of pressure fronts. For such cases the time step can be limited by the velocity of sound across the shortest pipe section. OLGA may be useful for safety analysis in the design phase of a pipeline project, such as the positioning of valves, regulation equipment, measuring devices, etc. Critical ranges in pipe monitoring equipment may be estimated and emergency procedures investigated. Consequence analysis of possible accidents is another interesting application. The state of the pipeline after a specified pipe rupture or after a failure in any process equipment can be determined using OLGA. Simulations with OLGA can also be of help when defining strategies for accident management, e.g. well killing by fluid injection. Finally it should be mentioned that the OLGA model is well suited for use with simulators designed for particular pipelines and process systems. Apart from safety analysis and monitoring, such simulators are powerful instruments in the training of operators. [2] Front End Engineering and Design OLGA Model Basics OLGA is a three-fluid model, i.e. separate continuity equations are applied for the gas, for the oil (or condensate) and water liquids and also for oil (or condensate) and water droplets. Gas is always assumed to be lighter than oil and water in OLGA, but oil may be both lighter or heavier than water[1]. These fluids may be coupled through interfacial mass transfer. Three momentum equations are used; one for each of the continuous liquid phases (oil/condensate and water) and one for the combination of gas with liquid droplets. The velocity of any liquid droplets entrained in the gas phase is given by a slip relation. One mixture energy equation is applied; assuming that all phases are at the same temperature. This yields seven conservation equations and one equation of state to be solved: the seven conservation equations are three for mass, three for momentum, and one for energy, while the equation of state is for pressure. Two basic flow regime classes are recognised ; distributed and separated flow. The former comprises bubble and slug flow [2], the latter stratified and annular mist flow. Figure A Flow patterns in horizontal flow Transition between the regime classes is determined by the program on the basis of a minimum slip concept combined with additional criteria. To close the system of equations, fluid properties, boundary and initial conditions are required. The equations are linearised and a sequential solution scheme is applied. The pressure and temperature calculations are de-coupled i.e. current pressure is based on previous temperature. The semi-implicit time integration implemented allows for relatively long time steps, orders of magnitudes longer than those of an explicit method (which would be limited by the Courant Friedrich Levy criterion based on the speed of sound). The numerical error is corrected for over a period of time. The error manifests as an error in local fluid volume (as compared to the relevant pipe volume). [1] Note that the OLGA model has only been verified and tuned for fluids where oil is lighter than water. [2] In standard OLGA a slug unit model is applied which calculates average liquid hold-up and pressure, but which does not give any details about individual slugs. To follow individual slugs through the system the slug tracking module must be applied. Network In OLGA the network comprises flow paths coupled with nodes which have a volume. General networks with closed loops can then be modelled, see below. The flow paths have a user defined direction but the flow is invariant to direction as such and any fluid phase may flow co-currently or counter-currently with respect to the pre-defined direction at any time and position. Pipe-bends are not accounted for as such (except for differences in static head). The user may apply pressure loss coefficients at boundaries between numerical sections. Equipment is positioned on the flow path – usually on a pipe-boundary. However, the separator in OLGA is a network component similar to a node. Controllers are specified as integral parts of the simulation model and they have their own network formalism. Threaded Execution Pipe sections belonging to the same branch may be updated in parallel. Suppose a branch has 100 sections, and that two threads are available to the OLGA engine: Section 1 and section 51 will be updated simultaneously, then section 2 and section 52 are updated, and so on. Depending on the computer hardware, this method can drastically reduce the time OLGA takes to advance one time-step. Normally, you do not need to change the default settings of neither OLGA nor your operating system. Parallel updating of segments is usually activated in the OLGA engine if your PC supports it. Controlling the degree of parallelism The Windows operating system decides how many threads will be used. If your PC is equipped with a quad-core CPU, typically four threads will be simultaneously running to update four sections in parallel. Is your CPU a single-core Intel Xeon processor with "hyper-threading" (HT), probably two engine threads will be used. It is possible to overrule the choice of the operating system by setting the environment variable OMP_NUM_THREADS; use Windows' Control Panel to do this. However, the preferred way to change the degree of parallelisation is do so from the OLGA menu system. Setting the value here takes precedence over the OMP_NUM_THREADS environment variable. A situation where you might want to reduce the number of threads, arise if you execute parametric studies. Given that your license permits, it would be preferable to spend the CPU's cores on simultaneous simulations, rather than on speeding up each simulation in the study. Another situation could be when you don't want OLGA to consume all your computing power, e.g., if you want to write a report while OLGA is working. Most large cases will benefit from the parallelisation. Still, please note that some of your PC's cache memory will be used for forking and joining the threads, and doing the necessary book-keeping. As a consequence, special cases will run faster with a single engine thread. Parallel speed-up The parallelisation encompasses heat calculations in section walls, updating fluid properties and flashing, and, most importantly, calls to the flow model which decides friction factors, liquid holdup and the flow regime. If the flow model calculations dominate the overall simulation, the utilization of the CPUs is most efficient. Monitoring the OLGA process The Task Manager can be used to check how OLGA loads your CPU. When the number of engine threads equals the number of cores (or equals two on a single core HT-CPU) you should see the CPU usage being clearly over fifty percent when OLGA is simulating. In the Task Manager's list of processes it is possible to view the number of threads for each process. With 1 engine thread, it uses a total of 5 threads in batch mode, and 8 threads while running under control of the GUI. With 2 engine threads allowed, the task manager would display 6 threads for a batch run and 9 threads for a GUI run; with 4 engine threads the total number of threads would be 8 and 11, respectively. Files and file extensions When using the OLGA GUI understanding the different files used by the GUI and the simulator are not required. A basic understanding of the different file types is still useful when backing up files in Windows Explorer or running simulations from the command line. The figure below illustrates some of the files used by OLGA. Project File (*.opp) The project file is a file with references to other files (e.g. case files) Case File (*.opi) The case file contains all user input in addition to graphical layout of the model, parametric study input and more. Generated input files (*.genkey) The genkey file is generated when starting an OLGA simulation from the graphical user interface (GUI). Output files During the simulation, the simulator will produce several types of output files. The most common are trend plots (*.tpl), profile plots (*.ppl), general output information (*.out) and restart files (*.rsw). The files with a ~ prefix e.g. ~Case-0.opi is the case file from the last save. With auto-save turned on for all case files in a project, files are saved at user-specified intervals. Input files The OLGA simulator uses text files for describing the simulation model: .opi; generated and used by the OLGA GUI .inp; input format used by OLGA 5 and earlier versions .key; input format used by OLGA The .key format has been introduced as the new input file format for the OLGA engine. The OLGA GUI will automatically generate files in this format (with the extension .genkey). The .key format reflects the network model described in the simulation model and should be the preferred format. In addition to the simulation file, OLGA handles input in several other formats as described in Data files. Simulation description The input keywords are organised in Logical sections, with Case level at the top, followed by the various network components and then the connections at the end. Case level Case level is defined as the global keywords specified outside of the network components and connections. Case level keywords can be found in the CaseDefinition, Library, FAmodels and Output sections. The following keywords must or can be defined at Case level: CaseDefinition; Case, Files, Integration, Options, Dtcontrol, Restart, Serveroptions, Udoptions Library; Material, Wall, Shape, Table, Drillingfluid, Hydratecurve, Timeseries, Tracerfeed, Udphase, Uddispersion, Udpdf, CentPumpCurve, Reservoirinflow Compositional; Compoptions, Feed, Udfeed, Blackoiloptions, Blackoilcomponent, Blackoilfeed, Singleoptions FA-models; Wateroptions, Fluid, Slugtuning Output; Animate, Output, Trend, Profile, Outputdata, Trenddata, Profiledata, Serverdata, Plot, Xyt Drilling; Tooljoint CASE PROJECT="OLGA Manual", TITLE="Example case", AUTHOR="SPT Group AS" INTEGRATION STARTTIME=0, ENDTIME=7200, DTSTART=0.1, MINDT=0.1, MAXDT=5 FILES PVTFILE=fluid.tab MATERIAL LABEL=MAT-1, DENSITY=0.785E+04, CAPACITY=0.5E+03, CONDUCTIVITY=0.5E+02 WALL LABEL=WALL-1, THICKNESS=(0.9000E-02, 0.2E-01), MATERIAL=(MAT-1, MAT-1) Network components The network components are the major building blocks in the simulation network. PRESSURE=50 bara. position and time for printed output. PLOT. position and time for printed output. CD=0.PHASESPLITNODE. as shown below.28E-04. GL) NODE Boundary&Initialconditions PARAMETERS. HAMBIENT=6. BRANCH LABEL=BRAN-1. Defines variable names and time intervals for writing of data to the profile plot file. Each pipe can again be divided into sections as described above. GEOMETRY. GASFRACTION=-1. Defines name.FLOWPATH. Defines initial values for flow. TYPE=PRESSURE. NEARWELLSOURCE. VARIABLE=(PT bara.12. position and characteristic data for a heat exchanger. NSEGMENT=4. NETWORKCOMPONENT TYPE=Node. The source flow can be given by a time series or determined by a controller. LOSS. VALVE. Each data group belonging to this network component will be written within these tags.Each network component is enclosed within start (NETWORKCOMPONENT) and end (ENDNETWORKCOMPONENT) tags as shown below.. Each pipe in the system can also have a pipe wall consisting of layers of different materials. HOLHL. TAG=NODE_INLET PARAMETERS LABEL=INLET. INITIALCONDITIONS is not required when a steady state calculation is performed. It should be noted that the steady state preprocessor ignores the process equipment marked with (*) in the list below. The leak can also be connected to another flowpath to simulate gas lift etc. position and flow characteristics. INITIALCONDITION. GEOMETRY=GEOM-1. TM. TEMPERATURE=62. WALL=WALL-1 Boundary&Initialconditions For the solution of the flow equations. Defines variable names. Specifies end point or length and elevation of a pipe. Defines variable names and time intervals for writing of data to the trend plot file. DIAMETER=0. and data necessary for calculating the mass flow into or out of the system. NODE ProcessEquipment. SECTIONBOUNDARY=4. Defines a mass source with name. PROFILE(DATA). PUMP (*). Further discretization. Defines starting point for flowpath. The following keywords are used for Output: OUTPUT(DATA). all relevant boundary conditions must be specified for all points in the system where mass flow into or out of the system. FLUIDBUNDLE. GASFRACTION=-1. SECTION=1.. diameter. TRANSMITTER (*). Defines a named position for reference in other keywords. COMPRESSOR (*).CONTROLLER ThermalComponent. Defines name. This keyword is hidden in the GUI. position and characteristic data for a choke or a valve. Defines name. Initial conditions at start up and parameters used for calculating heat transfer must also be specified.0 Output OLGA provides several output methods for plotting simulation results. TOTALWATERFRACTION=-1.4E+03. Defines variable names and time intervals for writing of data to the trend plot file. PIPE. TREND(DATA). LEAK. HEATEXCHANGER.ANNULUS. SEPARATOR Controller. TYPE=CLOSED ENDNETWORKCOMPONENT NETWORKCOMPONENT TYPE=Node. TOTALWATERFRACTION=-1. Defines the position of a leak in the system with leak area and back pressure. OLGA supports a broad range of different types of process equipment. SOURCETYPE=PRESSUREDRIVEN Process Equipment In order to obtain a realistic simulation of a pipeline system. FLUID=1 GEOMETRY LABEL=GEOM-1 PIPE LABEL=PIPE-1. position. temperature and holdup. type and characteristic data for a pump. Defines a transmitter position and the variable to be transmitted. position and values for local pressure loss coefficients. HMININNERWALL=0. The following keywords are used for Output: OUTPUTDATA. SOLIDBUNDLE FLOWPATH Piping The flowpath can be divided into several pipes. pressure. Defines name. DIAMETER=0. TIME=0. and wall name are specified. POSITION. ELEVATION=0. OPENING=1. inner surface roughness. SOURCE. GG. TIME=0. A collection keyword for all node keys. Defines name. position and allowed flow direction for a check valve. position and operating characteristics of a compressor. VALVE LABEL=CHOKE-1-1.5E+03 SOURCE LABEL=SOUR-1-1. ENDNETWORKCOMPONENT The following network component keywords can be specified (see links for further details on each component): FlowComponent. TRENDDATA. HEATTRANSFER PIPE=ALL. Defines variable names and time intervals for writing of data to the OLGA viewer file.7. Definition of the heat transfer parameters. The following keywords are used for Process equipment: CHECKVALVE (*). Defines name. Output OLGA provides several output methods for plotting simulation results. TAG=NODE_OUTLET PARAMETERS LABEL=OUTLET. PIPE=PIPE-1. PIPE=1.5. TEMPERATURE=32. DIAMETER=0. HOLWT) PROFILEDATA VARIABLE=(GT. Defines a near-wellbore source used together with OLGA Rocx. it is normally required to include some process equipment in the simulation. PRESSURE=70 bara. TRENDDATA PIPE=1.12. FLUID=1 ENDNETWORKCOMPONENT . SECTION=1. ROUGHNESS=0. All sections defined within the same pipe must have the same diameter and inclination. LENGTH=0. NETWORKCOMPONENT TYPE=FlowPath. TIME=0. TAMBIENT=6. WELL. The following keywords are used for Piping: BRANCH. Defines a well with name. TAG=FP_BRAN . Defines geometry and fluid labels. Defines variable names. The following keywords are used for Boundary & Initial conditions: HEATTRANSFER.12. which can have an inclination varying from the other pipes in the flowpath. CLOSED. Defines variable names and time intervals for writing of data to the trend plot file. TRENDDATA. A collection keyword for all controller keys. Output PROFILEDATA. MASSFLOW. AmbientConditions AMBIENTDATA. Defines variable names. A collection keyword for specifying the Annulus ambient conditions. The following keywords are used for Output: OUTPUTDATA.2000.NODE_OUTLET FLOWTERM_1) Separator and PhaseSplitNode have special handling of terminals. TRENDDATA. Defines variable names and time intervals for writing of data to the trend plot file. TIME=(0. TRENDDATA.NODE_INLET FLOWTERM_1) CONNECTION TERMINALS = (FP_BRAN OUTLET. Defines variable names and time intervals for writing of data to the trend plot file. A component to place within the solid bundle definition. A collection keyword for specifying the fluid bundle ambient conditions.3). A collection keyword for all annulus keys. position and time for printed output. PRESSURE) has one terminal. A collection keyword for specifying the solid bundle ambient conditions. Defines variable names. Defines variable names and time intervals for writing of data to the profile plot file. A component to place within the annulus definition. MAXCHANGE=1. position and time for printed output. This keyword is hidden in the GUI.2.0 ENDNETWORKCOMPONENT ANNULUS Initialconditions PARAMETERS. CONNECTION TERMINALS = (FP_BRAN INLET. Defines variable names. . Defines variable names and time intervals for writing of data to the trend plot file. while internal nodes has an arbitrary number of terminals where flowpaths can be connected to. This keyword is hidden in the GUI. The following keywords are used for Output: OUTPUTDATA. A collection keyword for all solid bundle keys. This keyword is hidden in the GUI.e.0. Defines variable names and time intervals for writing of data to the profile plot file. Connections The CONNECTION keyword is used to couple network components. This keyword is hidden in the GUI. NETWORKCOMPONENT TYPE=ManualController.2010. Output OLGA provides several output methods for plotting simulation results. TAG=SetPoint-1 PARAMETERS SETPOINT=(2:0. A collection keyword for all phase split node keys. Defines variable names and time intervals for writing of data to the trend plot file. SOLIDBUNDLE Initialconditions PARAMETERS. Output OLGA provides several output methods for plotting simulation results. SEPARATOR Boundary&Initialconditions PARAMETERS. such as a node and a flowpath. TRENDDATA. TRENDDATA.4010) s. This keyword is hidden in the GUI. AmbientConditions AMBIENTDATA. Each flowpath has an inlet and an outlet terminal that can be connected to a node terminal.2:0. A collection keyword for all separator keys. AmbientConditions AMBIENTDATA. Output OLGA provides several output methods for plotting simulation results. Defines variable names and time intervals for writing of data to the trend plot file. This keyword is hidden in the GUI. TRENDDATA.PHASESPLITNODE Boundary&Initialconditions PARAMETERS. Boundary nodes (i. The following keywords are used for Output: OUTPUTDATA.0. position and time for printed output. BundleComponents COMPONENT.1. Output PROFILEDATA. FLUIDBUNDLE Initialconditions PARAMETERS. CONTROLLER Boundary&Initialconditions PARAMETERS. A component to place within the fluid bundle definition. STROKETIME=0. AnnulusComponents COMPONENT. BundleComponents COMPONENT.4000. Defines variable names and time intervals for writing of data to the profile plot file. Output PROFILEDATA. A collection keyword for all fluid bundle keys. FLUID=1 GEOMETRY LABEL=GEOM-1 PIPE LABEL=PIPE-1.2010.785E+04.e. 0. velocity.5E+03 SOURCE LABEL=SOUR-1-1. DTSTART=0. SETPOINT-1 OUTSIG_1) See also connecting the controllers for more information. Each data group can be seen as either a simulation object. TEMPERATURE=32. WALL=WALL-1 HEATTRANSFER PIPE=ALL. NSEGMENT=4. TAMBIENT=6.28E-04. TAG=SetPoint-1 PARAMETERS SETPOINT=(2:0. volume fractions) as average values in the middle of the section. The simulation objects can again reference both information and administration objects.1. TM.1. control volumes).0 ENDNETWORKCOMPONENT CONNECTION TERMINALS = (FP_BRAN INLET. TEMPERATURE=62. TIME=0. HOLWT) PROFILEDATA VARIABLE=(GT. simulation objects for flow manipulation · ThermalComponent.1.4000. controller simulation objects · FlowComponent. a special node model that can separate the fluid into single phases · Controller. Example file The keyword examples shown above can be combined to an OLGA .NODE_INLET FLOWTERM_1) CONNECTION TERMINALS = (FP_BRAN OUTLET. PIPE=PIPE-1. thermal simulation objects · FA-models. PRESSURE=50 bara. PRESSURE=70 bara. SETPOINT-1 OUTSIG_1) ENDCASE Simulation model An OLGA simulation is controlled by defining a set of data groups consisting of a keyword followed by a list of keys with appropriate values. DENSITY=0. administration and information objects for component tracking · Output. MINDT=0. mass flow. The network objects can be of the following types: · Flowpath. a boundary condition or connection point for 2 or more flowpaths · Separator.12. . GASFRACTION=-1. information object. administration objects for output generation · Drilling. The staggered spatial mesh applies flow variables (e. HOLHL.9000E-02.4E+03. THICKNESS=(0. TYPE=CLOSED ENDNETWORKCOMPONENT NETWORKCOMPONENT TYPE=Node. information objects referenced in one or more simulation objects · Controller.2:0.7.key file. MAT-1) NETWORKCOMPONENT TYPE=FlowPath. temperature. objects that perform supervision and automatic adjustments of other parts of the simulation network · Thermal.4010) s.5.5E+03. GASFRACTION=-1.0 TRENDDATA PIPE=1. pressure. ELEVATION=0.12. the pipeline which the fluid mix flows through · Node. FLUID=1 ENDNETWORKCOMPONENT NETWORKCOMPONENT TYPE=ManualController. GG. CONDUCTIVITY=0. TIME=(0. where information objects can be used within the simulation objects and the administration objects control various parts of the simulation.NODE_OUTLET FLOWTERM_1) CONNECTION TERMINALS = (FP_BRAN Transmitter-1@INPSIG. administration objects for flow assurance models · Compositional. The figure below shows a flow path divided into 5 sections. HMININNERWALL=0. CONNECTION TERMINALS = (FP_BRAN
[email protected]. ENDTIME=7200.0. STROKETIME=0.0. administration objects for simulation control · Library. HAMBIENT=6. OPENING=1. TOTALWATERFRACTION=-1. CD=0. TOTALWATERFRACTION=-1. DIAMETER=0. or administration object. SOURCETYPE=PRESSUREDRIVEN VALVE LABEL=CHOKE-1-1. MATERIAL=(MAT-1. SECTION=1. MAXDT=5 FILES PVTFILE=fluid. CAPACITY=0. SECTION=1. DIAMETER=0.g. OLGA Well simulation object Network model A simulation model is then created by combining several simulation objects to form a simulation network. TIME=0. network simulation objects · Boundary&InitialConditions. Logical sections The different keywords are divided into logical sections: · CaseDefinition. drilling simulation object · OLGA Well. TAG=FP_BRAN BRANCH LABEL=BRAN-1.12. TAG=NODE_OUTLET PARAMETERS LABEL=OUTLET. TAG=NODE_INLET PARAMETERS LABEL=INLET. CASE PROJECT="OLGA Manual". GL) ENDNETWORKCOMPONENT NETWORKCOMPONENT TYPE=Node. TYPE=PRESSURE. DIAMETER=0. LENGTH=0. GEOMETRY=GEOM-1. flux) at section boundaries and volume variables (e.3). TITLE="Example case". objects for ambient heat conditions The simulation model can handle a network of diverging and converging flowpaths. simulation objects for flow in and out of flowpath · ProcessEquipment. TIME=0. ROUGHNESS=0. These sections correspond to the spatial mesh discretization in the numerical model. AUTHOR="SPT Group AS" INTEGRATION STARTTIME=0. MAXCHANGE=1.2E-01).g. SECTIONBOUNDARY=4.The CONNECTION keyword is also used for coupling signal components.2000. Each flow path consists of a sequence of pipes and each pipe is divided into sections (i. PIPE=1.tab MATERIAL LABEL=MAT-1.5E+02 WALL LABEL=WALL-1. mass. VARIABLE=(PT bara. ten times faster than real-time). the device is always the simulation of the current OLGA model. a display or a simulator that implements a client for OPC DA.g. and controllers. and manipulate valve openings. and both server and client is run as administrator. and removes it when it stops. There are two modes for controlling OLGA's time-stepping: SIMULATOR and EXTERNAL.Each flowpath must start and end at a node. one sets a speed relative to the computer's clock (say. boundary node for specifying boundary conditions · Internal. By toggling SaveSnap or Stop. default settings. Through OPC. well pressures. One uses the SERVEROPTIONS keyword to set up the OPC Server.. When in EXTERNAL mode however. the setpoint of a PID controller or the massflow from a source. and may also write values to the simulation. and can also contain other simulation objects (e. hybrid node for creating a closed-loop network The figure below shows a simple simulation network consisting of three flowpaths and four nodes. and so the client takes control over the time-stepping. The flowpath is the main component in the simulation network. respectively. and there are currently three different kinds of nodes available: · Terminal. An OPC DA client connected to the OLGA OPC Server. a process simulator or a user interface is allowed to connect to the OLGA simulation. by the same user.g. not shown in the figure above). Since OLGA owns the OPC Server. for coupling flowpaths (e. and can be used with both trend and profile output variables. When the OLGA OPC Server is in SIMULATOR mode. Input can be configured for certain keys in the keywords NODE. and the receiver could be a scheduler.one has to rely on the general. A good understanding of DCOM security may be necessary to set up communication between a server at one computer and a client at another computer. split or merge) · Crossover. OPC DA relies on DCOM security. In the case of the OLGA OPC Server. it is possible to interact with the running model. found with the OLGA documentation. which is very similar to TRENDDATA. The OLGA OPC Server also have some special writeable items that serve as commands. which can be difficult. It is also possible to describe the simulation model with a text file. Output is specified with the SERVERDATA keyword. OPC Server If asked for in the OLGA model. it is not possible to set specific DCOM security for the OLGA OPC Server -. may read output from the running simulation. It is usually quite easy to establish the connection when server and client is run on the same computer. process equipment. these keys form a set of parameters for the OLGA model being simulated. OLGA loads a snap file (i. The client updates the time on the server. Graphical User Interface . for further reference. OLGA will run a server for OPC Data Access. See the document OLGA OPC Server User Guide. OPC Data Access (OPC DA) is a specification for continuous communication of real-time data from a device to a receiving process. WELL. SOURCE. See Input files for further descriptions. OLGA reads a time from the OPC Server. and steps forward until it reaches that time. a restart file) or stops.e. With the OPC Server. VALVE. and OLGA slows down its time-stepping process to try and keep this speed. In addition it contains information about simulation options. viewing results and much more. When a case is opened. The simulation is usually started from the GUI but it can also be started independently (using a command line interface. When working in the OLGA GUI.Relationship between GUI and Simulation engine When starting OLGA there are two major components that come into play: OLGA GUI The OLGA GUI (GUI) is the graphical user interface which allows for the creation of new OLGA cases. starting simulations. remove from project delete or delete all output files as well Saves the case Opens a dialogue with the option to save the case with a new name Copies the selection Pastes the copied object(s) Deletes the selection Opens custom input dialogue if available or sets focus in the properties editor Μακεσ τηε γριδ ον τηε διαγραµ ϖιεω ϖισιβλε Σναπσ ιτεµσ το τηε γριδ ωηεν µοϖινγ τηεµ. It normally consists of pipelines. The results from the simulation are stored in plot-files which can be displayed in the GUI. OLGA Simulator The OLGA simulator is the component that performs the simulation. The fluid files referred to in a case are automatically included in the project. that influence the simulation. ωιλλ ωορκ εϖεν ωηεν τηε γριδ ισ νοτ ϖισιβλε Rearranges the graphical layout with mainly . This is what is described in detail in this document. files with compressor characteristics etc. editing input. reports. A project can contain other information like Word documents. boundary conditions. work is always performed within the context of a project and will create a project when one doesn’t exist. Case toolbar Toolbar icon Tooltip Duplicate case Remove case Save Save as Copy Paste Delete Properties Show Grid Snap to Grid Arrange Horizontal Ctrl+C Ctrl+V Delete button Double click on object Ctrl+S Shortcut key Description A new identical case will be created and added to the project Gives three options. An OLGA project is a container for one or more OLGA cases and is a way of organizing relevant files. etc. Excel calculations and more. Introduction to projects and cases An OLGA case (model) is the collection of all the input data that is sent to the simulator when clicking ‘run simulation’. process equipment and more to simulate the real world objects. A case may also consist of references to other files like tab-files for fluid definitions. the GUI will create a project for it and when closing the GUI it will prompt to save the project and the case(s). They may be detached from the frame (floating) and may be docked again by moving the window to the border of the frame. all valves on one flowpath Shows all instances in a case of the selected object in an editor table Unlocks keywords generated in Well GUI Distributes the inline equipment on a flowpath equally Duplicates the selected object to all flowpaths Οπενσ τηε νετωορκ οϖερϖιεω/χοννεχτιον ωινδοω Adds selected object to the User's Library Opens the User's Library with a list of objects that can be imported Opens the parametric studies Χοπιεσ τηε διαγραµ ϖιεω ορ πλοτ το τηε χλιπβοαρδ δεπενδινγ ον ωηατ ισ ιν φοχυσ ιν τηε χεντρε αρεα Opens a dialogue with easy configuration of bundles/annulus and burial of flowpaths Adds a OLGA well to the case. When the cursor is moved over one of the arrows towards the edge of the screen the window will dock on the corresponding border of the frame. When dropped on one of the four arrows in the centre of the screen the window will dock towards the corresponding side of the frame of the pipeline schematic window. independent of GUI Runs the simulation well integrated with GUI Pauses the simulation if run interactively Runs one step (only interactively) Option to configure the length of the step Shift+F5 F7 Stops the simulation Checks input file and reports errors and missing information in the output view Adds a plot tab to the case with the option to select and configure multiple plots Adds a trend plot to the case if trend variable(s) are selected Adds a profile plot to the case if profile variables (s) are selected Adds a 3D holdup profile plot Gives the option to plot the fluid properties defined in a tab file Opens an input report of the case F3 Saves a restart file (only available for interactive simulation and when the simulation is paused) Opens the out file in a text editor Local instances Global instances Unlock Distribute Inline Equipment Duplicate to all Flowpaths Network connections Add to User’s Library Import from User’s Library Parametric Studies Copy as Image Add FEMTherm Add OLGA Well Run Batch Run Interactive Pause Step Step length Stop Verify Multiple Plots Trend Plot Profile Plot 3D Plot Fluid Plot Report Save Restart Output File F4 F5 F9 Ctrl+F5 Moving windows Windows may be hidden and re-opened through the view menu.horizontal flow lines Arrange Vertically Fit to page Ctrl+Q Ρεαρρανγε τηε γραπηιχαλ λαψουτ ωιτη µαινλψ ϖερτιχαλ φλοω λινεσ Ζοοµ ιν ορ ουτ το χαπτυρε τηε ωηολε γραπηιχαλ νετωορκ ιν τηε ϖισιβλε παρτ οφ τηε διαγραµ ϖιεω Shows all local instances of the selected object in an editor table. . the Well GUI will be opened for configuration of the well Runs the simulation from a command shell window. Double click on a floating window to move it back to the last docked position. In the picture below the blue area indicates where the window will end up if dropped at the current location. Double clicking on the top bar of a docked window makes it float and double clicking on the top bar of a floating window makes it dock. File view The File view shows the files associated with the project.opi file. However. This information is stored in the *. Note that the graphical layout will be recreated on reload from a text file as the text file doesn’t contain any information about the layout. Components view The Components view contains a library of objects that can be used to build the case. This will typically be the input file as well as pvt-files and other files used in the case.). any type of file can be added to the project (word-files. The text file may be edited and reload it into the GUI by right-clicking the opi-file and selecting Reload from text file. Simulation objects may be dragged from the Components window and dropped onto the Diagram view. By right clicking on a file the file can be removed or the input file can be opened in a text editor. Excel-files etc. . There are two modes: Display case and Display current object. Display current object will only show the signal connections for the selected object on the diagram view. process equipment and boundary conditions.The view is divided into several groups: Flow Component Process equipment Boundary and Initial Conditions FA models Controller Results covering nodes and flowpath covering all equipment covering only boundary conditions keywords covering pigs covering all types of controllers covering interactive plots and values Connections view The connections view gives information about the signal connections between transmitters. Display case will show all signal connections for the entire case. pressure) is connected to the PID controller’s measured input signal (MEASRD). The transmitter’s (TM-1) output signal (which depends on the variable specified for the transmitter e. Model view . The INPSIG for a valve is the same as the valve opening. controllers.g. The sample below shows that a PID controller’s output signal (CONTR) is connected to VALVE-1’s input signal (INPSIG). all valves on one flowpath. updates the geometry with the geometry available from the geometry editor Checks input file and reports errors and missing input in the output view. If the case overview window is not visible it can be opened from the View menu. Output and Network Components. Shows all instances within the case of the selected object in an editor table. modelling and simulations. A case contains Case Definitions. Network Components describe the properties of the flow network (currently either a node or a flow path). the object is made active and its properties may be edited in the Properties view. Libraries. Compositional has input to the compositional model. Adds selected keyword(s) to the user’s library. The information is divided into three categories: Errors. FA-models contain input to flow assurance models. The visible area can be moved by clicking and dragging (left mouse button) the white area. The model view contains input for all cases in the project. Case Overview The case Overview window is used for helping with orientation in the diagram view for larger network cases. Deletes selected object. Nonvisual objects (for instance case options) are not shown in the diagram view but are listed in the model view. Libraries contain keywords that can be accessed globally (for instance Material and Wall). The white frame shows what is visible in the diagram view. Thermal Components contains input to the FEMTherm and bundle models and input to annulus calculations. Shows all local instances of the selected object in an editor table. For a flowpath this would be the geometry editor. . When selecting an object in the model view.. Output view The Output view (not to be confused with the OUTPUT keyword/OUTPUT file) gives information about the state of the cases. · · · · · · · Case Definitions describe information common to the whole system being simulated. Switching between the different cases is done by clicking on the file name in model view. Pastes the copied item onto the currently selected item. Right-click while pointing to an object in the Model view brings up various menus depending on the object: Add -> Exchange Geometry -> Verify Copy Paste Delete Unlock Local instances Global instances Add to user’s library Import from user’s library Properties Add items to the network object. in the upper right corner. Warnings and Info. the size of the frame is dependent on the zoom level. The objects are ordered hierarchically with a project on top comprising one or more cases. Only for flowpaths. Note that the model view lists all objects in the case whereas the diagram view only shows the visual objects. Imports from the available keywords/components from the user’s library. Output contains global output definitions. profile and output.The Model view is used for navigating between the objects of the system. such as plotting intervals for trend. Unlocks keywords created in the Well GUI. Copies selected item. Starts the property editor for the selected object. Fixed points on a signal line can be added by selecting the signal line. select the flowline. This does not change the actual geometry of the flowline. select the signal line.g. pressure boundaries and process equipment are also visible. Fixed points can be removed from the flowline by right clicking on the point and selecting Delete segment. are indicated by an “orange” background colour. If the inline equipment is given a position (e. left click and hold one of the green ends while dragging it away from the node/separator. will appear on the flowline. process equipment and more. A fixed point. The fixed points can be moved to shape the signal line to improve the layout in the diagram view. clicking and holding the left mouse button and drag to where the fixed point should be added. Below is a snapshot from the GUI with the template basic case. nodes. pipe and section) the position will be adjusted to reflect the real location along the flowline. loaded. o Click on the symbol to go to the incomplete keyword · · Warnings - : The simulation may still be performed [1] Information o Simulator state changes o Progress during simulation o Any messages during simulation (info previously directed to the DOS window) The windows can be cleared from the context menu (right click). Output from other cases can be selected from the pull-down menu at the top of the output window. Sources. located in the top left of the output window. A left mouse click on the text will activate or deactivate the category.. See also Editing a case using the Diagram view Context menus Network connection overview Configuration of separator/phase split nodes Configuration of controller connections Short-cut keys Editing a case using the Diagram view Flowlines Nodes and flowlines are drawn schematically.· Error messages (and task list) : Cannot simulate o Errors in input o Errors from initialization phase o Errors during simulation o List of incomplete keywords. The diagram view displays pipelines. To disconnect a flowline from a node. left click and hold one of the green ends while dragging it away. Fixed points can be moved to shape the flowline to improve the layout in the diagram view. The navigator then hosts the workflow of creating a well case. indicated by a small square. Diagram view When a case is opened or created the central window of the GUI displays a graphical view of the case. In the diagram view. All objects shown in the component list can be dragged onto the diagram view. a link is available from the Help page from the File menu. By default the position of the equipment will be where it is dropped on the flowline. A fixed point. appears on the signal line. Flowlines can be created either by dragging the Flowpath component from the component list or by dragging from the middle of a node or from a separator’s inlet and outlets. The process equipment needs to be dropped on a flowline to be added to the diagram view. click and hold the left mouse button and drag to where the fixed point should be added. Navigator view The navigator view is only used when the Well GUI is active. All visible objects are listed in the components view. Case-1. not reflecting the real geometry of the case. Text can be copied: · Mark text · Right click and copy Active Output categories. indicated by a small square. To find out more about the Well GUI please read the User Manual for Well GUI. To disconnect a signal from an object. Fixed points on a flowline can be added by selecting the flow line. By default the output from the active case is shown. . Signal connections Signal connections are also based on dragging from one object to the connecting object. nodes and flow lines are drawn schematically. Starts the property editor for the selected object. Shows all instances within the case of the selected object in an editor table.Context menus for diagram view Right-click in the Diagram view activates a menu with the following items: Arrange diagram horizontally Arrange diagram vertically Fit to page Σηοω γριδ Snap to grid Νετωορκ Χοννεχτιονσ Παστε Copy as image Rearrange the graphical layout with mainly horizontal flow lines Rearrange the graphical layout with mainly vertical flow lines Zoom in or out to capture the whole graphical network in the visible part of the diagram view Μακεσ τηε γριδ ον τηε διαγραµ ϖιεω ϖισιβλε Snaps items to the grid when moving them. The Network Connection dialogue can be access through the case toolbar or by right clicking on the diagram view and selecting Network Connection. : Network connection overview Connection of flowlines and nodes can also be done through the Network Connection dialogue. For a flowpath this would be the geometry editor. Αδδσ σελεχτεδ κεψωορδ(σ) το τηε υσερ σ λιβραρψ. First. Brings the selected object forward.. Release on the separator’s inlet terminal . Then connect the flowline from the node to the separator as follows: 1. Sends the selected object backward. Opens a dialogue for selection of which controller signals should be shown graphically. all valves on one flowpath.(only available for controllers) Shows all local instances of the selected object in an editor table. Υνλοχκσ κεψωορδσ χρεατεδ ιν τηε Ωελλ ΓΥΙ. Configuration of separator/phase split nodes The multi-phase coupling of a separator is performed in a similar manner as the coupling between a node and a flowpath. add a node and a separator to the case from the component view. will work even when the grid is not visible Οπενσ τηε νετωορκ οϖερϖιεω/χοννεχτιον ωινδοω Παστεσ οβϕεχτ τηατ αρε χοπιεδ Copies the diagram view or plot to the clipboard depending on what is in focus in the centre area Right click in the diagram view on an object activates a menu with the following items: Χοπψ Paste ∆ελετε Bring forward Bring to front Σενδ βαχκωαρδ Send to back Edit visible signals. Χοπιεσ σελεχτεδ ιτεµ.. Sends the selected object to the back. Local instances Global instances Αδδ το υσερ σ λιβραρψ Import from user’s library Υνλοχκ Properties ∆ελετεσ σελεχτεδ οβϕεχτ. The network should appear as specified. Pastes the copied item onto the currently selected item. Select the "from-to" nodes for each Flowpath and click OK. Brings the selected object to the front. The coupling of a phase split node works again in a similar way as the separator. Imports from the available keywords/components from the user’s library. Select the node and drag to the separator 2. The variable required from the separator must be specified as a property (key) on the transmitter. A signal connection is made betweenthe two components. Click on the outlet terminals of the separator one at the time (gas. Blue dots that appear when dragging towards a component are available input signals. check mark means that the signal will be visible on the diagram view. Select which signals to configure. . By default only the required input signals are shown and the controller output signal. Note that all connected signals will be visible in the diagram view independently of the check marks. In the figures shown the out signal (equal to the variable listed for the transmitter at it's position) from a transmitter is connected to a PID controller's measrd input signal. The configuration will be saved with the case. This means that if e. Click the component's blue dot (available out signal(s)) and drag towards another component in the network. Both the input signals and the output signals can be configured. for each type of controllers. i) ii) Coupling with drag and drop .3. select the type of controller if the selected one is not the correct one. the liquid level from a separator is required as input to a controller. The controllers have many input and output signals. a transmitter needs to be added to the separator first. contr. The only exception here is the controllers which also can operate as transmitters. This option will bring up the dialogue presented below. in or out.g.or Coupling through the connection view (see connection view) Drag and drop coupling The drag and drop coupling between two signal components is done in the same manner as between two multiphase network components: 1. Release on the second component’s wanted input signal. 2. Then. In this dialogue one can configure which signal that should be accessible/visible on the diagram view. water and oil) and drag Configuration of controller connections All out signals need to be transmitted through a transmitter in OLGA. Coupling of signal components is possible with two different techniques in the graphical user interface. All controllers have a context menu item called Edit visible signals… . All available output and input signals are shown for all components except for the controllers. Hover over the component which the output signal is taken from. The variables may be sorted: · · · Alphabetically (by name or description) Categorized (as seen below) Those already selected (click the check box) The units for plotting variables can be changed when actually plotting. These property pages can be accessed through the property editor button located in the top bar of the property editor window. Grey : Property will not be used. Mouse wheel Ctrl+/CtrlCtrl+0 Ctrl+A Delete Shift+left drag Ctrl+left click/drag Zoom in or out in diagram view Zoom in or out in diagram view Return to un-zoomed view Selects all items in diagram view Deletes selected object(s) Pans Multi. e. Both will then initially be red (required). As an example: Two properties are mutually exclusive and one of them must be provided. There are three options for sorting of data: Alphabetic: the keys are listed in an alphabetic order Original: the keys are sorted by key groups State: the keys are sorted based on selection (required keys and optional keys with value) and not used keys (optional keys without value and n/a keys) Some keywords have a special property page to make the process of entering data easier. When a property is selected. press the Shift key while changing the unit.box. There is also an option to specify a label for the variable selection and save it.1 is the same as GASFRACTION=0.0. for more information regarding short cut keys.select Property editor The Property editor displays the properties of the selected object. The left column is the property name. The objects can be altered by modifying the values of the different properties/keys. Units may be altered. Red : Property required. The notation “:” can be used as multiplier. Select variables from the window shown. Note that the colours of the properties will change as input is given. .1.0. Values may be inserted by typing them in one at a time or by selecting one or more values presented by the interface. These variables can then easily be re-used at several positions.0. When a value is entered for one of the properties its colour will change to black (property is given and no more input required for that property) while the other property will change to grey (cannot be given). GASFRACTION=2:0. By default the value will update when the unit is changed. To keep the value.Short-cut keys Given below is a list of some short cut keys.g. See also Adding variables Time series editor Custom dialogues Centrifugal pump Adding variables Click in the VARIABLE field in the Properties window and then the . a description is shown in a region at the bottom of the Property Editor. The colours of the property have the following meaning: Black : Property can be given but not required. see Case toolbar. while the right is its value. Note that this custom dialogue can only be access if only one heat transfer statement (keyword) exists. These will help input the desired data. The heat transfer properties could be as shown below: . Also. If there are several independent time-varying parameters within one keyword the graph of these can be displayed by checking them in the graph legend (which shows the minimum necessary input parameters). see below: Heat transfer One can access the custom dialogue for heat transfer through the property editor button on the HEATTRANSFER statement. a number of interpolation options are available. the dialogue window will close and focus will return to the properties window. However. Also. An example of a heat transfer specification is also given. Time series editor Input keys with time series can be edited in a time series editor. To activate the custom dialogue click the property button on top of the properties page. Initial conditions One can access the custom dialogue for initial conditions through the property editor button on the INITIALCONDITION statement. if incomplete data is given it will automatically be completed when exiting the editor. all selected variables will appear in the Properties window: By clicking OK.By clicking OK in the relevant variable selection window. The input is graphically displayed together with the data. An example of an initial condition is shown in some detail below. a number of interpolation options are available. This custom dialogue can only be used when entering data section-wise. However. The time series editor is accessed through the Property editor for the relevant keyword. Note that this custom dialogue can only be accessed if only one initial conditions statement (keyword) exists. by selecting cells in a spread sheet and right clicking. Custom dialogues Special editors are available for editing initial conditions and heat transfer statements. This custom dialogue can only be used when entering data section-wise. if incomplete data is given it will automatically be completed when exiting the editor. by selecting cells in the spread sheet and right clicking. Enter the pipe selection again and complete the specification by giving the section(s). These will help input the desired data. two or more static curves Two Phase Head . This scenario is straight forward if the input data follow Multiple speeds and one speed per curve the pump laws. Generate two phase multipliers Interpolation in gas volume fraction . There are two scenarios for curve input: This scenario is straight forward.two or more static curves Head vs Volume flow . Generate two phase multipliers Calc multipliers and degraded head . Centrifugal pump Pump curves are required input for the centrifugal pump. At least three data sets need to be entered. and might be difficult to use in simulation. The multiplier for two phase will be ignored. more pump curves can be added. Further. Note that only the pump curves with a check mark will be used for the selected centrifugal pump. One pump curve can be used by several centrifugal pumps or not used at all. Generate degraded head curves from maximum GVF given in.two or more static curves Two Phase Multipliers . Next. click on Add in the Pump curve frame to enter the pump curve data. This can be accessed in one of the following ways: · · · Double click on the centrifugal pump in the diagram view Select the centrifugal pump and press the Properties button in the case toolbar Select the centrifugal pump and press the property page button in the Properties editor The following dialogue will then appear. and then enter the data. The Update plots button in the Normalized pump curves frame to the right will be enabled when enough information is given. These curves are only for information.generates one “single phase” curve per GVF. Several pump curves can exist. Several plots are shown: · · · · · · Single phase Head . the pump curves together with some key parameters can be specified in a custom dialog. choose the centrifugal pump phase mode. This means that the only single phase curve will be used in the simulation. enter the gas volume fraction and density. The centrifugal pump curve is a keyword named CENTPUMPCURVE. the options to choose between are: Calc multipliers .By clicking the properties icon of this window. decide to specify the rated values or chose the option to auto generate them. the generated pump curves will become “bumpy”. First. I order to avoid bad data. The auto generate option can be used if rated data is not available.one static curve per centrifugal pump curve Torque vs Volume flow . · If phase mode = liquid (single phase). Note that the gas volume fraction needs to be 0 if phase mode = liquid (single phase – no gas present). located on the library level. An option to generate multiple homologous curves. If the data deviate from the pump laws. the option “One speed per curve” is given. which will be interpolated in speed. When this is done.generates single phase curves from input with GVF=0. this is the input that will be used for the OLGA simulation. plot the input curves and the generated homologous . will therefore be added Single curve · o o If phase mode = two (two phase). choose which type of input data the pump curves should be specified in (head/delta pressure.one static curve per centrifugal pump curve Note that the pump curves data can contain large errors that may give the curves a strange form. First. To help the user with the input.generates single phase curves from input with GVF=0.two or more static curves Single phase Torque . and efficiency/head/torque). the input data will be one curve per GVF (gas volume fraction). the heat transfer’s custom dialogue is presented. The conversion of centrifugal pump curves to homologous curves will be then be performed. and interpolate the curves using actual GVF o Secondly. The best efficiency point is used as rated values for the centrifugal pump. Reports A case report is generated and viewed in the default web browser from Report on the case toolbar. Run Project and Run Project Batch If the project contains more than one case there are two alternative options. Run interactive and Run batch case by case or the entire project. ‘Run Project’ and ‘Run Project Batch’.curves to adjust the input data. Run interactive Run interactive makes it possible to open and view output results while running. An interactive simulation may be paused and continued. These options are available in the project menu located in the upper right corner. Run in batch Press Run Batch to start the simulation in the background. Use the buttons on the top to jump to specific sections in the report or check "Printer Friendly version” to remove the menu system. The sequence can be specified by setting the project dependencies. . Allow the blocked content to activate the menus in the report. Simulation There are some alternative ways to run a simulation. This will open a command prompt Showing output and progress. ‘Project Dependencies…’ can be access either from the i) Project menu or ii) By Right clicking the project in the Model View Set dependencies in the dialog to obtain the wanted simulation order. A batch simulation is running in a separate process than the GUI which means that it is possible to close down the GUI without disrupting the simulation. The menu system in the report uses JavaScript which may trigger a security warning from the web browser. and will run all cases in the current project in sequence. use the tab button to move from left to right and use enter to move from top to bottom. Navigating in the pump curve grid In the pump curve grid. Plots There are several types of plots that can be activated in OLGA. profile and fluid plots Common behaviour in trend. Most functionality is accessed through the context menu (right click on the plot to bring up the context menu) . The dialog allows text to be entered and attached to the case to one of the series in the graph. Trend plots Profile plots Fluid plots 3D plots Interactive plots OLGA viewer See also Common behaviour in trend. The notes can be toggle on and off by the notes button on the toolbar. Use of the plotting context menu The plotting tool is a sophisticated program and provides access to several functions for modifying graphs. profile and fluid plots Adding notes on the plot Add a descriptive note to the plot by selecting Edit àAdd Note from the context menu. Change or delete the note by right clicking it and select Edit à Edit Note from the context menu. only the position can be edited (the other options will be disabled for collapsed axis). font-size and position of the legends... This dialog can also be brought up using the Select button in the toolbar. Note(s) A descriptive note may be added to the plot by selecting Edit àAdd Note from the context menu.. The size of the plot can be adjusted so that all copied images will get the same size (this can be useful when copying several plots into a report). the format on the numbering. This option brings up the dialog below which enables editing the name of the axis.. This option brings up the dialog below which enables editing of the header and footer. .File-menu Save As Image Displays a dialog for saving current plot to an image file Print Setup Displays a dialog for modifying print settings like portrait/landscape. Note that for collapsed axis. Axis. margins etc. Copy There are two options: copy the underlying data for the plot (to clipboard) or copy the current graph as an image (to clipboard). This option brings up the dialog below which enables setting the font. By default the minimum and maximum values are reset when the plot file is reloaded. The visibility of the header and/or footer can also be set. be turned off. Titles.. the position (top/bottom or left/right) and the colour of the axis. The dialog allows text to be entered and attached to the case to one of the series in the graph. Edit menu Select This option is used to add and remove plot variables. This option brings up the dialog below which enables changes to the title used for the series and change the colour and linestyle for the series... This can however.. Series. Legend. Min/max values The minimum and maximum values can be adjusted on the axis to zoom in on a subset of the graph. The slug duration interval and calculation time span can be changed using the dialog below. The surge volume variables can be plotted as surge liquid volume (SURGELIQ). . This is done by adding the plot variables LSLEXP (slug length) and LSBEXP (bubble length) to the trend data. a bar-chart will be created that shows the distribution of slugs/bubbles that have a duration which is a multiplicity of the given slug duration interval. By plotting these variables. surge oil volume (SURGEOIQ) and surge water volume (SURGEWAQ). Surge Volume The plot module will calculate and plot the surge volume if the plot variable ACCLIQ is included (accumulated liquid volume flow) as a plot variable in the trend data. Based on these plot variables two synthetic variables are calculated. LSLEXP_STAT and LSBEXP_STAT.Slug statistics It is possible to plot slug statistics using the plot module. tpl.ACCLIQ@starttime)/(Endtime-starttime) Start time.e. Plot templates are convenient when running the same case several times or when several nearly identical cases exist (e. units and more. Default Qmax is given as: (ACCLIQ@endtime . To create a plot template the plot must first be configure. Setting empty values in an option field causes default values to be used for this field. end time and Qdrain can be changed in the Surge Volume Options dialog (see below). the plot configuration may be saved as a plot template. and then select FileàSave As Template… The template is stored as a . Legend This option is used to hide/show the plot legends Track Values This option is used to see the numerical values used as basis for the plot. colours. i. . Notes This option is used to hide/show notes added to the plot (see Edit-Notes above). restart cases). sequence of selected variables. View menu Black/White Collapse Axes If two variables use the same unit the axes for these variables will by default be collapsed.ppl.g. Plot templates If the same plot is to be generated several times.The default calculation interval is from the simulation start to the end time. This option is used to switch between collapsed axes and individual axes for each variable.tz/. an empty value in end time cause last simulation time step to be used as end time. To use a plot template click on the arrow on the right side of the profile/trend plotting buttons. A plot template includes information about the selected variables.tz file in the location specified. Export/import data to/from MS Excel · Export data: In the Select variable… dialog. the marked variable data is now copied to the clipboard and can easily be pasted into MS Excel. Note that a plot template will overwrite the current plot when opened this way. After the case is run. If desired. If exporting to file. mark the variables to export and then press the Export button. a location and filename will need to be specified. the slugs will be identified in red. 3D plot toolbar: .Select template from the drop down with recent templates or select ‘Browse’ to locate a template not in the list. If exporting to clipboard. The plot is activated by defining the keyword ANIMATE at the case level: Only the plotting frequency needs to be specified. Some examples are shown below. In Plot window right click and select Dataset->Paste. This tab can be undocked and docked. select several files. click on the 3D plot button in the case toolbar to open a separate tab with the holdup view. · Paste from Excel: Select data columns in and select copy. either trend (. Multi-case plotting It is possible to plot results from several cases/projects simultaneously. The file can be opened in any text editor. Several results files can also be opened via the Toolsà Plot menu. see below. A plot template can also be opened from within the plot (FileàOpen Template).plt) or within the plot tool itself by adding files. 3D Plots The 3D plot shows the holdup for liquid along a single flowpath (pipeline length) in a three dimensional view.tlp) or profile (. For example data from all the cases in a project can be plotted (use the Plot Project button in the select variables… dialog). Note that for profile plots where different plotting intervals have been used in the different files the profile closest to the selected time will be used and no interpolation is currently applied. select export data to clipboard or to file. Note if slugging appears in the simulation and slugtracking is turned on. VALVE = valve label.tab). Select Fluid Plot from the case toolbar and then open a fluid-properties file (. All process equipment variables are trend variables and require that a position is given e. Note: Server data given for a controller or specified with absolute position do not work for interactive plotting. will only work for global . Click the nail and then the play button. Server data statements with only the variable given are treated as profile variables. The freeze-function as for profile plots can be used.Reset window Point view Pan view Rotate view Zoom view Context menu: Select Branch -> Animation settings > resets the zoom level toggle point view toggle pan view (Shift+drag) toggle rotate view (Ctrl+drag) toggle zoom view (Mouse wheel) Πρεσεντσ α δροπδοων οφ αλλ βρανχηεσ Τογγλεσ τηε Τιτλε/Τοολβαρ/Ανιµατιον ανδ ανιµατιον σπεεδ Οπενσ α διαλογυε το σπεχιφψ α σαϖεδ λαψουτ Οπενσ α διαλογυε το σαϖε τηε λα ψουτ Οπτιον το αδδ α πλοτ αβοϖε/βελοω /ριγητ/λεφτ οφ τηε σελεχτεδ πλοτ Τηε σελεχτεδ πλοτ ωιλλ βε δελετεδ Αλλ πλοτσ ιν τηε πλοτ ταβ ωιλλ βε δελετεδ Οπτιονσ το χοπψ ιµαγε/δατα Οπτιονσ το µαξιµιζε. Interactive trend and profile plots Interactive plots means that one can view a parameter while simulating and the data in the plot will automatically be updated. µινιµιζε ανδ φλιπ Σελεχτ τψπε οφ πλοτ − ποστ προχεσσεδ ορ νοτ Λοαδ Λαψουτ φροµ Φιλε Σαϖε Λαψουτ το Φιλε Αδδ Πλοτ Ρεµοϖε Πλοτ Ρεµοϖε Αλλ Πλοτσ Χοπψ −> Layout-> ςιεω−> Fluid plots The plot-tool can be used to plot fluid-properties. The default x-axis is temperature.g. The SERVERDATA keyword can be added through the model view on flow component level. One has to define trend and profile variables through the SERVERDATA statement to be able to view these variables in interactive plots. Clicking the nail multiple times allows for the freezing of more curves. It can be changed by moving the column header fields in the right-hand side window to locate the "X-Axis" field (which is in the far right position by default) and select Pressure instead of Temperature (see figure below). Select the variables to plot and press ok. If the position is specified the variables listed in the variable field are trend variables. Server data keyword placed on case level. After the plot variables are defined. Plot tabs are created by pressing the Interactive plot button on the case toolbar or pressing the + on the right most side of the tabs. Each individual plot can be configured through the context menu. one can add several plots to one frame. no history is saved.variables in interactive plots. interactive plots can either be added to the diagram view by dragging from the component list or opened as separate plot tabs..post processed or not The context menu for the plots added to the diagram view contains a subset of the above menu. Note. For profile plots one can only see the last available profile. Context menu: Edit/select Variables… Opens the variable selection dialogue Remove All Variables Removes all variables in selected plot Toggle automatic pop-up of the variable selection dialogue (only used for Show variable selector the plot and value on diagram view) Max/Min Settings… Open a dialogue to set the max and min values of the axis Edit X-axis Unit… Makes it possible to change the unit of the x-axis Show border Toggles the border around the plot Load Layout from Opens a dialogue to specify a saved layout File… Save Layout to File… Opens a dialogue to save the layout Add Plot Option to add a plot above/below /right/left of the selected plot Remove Plot The selected plot will be deleted Remove All Plots All plots in the plot tab will be deleted Edit Title… Opens a dialogue to edit the plot title Layout-> Options to change the plots position and size Copy -> Options to copy image/data Configuration… Opens a configuration dialogue to edit the selected plot View-> Select type of plot . In the plot tabs within the case. Show variable selector Show boarder Show Name Opens the variable selection dialogue Toggle automatic pop-up of the variable selection dialogue (only used for the plot and value on diagram view) Toggle the boarder around the value and name of the variable Toggle the variable name . An example is shown below.. Single values added to the diagram view have the following context menu: Edit/select Variables. The keyboard arrows can also be used to navigate. Note that the plotting frequency can never be lower than the time step of the OLGA simulation. select trend plot from the button in the case toolbar. either by dragging the slide or by clicking play.g. in the profile plot integrated in the case tabs use the key ctrl in combination with the right and left arrows. To "un-freeze" a curve. All trend variables use the same plotting frequency. In the trend data statement the user has to select a variable and then a position e. One can also freeze a curve by clicking the nail button. A list of the different trend variables are given in the variable section. . A profile variable needs to be added to the case before the simulation is started to be able to plot it afterwards. To view the profile plot. select the profile button on the case toolbar and then select the variable(s) to plot: It is possible to "play-back" the profile plot. however. Play-back is stopped by Trend plots Trend plots are variables varying with time e. disable the nail clicking stop.g. A list of the different profile variables are given in the variable section. Click OK to see the graph. Trend variables can be added at the case level and at the flow component level through the keyword TRENDDATA. This gives the Select variable dialogue below. One can read more about the TRENDDATA in the Keywords section. A trend variable needs to be added to the case before the simulation is started to be able to plot it afterwards. Select the variables to plot. by ABPSPOSITION = 100 m. Several profiles can be played back simultaneously. One can read more about the PROFILEDATA in the Keywords section. The plotting frequency is given through the keyword PROFILE on case level. Double click on the selection or right click and choose one of the options displayed. In the profile data statement the user has to select a variable e. the speed will depend on the capabilities of the PC. Note that the plotting frequency can never be lower than the time step of the OLGA simulation. All profile variables use the same plotting frequency. After the simulation is run. Profile variables can be added on case level and on flow component level through the keyword PROFILEDATA.Profile plots Profile plots are variables plotted along a distance (flowpath). Each time the button is clicked. a curve is stored.g. There are many different profile variables. The plotting frequency is given through the keyword TREND on case level. There are many different trend variables.g. VARIABLE = PT (pressure) and position given e. VARIABLE = PT (pressure). how the pressure varies with time at a given location. . genkey Closes the project with option to save project New case or project can be created in this page Save Project as… (Ctrl+Shift+S) Open Case… (Ctrl+O) Open Project… (Ctrl+Shift+O) Import… Close Project New .opi. The File menu can be accessed by clicking on File at any point in time.opp Opens a case of file type *. The File menu covers the following: Save Project Saves the project and all open cases Saves the project and all open cases with a new name Opens a case of file type *. *.inp or*. From the New page. The templates are complete cases that are ready to simulate.geninp or *. File menu When starting OLGA the File menu will appear with New in focus.key Opens a project of file type *.There are many ways to filter the content of the dialogue above. The selected variables are plotted even if they are ‘filtered away’. Note that filtering is a tool for locating the variables. a case can be created by selecting an empty case or a Template. To exit the File menu click either on the File tab again or on a case tab. .Recent Tools Help Options… Exit Recent projects and cases are listed in this page Internal and external tools can be accessed in this page Information about manuals. This opens a file dialoueg to specify the location and name of the project. The template view is selected with the two toggle buttons in the top right. An empty Well case is created from the New →Well icon. The selected template is the front most template highlighted in the orange selection colour. There are two ways to select a template for a new case: From the carousel view or from the icon view. In carousel view. A new case is created either by selecting Empty case or by choosing an appropriate template. sample cases and support Opens the options dialogue Closes OLGA with the option to save project New New cases or projects are created from the New page. the templates can be navigated sequentially and shows a preview of the network and a description of the template. A new project is created by clicking on the Empty project icon. Navigation is done by clicking to the right or left of the selected template which will scroll the new selected template to the front. This can also be done using the left and right arrow keys on the keyboard. In icon view the template categories are shown on the left side of the window and the templates in each category are shown on the right. If no project is open. The new case will be added to the currently open project. The name and location of the new case can be set at the bottom of the window. Tools The Tools page is accessed through the File menu. a new project with the same name as the case will be created. Recent Previously opened projects and cases can be accessed from the Recent page. When selecting a template OLGA suggests a default case name based on the template selected and a number if a case with that name already exists. Selecting a recent case will open it and add it to the currently open project or create a default project if no project is open. The default location of new cases can be changed in the Option dialogue. Selecting a recent project will open all cases from that project in separate tabs. The new case is created by clicking the Create button or double-clicking on the template. Use the Browse button to bring up a file dialogue to choose a different location of the case. . Delete . Restore to Factory Settings: The layout of the GUI windows. requires internet access Zips the projects with all cases and data files and attaches it to an e-mail template List the version information Options The overall simulator settings are specified under Options. Some programs are set by default during installation and additional programs like Excel. . See also Tools available with OLGA Help The Help page is accessed through the File menu.This page gives access to useful utilities which are installed with OLGA. However. The Options dialogue is located under the File menu Settings under the General tab are: o o o o o o My Project Location: Location where file dialogs will open. It is useful to use for quality assurance as it shows all inputs used. default unit set and similar will be restored. can be specified. Select Add… to browse for an external tool to include in this list. By default the number of treads available will be used in an optimal way. Write default values – this option will print the default values to the opi file. Specify if the program shall execute auto-save at specified intervals. These tools are documented separately. a text-editor etc. External programs that should be available from the Tools page can be specified under the External Tools tab.bat file after batch simulation Simulation threads – number of treads to run simultaneously. OLGA Help Wells Help Getting started with OLGA 7 Samples Support Centre Send to support About OLGA Opens the general user documentation Opens the well GUI documentation Opens a video showing some of the steps to build a case in OLGA 7 Open the folder where the sample cases are stored Link to the SPT Group's support centre on the internet. Other external tools may be added to this page via the Options dialogue. There are some limitations and a runnable case will not always be runnable if this option is used. this option should not be used when running the case. 2nd order scheme Mass equations can be solved with two different schemes in OLGA. Metric and Oilfield) or a customized set may be specified. Examples are: 1. The smoothness of the data is measured on the control volume boundary like this Where m is the mass and θ is the measure of smoothness. Units can select from three predefined sets (SI. In OLGA the limiter known as the van Leer limiter is chosen. In the 2nd order region the numerical scheme is determined based on a 2nd order limiter. See also: When to use Methods and assumptions Limitations How to use When to use The 2nd order scheme for mass equations is to be used when it is important to track relatively sharp holdup fronts. If θ < 0 the method reduces to first order upstream and if θ > 0 the method uses 2nd order methods. The 2nd order scheme has less numerical diffusion and therefore keeps holdup fronts better. Oil-Water fronts 2. The default is a 1st order scheme (upwind implicit) and the alternative is a 2nd order TVD scheme. The 1st order scheme is more robust and should be the preferred choice in most situations. Simulation differences between the 1st order and 2nd order schemes . Gas-Oil fronts Methods and assumptions The 2nd order method used for the mass equations is a combination of different numerical schemes in order to get a stable method which satisfies the TVD (Total Variation Diminishing) condition. Inhibitor fronts 3.The Default Units tab is used to select the preferred set of units. For smooth gradients the method is 2nd order while for non-smooth flow (shocks) the method reduces to 1st order upstream. The default units affects the none given properties and the default values in the property editor and also which units the plotting variables are shown in. 500 and 1000. respectively. Figure 4 Trend plot showing the hold-up at the top of a riser. 100. The number of sections in the riser are 15. The number of sections in the pipeline are 50.Figure 2 Profile plot of an oil–water front showing the differences between the two schemes. 200. 100 and 500. . The number of sections in the pipeline are 50. 30 and 60. Figure 3 Profile plots of a gas–oil front. respectively. respectively. The gas component consists of hydrocarbon gas. the example network in Figure A below. CO2 and N2 components. It is possible to specify more than one blackoil feed. and optionally H2S. . cf. Since the 2nd order method is only implemented for the mass transport equations the final result from the equation set will not converge to 2nd order accuracy. Limitations The 1st order scheme diffusive behavior reduces unphysical numerical instabilities in the simulation if they occur. The physical properties of gas and oil are calculated from correlations belonging to a specific blackoil model – the user has a choice between four different blackoil correlations. How to use The 2nd order scheme for the mass equations is activated by setting MASSEQSCHEME=2NDORDER in the OPTIONS keyword. specific gravity of gas and oil and the gas–oil ratio (gor) at standard conditions are the only necessary data. For simulations where propagation of holdup fronts is of interest the improvement can be significant. the specific gravities and the gor are mixture values. Details about the fluid composition are not required for a blackoil simulation. For simulations where instabilities are observed it is not recommended to use the 2nd order scheme. the blackoil module is faster in terms of cpu cycles. In the case of multiple feeds. Water properties are calculated by the standard OLGA routines. A blackoil feed can consist of one gas. Compared to compositional tracking. Note that no fluid table is needed. If water is present. and it treats shut-in cases more accurately than does the standard pvt table option. oil and water. The module makes it possible to perform calculations with a minimum of information about the production fluids. For example simulations where pressure waves or temperature waves are of interest the improvement from the 2nd order method will be small. Inside the area filled with water. Inside the OLGA engine. The improvement in the result will also differ depending on which physical phenomena which are of interest. To find the properties at a position in a pipe. Blackoil Blackoil modelling allows one to make a compositional model with a minimum of input. one oil and one water component. and for such a mixture each component of each feed is tracked. there are three areas containing MEG. as well as the specific gravities of gas. at that position. For such problems the 2nd order will only make matters worse because it enhances the numerical oscillations. and the GOR. the blackoil module uses the framework of the compositional tracking module to track the components through the pipelines.Figure 5 The above figures show profile plots of an oil–water front. the correlations use the pressure and the temperature. also the specific gravity of water must be input. The 2nd order method only works if the CFL criterion is fulfilled. The mixture is the average taken over the constituting blackoils weighted by volume at standard conditions. This means that it is not possible to violate CFL criterion by increasing MINDT when the 2nd order options is set. and cannot provide the detailed analyses of compositional tracking. it is recommended to tune the correlations for RSGO(P. Lasater Correlation The basis for the Lasater correlation is the following relationships: (a) with . That is. φουρ διφφερεντ χορρελατιονσ αρε αϖαιλαβλε ιν ΟΛΓΑ. the module is not suited for studying gas condensate systems. Τηε δεφαυλτ χορρελατιον ισ Λασατερ. If measured values for GOR and the bubble point Pb(Tb) are available. and Pb replaced with the actual pressure P. 2. the above equations are inverted with GOR replaced by RSGO.5 yg = mole fraction of gas γg = specific gravity of gas γo = specific gravity of oil Mo = effective molecular weight of tank oil GOR = gas-oil ratio = tabulated function of yg f1(yg) f2(API) = tabulated function of API CPb = tuning coefficient (default = 1) CRSGO = tuning coefficient (default = 1) (d) . However. viz. ανδ ηαϖε ρεχοµµενδατιον φορ υσε ασ µεντιονεδ ιν Table 1.Figure A: Network case with several blackoil fluids (feeds) specified. and possibly make use of the module’s tuning mechanism to further improve the match between observations and the predictions made by OLGA.: . this assumption does not exclude the dispersion of oil and water. then RSGO = GOR. Later when production is established. Τηεψ αρε βασεδ ον φλυιδσ φροµ Lasater /27/ ςαζθυεζ & Βεγγσ /29/ Γλασ /30/ API > 15 API > 15 API > 15 Based on fluids from Canada.S. Blackoil Correlations διφφερεντ αρεασ. the blackoil module can be a good choice when little is known about the production fluids. find yg from Equation (c) with P instead of Pb.T) and Pb(T). Each component is tracked through the network. See also: When to use Methods and assumptions Limitations How to use When to use Due to the limited amount of input.5 / γo . Table 1: Blackoil correlations and their recommended usage. Please note that if P > Pb.131. An oil component cannot exist as gas in the gas phase. and South America Similar as Lasater Based on fluids from the North Sea These correlations can be used to calculate the bubble-point pressure. In the following. Pb. for a given GOR or an equilibrium value of RSGO (< GOR) at any pressure below Pb. The fluid properties are calculated based on the fluid mixture. In these equations we have that API = 141. Methods and assumptions The following three assumptions are made for the blackoil module: 1. This method should also be used if salts are present. It is however possible to include the effects of meg in the density calculations by specifying a larger specific gravity for water. As mentioned above. one may insert the actual values. the four sets of correlations are presented with their tuning coefficients. the blackoil module is related to the compositional tracking module. This is due to the fact that blackoil models are intrinsically crude. and . Στανδινγ /28/ API < 15 Based on fluids from California Το χαλχυλατε τηε σολυτιον γασ−οιλ ρατιο RSGO ανδ τηε βυββλε ποιντ πρεσσυρε Πβ. the existence of water/oil droplets in the gas or gas bubbles in the liquids. For instance. and invert Equation (c) to get RSGO. (b) (c) For the purpose of calculating the RSGO. during planning or design one may use specific gravities and a gor typical of the geographical area. U. and may be preferred as the computationally faster alternative. As a consequence. Gas can dissolve in oil. Units for pressure and temperature are psia and 0F. then RSGO = GOR. Symbols have the same meanings as for the Lasater correlation. moles and 0R. the oil density is calculated as . (n) (l) (m) Oil and Gas Density The oil density depends on pressure. (r) (s) pressures in psia. pressure is measured in psia. If P > Pb. and . The gas density is obtained from (u) . Units for pressure and temperature are psia and 0R. respectively. then RSGO = GOR. Standing Correlation The bubble-point pressure at a given GOR is given by (e) where (f) Symbols have the same meanings as for the Lasater correlation. and . lbm. ft3. If the pressure is above the bubble-point pressure. If P > Pb. With the Standing correlation. Units for Equations (o) to (s): Temperature is given in 0F. For API > 30: . then RSGO = GOR. the compressibility is taken into account. To calculate RSGO. BO is given in bbl/STB. and the density is calculated by . temperature in 0R (degrees Rankine). the oil volume formation factor BO is calculated. respectively. the gas constant R has the value 10.72. where . At pressures below the bubble-point the procedure is as follows. and . temperature and the amount of gas dissolved in oil. is given by the above equations with RSGO = GOR. the bubble-point pressure is given implicitly by . the gas volume formation factor. viz. see /28/. Substitute RSGO for GOR and P for Pb to obtain . and invert Equation (f) to obtain .: pV = znRT. Symbols have the same meanings as for the Lasater correlation.Pressure must be given with a unit of psia. . and temperature is measured in 0F. (g) Vazques & Beggs Correlation For API < 30: . (j) (k) (h) (i) Glasø Correlations For known GOR. co is the isothermal compressibility of undersaturated oil. BG. ρob. First. and replace GOR with RSGO. (q) (p) (o) The density at the bubble-point. . can be expressed as . replace Pb with the actual pressure P. At pressures above the bubble-point. and GOR and RSGO in scf/STBO. The basis for calculating the gas density is the compressibility equation of state. Now. Now. (t) When other variables have units of psia. ε. is assumed to have no significant effect on the z-factor. If the pressure is above the bubble pressure Pb. The expression used for the gas-water surface tension is . An algebraic relationship. we can use (am) for dead oil. temperatures in 0F.0764 γg. where RSGO = GOR.RS) is used. The gas compressibility z expresses the deviation of the real gas volume from the ideal gas behaviour. (ap) . and Note that Covisc is a tuning coefficient. µg in cp. Values for Tpr and Ppr are found from the pseudocritical temperature Tpc and the pseudocritical pressure Ppc: Ppr = P/Ppc and Tpr = T/Tpc.2 + 19.0). The implicit set of equations that emerges. T (0R) and P (psia).e. Empirical equations exist for Ppc and Tpc.(v) where ρgsc = 0.0. and Ppc’ = Ppc Tpc’ / (Tpc + B(1-B) ε). (ag) viscosities in cp and RSGO in scf/STB. The corrected values become Tpc’ = Tpc . Nitrogen.B4.: . and tabulated as a function of Ppr and Tpr. Liquid viscosity is calculated as for the standard pvt table option with oil viscosity as above. and we use them: . and then correct the value for saturated oil at saturation pressure: .9 .0764 is the density of air at standard conditions expressed as lbm/ft3). i.379 + 0. (ao) For oil-water surface tension empirical data are scarce. Oil and Gas Viscosity Dead oil viscosity is calculated using the following equation: (ad) Now.447 . where .4 / T + 0. For these pressures the viscosity is modified. cf. γg denotes specific gravity of gas at standard conditions. (ab) (ac) (z) (aa) (x) (y) (w) ε = 120 (A0. The presence of CO2 and H2S is accounted for by correcting the pseudocritical values Ppc and Tpc. Given values of API. the corresponding saturation pressure for P(T. /28/.26Ma + T ) B = 3. has been developed.. with Units: Pressures are measured in psia. (af) . Surface Tension The expression for the gas-oil surface tension needs to be simple without the information about the fluid composition.5 . the z-values have been pre-computed. T in 0R.448 + 986.5 / (209. is used to determine the value of z.A1. N2.6) + 15 (B0. As already mentioned. viz.01009Ma C = 2. the above expression corresponds to the viscosity at the bubble point µob. (ae) . the units are psia and 0R. (an) (ai) (aj) (ak) (al) (ah) For undersaturated oil. requires an iterative solution procedure. /28/. its default value is 1. The assumption that real gas mixtures will have the same z-factor for the same values of pseudoreduced pressure Ppr and temperature Tpr. (The value 0. In order for OLGA to save cpu cycles.001 N/m). The gas viscosity is calculated. the live oil viscosity µo is found by modifying the dead oil viscosity according to the gas dissolved in the oil.016Ma)T1. with A = (9. The unit of a surface tension σ is dynes/cm (1 dyne/cm = 0.2224B Ma = 29γg (Ma is the apparent molecular weight) Units: ρg given in g/cm3. and this relates z to Ppr and Tpr. according to /27/. and . and a preliminary relation is used: . B = yH2S (yCO2 and yH2S are mole-fractions). from the correlation . where A = yCO2 + yH2S. . ∆Hgosc = 4.9 66 93 116 132 165 202 222 252 274 220 205 294 Thermal conductivity Data for the thermal conductivity of gas as a function of M and T is plotted in /31/. the data available will typically be for the mixture. 00C and 1 bara is used as the zero point. according to ∆Hgo = ∆Hgosc . /32/: .0.75 + 4.. A function has been developed that gives a reasonable approximation to these data. Enthalpy of Oil The enthalpy of oil Ho is calculated directly by integrating cpo from zero to the actual temperature.with default coefficients A1 = 30. See the description of the correlations for how the tuned parameters enter the calculations.: . viz. and . A2 = 0. The data are taken from /31/. a table for Hg can be generated.0. The above correlations are based on data from /31/ and /33/. Thus the term (dH/dP)TdP in Equation (ar) can be expressed in terms of Tpr and Ppr: . (au) where Tabp is the atmospheric boiling point measured in K. can be calculated using the following equation. Little data are available for oil. one must either tune to one of the fluids or to a mixture of the fluids. First. (ax) (aw) Blackoil Tuning It is possible to tune the correlations for gas dissolved in oil RSGO. Enthalpy of Gas The enthalpy of gas. . Please note that the tuned correlations are used for the whole network. bubble pressure Pb and oil viscosity to measured data.57 log(Tabp)) / M. and this function is used by OLGA. Hg is calculated from the equation (aq) (ar) The term (dH/dP)T can be expressed as -(RT2/P) *(dz/dT)P . and so a simple linear function is used.7 (P . Enthalpy of Gas Dissolved in Oil The latent heat for gas dissolved in oil ∆Hgo will be used to calculate the enthalpy of liquefied gas Hgo. a network case). the latent heat is extrapolated for pressures above 1 bara. Second. From tabulated values for cpg and z. cpl. Table 2: Tabp as a function of specific gravity of oil and molecular weight.0 and A3 = 0. The compressibility factor z is tabulated as a function of Tpr and Ppr. If the measurements are from a separator. It is assumed that the specific heat of a gas mixture corresponds to the specific heat of a pure gas with the same specific gravity.19 Tabp (8. Figure 4-49. The unit of the latent heat thus becomes kJ/kg. 0. cf. We have Hgo = Hg . Thermodynamic Properties of Blackoil Specific Heat of Gas The specific heat or heat capacity of gas cpg will be tabulated as a function of temperature and specific gravity of gas. Tabp (0C) 70 80 90 100 120 140 160 180 200 M Spec Tabp grav. see Table 2 below. Tuning is specified through the BLACKOILOPTIONS keyword. If there are several blackoil feeds (e. cf.g. The default values for the coefficients are: .1) (av) Tabp is tabulated as a function of oil specific gravity and molecular weight. the latent heat is estimated at 1 bara. Tuning of the correlations use data for a single fluid or a mixture.6 27 42 60 79 104 128 146 165 190 0.∆Hgo (at) (as) The term ∆Hgo can be approximated by a simple correlation from /32/. Atmospheric boiling point. /32/. where γo = specific gravity of oil T = temperature in 0C The unit of cpl is kJ/kg0C. Specific Heat of Oil The specific heat of oil.1. Modifications of Ho at elevated pressures are ignored. and specify GOR and WATERCUT. The purpose of the complex fluid model is to predict such behavior. without slug tracking activated. e. Furthermore. The fluid viscosity model to be used is determined by the keys CFLUML and CFLUMW for the liquid hydrocarbon phase and water phase. it yields a better model of the liquid flowing below the slug bubble as well as a better prediction of the slug fraction. and. The density from the blackoil correlations does not give the same density as the input. For stratified flow. oil.g. Non-Newtonian behavior can be modeled for the liquid hydrocarbon phase. NODE/SOURCE/WELL to set flow rates or volume fractions of the feeds to enter the pipeline system The steady state pre-processor may be used with the blackoil module. As opposed to the complex viscosity model. How to use The Complex Fluid module is activated in the FLUID keyword by setting the key TYPE=COMPLEXFLUID. i. yield stress. fluid viscosity can be modeled using either the Bingham model or the power law model. For production rates below this minimum. the use of complex fluid yields an important improvement since the slug flow model includes the effects of the above rheologies and at the same time as it covers the range of Reynolds numbers from laminar to turbulent flow. The Newtonian option is included to capture the peculiarities of higher viscosity liquids. waxy oils). gelled waxy crude. respectively. consequently. or liquids exhibiting shear thinning. the complex fluid model includes numerous modifications to the physical models for both separated and distributed flow taking into account the non-Newtonian behavior of the fluids. Hydrate is a snow like substance formed by water and natural gas that might occur in hydrocarbon transport lines at ambient temperatures well above the normal freezing point of water at elevated pressure.. Therefore. License requirements The Complex Fluid Module requires a separate license. How to use Set the following keywords to use the blackoil module: OPTIONS to set COMPOSITIONAL = BLACKOIL BLACKOILOPTIONS to set GORMODEL (optional) BLACKOILCOMPONENT to set the properties of the gas. the standard volumetric flow rates that are calculated by flashing the in-situ mass flow rate to the standard conditions differ from the standard volumetric flow rates given in the input. can only be approximated using complex fluid models. Such properties might arise in waxy oil or emulsions which often exhibit shear thinning and high viscosity. . For Newtonian liquids. heavy oils) or influence of yield stress (e. the water phase or both. the module should be used when modeling fluids with viscosity above 50 cP and it has been tested up to 1000 cP. even for horizontal pipes.g. more well known. When converting the in-situ mass flow rates to the volumetric flow rate at the standard conditions.. the densities of gas.. See also: Sample case for Blackoil Complex Fluid Complex fluids are liquids with high viscosity.. the densities at the standard conditions are calculated from the blackoil correlations. which is very important for more viscous liquids. This affects the bubble front velocity. whereas a slurry of hydrate crystals in oil may have a yield stress depending on the particle concentration. These instabilities can interact with other.Converting to mass flow rate When converting the volume flow rate at the standard conditions to the mass flow rate. The difference is however within the uncertainty of the blackoil correlations. while the Power law is used for shear thinning fluids. Fluids that demonstrate both shear thinning and a yield stress.g.e. the wall friction calculations should yield better results than when using an equivalent viscosity. Using this as basis for pressure drop predictions is a major difference from the complex viscosity model. Except for the default Newtonian modeling. The presence of yield stress or shear thinning in the liquid might result in a decreasing pressure drop with increasing production rates up to a certain point where the pressure drop is at a minimum. the initial volume fractions for the feeds must be given. Methods and assumptions The complex fluid model utilizes the Bingham model for fluids exhibiting yield stress. multiphase flow phenomena such as terrain slugging and give rise to a wider range of unstable operational conditions. Limitations The blackoil module has the same limitations to its usability that the compositional tracking module. If one chooses to start from INITIALCONDITIONS. = viscosity When running standard OLGA. oil and/or water components BLACKOILFEED to combine the gas/oil/water blackoil components into feeds. and water that are used are taken from the corresponding blackoil components as given in BLACKOILCOMPONENT. either by shear thinning (e. Bingham plastic model (a) where Power law model (b) where K = consistency factor Newtonian fluid (c) where &mu. unstable operation might occur depending on the boundary conditions of the transport line. See also: When to use Methods and assumptions How to use When to use The complex fluid module should be used whenever a fluid exhibits significant deviation from Newtonian behavior. the liquid accumulation. g. they are reset to the upper or lower limits. the mass transfer between the phases needed for the mixture to be at equilibrium is calculated. FULL=NO. For both options. every single fluid component is accounted for throughout the calculation. PVT package The material properties of the fluid along the pipeline will be calculated continuously during the simulation. Restart The Compositional Tracking model is available with full restart functionality. gas. Note that a higher number of components will also increase the simulation time. Physical limits for the temperature and pressure used in the PVT calculations are introduced and can not be changed by the user (as it can with fluid tables). there are no special limitations associated with the Compositional Tracking model. Compositional Tracking The compositional tracking model combines the powerful multiphase capabilities in OLGA with customised calculations for fluid properties and mass transfer. These reset values are used in the PVT calculations only and are not fed back to the overall calculations of temperature and pressure. These feeds may only contain a set of the components defined in the feed file. The fluid data in the feed file are based on one of these equations. enabling simulation of scenarios such as start-up and blowdown with a high level of detail and accuracy. local pressure. It is not possible to define additional components outside the feed file. Limitations Maximum number of components allowed in a feed file is 30. and will ensure a more accurate fluid description compared to using the standard OLGA model. the viscosity given in the fluid file is interpreted as the plastic viscosity for Bingham fluids and as the consistency factor for Power law fluids. C14-C22) in each phase (e. Different compositions can be used for each branch in a system. the molar fractions and their derivatives with respect to the current conditions at phase equilibrium are also delivered by the package. and changes in fluid composition at the inlet.e. Thus. check valves. PVTsim must also be used to characterize the fluid and generate the feed file to be used as input to the model.g. The feed file contains information about the feeds (fluid composition used in a source or well and as boundary or initial conditions) that the user wants to use in the simulation. The temperature range is from -200 to 500 C and the pressure range is from 0. on the other hand. valves. Flow model The descriptions of the flow regimes. liquid droplets. Moreover. In addition. If the key FULL=YES. See also: When to use Methods and assumptions Limitations How to use When to use It is important to acknowledge that the extra level of detail given by compositional tracking compared to table-based approach is CPU-intensive and will increase the simulation time. the model will keep track of the changes in composition in both time and space. In the Compositional Tracking model the mass equations are solved for each component (e. This PVT package uses functions that are similar to the ones used by PVTsim. temperature and composition). However. separators. with or without the Peneloux volume correction [Peneloux et al. Process equipment The system can include process equipment such as critical and sub-critical chokes. but with compositions that are constant with time. the fluid viscosity parameters (yield stresses/power exponents) are read from the fluid property file as functions of pressure and temperature. and this composition is assumed to be constant throughout the whole simulation. If. blackoil or wax. Based on these results. the yield stresses YIELDSRL and YIELDSTW or power exponents POWEXPL and POWEXPW have to be given if the liquid hydrocarbon or water viscosity model is set to BINGHAM or POWERLAW respectively. although they are optimised for increased computational speed.. Standard OLGA will in many cases. elevated geometry. and controlled mass sources and sinks. These calculations are part of a PVT package delivered by Calsep. compressors with controllers. (1982)]. the user may define additional feeds through the FEED keyword. Methods and assumptions The standard OLGA model uses a fluid table with material properties calculated for a predefined composition. How to use . Instead of using a fluid file with pre-calculated material properties. such as for single pipeline flow and networks where the fluids in the pipelines are similar. a so-called feed file must be generated (by PVTsim) and given as input to OLGA. heat exchangers. H2O.The parameters of the viscosity models can be given in two ways. Typical cases where compositional effects may have influence are: Networks with different fluids Changes in composition at boundaries Blowdown Gas injection / gas lift Start-up Shut-in and restart License requirements The Compositional Tracking Module requires a separate license. C1. Except for this. However. based upon the current conditions (i. as described. and the same EOS will be adopted in the OLGA simulation. Part of this module is a software package developed by Calsep. If the temperature or pressure goes out of range. friction factors and wetted perimeters etc in the compositional tracking model are as in the standard OLGA model. Combination with other models The Compositional Tracking model can not be combined with other compositional models such as inhibitor tracking. apart from those described in Limitations in the use of fluid properties. merging network with different fluids. and about the components comprising the feeds. In reality the composition may vary along the pipeline due to slip effects (velocity differences between phases). Other considerations Steady state pre-processor A compositional steady state pre-processor is implemented in OLGA. pumps. give satisfactorily accurate results.05 to 1000 bara. it is not possible to switch from or to the compositional model in a restart case. interphasial mass transfer. With the compositional tracking model. be aware of the additional CPU-intensive calculations that are performed. bulk hydrocarbon liquid and bulk water). The phase equilibrium calculations in PVTsim are based on either the Soave-Redlich-Kwong (SRK) or the Peng-Robinson (PR) equation of state (EOS) [Soave (1972) and Peng and Robinson (1976)]. This is the only option allowed when performing simulations with fluids consisting purely of non-aqueous components. to specify initial feeds. INITIALCONDITIONS. SOURCE. It is recommended as an option to make a final check of whether the accuracy obtained using the simplified three phase flash is adequate for the given case. and requires all fluid properties such as critical temperature. Note: Output variables for rates at standard conditions (e. Step 2: Prepare the OLGA input using the following keywords. and is expected to provide accurate results for most simulations involving fluids consisting of both hydrocarbons and aqueous components. Plot data for individual components can be specified with the addition of the COMPONENTS=(<component names>) key to each plotting keyword. It may also be used with fluids containing aqueous components when high simulation speed is wanted. provided the amount of free water is believed to have little impact on the conclusions. Viscosity correlations (key VISCOSITYCORR) . any component can dissolve in any phase. This is due to the full three phase option being significantly slower than the simplified three phase option. PROFILEDATA to print compositional variables to profile file (*. and hydrocarbon components and inorganic gasses are added to the aqueous phase until the fugacity is the same for all the phases. NODE. Flash algorithms (key FLASHTYPE) The FLASHTYPE key specifies the flash algorithm to be used. The ”Plus” and ”No-plus” fluid types only require mole or weight fractions.e. accentric factor. to define calculation options to be used by the PVT routines. The user can also choose to use the default values. In this window the feed file that is an input to the Compositional Tracking module is generated. It should not be used if: Hydrate control is important and MeOH or another component more volatile than H2O is used as inhibitor. Tracking of aqueous components dissolved in a hydrocarbon liquid phase or a dense gas phase is important. with the name specified in the Well column in the Fluid box in PVTsim as feed name. FEEDFILE to specify the feed file name. and should be used with care for Compositional Tracking simulations. Note that simplified three phase is the recommend option for performing screening/approximate simulations where high accuracy may not be required even in the aforementioned cases. FLASHTYPE = SIMPLETHREEPHASE means that the water components are treated as an inert phase initially. Tracking of hydrocarbons and inorganic gasses dissolved in the aqueous phase is important. to specify feeds and feed flows in the mass source. The ”Characterized” fluid type is used when the fluid characterization has been performed in another PVT tool. and then choose ”Compositional Tracking”.e. it will be plotted for all components for the specified variable. and if needed specify the density limit for the dense phase region. This option is significantly slower than the simplified three phase flash option. PLOTDATA to print compositional variables to OLGA Viewer file (*. FEED.out). follow the steps below. QGST) are CPU demanding since a flash must be performed. This approach involves two simplifications relative to full three phase flash The change in phase equilibrium due to dissolution of components in a phase is not taken into account. A simplified model for the solubility of hydrocarbon components and inorganic gasses in the aqueous phase and vice versa is used. Tracking of aqueous components dissolved in a hydrocarbon liquid phase or a dense gas phase is important. Step 1: Use PVTsim to characterize the fluids to the same pseudo components and generate the feed file with all the necessary compositional data for the fluid. FLASHTYPE = TWOPHASEFLASH treats water as an inert component. if any of the fluid components should be assigned delay constants. Choose ”Interfaces” from the Main Menu in PVTsim. etc. If COMPONENTS is not specified. This is the default option when at least one aqueous component is defined in the feed file. what kind of viscosity correlation to use. There will not be any aqueous components in the hydrocarbon phases and no hydrocarbon components in the water phase.tpl). Step 3: Specify output variables for detailed plotting of simulation information. the result is not rigorous equilibrium but approximated equilibrium. Special considerations In the keyword COMPOPTIONS the user should evaluate what flash algorithm to use.g. PVTsim will generate pseudo-components based on the last (plus) component. Tracking of hydrocarbons and inorganic gasses dissolved in the aqueous phase is important. This is the only option allowed when performing simulations with fluids containing salts.Input In order to use the Compositional Tracking model. Full three phase flash is recommended for rigorous simulations if Hydrate control is important and MeOH or another component more volatile than H2O is used as inhibitor. Tracking of aqueous components dissolved in a hydrocarbon liquid phase or a dense gas phase is important. OPTIONS. FLASHTYPE = FULLTHREEPHASE means that a full three-phase flash is performed for the total composition. mole weights and liquid densities. The fugacity of all the components in all the phases is the same. Classical mixing rule is used for component pairs not involving aqueous components while the Huron-Vidal mixing rule is used for all component pairs involving aqueous components. A two-phase flash is carried out for the hydrocarbon components. i. FILE. Full three phase flash is also recommended if Hydrate control is important and MeOH or another component more volatile than H2O is used as inhibitor. Note that simplified three phase is the recommend option for performing screening/approximate simulations where high accuracy may not be required even in the aforementioned cases. Hydrate inhibitors such as MeOH and glycols in the water phase will also be inert. All the phases are in rigorous equilibrium. Classical mixing rule is used for all component pairs for the two-phase flash calculation. COMPOSITIONAL set to ON.ppl). For the ”Plus” fluid. to specify feeds and feed flows in mass flow and pressure nodes. Classical mixing rule is used for all component pairs throughout the calculation. The feeds defined in the feed file will then be available as feeds in OLGA. A two-phase flash is performed for the hydrocarbon components. This is due to the full three phase option being significantly slower than the simplified three phase option. i. TRENDDATA to print compositional variables to trend file (*. Then aqueous components are added to the hydrocarbon phases. to define additional feeds and their composition (use components from the feed file) COMPOPTIONS. WELL. in which case none of these parameters have to be specified.plt). Tracking of hydrocarbons and inorganic gasses dissolved in the aqueous phase is important. OUTPUTDATA to print compositional information to output file (*. to specify feeds in the well stream. The viscosity calculations can be based on the corresponding states principle (CSP) or the Lohrenz-Bray-Clark (LBC) correlation (1964). Evaluate gas viscosity before and after tuning if the a-coefficients are changed considerably. The local non-equilibrium mass transfer term is derived from the following equation: (b) where is the local mass transfer term calculated by the equilibrium model and sign of the equilibrium mass transfer term. In the dense phase region. and the "chosen" phase does not affect the fluid properties for simulations with Compositional Tracking. In the non-equilibrium model the convective mass transfer terms are calculated according to: (a) where u is the superficial velocity of the mixture flowing into the section calculated for the equilibrium conditions at the section and ∆Z is the section length. The predictive capability of the CSP model is within 10% up to viscosities of approximately 1 cP. If the user gets an error saying there is no gas for this branch the DENSITYLIMIT should be increased. The CSP and LBC models may still be forced to follow the apparent oil viscosities. nor the non-Newtonian effects associated with the precipitation. The keys can be introduced for each component. voidfraction=0 for an entire branch.fc is the non-equilibrium delay factor for component fc. which adds to the confusion. Since the Compositional Tracking module does not account for wax precipitation/ deposition. and separate values can be given for vaporization (TVAPORIZATION) and condensation (TCONDENSATION). The following steps should therefore be taken when using LBC: Tune LBC to experimental or simulated CSP viscosity data in PVTSim. which has the dimension seconds. use the CSP viscosity model in OLGA Compositional Tracking module (a mismatch is more likely for heavy oils). there are no good criteria to distinguish gas from oil. viscosities will follow the apparent oil viscosity. Dense phase specification (key DENSITYLIMIT) The DENSITYLIMIT key specifies the limit for the dense phase region density. When using CSP the PVT code executes 2-3 times slower than when LBC is used.g. If a good match cannot be obtained. In the dense phase region (see Figure A below). internal routines will be used to decide phase (which may cause instabilities when crossing bubble/dew point). The user then has to specify voidfraction pipe-wise. such as for cases with decreasing pressure where different sections cross from the dense phase region to the two phase region on each side of the critical temperature. It is further recommended to consider if oil viscosities at temperatures below approximately 20-40 C are influenced by precipitated wax. Also. Note: The use of DENSITYLIMIT can also reduce oscillations. it is not possible to choose a different correlation in OLGA Compositional tracking module (an error will be given if the other correlation is chosen). is the convective mass transfer term calculated by the equilibrium model for component fc. The DENSITYLIMIT should preferably be set equal to the density found in PVTsim when performing a flash at the critical point. If the fluid has been tuned to one of the correlations in PVTsim. which can be a lot of work. the cost of using CSP instead of LBC may vary a lot. TDELAY. PVTsim might predict another phase than Compositional Tracking since a different and more time demanding approach is used. it is still recommended to tune to experimental viscosity data if available. Since 10-90% of the calculation time in an OLGA simulation is spent in the PVT code. Substantial tuning of the a-coefficients in the LBC-model can affect the gas viscosity. The user must specify the value of this factor. In case the CSP viscosity model is chosen. For higher viscosities the capability is more uncertain. The default is no delay.The VISCOSITYCORR key can be used to specify the viscosity calculations. The default viscosity correlation is CSP. This yields: is the delay factor for component fc for condensation or vaporization dependent on the . Dense phase region. However. Check if tuned oil viscosity data match reasonably well with the experimental data. The CSP and LBC viscosity models cannot account for the influence of precipitated wax. and the equilibrium state reached in the flash calculations will be delayed. Figure A. Delay constants (keys TCONDENSATE/TVAPORIZATION) The keys TCONDENSATE and TVAPORIZATION are non-equilibrium delay constants for the mass transfer from liquid phase to gas phase and vice versa. a fluid with higher density than the given DENSITYLIMIT value is defined as liquid and a fluid with lower density is defined as gas. This can be a problem especially for INITIALCONDITIONS where a user specifies e. the LBC model is not reliable as a predictive model. If not specified. but gets an error saying that this is not valid input since there is no liquid for parts of the branch. To manipulate the mode of a controller by time series. The definition on MODE through the use of the MODE terminal overrules the definition of MODE given by the MODE sub-key.5 <= A. Other network components may be other signal components or flow components (i. oil film.MODE < 4.MODE < 1. The controller MODE can be manipulated either by time series or by another controller. A controller can be set to one of five different modes operation either by using time series in the MODE sub-key or hooking a defined controller up to the MODE terminal (see Controller modes for further details). which are used to identify the controller. water droplets. and gas) Mass rate of flashing for each component to gas phase. The trend file and profile file are ASCII files that can be plotted graphically in the OLGA GUI.MODE < 3. trend file (*.MODE connect controller A.MODE A. A controller A might be deactivated and activated by connecting an external controller A.ACTIVATE to the ACTIVATE terminal of controller A. The difference between analogue and digital sampling in an OLGA simulation is as follows: The analogue controller collects input and gives a corresponding output at each simulation time step. Then controller A is active if the output . The automatic time step control assures that a simulation time point always agree with a sample time point (to the accuracy specified in the MAXCHANGE sub-key). Controller introduction: Controllers is in OLGA terms a network component labeled “signal component” which mean that they can communicate with other network components by sending and receiving signals.tpl).plt) can be used to show detailed compositional information: Mass flow rate for each component in each phase (oil droplets.ppl) and plot file (*. the controller function is bypassed and the controller output is set according to the external controller connected to the SIGNAL terminal.5 <= A. For those controllers that make use of setpoint the value in MODE = AUTOMATIC is taken from the SETPOINT key. External setpoint The controller MODE = EXTERNALSETPOINT is similar to MODE = AUTOMATIC except that the setpoint is taken the controller connected to the SETPOINT terminal. Controllers are typical signal components but also other types of network components may be signal components.MODE < 2. There are 13 different types of controllers: Algebraic Controller ASC Controller Cascade Controller ESD Controller Manual Controller Override Controller PID Controller PSV Controller Scaler Controller Selector Controller STD Controller Switch Controller Table Controller Both analog and digital controllers can be simulated in OLGA (see Analog vs. All controllers have one common key. The MODE sub-key is interpreted together with the TIME sub-key. The output signal from the controller is kept constant during the sample time interval. oil phase and water phase Mass fraction for each component in gas phase. digital controllers For all the controller types.(c) Output The keywords OUTPUTDATA. The automatic integration time step mechanism ensures that the relative change in the output signal of the controller from one time step to the next will never exceed MAXCHANGE.g. The MAXCHANGE sub-key specifies the maximum allowed change in controller output from one time step to the next. oil phase and water phase Total mole fraction (all phases) for each component Total mass in branch for each component The output file shows information textually and is structured for easy reading.MODE to the MODE terminal of controller A. The controller output is constrained. oil phase and water phase Equilibrium mass fraction for each component in gas phase. which reduces the file size.5 gives EXTERNALSIGNAL 3. The output file (*. Manual In MODE = MANUAL. water film. a branch).5 <= A. In the most advanced usage of the OLGA controllers utilizes the possibilities of interconnecting controllers by the use of terminals. The plot file is a binary file that is viewed in a separate plotting tool called the OLGA Viewer. In addition to implementing the possibility to switch the controller mode. Due to the binary format. A description to the different terminals is given in controller details. PROFILEDATA and PLOTDATA in the input file specify the data collection from the simulation.5 gives EXTERNALSETPOINT 4.out). Controller mode A controller in OLGA can be set in one of the five different modes: Automatic In MODE = AUTOMATIC.e. specify the sequence in the MODE sub-key. The predefined literals: AUTOMATIC value 1 MANUAL value 2 EXTERNALSIGNAL value 3 EXTERNALSETPOINT value 4 FREEZE value 5 are used when specifying the MODE through MODE sub-key in the GUI and input file. There may be one or more OLGA integration time steps in between each sample time point. the current version of OLGA also implements the possibility to “activate” and “deactivate” the controllers by hooking an external controller up to the ACTIVATE terminal (see controller activation/deactivation for further details).2. Controller activation/deactivation In addition to implementing the possibility to switch the controller mode. the current version of OLGA also implements the possibility to “activate” and “deactivate” the controllers by hooking an external controller up to the ACTIVATE terminal.5 gives AUTOMATIC 1. this form of data collection can use a shorter plotting interval and is useful for detailed analysis. total water phase. Analog vs. the controller function is bypassed and the controller output is kept constant (equal to the previous output value). total oil phase.5 <= A. the digital controller option can be selected by using the key SAMPLETIME. oil phase and water phase Equilibrium mole fraction for each component in gas phase. Freeze In MODE = FREEZE. the controller behaves according to the controller function as specified for the different controller types. see constraining the controller output for further details. External signal In MODE = EXTERNALSIGNAL. oil phase and water phase Specific mass for each component in each phase Mole fraction for each component in gas phase.5 gives MANUAL 2. The digital controller collects input and generates a corresponding output at time points separated by time intervals given in sub-key SAMPLETIME. profile file (*. E. The default value is 0. the controller function is bypassed and the controller output is set according to the time series definition of key MANUALOUTPUT. to manipulate the mode of controller A by a controller labeled A. TRENDDATA. When using the terminal to change the mode of a controller one need to connect an external controller to the MODE terminal.MODE gives FREEZE All controllers except “Table” and “Scaler” have MODE implemented. LABEL. digital controllers for further details). The mode of controller A id the dependent on the output value of A. If the controller output is less or equal to MINSIGNAL then the output is set equal to MINSIGNAL and the SATURATED output is set equal to -1. Figure B shows the implementation of modes and activation/deactivation mechanisms. When MODE is FREEZE the lower memory block is connected to the output of the switch (position five at the input of the switch). whereas controller type OVERRIDE does not use the setpoint subkey. it is value obtained through the terminal that determines the mode of the controller irrespective of what is set in the MODE sub-key. The signal constraints are specified in the keys MAXSIGNAL and MINSIGNAL. If a controller is connected to the MODE terminal. or value less than 0.5) the controller function is bypassed and the controller output is kept constant (equal to the previous output value). If the controller output is greater or equal to MAXSIGNAL then the output signal is set equal to MAXSIGNAL and the SAUTRATED output is set equal to 1. For further details see the description of the controller details. the controller modes and the controller activation deactivation. This switch cannot be changed during runtime. If the controller is activated (ACTIVATE = true.0 to signal a “low rate of change saturation”.0 to signal “high saturation”. Figure A: Overall block diagram for controller implementation. Controller Terminals Most of the controller types will have the following input terminals: MODE – used to set the mode of a controller . If MODE is MANUAL the manual output signal is routed through the switch (position two at the input of the switch). Constraining the controller output The controller output is constrained in two steps. Note. First controller output is checked against signal constrains. thus the output is frozen (kept constant). If the rate of change in the controller output violates the OPENINGTIME (or STROKETIME) the controller output is set equal to the maximum allowed output satisfying the rate of change constraint and the RATELIMITED variable is set equal 1. the additional outputs SATURATED and RATELIMITED. Figure A: Implementation of controller modes and activation/deactivation mechanisms.ACTIVATE < 0. or value greater or equal to 0. secondly the controller output is checked against rate of change constraints. Controller type PID is an example of a controller type that makes use of the setpoint sub-key. The lower left switch in the figure determines how MODE is set. If the controller is deactivated (ACTIVATE = false. In Figure A above and Figure B below: inputs in terms of sub-keys are given in boxes framed by an orange line.0 to signal “low saturation”. These are used to signal saturation and rate of change limitation to other controllers. If mode is AUTOMATIC (mode value one) the setpoint is taken from the subkeys and if mode is EXTERNALSETPOINT (mode value four) the setpoint is connected to the setpoint terminal. Finally.5) then the activate switch is in position one connecting the output A to the previous value. The deactivation of controllers takes precedence over controller function and mode.5. Output A from the “Controller function + Controller mode” block represents the unconstrained output. Thus the output is frozen (kept constant). Controller details Figure A below shows a block diagram of how different inputs and outputs relate to different part of the controller implementation.0 to signal a “high rate of change saturation”. When a controller is activated the output is calculated according to the controller function and any specification of MODE. This is illustrated by the upper left switch in Figure B. When the MODE is EXTERNALSIGNAL the SIGNAL TERMINAL is connected to the output of the switch (position three at the input of the switch). implements the controller functionality given by the controller type. If the rate of change in the controller output violates the CLOSINGTIME (or STROKETIME) the controller output is set equal to the minimum allowed output satisfying the rate of change constraint and the RATELIMITED variable is set equal -1. If MODE is AUTOMATIC or EXTERNALSETPOINT then the output of the controller function (CF) block is routed through the larger switch in the figure (position one or four at the input of the switch) and the corresponding setpoint is connected to the controller function. The unconstrained output is checked against sub-keys MAX/MINSIGNAL and forms the constrained output B. Depending on the controller type the controller function block may or may not need the setpoint sub-key.5) the activate switch is in position two connecting the controller to the output A. The activation/deactivation mechanism is illustrated by the switch with two inputs and memory block on the right in the figure. output B is checked against rate of change constrains (OPENINGTIME and CLOSINGTIME) to form the final constrained output CONTR.ACTIVATE is greater or equal to 0. inputs given through terminals are given in boxes framed by a green line and internal calculation boxes are framed by a black line and gray background color. If no controller is connected to the MODE terminal then it is MODE sub-key that determines the mode of the controller. The controller function block may also use additional terminals and sub-keys not shown in Figure B. The memory blocks hold the previous output value. When a controller is “deactivated” (A.of A. The larger block “Controller function + Controller mode” in Figure A. . 2) Note that the setpoint change in a step wise manner. whereas an output of 1 means that the valve is fully open. i. to show that the terminal OUTSIG can be connected an arbitrary number of times.. If it is given as a time series the keywords SETPOINT and TIME must be given. See controller details for further information.is previous output signal from the controller .N. The user specifies minimum and maximum controller output signal.. .is the minimum output signal from the controller The actuator time is specified as stroke time or the time required to open/close. Example: PID pressure control The PID controller has the following terminals: MEASRD (Required input) SETPOINT (Optional input) OUTSIG_1. The controller output can be connected to process equipment (Valve. 1.is output signal from the controller .N – Used to connect the controller output to another input signal terminal.. When connecting output signals the first available terminal will be named OUTSIG_1. But the user can connect an external setpoint to the controller. Figure A: Pressure control example In Figure A the measured pressure is taken from a transmitter (PT). ”PT bara” Connection (2): CONTROLLER OUTSIG_1 → VALVE INPSIG Controller Setpoint Most controllers take a setpoint as input.is the time step . The required input is different for the different types of controllers. The controller input is connected to output from another controller or a transmitter.g. These two parameters determine the operating range of the controller.close ∆t Uold U Umax Umin . Connecting the controllers All the controllers have a set of input and output signal terminals. an output of 0 from a controller operating on a valve means that the valve is closed. The output from the controller frequently changes faster than the device is capable of following. 1.).SIGNAL – used to override the output of the controller when MODE = EXTERNALSIGNAL SETPOINT – used to override the setpoint key when MODE = EXTERNALSETPOINT. The output terminals (OUTSIG) can be distributed to several receiving terminals. cascaded controllers ACTIVATE – used to activate deactivate the controller function All controllers will have the following output terminal: OUTSIG_1. e. Actuator time of controlled device There are no restrictions on the rate of change of the output from the controller algorithms. The next terminal will be named OUTSIG_2 etc.. It is required that some of the input terminals are connected. Umin and Umax. 0.is the maximum output signal from the controller . The setpoint can be connected as an input terminal or given as a time series.open tact.is the actuator time when decreasing U . Pump etc. Connection (1): TRANSMITTER OUTSIG_1 → CONTROLLER MEASRD A variable and unit must be defined in the transmitter keyword. Ex. Connecting the output terminals is optional. Normally the operating range is from 0 to 1.N (Optional output) The input terminal MEASRD is required. The variable transmitted is set-up (specified) in the signal connection. In the controller output terminal OUTSIG a number of output variables are available. while the input terminal SETPOINT is optional.is the actuator time when increasing U . In order to use the external setpoint the SETPOINTMODE must be set to EXTERNAL. The controller (PC) output is connected to the valve opening. The PID controller has internal setpoint given as key input.5) TIME = (0. In general it is written OUTSIG_1. This situation is taken care of by passing all output from the controllers through an actuator filter that computes a 'real' output (as observed by the devices) according to the rule: (d) or (e) where tact. Figure B shows how the controller setpoint is changed for the following SETPOINT/TIME input: SETPOINT = (0.e. Activate deactivate controllers according to a logical expression.N terminal(s). Specify the operators to act on the input signal(s) in the VARIABLEFUNCTION key. the controller shall apply one level of amplification and integral action to a positive error input signal and a different level of amplification and integral action to a negative error input signal. In essence. Valve. closing time or stroke time). Methods and assumptions The algebraic controller takes a number of input signals and combine these according to the specified VARIABLEFUNCTION key.. Algebraic Controller The algebraic controller is used to combine input signals to form algebraic equations and logical expressions. The figure below shows how multiple controller blocks can be combined in one algebraic controller. The algebraic controller issues a control signal to a device (e. the measured variable is delayed 10 seconds before it is taken into account in the control algorithm.g. Make the valve opening dependent on more then one signal and an algebraic expression. How to use Connect the required input signal(s) to the INPSIG_1.Figure B: Setpoint vs. Ex. ASC Controller The main purpose of the ASC unit. But the ASC must also be capable of managing a situation where the compressor inlet or discharge is closed. Ex. see terminal MEASRD and/or terminal INPSIG. See also: When to use Methods and assumptions How to use When to use Use to control the recycle flow for compressors.N to a device variable. Non-linear transformation a measured signal to a controller. is to prevent a compressor from operating to the left of the Surge Line in a compressor performance map. Ex. Ex. This can be achieved by choosing a high amplification factor for the ASC and selecting a recycle valve with a short stroke time. minimum constraints and by rate of change constraints (opening. Methods and assumptions An ASC should be able to open the recirculation valve very fast to prevent a dangerous surge condition. a valve) or as an input signal to other controllers. The computed output signal is affected by maximum. The high amplification factor could give excessive compensation. Therefore it is necessary to have a controller that can operate on a non-linear control algorithm. See also: When to use Methods and assumptions How to use When to use Use to change a variable in a process unit (e. Connect the controller output signal OUTSIG_1. Pump) or an input to another controller according to an algebraic function or a logical expression. Figure B: Recirculation loop and Figure A: Anti Surge Controller.. see Constraining the controller output and Actuator time of controlled device. In this way the recycle valve can be opened rapidly while an inertia is imposed when it is closed again. see Figure A: Compressor characteristic diagram. time Controller measured variable Most controllers take an input signal in terms of a measured variable. and to avoid compressor surge. Make the valve opening dependent on a logical expression. The measured variable can be delayed by specifying the DELAY key on the controllers (avaiable on most controllers). which would cause the recirculation valve to hunt between open and closed position and aggravate the surge due to pressure and flow pulsation. . If the DELAY key is set to 10 seconds.g. How to use See Connecting the controllers for an example on how to connect a controller. Methods and assumptions As illustrated below in Figure A a cascade control uses two (or more) controllers with the output of the primary controller changing the setpoint of the secondary controller. Figure A: Anti Surge Controller The cascade controller uses the PID algorithm. COMPRESSOR (i. Connect the gas volume flow QG to the ASC controller measurement terminal (MEASRD).e. see ProportionalIntegral-Derivative (PID) Algorithm. AMP1 is used when the deviation parameter (e) is negative (left of anti surge control-line in the compressor performance map) and AMP2 when it is positive. The surge flow increases with increasing RPM. See also the PID Controller Methods and assumptions. The separator holdup changes are slow compared to flow dynamics. The ASC controller have the same functionality as the PID controller. Examples of use is: Level control in a separator. The Cascade controller have the same functionality as the PID controller. See Figure A: Cascade control. Connect the compressor output (QGSURGE) to the ASC controller setpoint (SETPOINT). Figure A shows the ASC application. in addition to the functionality described in this section. The security factor is given in the compressor SECURITYFACTOR key. Temperature control when two fluid flows are heat exchanged. The surge flow at different RPM's. To improve the dynamic performance of the control loop.2 means that the set point for the ASC unit is 20% higher than the surge flow). The temperature dynamics are slow compared to the flow dynamics. the secondary controller shown in Figure A. Put a transmitter at the same section boundary as the compressor. a security factor of 1. Connect the ASC controller output to the Compressor ASCSIG input terminal. here the drain valve. The MEASRD terminal must be connected. which means that the setpoint for the ASC unit is not constant. Make sure QG and QGSURGE have the same units. See also: When to use Methods and assumptions Limitations How to use When to use Cascade control is used when there are disturbance associated with the manipulated variable. 2. That is.The ASC unit uses a standard PID controller formula except that it allows for two different controller amplifications (AMP1 and AMP2) that are necessary when operating on a nonlinear control algorithm. or when the final control element exhibits nonlinear behaviour. Figure A: Cascade control The OLGA cascade controller will represent the inner loop. To reduce the effects of some disturbances. see Proportional Integral Derivative (PID) Algorithm. Figure B: ASC controller connection terminals Cascade Controller The purposes of a cascade control loop are: 1. The anti surge control-line is the setpoint for the ASC unit and is calculated by multiplying the compressor surge flow at different RPM's with a constant security factor specified by the user through the compressor input group. . the anti surge control valve is forced to a rapid opening whereas the closing operation is more relaxed. (Connect the compressor OUTSIG to the ASC setpoint and specify QGSURGE as variable. See PID Controller Methods and assumptions (Jump to: PID controller Methods and assumptions). Figure B shows the connection possibilities of the ASC controller. in addition to the functionality described in this section. is specified in the compressor data file. To achieve this cascade control utilize multiple feedback loops. By using a large AMP1 and a (corresponding) small AMP2. The output of the secondary controller regulates the control device. The cascade controller uses the PID algorithm.) This is the volume flow (default unit m3/s) at predicted surge multiplied with a security factor. max Ps Dt PM Tav C C1 C2 Cswitch if if |PM . the drain flow rate will not be corrected until the increased drain flow decreases the liquid level. If the liquid level in a separator becomes to low. Φιγυρε Β: Χασχαδε χοντρολλερ χοννεχτιον τερµιναλσ ESD Controller Emergency-Shut-Down (ESD) logics are used to avoid damage on the process equipment and the pipeline. output goes from 1 to 0. the setpoint of the secondary controller is determined by the output of the primary controller: (α) Where S the setpoint of the secondary controller Smin minimum setpoint Smax maximum setpoint Cp output from the primary controller For the extended cascade controller.tn-1) moving averaged of the primary controller variable P user defined (moving) averaging time period constant that can take two different values user defined constant user defined constant user defined constant For the level control as illustrated above. With the cascade control loop. Τηε χασχαδε χοντρολλερ ρεθυιρε τηατ τηε µεασυρεµεντ τερµιναλ (ΜΕΑΣΡ∆) ανδ τηε σετποιντ τερµιναλ (ΣΕΤΠΟΙΝΤ) αρε χοννεχτεδ.min Cp. A ESD controller closes.Ps| > Cswitch |PM . Figure B show the connection possibilities of the Cascade controller. Methods and assumptions . How to use See Χοννεχτινγ τηε χοντρολλερσ φορ α εξαµπλε ον ηοω το χοννεχτ α χοντρολλερ. For the normal cascade controller. when a measured process variable rises above (or fall below) a safety limit. so the liquid flow will increase.The cascade controller can be in normal or extended mode. the flow controller (secondary controller) will immediately see the change in the flow rate and correct the valve opening to return the drain flow rate to the setpoint set by the level controller. Τηε χασχαδε χοντρολ λοοπ ισ βυιλτ ασ τωο σεπαρατε ΠΙ∆ χοντρολλερσ.Ps| £ Cswitch (δ) (ε) setpoint of the secondary controller at the current time point setpoint of the secondary controller at the previous time point output from primary controller minimum of output from primary controller maximum of controller output from primary controller setpoint of the primary controller numerical time step (tn . Limitations Secondary loop process dynamics should be at least four times as fast as primary loop process dynamics. ωηερε τηε ουτπυτ φροµ τηε πριµαρψ χοντρολλερ ισ υσεδ ασ α σετποιντ οφ τηε σεχονδαρψ χοντρολλερ. Example of use: Shutdown of a pump downstream a separator. The difference between the two is how the setpoint of the secondary controller are determined. With a single level controller. the setpoint is calculated differently: (β) Where (χ) C = C1 C = C2 Sn Sn-1 Cp Cp. See also: When to use Methods and assumptions How to use When to use Use to model safety control system. The pressure drop over the drain valve will be larger. gas might flow in the pump feed. Thus the separator pressure disturbs both the liquid level and the liquid drain rate. Gas in the feed might damage the pump. Thus it gives a better control on the liquid level and a smoother liquid drain rate. suppose the separator pressure increases. Ex. The input signal is filtered through with stroke time limitations. Simulate a manual change in valve opening. Include sufficient hysteresis for the reset value compared to the setpoint value. closes again in the next etc. Simulate a starting leak from the pipeline. Set the setpoint where the controller should close.The controller will monitor one or more variables (normally pressure). The manual controller issues a control signal to a device (e. See also: When to use Methods and assumptions How to use When to use When there are fewer variables to manipulate than there are variables to control. that is. Connect the measured value (e. . See Actuator time of controlled device. or as a input signal. A typical application of the controller unit in a process module is shown in Figure A. Ex.g. the ESD valve will open again when all of the controlled variables become greater or less than the reset value. If the controller should automatically open. a valve). The controllers (or measurements) of the controlled variables need to share the manipulated variables. How to use See Connecting the controllers for an example on how to connect a controller. The changes in setpoint will be applied immediately. Figure A: ESD controller connection terminals Manual Controller The manual controller is used to simulate the actions of an operator. Methods and assumptions The override controller can be a low select or high select operator. Valve. This can be avoided by setting a low stroke time. Figure A show the connection possibilities of the ESD controller. a situation where the ESD closes in one time step. a pressure). If a reset value is specified. The ESD output is typically connected to some process equipment or a pressure driven source/leak. It can be configured to select the lowest or highest value among several inputs. opens the next. Figure A: Manual controller connection terminals Override Controller The Override controller acts as a minimum or maximum operator on its input. The output signal is limited with stroke time. depending on opening mode. The override controller requires one or more input signals.g. In low select mode the minimum input signal is selected as the final output signal from the unit. a controller signal activates a valve that will close within a certain time. The input signals can come from any other output terminal. Ex. Figure A shows the connection possibilities of the manual controller. The manual controller don’t require any of the signal terminals to be connect. Simulate a manual ramp-up of a choke. Methods and assumptions The manual controller take a setpoint as an internally defined time series. See Actuator time of controlled device. enter a reset value. the setpoint will change in a step wise manner. Pump) inputs manually. See also: When to use Methods and assumptions How to use When to use Use to change the process unit (e.g. In this way a situation where the ESD output oscillates will be avoided. That is. The MEASRD terminal must be connected. How to use Give the required setpoint changes. As soon as any of the variables becomes less than or greater than the setpoint value. and connect to a device variable. One of the pressure controllers is controlling the suction pressure before the first compressor stage. as input signal. the speed is controlled by the suction pressure controller. . The override controller is in low select mode. Select the mode of operation by setting SELECTIONMODE. How to use See Connecting the controllers for an example on how to connect a controller. A typical application of the controller unit in a process module is to control a separator level (Figure A) and it is then called a level controller. the speed is controlled by the high pressure controller. or to stabilize an entire pipeline.Figure A: Double PID controller used as a turbine speed controller Here the output signal from two pressure controllers (PC) are connected as input to the override controller. the valve is controlled by the flow controller. and the other is controlling the pressure downstream of the second compressor stage. pressure etc. The controller may alternatively have flow. Input process parameter is liquid level in the separator and the output signal from the controller is used to control the opening of a drain valve. The Override controller require that at least one input terminal is connected. Figure B: Triple PID controller used as flow regulator The output signal is limited with stroke time. In situations where the pressure upstream of the control valve approaches the minimum operating pressure (set-point for upstream pressure controller). In situations where the pressure downstream of the control valve approaches the maximum operating pressure (set-point for downstream pressure controller). In normal operation. In normal operation. Figure B shows a typical application of the override controller (OC) with input signal from three controllers in a process module. See also: When to use Methods and assumptions How to use When to use To stabilize a process variable. and is then called a flow controller. To model actual control functionality used to stabilize pipe flow. but in situations where the outlet pressure approaches the maximum operating pressure. The flow controller (FC) is controlling the flow downstream of the control valve (choke) while the pressure controllers (PC) are controlling the pressures upstream and downstream of the control valve. Figure C: Override controller connection terminals PID Controller The main function of a PID controller is to maintain process parameters within specified bounds by controlling process equipment parameters like valve opening and compressor speed. a pressure controller etc. Figure C shows the connection possibilities of the Override controller. See Actuator time of controlled device. the valve is controlled by the low-pressure controller. the valve is controlled by the high-pressure controller. Connect the signals the override controller should operate on. 0 PD controller > 0. The PID controller require that a measurement value is connected to the controller. Valve). so that the controller is ready to resume action. See Actuator time of controlled device. The PID parameters keys for KC. everything is on hold. simpler controllers as P and PI controllers can be defined by giving proper values to the time constants in the PID formula. as soon as the control error changes. Transfer between setpoint modes are made bumpless. see below. An error is then given as a vector (keyword input). The nonlinear controller option is activated when the PID parameters are given as vectors. i and d must be specified as vectors with the same dimension as . If the option with normalised amplification factor is used. DEFAULTINPUT Compute output signal based on default input. and not as single values. The controller uses Anti-Windup. NORMAL No action for normal mode. e. d can be given in tabular form as a function of the error signal e. etc. If the PID controller output is connected to a Selector or a Override controller it might become inactive. How to use See Connecting the controllers for an example on how to connect the PID controller. Actions taken when the controller becomes inactive (keyword INACTIVEMODESUBC): ONHOLD Restore old values. Table 1: Time constants for P. the integral term is corrected to remove a sudden jump in the controller output. PI and PD controllers Time constants d P controller 0. Proportional Integral Derivative (PID) Algorithm A PID algorithm may be mathematically formulated as: (a) (b) where: x = input process parameter (pressure. There are four different modes for the controller when it becomes inactive. given in key DEFAULTINPUT. The PID controller limits the output with the stroke time of the connected device (e.g.Figure A: PID controller used as a level controller Methods and assumptions The PID controller uses the Proportional-Integral-Derivative (PID) Algorithm. The Selector or Override controller will automatically set the PID controller in a active/inactive state. The controller parameters are found by linear interpolation in the actual controller error. KC. INTERLOCK The PID controller get feedback on the output signal used (uused) from the connected controller (Selector or Override). The setpoint must be given in the key SETPOINT. (Signal terminal MEASRD). If the PID controller becomes inactive it will use uused to back calculate its integral error.0 PI controller 0. .0 i 109 < 108 109 This controller formula is frequently referred to as a standard PID controller in the manual.) = time constant u = output signal from controller t = time bias = initial value Subscripts: stp = set point (or reference point) i = integral d = derivative 0 = time at start of simulation The amplification factor Kc is a dimensioned quantity. i. By using this general formula. The anti-windup used is a tracking/back calculation scheme. See Selector and Override controllers. level. When the controller reaches maximum/minimum output (saturates) the integral is kept to a proper value. Figure B shows the connection possibilities of the PID controller. the program will calculate Kc using the range given with the following expression: (χ) For non-linear controllers. The table below shows time constants for simpler controllers. When the setpoint mode change. or connected to the SETPOINT input terminal. 7 will give satisfactory results for level control. if the stroke-time is given as 100 s the opening of the valve will at maximum change by 1% per second. Taking the time derivative of the above two equations with the use of the control equation (Jump to: Equation a in the following differential equation is obtained (c) Where f(t) is a disturbance that the control system should compensate for. one may use the following procedure to select the parameters for level control: . This results in rapid oscillations in the derivative of the signal. the opening and closing speed of the controller valve is limited by the stroke-time. Figure C: Response of level control to step disturbance. This could for instance be that the setpoint of the level control is changed. However. Level control A typical application of a level controller is shown in the Figure A: PID controller used as a level controller. Casting it into the standard form (d) we get the time constant of the control loop (e) and the damping coefficient (f) Kc must be positive for tp and z to be real numbers. However. We have the following relation between the symbols used in this description and the OLGA input variables in the CONTROLLER keyword: Kc td ti bias x xstp = AMPLIFICATION = DERIVATIVECONST = INTEGRALCONST = BIAS = VARIABLE = SETPOINT Note that the stroke-time of the controller valve (defined through STROKETIME) does not directly influence the controller output as discussed here. one can see that a damping coefficient from 0. since there is usually quite a lot of noise on the input process signal. Therefore. The change in the liquid volume fraction in the vessel (b) is given by (a) where Qin [m3/s] is the liquid volume flow into the vessel. and if the derivative term in the controller equation were included this would result in oscillations in the controller output.Figure B: PID controller connection terminals PID controller example Three parameters are at our disposal for tuning a PID controller. For the current case. From this figure. Qout [m3/s] is the liquid volume flow out of the vessel and V [m3] is the volume of the vessel.5-0. which is not desirable. for petroleum applications td is rarely used (td = 0). and the derivative time constant is set to zero. the error (e) is defined as liquid volume fraction minus the volume fraction at the setpoint. That is. The flow out of the vessel can be written (b) where Qmax is the maximum flow when the controller is fully open. td and ti. The figure below shows the performance of control loop for different damping constants for a step disturbance at t = 0 (f(t) has a step increase). Kc. g. the controller will open a selected PSV-valve.7. Size the valve so that it can deliver maximum flow rate = 2 times the designed value for the same pressure drop over the valve. the faster the response goes to the setpoint. Estimate the upstream and downstream pressure over the control valve at the design flow rate. 5. If all of the variables become greater or lower than the reset value.1. Connect the measured value (e. When the valve is opened the pressure is relieved.2 bar. See Actuator time of controlled device. depending on how fast you want the flow rate to reach e. 3. the same tp can be obtained for a different ti. The shorter the time constant. Set Kc < 2 and choose ti (the integral time constant) to make the damping coefficient between 0. Set with A ranging from 1 to 10. When tp has been chosen ti is found from the definition of tp. The MEASRD terminal must be connected.g. PSV Controller A Pressure-Safety-Valve (PSV) typically opens fast when the pressure rises above a defined value. 90% of the set point. 2. a pressure). One could use the following procedures to select the controller parameters for flow control. 1. How to use See Connecting the controllers for a example on how to connect a controller. If the pressure difference is less than e. 2. . 4. Kc must be negative. Use together with a valve or pressure driven source.5 and 0. The time constant of the solution is (j) Figure D shows the response of the flow to a step change in for example setpoint (f(t) has a step increase). If any one of the variable values becomes higher than or less than the setpoint.g. this valve is closed again. See also: When to use Methods and assumptions How to use When to use Use to model pressure safety valves. This is considered a convenient pressure drop over a valve being used for flow control. Size the drain valve so that it can deliver Qmax = two times the normal drain rate for the pressure difference between separator pressure and backpressure of the drain valve. Figure D: Response of flow control to step disturbance. The output signal is limited with stroke time. 0. tp can be selected from the above chart. The PSV controller and a valve (or source) simulates the behaviour of the Pressure-Safety-Valve.2 bar. the flow rate can be written as: (g) where: F = flow rate (mass or volumetric flow rate) Fmax = max flow rate through the fully open valve at the given pressure drop u = output signal from controller Taking the time derivative of the above equation and using the control equation we obtain (h) or (i) For the solution to be stable. The safety valves are included to avoid damage on the process equipment and the pipeline. By choosing a different A. Flow control Assuming constant upstream and downstream pressure over the valve. Methods and assumptions The controller will compare one or more input variables (normally pressure) with a setpoint. This could be the valve defined as a source valve. adjust the upstream or downstream pressure so that the difference is at least 0. Scale signal from transmitter range to controller input range. Specify input range and the output range by setting LOWLIMIT. a valve) or as an input signal to other controllers.100% to input valve signal range 0 . Limit transmitter signal to stay in configured range.. Methods and assumptions The scaler controller scales the input signal linearly from the input range (LOWLIMIT to HIGHLIMIT) to the ouput range (MINSIGNAL to MAXSIGNAL). How to use Connect the required input signal to the MEASRD terminal.1. See also: When to use Methods and assumptions How to use When to use Use to scale a variable in a process unit (e.Connect the PSV controller output to a valves. . Include a scaler controller between transmitter and main controller. MAXSIGNAL keys.g. to avoid a situation where the PSV output oscillates. see Constraining the controller output and Actuator time of controlled device. Valve. Ex. closing time or stroke time).LOWLIMIT) * (y . Include sufficient hysteresis for the reset value compared to the setpoint value. Change the default OPENMODE to BELOW if the controller should open when the measurement falls below the setpoint. Set the setpoint where the controller should open. Connect the controller output signal OUTSIG_1. u = (MAXSIGNAL-MINSIGNAL) / (HIGHLIMIT .g. If the controller should automatically close. Figure A: PSV controller connection terminals Scaler Controller The scaler controller is used to scale input signals linearly from an input range to an output range. The figure below shows transformation of input to output through a scaler controller C. enter a reset value. Figure A shows the connection possibilities of the PSV controller.unconstrained output The computed output signal is affected by maximum. HIGHLIMIT and MINSIGNAL.N to a device variable. minimum constraints and by rate of change constraints (opening. Includ a scaler controller between main controller and valev Ex. closes the next. Ex.LOWLIMIT) + MINSIGNAL where y . a situation where it opens in one time step. The scaler controller issues a control signal to a device (e.measured variable u . Pump) or an input to another controller. Scale controller ouptput signal from range 0 . opens again in the next etc. That is. pressure driven sources or leaks. Connect one or more limit signals (HIGHLIMITSIG/LOWLIMITSIG). reset to zero. HIGHLIMIT). selecting the signal from one of the sub-controllers. The controllers (or measurements) of the controlled variables need to share the manipulated variables. Define the controller used at start of simulation (keyword INITIALCONTROLLER). We also want this to trigger a faster operation of the separator liquid valve. Upstream of the separator. The operation is back to normal. or the time averaged gamma densitometer signal becomes higher than a given limit. the fast separator liquid outlet valve controller takes over. . and keeps it until the high (or low) variable limit is reached. If the separator liquid level reaches a given high level. Figure A: Separator using SELECTOR controller to control the liquid outlet valve. There is no restriction on the number of variables that can be used for switching between the sub-controllers. and using this sub-controller until the low (or high) variable limit is reached. How to use See Χοννεχτινγ τηε χοντρολλερσ φορ αν εξαµπλε ον ηοω το χοννεχτ α χοντρολλερ. 2. Figure B show the connection possibilities of the Selector controller. and for transient operation (when a slug arrives) we have a fast PID operation. If the separator liquid level drops below a given low limit. Connect the controller used below LOWLIMIT (SUBCONLOW). Then the controller selects another sub-controller. If a liquid slug arrives we want the level control on the separator liquid outlet to be faster to prevent the level from increasing to very high levels. Transient operation: 1. and the controller used above HIGHLIMIT (SUBCONHIGH). The variables and their low and high limits are given as input to OLGA. In addition. If the sub-controllers are PID controllers the integral term of the non-acting controller can be saved (interlocked). Slow separator liquid level controller used to control the liquid outlet valve. or still be integrated. As long as the liquid level is below a given value we want the controller to act slowly / moderately fast. a gamma densitometer is placed at some distance from the separator inlet. In addition there is a separator inlet valve having a fixed opening. The controller operates as a kind of hysteresis controller. is a gamma densitometer used for measuring the local liquid volume fraction. Define the limits where the Selector controller changes its output (LOWLIMIT. a slug is expected to arrive. in addition to an emergency liquid drain valve. the slow / normal separator liquid level controller starts controlling the liquid outlet valve. This will be determined in the input to the OLGA sub-controllers by the user. When the time averaged signal from the meter reaches a certain limit. The fast liquid valve controller that is controlled by the separator liquid level is acting. Methods and assumptions The controller algorithm is best described by an example: Figure A shows a system consisting of a pipeline with a separator. See also: When to use Methods and assumptions How to use When to use When there are fewer variables to manipulate than there are variables to control. This means that for normal operation we have a moderately fast PID level controller. at some distance from it. 2. The separator has liquid and gas valves attached to it.Selector Controller A SELECTOR controller is a controller that uses two sub-controllers that are selected based on the value of selected variables relative to low and high limits of these variables. We want to control the separator level by controlling the liquid level in the separator with a level PID controller. Our control structure for the separator liquid outlet valve will then be: Normal operation: 1. Standard conditions. Limitations Standard conditions. Alternative measured signals to controllers. Ex. Χοννεχτ τηε ΣΤ∆Χοντρολλερ ουτπυτ τερµιναλ ΟΥΤΣΙΓ το αν ΠΙ∆ χοντρολλερ ΜΕΑΣΡ∆ τερµιναλ.. pressure = 1 atm and temperature = 60 ° (~15.N . To convert from mass flow at to volumetric flow rate at standard conditions: Switch Controller The main purpose of the switch controller is to switch between alternative inputs values. Ex.5) <= SP unconstrained output A is set equal to controller at terminal INPSIG_N unconstrained output A is set equal to controller at terminal INPSIG_1 unconstrained output A is set equal to controller at terminal INPSIG_2 unconstrained output A is set equal to controller at terminal INPSIG_3 Where N is the number of connected input terminals INPSIG_1.5 1. Methods and assumptions The output of the switch controller is selected based on the setpoint in MODE = AUTOMATIC or SETPOINT terminal if MODE = EXTERNALSETPOINT.5 . Σπεχιφψ τηε ωαντεδ ΓΟΡ/ΧΓΡ/ΩΓΡ/ΩΑΤΕΡΧΥΤ/ΜΟΛΩΕΙΓΗΤ.. See also: When to use Methods and assumptions How to use When to use Use to select between alternative inputs to controllers or valves.5 2. See also: When to use Methods and assumptions Limitations How to use When to use Use to control a volumetric flow rate at standard conditions. the fluid table/composition phase distribution at standard conditions will be used to calculate the overall mass flow rate.Φιγυρε Β: Σελεχτορ χοντρολλερ χοννεχτιον τερµιναλσ STD Controller The controller converts mass flow rate to volumetric flow rate at standard conditions. The output of the controller is selected based on the setpoint in MODE = AUTOMATIC or SETPOINT terminal if MODE = EXTERNALSETPOINT. or composition (FEEDNAME) at standard conditions. Alternative inputs to valves.5 <= SP < 3.5 ° .. F C) If neither of GOR/CGR/WGR/WATERCUT/MOLWEIGHT are given. Fluid properties are calculated from the given fluid table (FLUID). How to use Σετ χορρεχτ πηασε ιν ΠΗΑΣΕ κεψ. SP < 1.5 ° must be included in the flui d table. pressure = 1 atm and temperature = 60 ° (~15. Methods and assumptions The controller converts mass flow rate to volumetric flow rate at standard conditions. ανδ τηε ϖολυµετριχ φλοω ρατε ατ στανδαρδ χονδιτιονσ ωιλλ βε χαλχυλατεδ.. F C).5 <= SP < 2. Σπεχιφψ τηε φλυιδ ιν τηε ΦΛΥΙ∆ ορ ΦΕΕ∆ΝΑΜΕ κεψσ. (N-0. Reference the table in the controller definition. Methods and assumptions The transmitter creates a trend object and update the signal terminal every time step. This is done in the table definition. u = f(x).. Figure B: Table controller connection terminals When to use The transmitters are used together with the controllers. process equipment. How to use Connect the required input signal(s) to the INPSIG_1. with XVARIABLE and YVARIABLE set to NOTGIVEN. Figure B shows the connection possibilities of the table controller. Table Controller The table controller make it possible to tabulate a relation between the controller input and the controller output. Make the input signal available from a transmitter with the correct units. The controller output is u. It is possible to use nested tables. where one table can reference another. The table controller require that the input signal (INPSIG) terminal is connected. see Constraining the controller output and Actuator time of controlled device. in a table. .N terminal(s). Methods and assumptions A table controller uses the input variables as lookup variable. The figure below shows how INPSIG_1. It is only possible to calculate u = f(x1). How to use Define a table. Limitations The table controller is limited to one variable tables. Specify the SETPOINT key or connect the SETPOINT terminal. the only exception is an output signal going from a controller. The signal is converted to user specified units. closing time or stroke time). nodes. The result from interpolating one table is used to interpolate in another.4 is connected to OUTSIG.. and connect to the controller. That implies that every variable available for trending is available from a transmitter. u = f(g(x)). The transmitters are used together with the controllers to provide measured values from flowpaths.. and not u = f(x1.N to a device variable.The computed output signal is affected by maximum. See also: When to use Methods and assumptions Limitations How to use When to use Use to define a non-linear relation for a process variable. x. Connect the controller output signal OUTSIG_1. the default unit is used. separators and phase split nodes. If no unit is given.x2) etc. that is. All output signals need to be defined by transmitter. minimum constraints and by rate of change constraints (opening. How to use The transmitter is positioned on:the flowpath. PCO2) (k) The flow field at each section along the pipeline/network is used to calculate the corrosion rate. /8/.5). the NORSOK model . OUTSIG_1). PCO2). /18/. (h) and the scale protection factor Fscale is a function of temperature and CO2 partial pressure: Fscale = g(T.8 * DH0. License requirements The Corrosion Module requires a separate license. three CO2 corrosion models. OUTSIG_2). pH.T) (j) where Rcond is the water condensation rate calculated by OLGA and the solubility of iron in the condensing water CFe is a function of CO2 partial pressure and temperature: CFe = f(T. using process equipment as position node (type pressure or massflow)separator phase split node Make the connection between the transmitter. but has now been replaced with the top-of-line corrosion model. Transmitter . connected the equipment directly. T) * g(T) * h(PCO2. Protective corrosion films can form especially at high temperature (above 60 ° a nd at high pH (above pH 5.) variables. See also: When to use Methods and assumptions Limitations How to use When to use CO2 corrosion should be expected whenever CO2 and water is present. the de Waard 95 model and the IFE top-of-line corrosion model have been implemented in the OLGA three-phase flow model /5/. the variable and unit as defined in the transmitter keyword. and the receiving signal terminal. CO2 partial pressure and wall shear stress: CR = f(pH.ions exceed the solubility limit. One transmitter can transmit an arbitrary number of variables (from a single position). For process equipment (Valve. The NORSOK model gives the corrosion rate as function of pH. using pipe and section/section boundary or absolute position flowpath. Methods and assumptions The basic chemical reactions in CO2 corrosion are: (a) which dissociates in two steps: (b) (c) In CO2 corrosion when the concentrations of Fe2+ and CO32.2. temperature. it can transmit to an arbitrary number of controllers (from a single position). a new terminal will be made available (ex. Currently. The NORSOK and de Waard 95 models are both regarded as conservative models as they include only limited effects of protective corrosion films. liquid flow velocity and hydraulic diameter: Vm = C * PCO2 * UL0. . CO2 partial pressure and pH: Vr = f(T. Corrosion The purpose is to calculate standard uniform CO2 corrosion and Top Of Line (TOL) CO2 corrosion. Corrosion dominated by H2S is at present not covered by the corrosion module. as more recent high temperature data also have been used. (g) Vm is the maximum corrosion rate based on the limiting mass transfer rate given as a function of CO2 partial pressure. but the NORSOK model takes somewhat larger account for protective corrosion films at high temperature and high pH than the de Waard 95 model. Pump etc. τ) (e) The de Waard 95 model gives the corrosion rate according to the following formula: CR = (1 / (1 / Vr + 1 / Vm)) * Fscale (f) where Vr is the maximum corrosion rate based on the limiting reaction rate given as a function of temperature. PCO2) (i) In the IFE top-of-line corrosion model the top-of-line corrosion rate is limited by the amount of iron that can be dissolved in the condensed water: CR = a * Rcond * CFe * (b . Both models are tuned to a large set of experimental data.Limitations The transmitters can only be connected to the flow path. After making a connection from the transmitter (ex. The de Waard 93 corrosion model was included in earlier versions. The corrosion rate will increase with temperature for both models up to a limiting temperature C) where formation of protective corrosion films are predicted. However. they combine to form solid iron carbonate films according to: (d) These films can be more or less protective for further corrosion.One transmitter can only measure one variable. 2 M. In cases where corrosion control by p H stabilisation is applied. WCWALL is equal to the liquid film water cut. For such cases. PVT table and Compositional Tracking). PHSAT = OFF The pH calculation is based on the CO2 partial pressure calculated as the CO2 mole % in the gas phase multiplied by the total pressure. ionic strength and water wetting limit are given as constants for a given branch. Experience in CO2 corrosion evaluation is therefore important to prepare input and evaluate simulation results properly. temperature (TM). the water cut must be below the flow model's inversion point (0. The water chemistry has a significant influence on the calculated corrosion rates. The same glycol reduction factor is used for both the NORSOK and the de Waard 95 models. Water only existing as droplets in a continuous oil film. INVERSIONWATERFRAC. water volume fraction (BEWT). It has no influence on the flow conditions. bicarbonate content and ionic strength by the formulas given in the NORSOK model. PHSAT = ON Water with specified bicarbonate content (e. WCWET. condensed water conditions are assumed.5 or T < 20° C. In the de Waard 95 model. Condition 2 will give water wetting if the water cut (and WCWALL converted to %) is above the water wetting limit. The input parameters for the corrosion models are specified in the keyword statement CORROSION. the corrosion rates assuming full water wetting are always calculated. from which the CO2 partial pressure for single phase liquid flow will be calculated (PTMAX) Currently. Full water wetting will always occur if WCWALL (in %) is larger than or equal to WCWET. zero corrosion rate follows.5 or if T > 150° C. or due to a water cut above the flow model's water-oil inversion point. . In addition. the water droplets will wet the wall. For ionic strengths larger than 0. For both the NORSOK and the de Waard 95 models the pH value in the bulk water phase is calculated as a function of CO2 partial pressure. oil film volume fraction (BEHL) and the near-wall water cut (WCWALL. When using compositional tracking (COMPOSITIONAL=ON IN OPTIONS). are pressure (plot variable PT). the models will give an upper bound for the corrosion rate.0) This flow information is sent to the corrosion module where tests are performed to determine if water wetting occurs: Condition 1 will always give water wetting of the wall.g. For slug flow (output variable ID = 3). the NORSOK model is presently not valid for pH < 3.2 M. See also: CORROSION Keys Corrosion Output Variables Sample case for Corrosion Limitations The corrosion models are not valid if pH > 6.0). Such cases are treated as full water wetting (condition 1). WCWALL is defined to be 1. The water wetting conditions are determined as follows: First. while the liquid slug might be in condition 2 or vice versa. This is not available when using the Black oil model. The default value is 30 %. In addition. The NORSOK and de Waard models can be used for all PVT calculation options (Black oil. For partial pressures ratios of CO2 and H2S between 20 and 500. An option for calculating pH based on saturated iron carbonate concentration in water (PHSAT) Maximum CO2 partial pressure in single phase liquid flow (PCO2MAX) Bubble point pressure . water velocity or mixture water/oil velocity. the case of no water wetting can only occur in condition 2 when the liquid film water cut (and WCWALL in %) is less than the water wetting limit (WCWET). The effect of corrosion inhibitors can be specified through the key INHIBITOREFFICIENCY. If the water cut is higher than this value. For ionic strengths lower than 0. the user may set the maximum CO2 partial pressure directly. 2. The input parameters BICARBONATE and PHSAT can be used to choose between different water chemistry conditions when calculating the pH value: Condensed water without corrosion products: BICARBONATE = 0. The corrosion models should not be used for CO2 partial pressures above 10 bar. the pH value might exceed the upper pH limit of the corrosion models. both conditions might be occurring intermittently. The user must ensure that these lim its are not exceeded. The top-of-line corrosion model does not account for increased corrosion due to presence of acetic acid in the gas. The user must then manually supply the bubble point pressure (PTMAX). TOL can only be used when specifying: FLASHTYPE= FULLTHREEPHASE or SIMPLETHREEPHASE in COMPOPTIONS. the water-oil flow regime is determined by the flow model. Parameters calculated by the three phase flow model OLGA. Input parameters for each branch of the network are as follows: CO2 mole % in the gas (key: CO2FRACTION) Bicarbonate concentration in the water phase (BICARBONATE) Total ionic strength in the water (IONICSTRENGTH) Inhibitor efficiency (INHIBITOREFF) Glycol concentration in the aqueous phase (GLYCOLFRACTION) The water cut limit where water droplets in oil will wet the wall (WCWET). There are mainly two flow regime conditions of concern for the corrosion model: 1. The OLGA code has been verified with 0. PTMAX or PCO2MAX can be found from measurements or calculations in a separator or in a pipeline further downstream where a free gas phase exists. TAUWL). the bicarbonate.0 < WCWALL < INVERSIONWATERFRAC < 1. given in the CORROSION keyword (default value 30 %). If the MEG tracking option is used. but may be conservative since iron sulphide films may be formed. temperature. The implemented corrosion models are not suitable for such cases. When using the PVT table option it is only available for a three phase table and when specifying: FLASHMODEL = WATER in OPTIONS. and USLHL is the superficial velocity of oil in the liquid film. The glycol concentration can either be set manually or be determined by the MEG tracking function if available to the user. If no free gas exists in the pipeline at all. formation water): BICARBONATE > 0. The CO2 corrosion models are not valid when the ratio between CO2 and H2S partial pressure (or the ratio between CO2 and H2S molar fraction in the gas phase) is lower than 20. and the scaling reduction factor is then dependent on the CO2 partial pressure and temperature. i.e.5 as inversion point. A continuous water film may be a result of stratification. In that case. the glycol concentration is constant through the whole pipeline. If water is present only as droplets in the oil film. For a situation with no free gas phase the CO2 content will be constant for pressures above the bubble point pressure. The water-oil inversion point has a default value of 0. If the gas contains acetic acid this should be evaluated separately.0 if there is any continuous water film at the wall. This parameter is only used for the water wetting test in the corrosion module.5 (water cut = 50%). but may be changed through the keyword WATEROPTIONS. If the manual option is used. The models should not be used when the H2S partial pressure is higher than 100 mbar. formation water is assumed and there will be no corrosion reduction due to scaling. which is given as a fraction). The maximum CO2 partial pressure is then calculated by the code for all pressures higher than PTMAX: CO2FRACTION * PTMAX. glycol concentrations. the glycol concentration will be diluted in accordance with water condensation rates. Alternatively. which are used by the corrosion models.How to use For Top Of Line (TOL) corrosion the water condensation rate is needed. wall shear stresses in water or alternatively liquid mixture (boundary variables TAUWWT. which may be found by running OLGA. even if no continuous water film is present. (PCO2MAX). This is done even though free gas is present. The presence of glycol will reduce the corrosion rate. Please note that changing this value might change the flow predictions significantly. the code only checks if the pressure is above PTMAX or not. A continuous water film exists (WCWALL = 1. a passing slug bubble might be in condition 1. PHSAT = OFF Condensed water saturated with corrosion products: BICARBONATE = 0. To sum up. corrosion reduction due to protective films is not accounted for when formation water is present. which can increase the solubility of iron in the condensed water and hence the top-of-line corrosion rate. The liquid film water cut can be expressed as USLWT/(USLWT+USLHL) where USLWT is the superficial velocity of water in the liquid film. the code uses the following sixteen fictitious components to keep track the amount of mixing of different drilling fluids: Component Component Description ID name Hydrocarbon 1 HC mixture 2 H2O Aqueous mixture 3 MEG Hydrate inhibitor Min gas density 4 GDENMIN tracer for drilling fluid (WATER/OIL) Max gas density 5 GDENMAX tracer for drilling fluid (WATER/OIL) Min gas viscosity 6 GVISMIN tracer for drilling fluid (WATER/OIL) Max gas viscosity 7 GVISMAX tracer for drilling fluid (WATER/OIL) Min oil density 8 ODENMIN tracer for drilling fluid (WATER/OIL) Max oil density 9 ODENMAX tracer for drilling fluid (WATER/OIL) Min oil viscosity 10 OVISMIN tracer for drilling fluid (WATER/OIL) Max oil viscosity 11 OVISMAX tracer for drilling fluid (WATER/OIL) Min water density 12 WDENMIN tracer for drilling fluid (WATER/OIL) Max water density 13 WDENMAX tracer for drilling fluid (WATER/OIL) Min water viscosity 14 WVISMIN tracer for drilling fluid (WATER/OIL) Max water viscosity tracer for 15 WVISMAX drilling fluid (WATER/OIL) 16 CUTTING Cuttings Limitations A fluid definition used to specify a drilling fluid cannot be reused as a fluid in a branch or a node. the drilling fluid properties like densities and viscosity are tabulated as a function of pressure and temperature. It is assumed that a defined drilling fluid is completely miscible with the specified predetermined phase to and immiscible with the fluids in the other phases. In drilling applications the inert fluids can be oil and water based mud and nitrogen for gas lift in underbalanced drilling. using one fluid definition to create the drilling fluid and the other as process fluid. MEG is tracked as a separate component. Methods and assumptions There are two methods for determining the physical properties of the drilling fluids: Interpolation in PVT tables or use of built-in correlations. The Wells module requires a separate license. Drilling fluids are defined on Library level through use of the DRILLINGFLUID keyword. oil and water phases along the pipeline and calculates the phase densities and viscosities by assuming ideal mixing together with the production fluid. CaseDefiniton OPTIONS DRILLING = ON. they were named drilling fluids. Therefore this option is suitable for displacement of different fluids of low volatility. In well applications drilling fluids are used to simulate well clean-up. The masses of the individual drilling fluids are tracked along the flow paths. it cannot be turned off in a subsequent restart from a RESTART file. The drilling . Common to these fluids is that they remain in a single phase during the entire operation envelope. How to use In order to invoke the Drilling Fluids. If the same fluid table is to be used in both places. In OLGA these fluids therefore belongs to a predetermined phase. In OLGA it is possible to combine drilling fluids and MEG tracking. As these inert fluids were first developed for drilling operations. The solubility of the drilling fluid into other phases than the miscible phase is neglected. the key DRILLING in the OPTIONS keyword must be set to ON. In well operation drilling fluid is useful for simulating gas-lift of wells. The drilling fluids does not affect the phase behavior/envelope of the process fluids. Only one method can be used in a single case. Interpolation in the PVT tables When using the PVT tables. Once the DRILLING option has been turned on. For example.Drilling fluid Drilling fluids were originally developed to describe the different inert fluids that are used in drilling operations. The non-Newtonian behavior is accounted for through the apparent viscosity for flow calculations. well work over and initial start-up of well after completion. License requirements Drilling fluid is dependent on option drilling which is part of the Wells module. See also: When to use Methods and assumptions How to use Limitations When to use The drilling fluids can be used when it is desired to track one or more fluids of low volatility (in addition to the production fluid) simulating one fluid displacing another. muds of different densities can be pumped into the well during the drilling operation. well clean-up. The production engineering simulators were quick to make use of the drilling fluids to simulate dead (stabilized) oil circulation in deep water oil production loops. In underbalanced drilling Nitrogen gas (N2) can be used as lift gas to create the underbalanced operation. well work over and initial start-up of well after completion. gas lift of deep water risers and simulating MEG distribution networks for gas condensate production systems. the fluid file needs to be copied and added twice. OLGA then tracks the amounts of the different drilling fluids in the gas. In on-line and engineering simulators drilling fluids are also used to simulate MEG distribution systems. Built in correlations When the built-in correlations are used. The physical properties of the drilling fluids and process fluid mixture are calculated based on the assumption of ideal mixture. Typical examples from flow assurance engineering are dead (stabilized) oil circulation in deep water production loops. To monitor the water hammer. MINDENSITY. However. This is the actual water hammer that will be discussed subsequently. The drilling fluid type determines which phase the drilling fluid enters. The fluid is flowing with a velocity of 4 m/s before a near instantaneous closing of a valve is performed 6 seconds into the simulation. κfluid. viscosity ranges specified in the DRILLINGFLUIDS keyword. generally kg/s. The case is a water filled 5 km horizontal pipe. Normally GASFRACTION and TOTALWATERFRACTION must be set to zero so the MASSFLOW specified refers to drilling fluid mass flow. and MINVISCOSITY. Units of conversions of these drilling fluid properties are supported. density and viscosity in the NODE must be consistent with the label and density and viscosity ranges specified in the DRILLINGFLUID keyword. TYPE = GASMUD. density.2. use the FLUIDTABLE key to refer to the file that contains the drilling fluid properties. oil or water. Output variables A number of drilling mud variables can be plotted as either TREND or PROFILE variables. Interpolation in the PVT tables The drilling fluid properties can be identified through a fluid property table in the fluid properties file.5. In addition. but the generated PVTSim tables cannot be used directly. This pressure increase/decrease. Time series of mass inflow rates are allowed. and wall flexibility. A drilling fluid FLUIDTABLE is normally generated using PVTsim. Theoretical comparisons . This label. Additional information In addition the keywords below provide useful information: · ANNULUS to specify the annulus configuration (thermal interactions) · POSITION to specify initial bit position and leak-to positions · LEAK to specify TOPOSITION (useful for simulating well unloading valves) Elastic walls The purpose of the elastic wall option is to account for radial pipe flexibility in simulations involving pressure surges due to sudden changes in liquid velocity. the pressure in the section upstream of the valve is plotted. Based on these standard properties. The magnitude of influence from the wall flexibility can be measured by the ratio of the fluid compressibility. can be significantly reduced if the pipe is allowed to expand/contract. commonly known as water hammer. However. The effect of the flexible pipe is most pronounced in the instantaneous change in pressure that occur 6 seconds into the simulation. The simulation is performed both with and without flexible walls (red and black curve respectively) . Built in correlations The built in correlations for drilling fluid density and viscosity can be specified using the keys.fluid type must be set to gas. the simulation results based on rigid walls may be very conservative. the flexible wall behaves much in the same manner as the rigid wall. A comprehensive list can be found on Drilling output variables. a period of packing can be observed. Boundary conditions using drilling fluid Drilling fluids can be injected into the models using either sources or boundary specifications in the SOURCE and NODE keywords. the density and viscosity at in-situ temperatures and pressures are calculated by correlations.tab file. MAXVISCOSITY. so a valid density unit (such as LB/FT3) or viscosity unit (such as CP) must follow the density and viscosity specifications. κwall (see Methods and assumptions). it should be observed that the packing phase is prolonged and the pressure increase due to packing is actually higher in the case with flexible walls. The following figure illustrate the effect when the compressibility ratio is approximately 0. MAXDENSITY. If κwall/κfluid << 1. After the initial hammer. The expansion/contraction will also reduce the propagation speed of pressure waves. In sources drilling fluid inflow must be specified in mass units.8 cm and a 9 mm thick steel wall. In this phase. It is also possible to inject drilling fluid into the model through a pressure boundary (NODE). OILMUD or WATERMUD. the drilling fluid used must be identified by label. The drilling fluid used must be identified by label in the NODE keyword. with a diameter of 20. and viscosity must be consistent with the label and the density. The fluid properties table referred must contain all liquid properties normally present in a *. Figure A: Pressure in section upstream of a near instantaneously closing valve. They need to be converted using the Fluid Definition Tool in the Wells GUI or the Mud Property Table application available in the Tools menu. These keys denote the drilling fluid density and viscosity at standard conditions. The drilling fluid label. if κwall/κfluid > 0. the effect of wall flexibility can safely be assumed to be small. along with its density and viscosity. The average value of w over the length L is presented in Figure D as a function of kL. . Figure C: Single section with pressure not equal to ambient pressure. where all problems with equal kL will have identical scaling functions. Timoshenko and Woinowsky-Krieger). Section length considerations The deflection of the section wall is assumed to be uniform (uniform expansion/contraction) and the deflection of the pipe wall in one section is assumed to have no influence on the deflection in neighboring sections. theoretical equations (rigid walls).speed of propagation of the disturbance (speed of sound) g . Similarly. the theoretical hammer pressure is usually derived from the Joukowsky equation: ∆Hmax = ∆c a / g (a) where H . given a case with the e = R.change in velocity In terms of the pressure. Although OLGA will over estimate the change in volume inside the section.g. we can look at the case presented in Figure C. It should be noted that the total pressure increase in the pipeline computed by OLGA may be higher than the maximum theoretical water hammer. In this graph. In order to argue the validity of this approximation. will rapidly diminish for increasing section lengths.In a perfectly rigid pipe. one can argue that the change in volume outside the loaded section.acceleration of gravity ∆c . The pipe is assumed to be relatively long compared with L. This relation assumes incompressible fluid and tends towards infinity at small t. Figure B: Water hammer calculation in OLGA vs. In normal circumstances this will not constitute a limitation as the thickness is generally smaller than the radius. it is apparent that the OLGA solution give a reasonable approximation for kL >= 10. For longer closing times. The solution to this problem can be expressed in terms of the solution of the uniformly loaded and uniformly expanding pipe and a scaling a function. L is the pipeline length [ft] and t is the valve closing time [s]. the rest of the pipe is in equilibrium with the ambient pressure Pa. not accounted for by OLGA. We therefore recommend using section lengths larger than 10 ( R e )1/2 when the elastic wall option is used. The function w has a natural length scale kL = L ( R e )-1/2. v is the fluid velocity [ft/s]. simulated results in OLGA without elastic walls will be comparable to the Jukowski equation. This is a simplifying assumption that is based the fact that pipes walls are normally relatively thin. this equation becomes: ∆Pmax = ∆c a ρ (b) where ∆P is the change in pressure and ρ is the fluid density For slow closing valve action the following equation is often used. ∆P = 0. the radius R and the wall thickness e. This illustrates a longitudinal slice of a pipe with a pressurized section of length L. and that section lengths are larger than the pipe diameter. Given that the valve closing time is small enough. This is because the momentum of the upstream fluid will continue to pack the pipeline after the valve is fully closed (see Figure B).07 v L / t (c) where ∆P is the change in pressure given in psi. w (reported by e.head in meters a . a value of 1 represents the solution given by OLGA and a value less than 1 represents a smaller change in volume. effects such as packing of pipeline before the valve is fully closed may give rise to an additional increase in pressure that is not accunted for in either Equation (b) or Equation (c). the section length will then have to be 5 times the pipe diameter. which will give a deviation of less than 2%. If the initial assumptions hold. Equation (g) is used to compute an equivalent value for γ. In the pressure evolution equation solved by OLGA. and external pressure. Uniform radial expansion (neglecting section end effects and interaction) 4.ELASTICWALLS = OFF. all walls are treated as inflexible . this amounts to using a modified compressibility. Using Equations (c) and (f) along with assumption 3. The external pressure. given that the elastic properties may change. This will lead to an initially undeformed state. If OPTIONS. is taken to be the pressure in each OLGA section when the simulation starts (after steady state preprocessor or initial conditions). the elastic wall option can also be used to dampen the effect of volume error induced pressure changes. The updated area is calculated as follows: (d) where R0 is the given radius of the pipe and ε(P) is relative change in radius.ELASTICWALLS = ON/OFF. See also: When to use Methods and assumptions How to use When to use The elastic wall option should be used when sudden changes in pressure is to be expected and the fluid is near incompressible. the equations can be decoupled and significantly simplified. Po. These cases may include liquid dominated systems with sudden changes in valve opening. but not flexible. Thus. P. In situations with liquid shut-in.Figure D: Average deflection of section wall in Figure C scaled with deflection of pipe with uniform internal pressure. for a unit change in internal pressure: (c) The pressure equation is also modified to account for the modified area. start up or shut down of pumps or jumps in source mass rates. by introducing some assumptions. the deformations in the previous run are automatically converted by OLGA to an initial (constant) strain: (h) εinitial is the initial relative change in radius. Linear elastic materials 2. which will then be used in Equations (d) and (e). No dynamic effects of pipe wall (no wall inertia) It is up to the User's discretion to verify that these assumptions are valid when using the elastic wall option in OLGA. a wall may be deformed. the effect on the flow will be marginal but its inclusion is mandated by the need for a consistent calculation of the volume error. κeff: (a) where κfluid is the compressibility integrated over all phases: (b) and κwall is the change in relative pipe area. the effect the flexibility has on the overall compressibility of the pipe-fluid system. given by the deformation in the previous run. Small deformations of pipe wall (change in diameter << diameter) 3. we get: (g) If κ is specified in the input to OLGA. Methods and assumptions The solution of the full fluid-structure interaction would entail solving an additional elliptic partial differential equation on a far smaller time scale than required by the isolated fluid flow problem. In the derivation of the equations used by OLGA we will make the following assumptions: 1. However. A. In order to get consistent results in restart. dependent on the internal pressure. the thick wall equation is used: (f) where i is the wall layer index and Ri is the inner radius of wall layer i. Po: (e) When OLGA is used to calculate the flexibility of the pipe. How to use The elastic wall option is activated at a global level with the key OPTIONS. When simulating flexible pipes. in a restart run even if flexible walls are turned off. OLGA accounts for both changes in flow area and more importantly. MDPPOS.EMOD).ELASTICWALLS = ON. This option is particularly useful when the equation used by OLGA is not valid. i. The difference between the fluid pressure and the hydrate formation pressure is then calculated. is included (see Figure A). The positions and the values of the maximum temperature and pressure differences for hydrate formation are calculated. If the stiffness of the steel protective casing is included.KAPPA. The difference between the hydrate formation temperature and the fluid temperature is then calculated. surrounded by soil or encased by a flexible medium. If this option is used. However. This is because the thickness of the wall is assumed to be unchanged and the wall flexibility can be significantly underpredicted if the contribution from a very rigid wall layer. Methods and assumptions The program does the following: 1. . 3. 2. See also: When to use Methods and assumptions Limitations How to use When to use HydrateCheck should be used when there is a risk of reaching the temperature/pressure region where water can form hydrates. For a given pressure and inhibitor concentration in a section. the pressure above where hydrate may form is determined from the hydrate formation curve. There are two methods available for the elastic properties of a wall (when WALL. For a given pressure and inhibitor concentration in a section.ELASTIC = ON/OFF. the wall flexibility will be very conservative. the branch variables MDPHYD. MDTHYD and MDTPOS are updated.e. OLGA will omit any wall layer that has a material with a Young's modulus less than WALL. INHIBCONC = 20% and INHIBCONC = 40%. the Young's modulus of elasticity will be a required key for materials (MATERIAL. while the highest/lowest temperature depends on the actual inhibitor concentration (Hammerschmidt). When hydrate curves for different inhibitor concentrations (HAMMERSCHMIDT = OFF) are used. if this key is set to ON. 2. i. This may also apply if a significant part of the wall rigidity can be attributed to axial stresses or other 2nd order effects. the volume variable DTHYD is updated. For HAMMERSCHMIDT = ON the highest/lowest pressure is defined by the hydrate curve for the inhibitor concentration of 0%. individual WALLS are treated as flexible/inflexible depending on the value of the key WALL. If OPTIONS. Figure A: Insulated pipe. Default option: Let OLGA compute the flexibility of the wall based on the radius of the pipe and material properties of the wall layers. Interpolation and extrapolation of the hydrate curves: An imaginary square is formed to define the limits of the hydrate curve(s). All subsequent wall layers will also be excluded. the temperature below where hydrate may form is determined from the hydrate formation curve. User given flexibility: The wall flexibility may be specified with the key WALL.e.ELASTIC = ON) 1.e.(infinitely rigid). HydrateCheck This module is used to get information on possible formation of hydrates. The user can specify hydrate formation curves for each flowpath that should be investigated. This may apply when the wall is stiffened with braces. All hydrate curves are extrapolated so they reach two of the square sides as illustrated in the figure below for INHIBCONC = 0%. the four sides are the highest/lowest temperature and highest/lowest pressure of the hydrate curves.ERATIOMIN times the Young's modulus of the inner adjacent wall layer. i. Elastic wall properties may be changed in restart runs. placed outside a very flexible wall layer. the volume variable DPHYD is updated. If the pressure in the section is above the square (Condition 2) the highest temperature in the square is used as the hydrate temperature. in which case DTHYD < 0 and the section temperature in reality may be far above the hydrate formation temperature. Hydrate Kinetics The hydrate kinetics model (CSMHYK) allows for the prediction of where and approximately where hydrate plugs will form in oil and gas pipelines. The equation is valid for inhibitor concentrations between 0% and 70%. The KINETIC model is suitable for systems with small mass and heat transfer resistances inside of the pipeline. use the HYDRATECHECK keyword to specify a list of hydrate curves to apply. This requires the Inhibitor tracking module or the Compositional tracking module with an inhibitor defined in the FEEDFILE. HAMMERSCHMIDT = ON: The Hammerschmidt equation (see ”The Inhibitor tracking module” ) will be used based on the hydrate curve for no inhibitor. the hydrate curve for the lowest inhibitor concentration is used. The hydrate formation curve can be specified either with keys PRESSURE and TEMPERATURE. This effect can be calculated in two ways: 1. Also. This can be misleading. If the temperature in the section is inside the square and no match is found. If the Hammerschmidt equation is used (HAMMERSCHMIDT = ON). See Condition 1 in the figure above. If the pressure in the section is inside the square and no match is found. 3 and 4 (especially the hydrate curve for 0%). MEGMFR. 2. Condition 1 and 2 has an inhibitor concentration of 40%. That is. see Condition 4. It should be noted that if the section pressure is above the highest pressure in the square the reported DPHYD will always be a positive value that indicates hydrate formation. Note that changes in the composition (except the specified inhibitor) does not affect the hydrate curve calculations. as well. the hydrate temperature is calculated based on the actual inhibitor concentration. and the transport properties of cold flow hydrate slurries. HAMMERSCHMIDT = OFF: One hydrate curve per inhibitor concentration (INHIBCONC) must be given. When DTHYD is computed the pressure in the section is used to find the hydrate temperature for the given inhibitor concentration. When OLGA computes DPHYD and DTHYD it uses the inhibitor concentration and the pressure and temperature in the section. the hydrate curve for the highest inhibitor concentration is used. especially if the section temperature also is higher than the highest temperature in the square. Using DEBUG = ON in OPTIONSOPTIONS. In each flowpath. The current version of CSMHYK model (version 2) incorporates three distinct models for hydrate formation. If the inhibitor concentration in the section is between two hydrate curves. the hydrate curves in Figure 1 are not well defined for conditions 2. the INHIBITOR must be defined in the FEEDFILE before it can be selected in the HYDRATECURVE. hydrate pressure always defined within the square with ON). If the temperature drops sufficiently below the hydrate equilibrium temperature . OLGA interpolates the two hydrate curves to generate a new hydrate curve for the inhibitor concentration in the section. The TRANSPORT model includes mass and heat diffusion through the particle boundary layer and hydrate shell so that both heat and mass transport limitation will be taken into account. the highest hydrate temperature is used if the pressure is above the hydrate curve (Condition 3) and the lowest is used if it is below (HAMMERSCHMIDT = OFF only. If is below the lowest inhibitor concentration. growth and transport. The Hammerschmidt equation (used when HAMMERSCHMIDT = ON) is only valid for inhibitor concentrations below 70%. while Condition 3 has 0%. This goes for pressure above/below the square and inhibitor concentrations above/below the given values. If HAMMERSCHMIDT = OFF it is checked whether the inhibitor concentration in a section is within the range given by the hydrate curves. One HYDRATECURVE keyword must be defined for each curve and concentration. When the temperature in the section is to the left of the square the lowest pressure in the square is used as the hydrate pressure.g. a warning is given the first time the fluid temperature is above or below the maximum temperature in the ”hydrate curve” square to alert the user. When the pressure in the section is below the square the lowest temperature in the square is used as the hydrate temperature. The COLDFLOW model is intended to simulate a fully formed cold hydrate slurry system in which only growth and possible agglomeration of already formed hydrate particles is considered. OLGA will then interpolate between the curves defined in the HYDRATECHECK. How to use Define the hydrate formation curves with the HYDRATECURVE keyword in the Library section. Each HYDRATECURVE specified in a flowpath must have a unique inhibitor concentration (INHIBCONC). The effect of an inhibitor on the hydrate formation temperature can be calculated. The inhibitor concentration can be verified by plotting e. Limitations For Compositional Tracking. To remove this source of error all hydrate curves should include both the minimum and maximum pressure in the pipeline. hydrate temperature always defined within the square with ON). If it is above the highest inhibitor concentration. the highest hydrate pressure is used if the temperature is to the right of the hydrate curve (Condition 2) and the lowest is used if it is to the left (HAMMERSCHMIDT = OFF only. or from an ASCII file where the hydrate formation curve is given.Figure 1 Hydrate curve square with different pressure/temperature conditions. it is recommended to always include the hydrate curve for an inhibitor concentration of 0% to avoid underestimating the hydration formation temperature. If the temperature in the section is to the right of the square (Condition 3) the highest pressure in the square is used as the hydrate pressure. When DPHYD is computed the temperature in the section is used to find the hydrate pressure for the given inhibitor concentration. See also: When to use Methods and assumptions Limitations How to use When to use Include the hydrate kinetics if the pipeline temperature is close to the hydrate formation temperature. transport and slurry behaviour is located in the keyword HYDRATEOPTIONS.5° Whether the nucleatio n is assumed F. denoted Co and Cw. In the standard three-phase model of OLGA. i. How to use The hydrate kinetics model is activated through the HYDRATEKINETICS keyword. The hydrate reaction rate is limited to the mass available to react. &gamma. then the oil mass will react. mg. and the initial emphasis has been on flowing liquid dominated systems with excess of water and gas for hydrate formation. The tuning keys for thermodynamic. VELOCITYRATIO and DRIFTVELOCITY keys: (d) It is also possible to increase the drag between gas and liquid by using the FOGEXPONENT key: (e) The FOGEXPONENT will reduce the velocity difference between gas and liquid when hydrate particles are present. The hydrate kinetics model determines the amount of gas and water consumed by hydrate formation and the effective viscosity of the hydrate particle laden oil phase. Methods and assumptions The hydrate kinetics module combines the hydrate kinetics and rheological model developed by Colorado School of Mines with the flow equations of the OLGA model. This model assumes that the water phase is fully dispersed in the oil phase. no slip between oil film and water film is used in the simulation. and the volume average liquid velocity. MEG (mono-ethylene glycol). TRANSPORT and COLDFLOW model use a file (METHANECONCFILE) containing concentration data for methane in bulk. respectively). Inhibitor Tracking Module The Inhibitor tracking module allows for tracking of the contents of a hydrate inhibior in the pipeline. Further.hos. The flow model integrates the mass consumption rate to obtain the amount of hydrate phase and uses the effective viscosity for the flow calculations. but information regarding the inhibitor concentration along the line is not available. Future versions will likely also address gas dominated systems and include a deposition mechanism. No deposition on wall is activated.e. HYDRATEKINETICS keyword is a FlowPath FA-Model (Flow Assurance Model). The TRANSPORT model takes heat and mass transport into account in addition to the reaction kinetics. For TRANSPORT and COLDFLOW data for methane is used for diffusion mass transfer. The HYDRATEKINETICS references a HYDRATECHECK that describe the hydrate equilibrium temperature. Immediate nucleation of the hydrate particles (no induction time). Limitations The model is still in the research phase. The HYDRATEOPTIONS key GASGUESTFRACTION is the mass fraction of gas available for hydrate formation to all the gas in a section. ug. is using it to ensure that the amount of hydrate inhibitor throughout the pipelines is sufficient to prevent the formation of hydrates. according to (b) An effective hydrate oil slurry viscosity. The default sub-cooling is 6. First the gas mass will react. The COLDFLOW model assumes that the hydrate nucleation is fully formed in the cold fluid and that only hydrate particle growth and agglomeration is taking place. Hydrate reaction The model assumes that hydrate formation will commence after sufficient sub-cooling (SUBCOOLING). which is added to the FlowPath along with the HYDRATEKINETICS keyword if these tuning keys are to be adjusted. The formation of hydrate will affect both the temperature of the pipeline and the pressure drop due to increased viscosity of the hydrate-oil slurry relative to oil viscosity. The hydrate formation reaction will by default react gas (methane) hydrocarbons with liquid water to form hydrate particles (OILGUESTFRACTION=0 and GASGUESTFRACTION=1). uof and uwf. By using the FULLDISPERSION key. m0. . respectively. independent of other thermodynamic properties than the hydrate equilibrium temperature at the given system pressure depends on the choice of model.hydrate will be nucleated. The hydrate equilibrium is pre-calculated and the kinetic model developed for methane is adapted. The hydrate particles are uniformly distributed in the oil phase. First the gas mass will react. and so assumes that heat and mass transfer resistances are low. the pipeline may contain water and inhibitor. Whether hydrates with properties of SI or SII structure are formed depends on the key STRUCTURE. intrinsic. and in equilibrium with hydrate to calculate mass diffusion. But it is possible to relate the hydrate velocity to both the oil and water velocity. and which must be present on the same FlowPath. the hydrate velocity will be the same as for the oil film (COIL=1 and CWATER=0. The hydrate reaction rate is limited to the mass available to react. The KINETIC model only considers the hydrate reaction kinetics themselves. It is assumed that enough free gas is present so that the bulk concentration of methane in the oil does not change. See also: When to use Methods and assumptions Limitations How to use When to use An important application of this module within flow assurance. Flow model modifications By default the hydrate particles will flow with the oil film. The module allows the choice between three inhibitors. it is not designed for shut-in and depressurization studies. ul by using the DRIFTFLUX. (a) The HYDRATEOPTIONS key OILGUESTFRACTION is the mass fraction of oil available for hydrate formation to all the oil in a section. then the oil mass will react. MEOH (methanol) or ETOH (ethanol). Special care should be taken when using the model since the model has only been validated against limited data sets. is calculated by the Colorado School of Mines code: (c) It is possible to force a drift flux relation between the gas velocity. That is. License requirements The Hydrate Kinetics Module requires a separate license.. The leak can transport mass between two pipelines. it cannot be used with Wax tracking. It is also used for gas lift valve (GLV) modeling. The leak area can be controlled by the control system. However. the flow rate is governed by the conditions . Limitations Inhibitor tracking is turned on through the COMPOSITIONAL keyword and cannot be used in conjunction with the other modules available through this keyword (e. The inhibitor tracking module must be used with a two-phase fluid table or with a three-phase fluid table that has only H2O in the water phase. and hence may not work properly in combination with e. Blackoil or Compositional Tracking). and also from the fluid composition in each section of the pipeline. The effects of the inhibitor are included in the calculation of the density and viscosity of the aqueous phase. and the Hankinson-Brobst-Thomson (HBT) technique yields an estimate of the liquid density. The water vapour content in the gas phase is adjusted by the mole fraction of MEG in the aqueous phase. Please also see the list of assumptions in Methods and assumptions. For sub-critical leak flow. the effects of the inhibitor are neglected and pure water properties from the three-phase fluid table or from OLGA are adopted.069 g/mol) Hammerschmidt constant. Specify the following keywords to use the Inhibitor tracking module: OPTIONS to set COMPOSITIONAL = MEG/MEOH/ETOH SOURCE to specify INHIBFRACTION in the mass source INITIALCONDITIONS to specify INHIBFRACTION at initial time (if STEADYSTATE = OFF in OPTIONS) NODE to specify INHIBFRACTION at the boundary TRENDDATA/PROFILEDATA/OUTPUTDATA to print compositional variables for given components HYDRATECURVE and HYDRATECHECK to calculate the effect on the hydrate formation temperature Note that either INHIBFRACTION or TOTALINHIBFRACTION can be given. the density. The inhibitors do not effect flashing between gas and oil. it should work with all the features of basic OLGA. The leak outlet must then be connected to another pipeline. H2O Water. Inhibitor (MEG. For critical leak flow.042 g/mol. or the Hammerschmidt formula for hydrate depression (/19/) can be used (the equation is valid for inhibitor concentrations between 0% and 70%): (a) ∆T M H W TMEGCONC TMEGCONC=0 = = = = = = Hydrate depression. one can specify a hydrate inhibitor (one of MEG. MEOH: 32. Descriptions and formulae for the Grunberg and Nissan method and the HBT technique can be found in the open literature. Wax or Corrosion. There is no diffusion of MEG in the aqueous phase. Methods and assumptions The following assumptions are made for inhibitor tracking: The only properties of the aqueous phase affected by MEG are the viscosity. MEOH. The user can either specify a hydrate curve for each inhibitor concentration and let OLGA interpolate between the values. The former is the mass fraction of the inhibitor in the total aqueous phase. ETOH: 46. The mole fraction of inhibitor in gas is equal to the vapor pressure divided by the system pressure. which can be in the gas and the aqueous phase. Methods and assumptions A leak or a pipe rupture is described as a negative mass source (mass out of the pipeline). the conditions in the pipe and the leak area. See also: When to use Methods and assumptions Limitations How to use When to use Use to simulate leaks and pipe ruptures. This flash is calculated based upon the gas mass fraction from the PVT table. At each time step the properties of the aqueous phase are calculated from the local pressure and temperature. namely 1. The inhibitor tracking module is not aware of any special physics the user may have activated. MEOH or ETOH). The method of Grunberg and Nissan is used to calculate the viscosity of the inhibitor-water mixture. How to use With the Inhibitor tracking module. Furthermore. and the density’s derivatives. There is no hydrocarbon component dissolved in the water. see /35/. It removes mass from the pipeline.g.License requirements The Inhibitor Tracking Module requires a separate license. or ETOH) to see the effect this will have on the formation of hydrates in the pipeline. oF Molecular weight of inhibitor (MEG: 62. Leak The leak is a negative mass source. default value is 2335 delta F Weight per cent of the inhibitor in the liquid Calculated hydrate temperature Hydrate temperature for no inhibitor For the other properties of the aqueous phase. Both sub-critical and critical flow is supported in OLGA. the latter is the mass fraction of the inhibitor in relation to the total aqueous phase + water vapour. The effect of inhibitor can also be included in the calculation of the hydrate formation temperature. the flow rate is governed by the difference between the internal and the external pressures.069 g/mol.g. 3. The active coefficients of inhibitor and H2O from UNIFAC correlations are used to calculate the chemical potentials of MEOH/ETOH and H2O in the aqueous phase. HC Hydrocarbon in oil and gas phase 2. The Inhibitor tracking module uses a fluid of three components. Backflow is allowed if CD/DIAMETER or TABLE/PHASE/CF is used instead. It is possible to route the flow through the leak to any pipe section in any branch by using the subkey TOPOSITION. If no controller is connected to the leak. The concept of the implicit coupling here is that Rocx calculates a sensitivity coefficient for the production rate with respect to the wellbore pressure at each time step and makes it available for OLGA. Neither the well models nor the reservoir models can account for the dynamic wellbore/reservoir interactions. the near-wellbore reservoir model Rocx has been developed and linked to OLGA. reservoir models use steady-state lift curves to represent the TPRs (Tubing Performance Relationship). During the simulation. The numerical coupling between OLGA and Rocx is implemented in an implicit scheme. See Valve How to use for details. See Gas Lift Valve (GLV) for information about GLV’s. which ignores the wellbore flow dynamics. Note: GASLIFTTABLES can also be used for functionality 1. The size of the near-wellbore domain contributing to the rate-pressure sensitivity calculation is specified by the coupling level that can be given as a simulation input. In this case the flow rate of each blackoil component is computed in addition to the phase rates. Connect a controller to the leak input signal terminal INPSIG. that is. The leak uses the valve model. which are used in this relation: (a) . Rocx. The leakage flow area is calculated from: where us = controller signal ( 0 ≤ us ≤ 1). The leak uses the valve model. the flow area of a leak can be manipulated by a controller. Limitations The leaks are not included in the steady state pre-processor. the mass is lost to the surroundings (requires the key BACKPRESSURE) It can also be used to model interconnections in the model. Typical examples are: Well Shut-in/start-up Onset of instability Dynamic gas/water coning Well loading and back seepage Cross flow License requirements Near wellbore is part of the ROCX Module that requires a separate license. The flow equations are solved in three dimensions. If the flow through the leak is calculated using CD/DIAMETER or TABLE/PHASE/CF. In case of injection or back seepage. and the integrated simulation is fully controlled by OLGA. The principle of the implicit coupling can be summarized as follows: 1. GASLIFTTABLES defines the gas lift valve (GLV) response curve. To bridge this modeling gap. OLGA uses this sensitivity coefficient to determine the new wellbore pressure. that is. The near-wellbore reservoir model. Backflow is not allowed for functionality 1. there will be no backflow if the section pressure is lower than the backpressure. is capable of simulating three-phase Newtonian Darcy flow in porous media. See valve limitations. in which case backflow is allowed. The leak flow is always limited to critical flow. BACKPRESSURE cannot be defined in this case as the backpressure is equal to the pressure in the section defined in TOPOSITION. where the mass out of one section is transferred to mass into another section (requires the key TOPOSITION). giving saturations and pressures varying in space and time as output in addition to the flow rate of each phase at the boundary. In OLGA the IPR is described with the WELL keyword. With this model some transient phenomena in the well are not accurately predicted while others are not predicted at all. there will be no backflow if the section pressure is lower than the given backpressure. A LEAK has two main functionalities: 1) 2) It can be used to model a valve or rupture where the mass out of the pipe is removed from the simulated system. OLGA provides the wellbore pressure to the reservoir model and the reservoir model calculates the flow rate of each phase at the interface. Backflow is not allowed when the BACKPRESSURE key is used. Near-Wellbore Module Conventional dynamic well flow models use steady-state IPRs (Inflow Performance Relationship) to describe the influx of oil and gas from the reservoir. the entire flow area is used. Furthermore. that is. How to use Position the leak. See Choke Methods and assumptions. Leaks can be placed anywhere along the pipeline. the wellbore model begins integration to time step n+1 by requesting the reservoir model to calculate the sensitivity coefficients and . For functionality 2 backflow is not allowed if GASLIFTTABLES is used. The flow rates can be positive or negative depending on the flow directions corresponding to production and injection respectively. the phase mass fractions in the wellbore section that the reservoir model interfaces to are converted to saturations in order to calculate the fractional injection rate for each phase. ignoring the transients in the near-wellbore area. The sensitivity coefficient is extracted from the Jacobian matrix of the reservoir model in the last iteration. At the next time step. A leak can also be used to simulate a gas lift valve (GLV).in the pipe and the leak area only. Rocx is also equipped with blackoil simulation functionality. Assuming the models have been integrated up to time step n. See also: When to use Methods and assumptions Limitations How to use When to use This link should be used when transient phenomena in the wellbore/reservoir are studied. Methods and assumptions The reservoir model is considered as a plug-in to the OLGA model. fluid transport properties. Limitations OLGA Rocx is not compatible with Compositional Tracking. Other limitations on the Rocx reservoir simulator are given in the ”Rocx User Manual”. Standard industry file formats are used for output. Input data to Rocx are permeability and porosities of the porous medium. 3. Like in OLGA. How to use Rocx is linked to OLGA through the NEARWELLSOURCE keyword. oil or water. only the three-phase fixed format OLGA PVT table can be used. The flow and thermal equations of Rocx are solved fully implicitly. e. the integrated model can run simulations with relatively long time steps while maintaining numerical stability.where PP is the pressure in the wellbore. The wellbore model uses the above relation as a boundary condition and solves for the complete wellbore. . Currently. The numerical and physical kernel code is not affected by the choice of grid. i. The simulation input information is stored in a keyword based text file. The wellbore model has now completed time step n+1 and sends and to the reservoir model.e. License requirements The OLGA HD Module requires a separate license. we assume local no-slip. The sensitivity coefficient is calculated by (b) which can be analytically derived from the reservoir model equations. It applies a parameterized 2-D velocity distribution to obtain frictions and velocity shape factors in the cross section. 2. scalable and accurate predictions of pressure drop and holdup for systems dominated by these flow regimes. The model is developed to provide more consistent. MP is the mass flow rate for each phase and the subscript p refers to a given phase. and thermal properties of the rock and fluids. Rocx has its own restart file with the extension . More details of the Rocx model can be found in the ”Rocx User Manual”.g. Dispersions are assumed to travel with the same velocity as the continuous phase. We have an analytic expression for the velocity distribution in the generic layer. gas. Necessary boundary and initial conditions must be given to enable simulation. Methods and assumptions The OLGA HD model is a friction model used for stratified and large wave flow. and uses a generic layer model as shown below. the boundary conditions of the reservoir model can also be specified in time series. For three-phase simulations Rocx uses the OLGA PVT table for looking up fluid properties. OLGA HD OLGA HD is a flow model applied for stratified and large wave flow. is simply given by (c) With this implicit coupling implementation. Rocx supports both radial and rectangular grids. Combining the 2-D velocity distribution with the 1-D conservation equations yields a 3-D representation of a slowly evolving flow. The steady-state preprocessor in OLGA can not be applied for OLGA Rocx blackoil simulations. See also: When to use Methods and assumptions Limitations How to use When to use The OLGA HD stratified flow model can be used for all simulations.rrs. This model is used for all three layers. The reservoir model completes its time step n+1 calculation by using the wellbore model supplied boundary condition. the perforation skin. using the Newton-Raphson iterative method at each time step. i. The simulation can be initialized by initial conditions or restart files. Rocx reserves the skin option for the situation when the inflow deviation from its ideal can not be properly accounted for by the reservoir model itself. The model handles 1-3 layers. Non-uniform distributions yield a profile slip (bulk slip).e. Coupling the layers yields a full three-phase model. … MIXTURE _N inlets and outlets · GAS_1.oil bulk Terminal = WATER . The OLGA HD stratified flow model is not compatible with the Complex Fluid module(FLUID TYPE = COMPLEXFLUID).all phases within the node itself(default) When the volume fraction of the connected phase(s) is sufficiently low(0. Pig A pig is a mechanical device which is inserted into a pipline that moves with the flow. 6. the flow in the outgoing branch will be as from an internal NODE. … GAS_N outlets · OIL_1. Limitations The Slug Tracking Module applies the standard flow model for stratified flow in the numerical segments containing slug fronts or slug tails. 2. It only distributes the phase fractions in the outgoing branches according to the user defined type of terminals chosen: • The phase split node is only treated as a simple volume tank with no internal separation equipment • There are no level controls and no separator efficiencies How to use Input Connections to external pipelines The following connections are defined: · MIXTURE_1. In some cases it might be more useful to give a larger value for the key VOLUME in order to get more stable node conditions during the simulations.water bulk Terminal = LIQUID . WATER.. Altogether this yields a consistent set of expressions for wall and interface frictions and velocity shape factors comprising a 3-D flow description at 1-D evaluation speed. Such devices can be used for. the liquid content of a pipeline before and after pigging. See also: When to use Methods and assumptions Limitations How to use When to use The phase split node is recommended to be used in a finger type separator and in nodes where the in/over pipe connections where the phases tend to have an uneven split. Methods and assumptions The phase split node has an arbitrary number of inlets/outlets. or pushing liquid out of the pipe.Pre-integration yields a generic wall friction law formulated as a generalized friction factor relation.. … DRYGAS _N outlets Internal volume If the volume is not given. the rate and total volume of liquid pushed out of a pipeline ahead of a pig. Continuity in forces and velocities across the interfaces is used to find a generic expression for the interface friction. DRYGAS and MIXTURE. It has six different types of terminals: GAS. OIL.oil and water bulk Terminal = DRYGAS ... the time for a pig to traverse a pipeline. For a normal internal node the composition flowing out of each terminal connected is equal to the total composition in the node itself. e. the pressure drop over a pig. Limitations The phase split node is not intended for design purposes. 4. e. the velocity of a pig. See also: When to use Methods and assumptions Limitations How to use When to use . LIQUID. …OIL_N outlets · WATER_1. LIQUID_N outlets · DRYGAS _1. inspection. Terminal = GAS . .01). 7. the flow restriction caused by a pig. 1. …WATER_N outlets · LIQUID_1. How to use The OLGA HD flow model is activated by setting OPTIONS FLOWMODEL = OLGAHD.gas only Terminal = MIXTURE .gas +droplets Terminal = OIL .g. amount of wax dislodged from the wall. 3. It reduces to the well known Colebrook formula in the case of single phase flow. Output All of the output variables specified under section “VOLUME VARIABLES” that are available for the internal NODE are also available for the phase split node. but the phase fractions can be specified in the outgoing branches. it will be default assigned a value by OLGA. In a way the behaviour of the phase split node might be seen as a simple type of network SEPARATOR where there are no level controls and no internal separator efficiencies included. Phase split node The phase split node is based upon the functionality of an INTERNAL NODE. When running a pigging operation. parameters of interest are. 5. but for a phase split node there will be different distributed phase flows through each of the outgoing branches according to the actual type of terminal chosen. internal cleaning.g. oil. In the present model. the average film velocity becomes (g) where Up = pig velocity [m/s] Using this. Viscous friction force — the frictional pig model When a pig is moving. Static friction force The static force between the pig and the pipe wall is denoted F0. it is optional whether or not the slug-tracking framework is to be engaged in order to track the liquid slug in front of the pig. This implies that the liquid film ahead of the pig is pushed through to the next control volume with no possibility of liquid build-up. The user can override this setting by specifying the pig diameter using the key DIAMETER. Wall friction force The wall friction force due to contact between the pig and the pipe wall is given by (a) where F0 = fw Up = = static friction force [N] wall friction factor [Ns/m] pig velocity [m/s] As the pig velocity. Furthermore. this is the force that needs to be overcome in order for the pig to start moving. When the gap between the pig and pipe wall is very narrow. Thus. the volumetric flow rate is then given by (h) where D = Dp = inner pipe diameter [m] outer diameter of pig [m] By default. the liquid pushed through the pipe by a pig is only treated in an average fashion and no distinct build-up of liquid is seen. the flow of the fluid film around the pig results in a viscous friction force. the interfacial friction boundary downstream of the pig is infinite. it is necessary to explicitly track the liquid slug forming in front of the pig. some fluid ahead of the pig will not be carried along by it but rather leaks between the pig and the pipe wall. but merely an artifact of averaged hold-ups not being able to capture the actual build-up of liquid. a pig only starts moving if the pressure difference over the pig yields a large enough force. please refer to separate section below. resulting in a more physical description of the flow downstream from a pig. Assuming laminar flow. the wall friction force decreases due to less contact between the pig and the pipe wall. pig-tracking and plug in OLGA 5. respectively.Ppig &rho. Contrary to OLGA 5. Cf. this restriction has been eliminated. as a consequence of the hold-up reaching 1. and water is proportional to the hold-up each respective phase at that position. resulting in equal gas and liquid velocities on the downstream section boundary. liquid can be pushed from behind the pig to in front of it. increases. The total volumetric leakage flow rate is split over the oil. Explicit tracking of the liquid slug in front of the pig yields a more stable and accurate simulation that properly accounts for the liquid build-up downstream of the pig. the total leakage of gas. For stratified flow. License requirements Tracking of the liquid slug in front of a pig (TRACKSLUG=ON) is part of the Slugtracking Module that requires a separate license. This implies that differences between two such simulations should only be attributed to effects associated with the differences between explicitly treating liquid slugs or treating them in an average manner. For a static pig. = = = leakage factor [-] pressure drop over the pig [Ns2/m2] density [kg/m3] Slip induced leakage (back leakage) Due to slip between the pig and the fluid surrounding it. the effects of gravity and the pressure gradient can be neglected when calculating the flow of the fluid film that passes around the pig. As the model allows for liquid build-up in front of the pig. the gap between the pig and pipe wall is equals two times the pipe roughness.The Pig keyword is used to simulate various pigging scenarios. it also runs at the risk of a hold-up approaching 1. this output variable will show large swings in connection to pigs crossing section boundaries. these two options use a unified scheme. Friction forces and pigs The friction forces acting on a pig are described in the following sections. . Any wax related features are part of the Wax Deposition Module that requires a separate license. Since the hold-up in front of the pig is an average hold-up between the pig and the downstream boundary. Methods and assumptions General When running a pigging operation. If the liquid slug is not explicitly tracked. The improved physical model comes at the price of a slightly less stable numerical scheme. This effect is approximated by the wall friction factor. Pressure drop induced leakage Due to the pressure drop over the pig. It should be noted that in order to properly capture the physics. This is not a physical result.0 downstream the pig.0 as the pig approaches a section boundary. water. The pressure drop induced volumetric flux is given by (f) where cpl &Delta. which in turn results in a seemingly less efficient pig as compared to the OLGA 5 plug model. there will be a larger leakage due to the numerical scheme. For all other flow regimes. This force is calculated through (b) where f1 = f2 Up = = linear friction factor [Ns/m] quadratic friction factor [Ns2/m2] pig velocity [m/s] Leakage There are two different types of leakage. gas leakage is not allowed and the total leakage is split over water and oil in proportion to the local water and oil hold-up. When running such a simulation in OLGA 5. Up. respectively. For effects related to wax. and gas phases. L d &eta.876 &sdot. Interpolation is applied for any intermediate situations. .. and if not specified. Limitations It is not possible to simulate the melting of a hydrate plug since the pig mass is constant. is the pig wax removal efficiency [-]. &Phi. This mass transfer rate is given by (f) where Up is the pig velocity [m/s]. It is not possible to simulate a pig traversing through a pipeline at the same time as slug tracking is enabled. an additional friction. The wax plug length depends on the pig leakage factor.y &phi. wax layer yield stress measurements or estimates are available.B.12 405.. normally be insignificant as compared to the friction generated by the "virtual" wax plug. when routing is given." N. = = = = = = = wax breaking force coefficient [-] wax layer yield stress [Pa] wax porosity [-] wax layer thickness [m] inner pipe diameter [m] pig wax removal efficiency [-] pig form factor [-] The wax breaking force coefficient. d&nu. A is the cross-sectional pipe area [m2].liq &Phi. C.Pig and Wax Wax related friction forces When there is a wax layer on the pipe walls. the wax plug shear stress is taken as the maximum of the yield stress and the shear stress from the Bingham friction calculations. 106 The plastic viscosity is found by setting the shear rate. The yield stress and plastic viscosity are then used in the Bingham related equations to calculate the friction forces acting on the pig and wax plug. The standard wall friction will. mwxw is the average wax mass on the wall in the control volume [kg/m3]. the gravitational effects of a wax plug are assumed to be taken into account by the standard scheme. accounting for the wax plug porosity.2 can be interpreted as an effective shear surface forming a 45° angle against the wall. N. Launch and trap position of the pig A pig is launched and trapped at the boundaries closest to the positions given by the keys LAUNCHPOSITION and TRAPPOSITION. the wax plug friction length is set to zero. a slurry or plug with high wax content is assumed to build up in front of the pig.. Fwbf. Wax mass transfer from wall due to pigging When performing a pigging operation to remove wax from the pipe wall. C=1 implies that the wax layer shear surface is normal to the wall whereas C=&radic. The mass removed from the wall is added to the fluid downstream the pig. 3. 2. An estimate of the friction effects caused by the interaction between the wax plug and the pipe wall is evaluated using the following procedure: 1. the pig traverses through the flow-paths until it exits through a terminal node and is removed. If the wax layer yield stress is determined internally. the standard scheme for wall friction is always applied regardless of the wax plug friction length. The trap position is optional. This will affect the rheological properties of the fluid near the pig. In cases where the pig has no through-flow. The wall shear stress for the wax plug is calculated by using standard correlations for Bingham plastics /22/ and the PVTSim 16 version of the Pedersen/Rønningsen effective viscosity model. can be used to account for the effective shear surface orientation. How to use General A pig is added to the simulation by declaring the PIG keyword on the flow-path where it is to be inserted. e. The coefficient can also be used to tune the yield stress if.1 7. Due to the upper bound on the effective viscosity. The resulting frictional force is applied directly to the pig since the wax plug does not enter the model explicitly but only as an "effective friction length. If there is full flow through the pig.x/dy D E F = = = = = = oil viscosity with no consideration to the precipitated wax [Pa s] volume fraction of precipitated wax [-] shear rate [1/s] 18. The standard Bingham correlations are used to calculate the shear stress as a function of average velocity.B. The wax layer breaking force is modeled as (c) where C &tau.g. Routing — Pig in network In a network with bifurcations. Find the wax plug friction length by searching along the pipeline for existing suspended wax (bounded by the accumulated amount of wax stripped from the wall). If there is no leakage. the pig will enter the flow-path having the largest volumetric flow unless its routing is specified by the key ROUTING. will occur due to the forces required to break the wax layer off the wall. it is given by: (d) This equation is derived from the viscosity equation used in PVTSim 16 from Calsep. the flow-path where the pig is launched has to be included in the routing.wax d&nu. In the transition from non-Newtonian to Newtonian turbulent flow (Hedstrøm number between 1000 and 2000). the full length of the wax plug is used. respectively. however. Furthermore. and &eta. splines are used in order to get a smooth transition between the friction factors calculated using the Darby and Melson formula /22/ (applied for Hedstrøm number > 2000) and Haaland’s formula /23/ (applied for Hedstrøm number <1000). The internal effective viscosity model may be used to find the yield stress and plastic viscosity for a given suspended wax fraction according to (e) where &mu.x/dy=1000 1/s whereas the yield stress is found through equation (d) above using the porosity of the wax plug in front of the pig instead of the wax porosity. an additional term is added to the standard shear related wax transport term (solid wax mass transport between bulk and wall) for the section where a pig is located. In addition. WPPLASETVISC: plastic viscocity of wax plug. WXBRFCOEF: wax breaking force coefficent. How to use Position the check valve at any section boundary in the pipeline. If ABSPOSITION is used the check valve will be moved to the closest section boundary. cpl. is dependent on the flow rate Q. ∆P. but there can be a negative flow of liquid and positive flow of gas through the check valve. See also: When to use Methods and assumptions Limitations How to use When to use Use to model check valves. subgroup Slug) apply when the liquid slug in front of a pig is tracked. OLGA calculations are based on either built-in nonlinear curves for a "typical" pump. or user input of special dimensionless OLGA curves for a particular pump that must usually be derived from given dimensional curves before OLGA entry. Set this parameter to -1 in order to use internal model.Leakage factor The leakage factor. pump speed N. Output Pig specific plotting variables are found in the subgroup Pig of the group Basic. a number of input keys become available when simulating a pigging operation. They remain closed until the pressure difference across them is sufficiently large to give flow in the desired direction. e. Can. and the pump inlet pressure PI: . Check valve A check valve prevents the total flow from flowing in the wrong direction. See also: When to use Methods and assumptions Limitations How to use When to use If the inlet pressure of a pipeline is too low to drive the fluid to the outlet of the pipeline. the pressure increase over the pump. slug related plotting variables (group SlugTracking or group Compositional. WXRMEFF: wax removal efficiency.g.g. Fpig. Methods and assumptions The check valve closes if the total volume flow is in the wrong direction. Specify the leakage factor directly through the key LEAKAGEFACTOR. Use the Centrifugal pump to rigorously model the real nonlinear transient operation of a particular multiphase centrifugal pump (including recycle and bypass). Set this parameter to -1 in order to use internal model. PGWXFORMFAC: wax cutting efficiency. specified through the LEAKDPCOEFF key. Pig and Wax When using the Wax Deposition Module (requires separate license). set TRACKSLUG=ON. the leakage factor is given by The pressure loss coefficient can calibrated by letting fluid flow past a stationary pig. Tracking the liquid slug In order to track the liquid slug in front of a pig.. WXBRFCOEF: yield stress of wax layer on wall. or if we want to increase the oil production. Set the allowed flow direction in the DIRECTION key. be used to account for effective shear surface orientation. Set this parameter to -1 in order to use internal model. and to prevent the flow from flowing in an undesirable direction. Centrifugal Pump The CENTRIFUGALPUMP keyword is used to model rotodynamic pumps. e. there can be a negative flow of liquid and positive flow of gas through the check valve. WPPOROSITY: porosity of wax plug. used in determining the volumetric flux of liquid from behind the pig to in front of it can be specified in three different ways in order to override the default value: 1. Specify the relative leakage opening Aleak/Apipe through the key LEAKOPENING and evaluate the leakage factor according to 3. Methods and assumptions Theory and multiphase dynamics For a generalized multiphase centrifugal pump. Using the pressure loss coefficient. Limitations A check valve close if the total volume flow is in the wrong direction. WPYIELDSTRESS: yield stress of wax plug. License requirements The centrifugal pump are part of the Multiphase Pump Module that requires a separate license. a pump can be installed to increase the flow rate in the pipeline. 2. inlet gas volume fraction aI.. the specific work delivered from the pump into the fluid is: (b) where PO is the pump outlet pressure. Figure A: Example of a Centrifugal Pump Characteristic at GVF=0% . For a compressible gas.(a) For the liquid (assuming incompressible). and the surroundings. most pump manufacturers do not publish performance curves directly in this normalized / homologous format required by OLGA. Each quadrant is defined in a specific normalized / homologous format (see Pump Data Table for Centrifugal Pumps for an exact definition of all quadrant formats). Equation (e) can be solved for PO/PI. For a two-phase mixture. Nor do they typically offer any curves at all for the operating quadrant representing Positive Speed with Negative Flow (where the pump is transiently unable to overcome external backpressure. PI the pump inlet pressure and rl the liquid density. If the adiabatic constant k for the gas and the compressor efficiency ηp are given. Together. equation (e) can then be rewritten by a series expansion to: (f) Modeling in OLGA OLGA's transient calculations for centrifugal pump performance utilize multi-dimensional interpolation across four separate (default. plus additional curves for increasing GVF's. up to a "Degraded Performance Limit" (often GVF=60-70%. Instead. typically during Startup/Speedup) or the operating quadrant representing Negative Speed with Negative Flow (where the centrifugal impeller is physically rotating backwards.I the gas density at pump inlet. but variable by manufacturer and model). Assuming n = 1. either due to reverse power input or overwhelming external backpressure). For a two-phase mixture (except for very high gas fractions) an isothermal compression of the gas may be assumed (i. The relationship between head H and specific work W is W = gH = ghHR.0.e. and assuming a polytropic process. in combination with either weak forward impeller rotation or actual reverse impeller rotation). the pump impeller / case. The work input to the gas is equal to the increase in the gas enthalpy. the pump power to the fluid is weighted by mass fractions (αm = gas mass fraction) as follows: (e) With W calculated from the pump characteristics. the polytropic constant n can be calculated.0) to account for rapid vapor-phase heat loss to all of the associated liquid. However. the work done by the pump is: (c) Where n is the polytropic constant and ρg. When the gas is assumed to be ideal Win can be written as: (d) The polytropic efficiency is defined as the ratio of the work done by the pump divided by the work input to the gas. or user-specified) quadrants of performance curves. where HR is rated head and h is the head ratio. n=1. these four quadrant curve sets give OLGA advanced capability to model all possible transient combinations of Positive and Negative Normalized Speed Ratios and Flow Ratios (including transient backflows that often occur during pump startup and shutdown. most manufacturers publish one Head versus Flowrate Curve (with Power or Torque overlaid) for the case of Gas Volume Fraction (GVF) = ZERO. Because the homologous curves are dimensionless. head. OLGA's special homologous centrifugal pump curves utilize the following non-dimensional variables: .torque ratio (g) where subscript R means rated value. one set of curves can be used to describe a variety of different pumps (i. This figure shows the single phase homologous head curves. flow rate and speed for each pump. within a single OLGA model) by specifying the desired rated density. torque.opi sample case installed with OLGA) . q/w h/w2 Table 2: Dependence of Pump Torque on Pump Speed and Flow Rate Curves Range Independent variables Dependent variables . In calculating the hydraulic torque. as defined in Equations (g) below. the user must first convert the manufacturer curves into homologous curves where the head and torque ratios (actual value to rated value) are functions of the pump speed and flow rate ratios. and are representative for typical centrifugal pumps. users can change these data easily by specifying their own experimental data through the pump data table. Each set of homologous curves consists of four curves. The transfer from single-phase conditions to fully-degraded twophase conditions is described by a two-phase multiplier. Each quadrant curve set includes: Single phase head HS Two phase head HT Single phase torque THS Two phase torque THT The two-phase head HT and two-phase torque THT curves should be based on fully-degraded two-phase conditions. These are defined in Table 1 and Table 2. w/q h/q2 4 w < 0.. q/w h/w2 2 q > 0. all defined in terms of the above non-dimensional variables.head ratio .flow ratio .e. These built-in default centrifugal pump curves are based on experimental data. w/q h/q2 3 q < 0. TM(a) is the two-phase torque multiplier and a the gas volume fraction at the pump inlet.Figure B: Example of a Centrifugal Pump Characteristic at GVF=70% In order to incorporate such manufacturer curves into an OLGA pump model. the difference between actual fluid density and rated density must be corrected as: (i) Table 1: Dependence of Pump Head on Pump Speed and Flow Rate Curves Range Independent variables Dependent variables 1 w > 0. A complete default set of homologous curves is tabulated in the code (and also documented in an external file that is linked to the example centrifugal pump in the pump. TH.speed ratio . OLGA interpolates over four quadrants of homologous curve sets. However. An example of a graphical presentation of the tabulated pump characteristics is shown in Figure C. The pump head H and hydraulic torque TH under two-phase conditions are determined as: (h) where HM(a) is the two-phase head multiplier. How to use General setup Add the CENTRIFUGALPUMP keyword to the desired flowpath.1 w > 0. because no pipeline is considered. ανδ Φιγυρε Α οφ τηε Πυµπ − Μετηοδσ ανδ τοπιχ. q/w b/w2 Figure C: Single Phase Homologous head curves The OLGA centrifugal pump model also includes embedded numerical models for typical recycle and bypass lines. Pumps can not be positioned at the first or last section boundary of a flow path. in order to scale the general transient response surface of either the built-in default or user-specified Homologous Centrifugal Pump Curves to your actual pump. or POSITION (an alias) σπεεδ. This pump also includes additional provisions for simple "branch-less" Bypass and Recycle modeling to further increase the realism of OLGA's transient responses for typical pump packages. Ψου µαψ οπτιοναλλψ εντερ χυστοµ τρανσιεντ χεντριφυγαλ πυµπ περφορµανχε χυρϖεσ το πρεχισελψ ρεπρεσεντ τηε εξαχτ τρανσιεντ ρεσπονσε συρφαχε φορ ψουρ αχτυαλ πυµπ. Χηοοσε ανψ αππλιχαβλε µεανσ οφ χοντρολλινγ τηε πυµπ σπεεδ Pump setup The OLGA Centrifugal Pump requires DENSITYR (same 900 kg/m3 default. Specify pump location by one of ABSPOSITION (length). The setup procedures and modeling assumptions for these Built-in Bypass and Recycle features are described in detail in Pump Bypass And Recycle. PIPE & SECTIONBOUNDARY. w/q b/q2 3 q < 0. νοτε τηατ µοστ µανυφαχτυρερσ δο νοτ πυβλιση πυµπ χυρϖεσ διρεχτλψ ιν τηισ φορµατ.Φορ µορε σπεχιφιχ ινφορµατιον αβουτ τηε τηεορετιχαλ βασισ οφ τηεσε σπεχιαλ ΟΛΓΑ ινπυτ ρεθυιρεµεντσ. Controlled manually by specifying time and speed series in the controller definition. The speed is calculated by: . Each flow is calculated with the given pressure difference between the two sides of the choke and the choke upstream conditions. ανδ ιτ µαψ αλσο βε διφφιχυλτ το οβταιν δεγραδεδ µυλτιπηασε περφορµανχε χυρϖεσ υπ το τηε µαξιµυµ δεγραδεδ Γασ ςολυµε Φραχτιον (ΓςΦ) φορ ψουρ παρτιχυλαρ ηαρδωαρε ανδ αππλιχατιον (οφτεν σοµεωηερε ιν τηε ρανγε οφ 30 − 70% ϖαπορ ϖολυµε). χονσυλτ Ταβλε 1. For more detail. HEADRATED and TORQR as a minimum. q/w b/w2 2 q > 0. or specified). w/q b/q2 4 w < 0. already representing a much more realistic transient modeling upgrade to the Simplified Centrifugal Pump model at only slightly greater modeling cost in setup time and runtime. Limitations The recycle flow and bypass flows around the OLGA centrifugal pumps are considered as flows through controlled chokes. Ασσυµπτιονσ τοπιχ The OLGA Centrifugal Pump will run without any further inputs. SPEEDR. see Pump Bypass And Recycle. including user-specified orifices that may be linked to OLGA controllers. Energy balance The total power input to the fluid from the OLGA centrifugal pump is: (j) where TH is the pump hydraulic torque. Ηοωεϖερ. Controlling the pump speed The following options are available for controlling the pump speed: 1. ω the pump speed and ηM the pump mechanical efficiency. Pump speed regulated by controller (All pump models(*) except PressureBoost): a. b. Regulated by a physical parameter. The recycle flow can only flow from the pump downstream section to the upstream section. It is impossible to insert any component in the recycle flowline or bypass flowline. The pipeline effect of the recycle flowline and bypass flowline is not considered. FLOWRATED. Ταβλε 2. and the bypass flow can only flow from the pump upstream section to the downstream section. The speed variation will stop once the recycle flow is within a defined range below MAXRECYCLE and above MINRECYCLE. liquid mixture. and is specified with RECV or RECVTABLE. and droplets moving through section boundary J.BYCVTABLE. A common multiphase transportation system with pump is shown in Figure A. Then connect a recycle controller of your choice. liquid.(a) where Nmax is the maximum pump speed (defined by user). Figure A: Multiphase Transportation System with Pump Within OLGA. which is referred to in the PUMP keyword. The recycle flow is out of section J and into Section J-1. The user can choose the recycle flow as gas only. Figure B: Multiphase Transportation System modelled in OLGA The centrifugal pump model requires a pump table with the characteristics of the pump. If the maximum pump torque has been given by users (Only for centrifugal and displacement pumps) The effective pump torque is calculated from the total power input to the fluid. The displacement pump model requires a backflow table. MINRECYCLE. this system will be simplified as shown in Figure B. Further details about the internal workings of these simplified Bypass and Recycle features are provided in the following text. There is a default implementation of such tables in OLGA. The user may then close that optional OLGA Valve to block any possible backflow transients (that may otherwise occur due to higher downstream pressure at any moment when the centrifugal pump is shut down). BYSTROKETIME sets the valve opening/closing time. . No-slip flow is assumed for all of gas. The pump manufacturers generally characterize their pumps by pump operating characteristics. Optional Built-In Bypass and Recycle The bypass and recycle line is included for the Centrifugal pump Displacement pump Framo pump To activate OLGA's simplified Bypass feature specify BYDIAMETER or BYCVTABLE and connect a bypass controller of your choice. (*) The Framo pump model has buildt in speed control.) To activate OLGA's simplified Recycle feature for any Centrifugal or Displacement Pump. Controlled by an override controller (Only for centrifugal and displacement pumps): To adapt the pump to the production change (because the recycle flow is at upper or lower limits). If the pump shaft torque is over the limit the pump speed is reduced. BYCHECK and BYSTROKETIME. and input speed changes will be restricted by a speed rate change. equations. and the bypass flow out of section J-1 and into section J. Nmin is the minimum pump speed (defined by user) and u the signal from the controller. 2. or fluid mixture. and ACCECOEFF. the pump speed will be changed automatically according to the required speed variation (speed acceleration). Use BYCHECK to enable/disable a check valve in bypass line. Note that in this implementation the pump is abstracted into a volume-less element on the section boundary J between section J-1 and section J. water only. specify at least RECDIAMETER and MAXRECYCLE. Each of the characteristics is assigned a label. The speed variation may be given in form of: (b) where A is a constant pump speed variation rate (acceleration). 3. The Framo recycle is required. QPt : (c) where QPt is the total power input to the fluid. (Only the Framo pump supplies . and a warning message will be given in the output file. plus any non-default values for RECPHASE. and block flow diagrams. If other tables are needed they should be given with the TABLE keyword. as: Ug = Ud = Ul = U (a) OLGA also permits the user to add a separate VALVE keyword at the same section boundary where a centrifugal pump or Framo pump is located. The recirculation loop secures stable conditions for the compressor. as OLGA cannot handle recirculation directly. . If the mass flow through the choke exceeds the critical flow rate. Equation (a) below.Recycle and bypass flow Recycle and bypass flows are only defined for centrifugal (not simplified) and displacement pumps. The choke upstream condition is taken from the pump downstream section (pump pressure side). Back flow is not allowed through the bypass line. (a) where p1 p2 G = = = = (-) is the pressure ratio (N/m2) is the inlet pressure (N/m2) is the outlet pressure (kg/s) is the mass flow Figure A shows a typical compressor characteristic diagram. GR is calculated by: (b) where Cd is the choke discharge coefficient and Ach the choke opening area. It is assumed that during operation the control system keeps the compressor within the bounds of validity of the characteristics. is controlled by a choke and calculated in the same way as for the recycle flow. If the recycle flow is in subcritical condition. The recycle flow. The surge volume flow calculated from the compressor tables is used together with an optional security factor to establish a set point for the controller that controls the recirculation around the compressor. See also: Methods and assumptions Limitations How to use Methods and assumptions The compressor is modelled as a flow-dependent and rotational-speed-dependent pressure jump and energy source. Pressure increase and derivatives of pressure increase are calculated from the pressure characteristics and are used for setting new coefficients in the momentum equations. critical flow conditions will be used. GR. ∆Pch. The compressor characteristics also give information about the minimum inlet flow (surge flow) that the compressor can operate on. In addition. a recirculation loop around the compressor is opened. If the bypass flow line is opened. The compressor speed and the recirculation around the compressor are governed by the control system. No forward flow is allowed in the recycle loop. the compressor speed is limited by a user-specified range. is considered as the flow through a controlled choke. Any recirculation around the compressor is treated by a source into the section upstream of the compressor. Gb. Compressor pressure step evaluation The compressor pressure characteristics give compressor pressure ratio as a function of reduced rotational speed and reduced mass flow. Compressor A compressor is included to increase the pressure of the gas. Temperature increase is calculated from the temperature characteristics and is used for setting new coefficients in the energy equation. The flow rate through a critical choke is governed by the choke upstream conditions and the choke opening. and the choke upstream conditions. The compressor is described by compressor characteristics that give the pressure and temperature increase over the compressor as a function of flow through the compressor and the rotational speed of the compressor. Compressor data needed for the model are found by linear interpolation in the compressor tables. The bypass flow. the fluid flows from the pump inlet to the pump outlet in the normal pumping flow direction without going through the pump. The flow is calculated with a given pressure difference between the two sides of the choke. The compressor characteristics and the surge volume flow are given in the form of tables. A heat exchanger (cooler) can be included in the recirculation loop. and a sink out of the section downstream of the compressor. The compressor surge volume flow is the lowest volume flow the compressor can operate on without becoming unstable. If the inlet flow drops below the surge flow multiplied by a safety factor. The choke flow can be regulated by a controller. since OLGA cannot handle recirculation directly. The polytropic factor (n-1)/n is calculated from pressure ratio and temperature ratio using Equation (f). with reduced surge mass flow as a function of reduced compressor speed. The surge volume flow is used together with an optional security factor to establish a set point for the anti-surge controller (ASC) that controls the recirculation around the compressor. Only gas is allowed to flow in the recirculation loop. temperature and the polytropic exponent n is: (e) The compressor temperature characteristics are also given in the form of tables. For calculation of the operating point.Figure A: Compressor characteristic diagram The pressure increase over the compressor is calculated from the compressor pressure characteristics. . and u is the signal from the control module. The range is normally determined by the speed range in the compressor tables. Figure B: Recirculation loop The pressure drop across the restriction is equal to the pressure difference between the sections downstream and upstream of the compressor. where u equal to 1 means that the compressor speed is at its maximum. The recirculation flow is restricted by the critical pressure difference. (f) Calculation of surge volume flow The surge flow is in the form of tables. The flow is controlled by a choke with the choke opening governed by the control system. and the temperature ratio is found by linear interpolation. the critical value is used. u is in the range from 0 to 1. The recirculation flow is treated as a source into the section volume ahead of the compressor boundary. The enthalpy source due to the compressor is: (c) where W is the mass flux through the compressor and Dz is the section length of the section downstream of the boundary where the compressor is located. The speed is governed by the control system and is limited by a userspecified range. the power required for compression to an outlet pressure p2 is: (d) The relation between pressure ratio. see Figure B. preventing unstable compressor operation. while the compressor outlet temperature is only used for informative purposes. For a compressor located at boundary j the surge volume flow is calculated as follows: (g) Recirculation flow modelling Recirculation flow around a compressor is modelled as a set of negative and positive sources. the power supplied by the compressor. If the pressure difference between the section upstream and downstream of the compressor is higher than the critical value. The recirculation is between two neighbouring sections with a compressor on the common boundary. Compressor temperature calculation In order to calculate gas temperatures. the compressor speed is necessary. Reduced surge mass flow as a function of compressor speed is found by linear interpolation. Polytropic compression is assumed. r = (rmax . see Figure A. The temperature resulting from this balance is used for calculating fluid properties. For an inlet at pressure p1 and a density of r1. is added as an enthalpy source to the enthalpy balance for the pipe section following a compressor boundary. PWC.rmin) u + rmin (b) where r is the compressor speed. and a source out of the section volume after the compressor boundary. (l) hg is the specific gas enthalpy in the compressor downstream volume. The energy source entering the upstream section in a situation with a heat exchanger in the recirculation loop is calculated as: (m) is specific gas enthalpy based on the desired heat exchanger outlet temperature and pressure in the section where the source is entering. the critical pressure difference is used for calculating the recirculation flow. SECURITYFACTOR. and AMP2 if the inlet is greater than the surge flow. and is in the range from 0 to 1. A security factor of 1. ρg is the gas density in the section it is flowing out of (section after the compressor). The orifice opening is calculated as: (n) where u is the signal from the control module. Recycle loop The anti-surge security factor. A typical value for security factor is from 1. D is the diameter of the section with the source. and Do is the orifice diameter of the controlled choke. Critical flow calculations are based on single-phase gas flow with a constant specific heat ratio of 1.2 means that the control valve in the recirculation loop starts to open at a compressor inlet flow that is 20% higher than the surge flow specified in the compressor tables. In this case. one needs to add a compressor and two controllers (speed controller and anti-surge controller). If the pressure in the section upstream of the compressor exceeds the pressure in the section downstream of it. Specific heat ratio of 1. The anti-surge controller (ASC) should be configured as a PI controller. A short stroke time for the recycle valve should also be selected. . Wrec. (j) (k) where g is specific heat ratio pcrit is critical pressure ratio p is the pressure in the section it is flowing out of Dpch. W is the mass flux.3. The speed is calculated by Equation (b) above. The heat exchanger is modelled as an ideal heat loss. It is recommended that a separator is located upstream of the compressor in order to avoid liquid flow through it. The orifice opening of the controlled choke is governed by the control system. For subcritical flow through the controlled choke the pressure difference between the section upstream and downstream of the compressor is used in equation (i). If the controllers are omitted the speed will be kept at minimum speed (MINRPM) and the recycle loop will be closed. and the absolute value of AMP1 should be higher than the corresponding absolute value of AMP2 in order to rapidly open the recycle valve and to impose an inertia to close it again. A controller can be used to regulate the speed within the operating range. AMP1 and AMP2. To send information from the compressor to the ASC about surge flow. the recirculation flow is set to zero. There must be one compressor table for each compressor. u equal to 1 means that the controlled choke is fully open. Limitations Only gas flows in the recirculation loop. These two parameters determine the operating range of the compressor and they must be within the rpm range of the compressor tables.3 is used. MAXRPM. g. The ASC is a kind of non-linear controller that have two amplification factors. and the negative sign relates to a negative source. connect the OUTSIG_n out-signal from the compressor to the MEASRD input-signal of the controller.3. Select also the controller initial output signal (BIAS). Numerically. How to use To use a compressor. are specified by the user. In that position. determines the anti-surge control line.1 to 1. A heat exchanger may also be included in the recirculation loop.g is the mass flux based on the section area of the section with a source and Dz is the section length of the section with a source. AMP1 is used if the inlet flow to the compressor is less than the surge flow. The energy extracted through the heat exchanger is limited by the heat exchanger capacity. Controlling rotational speed Compressor minimum rpm. equal to zero. crit is critical pressure difference The energy leaving the section downstream of the compressor and entering the section upstream of the compressor through the recirculation loop is calculated as follows. and maximum rpm. Critical pressure difference is based on single phase gas flow with constant specific heat ratio. If the speed controller is omitted the controller signal will be zero and the compressor will use its minimum speed. Then select QGSURGE as the measured variable. the temperature of the recirculation source entering the section upstream of the compressor has to be specified. Both AMP1 and AMP2 have to be negative. The compressor may not be positioned at the first or last section boundary of the pipeline. the compressor model works with liquid phase present but the results make no sense. always select a security factor > 1. To protect the compressor against surge conditions. For critical flow through the controlled choke. the controlled bypass is unrealisable since it is defined as going from the downstream section to the upstream section. The control module also takes care of the stroke time of the controlled choke. is specific enthalpy decrease in the heat exchanger. MINRPM. The aim of the heat exchanger is to extract energy to obtain a desired heat exchanger outlet temperature.The pressure drop over the restriction is: (h) Solving for W: (i) where the positive sign relates to a positive source. To add a cooler to the recirculation loop. See also: When to use Methods and assumptions Limitations How to use When to use If the inlet pressure of a pipeline is too low to drive the fluid to the outlet of the pipeline.ref QPvis. Mechanical friction loss: (b) Viscous friction loss: (c) where a b Nref QPmf. multiphase void fraction. to outlet pressure PI + ∆P. i. Displacement Pump The DISPLACEMENTPUMP keyword is used to model positive displacement (volume) pumps. License requirements The displacement pumps are part of the Multiphase Pump Module that requires a separate license. QPM. A default implementation of the backflow table is implemented in the displacement pump (and also documented in an external file that is linked to the example displacement pump in the pump. nl and PI. the specific flow rate Qspc is a constant. Other backflow tables may be given by using the TABLE keyword. is calculated as the isentropic compression work from inlet pressure. Methods and assumptions Theory and multiphase dynamics For the displacement pump. expressed through the specific flow rate. or if we want to increase the oil production. a pump can be installed to increase the flow rate in the pipeline. OLGA calculations are based on either built-in nonlinear curves for a "typical" pump. The backflow rate is a function of several parameters and is tabulated in a backflow table. ∆P. This can be summarized as follows: (a) where Q0 Qb Qspc N ∆P aI νI PI theoretical flow rate back flow rate pump specific flow rate pump speed pressure increase across the pump void fraction at the pump inlet liquid kinetic viscosity pressure at the pump inlet Modeling in OLGA For a given displacement pump. Use the displacement pump to rigorously model the real nonlinear transient operation of a particular multiphase positive displacement pump (including recycle and bypass). dP. set COOLER=ON and also set the COOLCAPACITY. and liquid-phase viscosity. The theoretical flow rate is a function of the pump speed and the characteristics of the pump.opi sample case installed with OLGA).If the anti-surge controller is omitted the controller signal will be zero which will cause the recycle choke to be closed. inlet pressure. aI. the pump flow rate is the theoretical flow rate minus the backflow through the pump.(See Pump Data Table for Displacement Pumps. Qb is tabulated in the backflow table as a function of N. Energy balance The total power input to the fluid is calculated by summing the mechanical work on the fluid and the different losses as following: The power used for mechanical work on the fluid. there will be no flow in the recycle loop. see the heading Pump Bypass And Recycle below. PI.) The OLGA displacement pump model also includes embedded numerical models for typical recycle and bypass lines. For more detail. including user-specified orifices that may be linked to OLGA controllers.ref experiment coefficient for mechanical friction loss experiment coefficient for viscous friction loss pump reference speed mechanical friction loss at the pump reference speed viscous loss at the pump reference speed . or detailed manufacturer's curves expressing that multiphase displacement pump's internal backflow rate as a 5-dimensional tabular function of speed.e. none of DENSITYR. However. Gas Lift Valve In the gas lift process. It is impossible to insert any component in the recycle flowline or bypass flowline. Each flow is calculated with the given pressure difference between the two sides of the choke and the choke upstream conditions. For example. and there is one curve for each casing pressure. standard volume gas rate along the y axis. and as the tubing pressure decreases this GLV shall close and the next one open (might already be open depending on the response curve). relatively high pressure gas is injected downhole through a gas lift valve (GLV) into the production string to lift the fluid to the surface. The setup procedures and modeling assumptions for these Built-in Bypass and Recycle features are described in Pump Bypass And Recycle. Figure A shows an example of these “response curves” where tubing pressure is along the x axis. If the tubing pressure is increased for any reason (e. You may optionally enter custom transient displacement pump backflow (performance) curves to precisely represent the exact transient response surface for your actual pump. As many leaks can be given as the actual gas lift well configuration requires. SPEEDR. The bottom hole pressure after shut-in is often much higher than the bottom hole pressure at normal production conditions. The pipeline effect of the recycle flowline and bypass flowline is not considered. The opening pressures are affected by downhole temperature as the temperature changes the forces acting on the valve stem. Several gas lift valves (unloading valves) are spaced along the depth of the well to lower the compressor discharge pressure required during startup phase of gas lift after a shut-in operation. choke back production at the wellhead.g. head. note that the required input format is a complex 5-dimensional matrix of internal backflow rates as a function of pump speed. At constant injection pressure (casing pressure) all GLV’s above the operating GLV should be closed. the characteristics of the GLV should be used through the keyword TALBE in the simulation model. Calculate compressor discharge pressure required to unload the well. because no pipeline is considered. Check the possibility of flow instability such as casing heading. BCOEFFICIENT. a big liquid slug coming from the productive formation.For more specific information about the theoretical basis of these special OLGA input requirements. The OLGA Displacement Pump will run without any further inputs. This cycle will be repeated till the injected gas reaches the operating GLV (lowermost active GLV). or POSITION (an alias) NOTE: See Displacement Pump . FLOWRATED. shut-in.When to use for OLGA module license requirements Choose any applicable means of controlling the pump speed. etc in order to tune the model very precisely. Like the Centrifugal pump. The keyword TABLE provides the channel for users to specify the GLV characteristics. it is possible to simulate different gas lift configurations and various operations such as startup. or TORQR are used. etc). and steady-state operation. and the bypass flow can only flow from the pump upstream section to the downstream section. The GLV dynamics have major impact on the flow stability of gas lift systems. density wave instability. Once the gas lift gas reaches the operating GLV. and liquid viscosity . Find various remedies to flow instability. Pump setup The OLGA Displacement Pump requires significantly different types of inputs than the Centrifugal or Simplified Pumps. The recycle flow can only flow from the pump downstream section to the upstream section. this PUMPTYPE also supports additional provisions for simple "branch-less" Bypass and Recycle modeling to further increase the realism of OLGA's transient responses for typical pump packages. as well as MAXSPEED. See also: When to use Methods and assumptions Limitations How to use When to use Whenever the gas-lifted well contains GLV of which the opening depends on the production and injection pressure.Methods and Assumptions section. Pumps can not be positioned at the first or last section boundary of a flow path. LEAK. Such a model can be used to: Dimension and space the unloading valves along the wellbore.information normally only available from the manufacturer's experts. You must enter SPECAPACITY (the total specific volume displaced per revolution or displacement cycle). inlet pressure. OLGA will then multiply these two inputs to determine the (gross) theoretical volumetric flowrate displaced (before subtracting internal bypass). Combining the functions that are provided by the keywords TABLE.Then. PIPE & SECTIONBOUNDARY. Methods and assumptions A gas lift valve (GLV) is used to inject gas into the tubing from the annulus/casing. gas is continuously injected through this GLV and stable production is optimised by regulating the optimum amount of gas (injection gas rate). Properly spaced and designed. The unloading valve opens or closes depending on the casing pressure and tubing pressure. although equipment manufacturers or others with detailed knowledge may wish to override the defaults for one or more of ACOEFFICIENT. this may cause the opening of some GLV’s.. HEADRATED. Trouble shoot problems such as interference of unloading valves during normal operation (simultaneous gas injections through more than one GLV). MDISSIPATION. and ANNULUS. . perhaps even requiring new eperimental work on a prototype pump for your particular fluid and operating conditions. The characteristics of a GLV are usually given by several sets of curves with each curve shows the gas injection rates at different production pressures at a constant injection pressure. The injection of gas will reduce the liquid head pressure in the tubing until the GLV’s are closed again. The keyword LEAK allows users to use the GLV characteristics and specify the lift gas injection position. void fraction. Typically more than one GLV is placed after each other down the annulus. The intention is that the GLV closest to the wellhead opens first. these unloading valves should close one after the other from top to bottom as the lift gas reaches the deeper valves. This opening is the automatic response of the GLV’s to stabilise the flow. consult the Displacement Pump Theory topic in the Displacement Pump . the total power input to the fluid is calculated as: (d) Limitations The recycle flow and bypass flows around the OLGA displacement pumps are considered as flows through controlled chokes. Gas lift distribution systems and production networks of wells can be simulated with the network capability of OLGA. How to use General setup Add the DISPLACEMENTPUMP keyword to the desired flowpath Specify pump location by one of ABSPOSITION (length). either continuous or intermittent. VDISSIPATION. For tubing pressures above the “opening pressure” of 330 psig the valve starts to open. and above 730 psig (Pt > Pc) there is no flow as there is a check valve that stops the flow going from the tubing to the casing. Figure B: Sketch of typical casing (injection) pressure operated GLV (with gas charge) The GLV in Figure B is characterized as an Injection or Casing Pressure Operated GLV since the injection/casing pressure works on the large part of the bellows (AINJ) while the tubing pressure works on the small part (APROD). Associated liquid (in case of liquid on the injection side) through the GLV is calculated by setting the total mass flux WTOT [kg/(m2s)] as: (b) where WG is the gas mass flux derived from the response curves. as would be the case for the injection pressure of 790 psig in Figure A).Figure A: Example of GLV Response Curves The GLV is constructed to respond on both the casing pressure and tubing pressure. The casing and tubing pressure work together to open the valve. respectively. and the well fluid flows up the casing. That is. if not given (allowed with a negative extrapolated value. (gas. the curve for the lowest injection pressure is used directly and vice versa for injection pressure above the highest given injection pressure. It is required that the last point in a response curve (the point with highest production pressure) has a gas rate of 0. Extrapolation is performed in the direction of decreasing production pressure to find the opening production pressure. the code finds the two response curves with injection pressures that are closest (higher and lower) the current injection pressure. For low tubing pressures the combined force is not enough to open the valve (Pt < 330 psig). First. see Figure B. PINJ and PPROD switch places in the equation for a Production or Tubing Pressure Operated GLV. In the input to OLGA the terms “injection pressure” and “production pressure” is used instead of “casing pressure” and “tubing pressure”. It is possible to create a curve with only one point for which this is not a requirement (a way to specify constant standard volume flow for all production pressures below the injection pressure). For each phase. oil. Temperature effect In the case of a gas charged dome (a GLV might have a spring instead) the pressure in the dome will increase with increasing temperature as the gas is contained in the dome. the “Throttling region” from 330 to approximately 600 psig is where the valve goes from closed to fully open. One gas rate is found for each curve by interpolating using the current production pressure. For a tubing pressure approaching the casing pressure the flow decreases as the differential pressure decreases. no extrapolation for injection pressures. rG is the gas density and rmix the volume averaged density. The curve for the casing pressure of 730 psig illustrates the behaviour.) the mass flux through the GLV is: (c) where xP is the mass fraction of the phase upstream the GLV (in the section where the GLV is placed). etc. This means that the required force from the production and injection side to open the GLV also increases with increasing temperature. and then the resulting gas rate is found by interpolating between these two rates using the current injection pressure. water. According to Winkler and Eads /20/ the increased pressure in a nitrogen charged dome/bellows (based on reference temperature TREF of 60 F) is expressed like: . The intention of the GLV is to allow flow from the injection to the production side. Calculation of flow from curves The standard volume gas rate through the GLV is found by linear interpolation in the response curves using the calculated injection pressure (upstream the GLV) and production pressure (downstream). while the gas (typically nitrogen) charged dome works in the opposite direction. P. If the current injection pressure is below the lowest given injection pressure. The response curves can be user-given (defined in LEAK/GASLIFTTABLES). The force balance for the point where the GLV starts to open is then: (a) where R = ASEAT / ABELLOW. since the injection gas may be injected in the tubing instead of the casing. so using the terms injection/production makes the input more general. E. For the curves which do not have the maximum point. The point with maximum gas rate (for each of the curves) is identified. geometry of GLV. In reality. and the points to the left of this maximum point are shifted with the calculated DPPROD. Based on the difference between the setpoint and the measured temperature. For example.. The controlled heat exchanger has a simpler model. specify the position. The bellows temperature will depend on the production temperature. How to use To select between a setpoint heat exchanger and a controlled exchanger. Use the keyword LEAK to specify the gas injection position and the name of the table the GLV performance curves are given. the temperature distribution within the valve is more complex because of interaction between the production string and the injection string. the original right side of the curve. Both can be configured to give practically the same results. and the pressures and temperature are given in psia and F. open + DPPROD > PINJ. Different types of controllers can be used. The CONTROLLER for the heat exchanger knows the current temperature and the target temperature and adjusts the effect of the heat exchanger to obtain the target temperature. placement of GLV. Use ANNULUS keyword to configure the injection and production strings. the curve for a casing/injection pressure of 850 psig in Figure A will not be affected by temperature with this procedure. the effects of temperature on the closing of the valve are not considered. the expansion of lift gas through the valve. To use a controlled heat exchanger. etc. More specifically. the effect of the heat exchanger is determined by the controller system. making the input of a controlled heat exchanger more flexible than that of the setpoint heat exchanger. it is specified through the keys of the COMPRESSOR keyword (keys COOLER and COOLCAPACITY). How to use Use the keyword TABLE to specify the curves of gas flow rate as a function of production pressure for different injection pressures. The controller will typically measure the temperature at a specified position along the pipeline and compare the measured temperature to a setpoint. but instead of setting the outlet temperature. The user must give a parameter a where the bellows temperature is a linear interpolation between the injection and production temperature: (e) From the force balance equation (a) we get the following expressions for the increase in required production pressure to open the GLV (assuming constant injection pressure): (f) where DPB is calculated in equations (d). These equations have been implemented in OLGA. use this HEATEXCHANGER keyword to create a heat exchanger. the controller will deliver a signal to the heat exchanger which determines how large a fraction of the heat exchanger’s capacity will be applied. To use a setpoint heat exchanger. In the setpoint heat exchanger. Methods and assumptions The setpoint heat exchanger is an idealised heat source/sink. Otherwise. That is. and a new maximum point where they cross each other. the capacity. It is also assumed that the maximum flow rate point of the GLV performance curve corresponds to the flow rate of a fully opened valve. injection temperature. consistent with the energy equation in OLGA. specify the position and the capacity. connect the heat exchanger to a controller.’Setpoint Heat Exchanger’ and ’Controlled Heat Exchanger’. There are two different types of heat exchangers in OLGA. and axial heat transfer along the pipes.(d) where TB is the bellows temperature. one can measure the average temperature over several sections by using a Linear Combination Controller. only the opening point is correctly calculated (except for the uncertainty in using equations (d) for a reference temperature different from 60 F). This is not physically correct. and no description of the real heat transfer process is included. It simply provides a way of specifying a temperature at the heat exchanger outlet. This effect can be very significant. a heat source/sink is estimated that will give the specified fluid temperature for a particular section. flow conditions. Limitations A heat exchanger can not be positioned at the first or last section boundary of a pipeline. Limitations The temperature effects on the opening/closing of a GLV are mainly uncertainties in using the GLV characteristics.g. The average of the temperatures on the production and injection side is used as temperature inside the valve body. See also: When to use Methods and assumptions Limitations How to use When to use When a heat exchanger is used in the anti-surge recirculation loop of a compressor. In the controlled heat exchanger. but with a user given reference temperature. The heat source/sink is not estimated as the heat exchanger has no knowledge of any target temperature. simply set the TYPE. but each is configured differently and this allows for different usages. In OLGA this effect is included with a right-shift of all the response curves associated with the GLV. This procedure is a simplification of how the response curves are affected in the dynamic region. an outlet temperature and an upper limit of the heat source. Pressure boost . Heat Exchanger A heat exchanger is included to raise or lower the temperature in the fluid. The new response curve will then consist of the adjusted left side of the curve. the heat exchanged is equal to the enthalpy difference corresponding to the difference between the inlet temperature and the specified outlet temperature of the heat exchanger. For a sufficiently high temperature above the given reference temperature the GLV might never open: PPROD. it has been assumed that the equations give reasonable results also for other reference temperatures than 60 F. We define the pump battery through a proportionality factor for the volume delivered at a certain pump rate: (a) where QP PFAC SPES Volume delivered by the pump battery Pumping factor Strokes per time unit The pump rate is normally controlled by the following set of controllers: Controller on the maximum hydraulic horsepower allowed Controller on the maximum pump rate Controller on the minimum pump rate Controller on the maximum pump pressure allowed . No bypass or recycle line is available for this pump module. Limitations The defined pressure increase is independent of the flow. and define the pressure increase in the DELTAPRESSURE key. Methods and assumptions Theory and multiphase dynamics Accurate simulation of the pumps used for a standard drilling operation is important for the overall estimation of the pump power needed as well as the volume of mud/water required during the operation. By specifying a proportionality constant relating operating speed to total volumetric flow rate. and is only available with the Wells Module.Give an pressure increase in the pipe without knowing the details of the pressure boosting equipment. Defining the total flow rates proportional to the rate of pump strokes simulates the battery of positive displacement pumps. The maximum pressure increase of the pump is set in the DELTAPRESSURE key (∆ΠΜαξ). See also: When to use Methods and assumptions Limitations How to use When to use If the inlet pressure of a pipeline is too low to drive the fluid to the outlet of the pipeline. License requirements The pump battery model is used for drilling applications. Use before the actual pump is choosen to include a pressure increase in the pipeline. The actual pressure increase (∆Π) is calculated from ∆ΠΜαξ and the pump input signal INPSIG: ∆Π = INPSIG · ∆ΠΜαξ INPSIG is limited upwards and downwards: 0 < INPSIG < 1 The heat added to the fluid (ΩΦλυιδ) is calculated from the heat of an isentropic compression (ΩΙσεντροπιχ) from upstream pressure (PUp) to PUp + ∆Π: Where ?Ισεντροπιχ is an user given isentropic efficiency. When to use Methods and assumptions Limitations How to use When to use The PressureBoost pump is used to model a pressure increase in the design phase. Methods and assumptions The PressureBoost pump increase the pressure between two sections in Olga. a pump can be installed to increase the flow rate in the pipeline. or if we want to increase the oil production. The Pump Battery is used to simulate the special case of positive displacement liquid-phase drilling mud pumps. Pump Battery The PUMPBATTERY keyword is used to model a special case of positive displacement liquid-phase drilling mud pump. How to use Add a PressureBoost pump the pipeline. subject to specified control limits for minimum and maximum flow rate. Combine the PressureBoost pump and a flow controller to achieve the desired flow through the pipeline. as well as maximum hydraulic horsepower and outlet pressure. and set critical levels for oil and water drainage. Choose any applicable means of controlling the pump speed. See also: When to use Methods and assumptions Limitations How to use When to use It is recommended to use the separator model whenever a ”real” separator is present in the flow network and the effect of the downstream flow pattern is of interest. Separator The network separator is not intended to accurately model separation phenomena. This may reduce unwanted flow oscillations in the network compared to using a constant pressure boundary condition. is calculated as the isentropic compression work from inlet pressure. Valves/controllers The separator has no internal valves and controllers. the water level limit for when the water will be drained together with the oil can be specified in the separator keys: HHWATHOLDUP or HHWATLEVEL Separation efficiencies a) Liquid carryover in gas outlet. fluid rate. oil/water). How to use General setup Add the PUMPBATTERY keyword to the desired flowpath Specify pump location by one of ABSPOSITION (length). and HPMAX. inflow rate) can be used to control the pumps. Connections to external pipelines The separator has an arbitrary number of inlets/outlets.g. For three phase flow the liquid droplet volume fraction is distributed to water and oil droplet volume fractions according to the water and oil volume fractions in the settled liquid in the separator. Methods and assumptions Separator type The separator may be two-phase or three-phase and the geometry orientation is horizontal. flowrate. vertical or table specified. The user can. If it is only interesting to look at the upstream flow pattern. MINCAPACITY. Level control The separator levels are controlled by the valves and controllers in the outlet pipes. The gas-liquid separation efficiency is defined as one minus the volume fraction of the liquid droplets in the gas outlet stream. The number of controllers can be extended above the number shown above and different variables (e. so they have to be specified on the outgoing pipes. . QPt. it sometimes is appropriate to replace the separator with an ordinary pipe with large diameter to stabilize the boundary conditions and in that way avoid the needs for more complex specification of outgoing pipes. and pressure. effg by the key EFFICIENCY in the keyword SEPARATOR. The behaviour of the separator is mainly based upon user given input for the separation efficiency (gas/liquid. It can also be useful to employ a separator as a downstream boundary condition for controlling the boundary pressure. valves and controllers linked up to the separator.If any one of these controllers is set into action the pump rate is adjusted automatically. MAXPRESSURE. no liquid carryover in the gas outlet. Limitations Pumps can not be positioned at the first or last section boundary of a flow path. For a three-phase separator. that is. By default. the gas-liquid separation efficiency is equal to one. MAXCAPACITY. Pump Battery setup Setup of and use of the special Pump Battery model (for a battery of dtilling mud pumps) is primarily described within the Pump Battery topic of the Pump Battery . Three phase separators must in addition also have one water-outlet connected. The total hydraulic horsepower. HHP. however. PI.When to use for OLGA module license requirements. Required inputs include MAXSPEED. is calculated from the following definition: (b) where Qinj WHP Pump injection rate of mud or water (bbl/min) Pump injection pressure (bara) Energy balance The total power input to the fluid. or POSITION (an alias) NOTE: See Pump Battery . The liquid droplet volume fraction in the gas stream is then equal to one minus the value assigned to EFFICIENCY. to outlet pressure PI + ∆P. These inputs are used to simulate simple limit controls on horsepower.Methods and Assumptions section. one gas-outlet and one oil-outlet to pipes. MINSPEED is optional. but is meant to include the influence of a separator on transient pipeline dynamics. PIPE & SECTIONBOUNDARY. specify a constant gas-liquid separation efficiency. Two phase separators must have connected at least one inlet. U is set to zero for all separators in the network.eff0. EFFLOW is the liquid volume fraction when efficiency is being reduced and EFFHIGH is the liquid volume fraction when efficiency becomes zero and the gas outlet is treated as a normal flow path. HHWATHOLDUP or HHWATLEVEL. effg is modified by the following set of rules: The liquid volume fraction. c) Water in oil drains. Due to the internal geometry of the separator. The water volume fraction in the oil stream is then 1effw.To prevent instabilities in the separator when the liquid holdup becomes very large. qtr into the separator or out from the separator is given by: (γ) where U is the overall heat transfer coefficient. OILTCONST. Tsep is the separator temperature and Tamb is the ambient temperature. How to use . Heat transfer The heat transfer. EFFLOW and EFFHIGH. The total mass internally is taken into account and treated as at equilibrium. to assure a continuous transition from effg = EFFICIENCY to effg = 0. WATTCONST.0. Limitations The network separator is not intended for design purposes. The oil volume fraction in the water drain is determined by the following relation for separation efficiency: (δ) where Kso is the time constant. A is the surface area. If adiabatic temperature option is given for the total flow network. for separating water from oil. this might give incorrect results if the separator pressure or temperature suddenly changes. αl ≤ EFFLOW: (α) αl > EFFLOW and αl < EFFHIGH: (β) αl ≥ EFFLOW: (χ) b) Oil in water drain. the water above this limit is assumed to be drained together with the oil and the separation efficiency for separating water from oil is modified as follows: (φ) where Hof is the ratio of the water layer height above the limit to the liquid height above the same limit. The separator is only treated as a simple volume tank with no internal separation equipment The separator efficiencies is user given No wall temperatures is calculated There are no time restrictions for calculation of the flash contributions. The gas-liquid separation efficiency. The oil volume fraction in the water drain is then 1 . it is possible to specify two input keys. If the water level is above a certain limit. for separating oil from water and Trsp is the residence time which is defined as the separator liquid volume / liquid volume flow into the separator. It only simulates a predefined behaviour of a ”real” separator. The water volume fraction in the oil drains is determined by an equation similar to the one above: (ε) where Ksw is the time constant. as either constant or linearly sensitive to transient fluctuations in speed. See also: When to use Methods and assumptions Limitations How to use When to use If the inlet pressure of a pipeline is too low to drive the fluid to the outlet of the pipeline. Using this method the surface area. LENGTH and the separator diameter.Nr ) + E2 ( Q . …OIL_N outlets(Use OIL_2 to model emergency outlet) For a three phase separator. flowrate. a set of user defined values giving the volume as a function of the level (height). …WATER_N outlets(Use WATER_2 to model emergency outlet) Initial conditions Key INITTEMPERATURE gives initial value for the separator temperature Key INITPRESSURE gives initial value for the separator pressure Key INITWATLEVEL gives initial value for the water level Key INITOILLEVEL gives initial value for the oil level Geometry There are two ways to specify the geometry of the separator. It is recommended that the water valve opening is controlled by a water level controller.Nr ) + D2 ( Q . Methods and assumptions Theory and multiphase dynamics The simplified centrifugal pump in OLGA is intended for quick. Separator valves/controllers The separator has no internal valves and controllers. and void fraction. The surface area and volume is then calculated by using the knowledge of the cylindrical form. One method is to specify the separator length. or if we want to increase the oil production. All valves must be defined on the outgoing pipes and might be positioned at the first section boundary of the pipes. … GAS_N outlets (Use GAS_2 to model flare outlet) OIL_1.Qr ) ) ( 1 . the following connections are defined: INLET_1. a pump can be installed to increase the flow rate in the pipeline.Qr ) ) ( 1 . approximate modeling. … GAS_N outlets (Use GAS_2 to model flare outlet) OIL_1.D3 a ) η = ηr ( 1 + E1 ( N . DIAMETER. SURFACEAREA also has to be given.E3 a ) ∆P = ∆Po ρ / ρr where: (χ) (α) (β) .Φιγυρε Α Αν ιλλυστρατιον οφ α τηρεε−πηασε σεπαρατορ Input Connections to external flow paths For a two phase separator. These simple algebraic expressions are used to calculate the pressure increase over this simplified pump. The controllers are connected to the valves and must also be defined outside the separator. …INLET_N inlets GAS_1. and is therefore only accurate for use across small excursions from its specified local operational point (where the tangent to the real nonlinear operating curve does not change significantly). …INLET_N inlets GAS_1. …OIL_N outlets(Use OIL_2 to model emergency outlet) WATER_1. The other method is to define a specific level table LEVELTABLE. the oil valve opening is controlled by a oil level controller and the gas valve opening is controlled by a separator pressure controller. It models a linearized approximation to the local behaviour of a real centrifugal pump. as well as its pump efficiency: ∆Po = ∆Pr ( 1 + D1 ( N . water) Separator efficiency Simplified Pump The SIMPLIFIEDPUMP keyword is used to model simplified centrifugal pump. Output Many of the plot variables specified under volume variable are available for the separator. Use the Simplified pump to roughly simulate multiphase transient ∆P and efficiency with only three algebraic coefficients. the following connections are defined: INLET_1. In addition a number of separator specific plot variables also are available: Mass flow rates for each mass field for each pipe connection Separator levels (oil. 7) EFFIMECH. flowrate. and void fraction via the linear departure coefficients DCOEFF1 . The actual enthalpy change is then calculated by following formula: (δ) 2. FLOWRATED. flowrate.0. and ηM the pump mechanical efficiency. Outlet enthalpy is calculated from: Hd = Hs + ∆H 3. You may also override the default (0.2. Limitations Pumps can not be positioned at the first or last section boundary of a flow path. a pump with a constant pressure increase will be simulated.3 Pump pressure increase at rated density ( bar ) Pump pressure increase ( bar ) Pump speed ( rpm ) Flow rate ( m3/s ) Gas volume fraction Pump efficiency ( adiabatic ) Specific density ( kg/m3 ) Input coefficients for pressure increase Input coefficients for efficiency Subscripts: r = rated The power to the fluid is calculated in the following manner: 1.5) adiabatic efficiency by entering EFFRATED. (h) (g) (f) (e) (i) Modeling in OLGA Note that by setting the coefficients D1. If more accurate estimation of Total Shaft Power is also required.2.DCOEFF3.Methods and assumptions. The power input to the fluid is calculated from: Wfluid = GT × ∆H where Wfluid is in W. Allso override the (900 kg/m3) default of the required DENSITYR with your actual rated liquid density. The enthalpy at discharge pressure is found assuming isentropic conditions (Hiso).3 E1. through the relations documented in Simplified Pump . Valve . hydraulic horsepower. Total shaft power: Wtot = Wfluid / η M Pump torque: Γ = Wtot / ω Pump hydraulic torque: TH = Γ ηM where ω = 2 π N / 60. then make that efficiency sensitive to speed. If the user wants to obtain a certain flow rate in a simple way.3 = 0. you must specify DPRATED. Simplified Centrifugal setup In addition to the General Setup above. Energy balance The total power input to the fluid is: (ϕ) where TH is the pump hydraulic torque. and void fraction if desired by also entering ECOEFF1 . Inlet enthalpy (Hs) (J/kg) and entropy (Ss) are found from the fluid file. and MAXSPEED. total shaft horsepower and torque. PIPE & SECTIONBOUNDARY. one can either iterate on the input value for ∆Pr or assume some value for D1 and let a controller determine the necessary speed.3 and E1. You may also specify related sensitivity of pump DP to varying speed. or POSITION (an alias) Choose any applicable means of controlling the pump speed. SPEEDR.ECOEFF3. NOTE:Adiabatic efficiency of the Simplified Centrifugal Pump affects OLGA calculations for fluid heating. How to use General setup Add the SIMPLIFIEDPUMP keyword to the desired flowpath. w the pump speed and ηM the pump mechanical efficiency. if significantly different. the OLGA simplified centrifugal pump defaults to a constant DP = DPRATED regardless of any transients. NOTE: Without these optional user inputs.∆Po ∆P N Q a η ρ D1. and GT is the total mass flow in kg/s.2. Specify pump location by one of ABSPOSITION (length). you may also override the default (0.2. a fully open valve can be used to limit the flow to critical flow. Slip ratio: (d) where υγ is the gas velocit and υλ is the liquid velocity.The valve models the pressure drop for flow through chokes and valves. Position the Valve at the last section boundary of the pipe where the flow rate should be limited. The pressure drop to throat — Bernoulli and continuity equation Bernoulli Equation: (a) where υµ Π ?µ mixture velocity (m/s) momentum density (kg/m3) pressure (Pa) Momentum density: (b) where κ is the slip ratio. Differentiating equation (a) w. Compression of gas into the narrow throat is accounted for in the model. The choke model describes the effects of both subcritical and critical chokes. or be fixed. Choke model The flow through the choke is assumed frictionless and adiabatic. See Selmer-Olsen et al. The flow rate through a critical choke is governed by the upstream conditions and the choke opening (choke flow area). Continuity equation: (e) where A is the cross sectional area. Methods and assumptions The choke model uses mixture balance equations for mass.t.It is possible to enable full mass equilibrium in the choke by setting EQUILIBRIUMMODEL = EQUILIBRIUM. but it is possible to enable slip using the SLIPMODEL key. Fluid is flowing from position 1 to position 2. Recovery after throat — Momentum and continuity equation Momentum equation: (f) The overall pressure drop over the choke is found by combining equations (a) through (f). Use a choke with choke diameter equal to the pipeline diameter.The pressure recovery can be disabled by the user.If RECOVERY is set to NO equation (f) is not used. See also: When to use Choke — Methods and assumptions Valve — Methods and assumptions Limitations How to use When to use Use to model orifices. The choke model in OLGA describe the pressure drop from upstream (position 1 in Figure A) to downstream (position 2 in Figure A) an orifice or other constriction in the pipeline. for the full model description [34]. The choke opening may be controlled by the control system. Figure A: An illustration of a choke. chokes and different types of valves. Flowing gas mass fraction: (c) where M is the overall mass flow through the choke and Mg is the gas flow through the choke. by a predefined time series. momentum and energy.r. The then phase change occur after the throat. The flowing phase fractions can be frozen at inlet conditions (EQUILIBRIUMMODEL = FROZEN/HENRYFAUSKE). The choke has finite opening and closing time (stroke time) specified by the user. The default choke model assumes no slip between the gas and the liquid. Default is to enable pressure recovery (RECOVERY=YES). pressure and combining with equation (e) yields the following relation for the critical flow. For high velocities in the pipeline. A subcritical choke is represented through its pressure drop as a function of flow rates and choke openings. A circular-symmetric flow geometry and steady-state over the choke is assumed. The choke flow rate is limited to critical flow. ?γ is the gas density and ?λ is the liquid density. ξ is the flowing gas fraction. . and the fluid reaches equilibrium in position 2. The model include pressure drop from position 1 to throat (position t in Figure A) and pressure recovery when the fluid expands from the throat to position 2. MC. Critical flow The critical flow through the choke is found at the maximum of equation (a). (g) The throat area. If the EQUILIBRIUMmodel is used the entropy values have to be given in the fluid property table file (with the word ENTROPY in the heading of the fluid file). The phase properties are calculated using the same PVT properties. It is possible to give a table representing the valve sizing coefficients either for gas flow or for liquid flow. from P1 to P2 at T1 and from T1 to T2 at P2. Otherwise. It is possible to enable slip between the phases by setting the SLIPMODEL ket to CHISHOLM. orel. versus valve opening. is corrected with the choke discharge coefficient. Methods and assumptions In the valve model the pressure drop and critical flow are calculated according to a valve sizing equation. The valve model uses a table (keyword TABLE) that contains the valve sizing coefficients. Note: The input data for the valve sizing coefficients must be consistent with the units specified together with the valve sizing equations below. Cd. If the HENRYFAUSKE model is used and entropy values are given in the fluid property tables file (with the word ENTROPY in the heading of the fluid file). οιλ. (q) Note that it is possible to simulate a choke without a controller. the choke area is then given by a time series. EQUILIBRIUM: Full mass and thermal equilibrium is assumed through the choke. no slip is allowed. At. If slip is activated. By setting THERMALPHASEEQ to YES thermal equilibrium between gas and liquid are assumed. The flow is homogeneous. the choke flow area is varied according to the time tables of the relative choke area. (m) Controlled choke In the case of a controlled choke. (p) In the case of a fixed choke. The sizing coefficients are tabulated as functions of the relative valve opening. ωατερ}): (k) The reported throat temperature (TVALVE) is the gas temperature (l) Gas liquid slip calculations By default there is no slip between the gas and the liquid flowing through the choke. it is calculated from an modified Chisholm slip equation (m). 3. By default the liquid expansion is assumed isothermal. the choke area. The liquid sizing . A valve can be located anywhere in a pipeline. is varied according to the controller signal us : (n) where (o) Do is the choke diameter and Amax is the maximum choke area. Ao. isentropic expansion of gas. 2. Cv or Cg. The flow in the choke must follwo an isentropic path. and no heat transfer between the gas and the liquid is assumed. Gas density: (i) where γ is the isentropic gas expansion coefficient. The liquid valve sizing coefficient can also be given as a function of both relative valve opening and pressure drop over the valve. In the case of an uncontrolled choke. mass fraction and density by integrating the following equation from the upstream conditions (position 1) to the throat conditions (position 2): (h) The integration is performed in two steps. the entropy changes will be calculated from enthalpy. Liquid Valve sizing equation If a liquid sizing table is given. Phase and thermal equilibrium Three main options are available when calculating the phase fractions in the choke (EQUILIBRIUMMODEL): 1. FROZEN: No mass transfer. Simplified fluid property calculations The liquid properties are calculated in position 1 and treated as constant. the valve flow rate (even three-phase flow) will be calculated using the choke model in OLGA. to find the minimum flow area. The phase properties are calculated using the simplified fluid properties described below. the choke flow area is constant. It is not possible to give a table for two/three-phase flow. while the gas is compressed/expanded isentropically. but the critical flow is corrected for mass transfer in the throat [3]. (j) If thermal phase equilibrium is used (THERMALPHASEEQ=YES) the isentropic expansion coeffiicient is form all phases (ι ? {γασ. HENRYFAUSKE: Same model as FROZEN. the entropy values in the fluid file will be used. a choke area can be calculated. the choke area can be calculated. The mixture density is used in the calculation. Cg/Cv (-) The critical flow rate is obtained by setting the sine-term equal to one. The pressure drop through a valve is calculated as follows: Liquid sizing equation: (o) where Q Cv G ∆P Flow rate (gallons/min. Gas sizing equation: (q) where Qm ρg p1 Cg ∆P Cf Mass flow rate (lb/hr. Pressure difference across the valve (psi) OLGA converts Cv for liquid to the choke flow area. (film velocity. regardless if the flow is gas. The critical flow will then be determined by the choke model. The upstream density is used in the calculation. the gas sizing equation is used in the same manner as the liquid valve sizing. the gas sizing equation will be used for both subcritical and critical flow. Orifice equation: (p) where Cd A Ao Wtot Ui αi ∆Porf Discharge coefficient Pipe flow area Choke (orifice) flow area Total mass flux Velocity of flow field i. near incompressible gas flow and two/three-phase flow.) Gas density (lb/ft3) Upstream pressure (psi) Gas sizing coefficient (lb/hr / (psi × lb/ft3)1/2) Pressure drop (psi) Coefficient ratio. The choke model will not be used. Conversion between liquid valve sizing coefficient (Cv) and orifice area The orifice equation for an incompressible fluid: (a) ρFluid Q αi Ui A AOrifice Cd ∆POrifice Is the fluid density Is the volumetric flow rate Volumetric fraction of mass field i Velocity of mass field i Pipeline area Orifice area Orifice discharge coefficient Orifice pressure drop The valve sizing equation: (b) Valve sizing coefficient (gal/min/psi1/2) Is the volumetric flow rate (gal) Sizing pressure drop (psi) Cv Q ∆PSizing .table should be used for liquid flow. used in eq. Water = 1.0. droplet velocity etc. Equations (p) and (o) will produce a relation between Cv and Ao. liquid. If instead the model option GASSIZING (keyword MODEL) is used. Gas valve sizing equation If the MODEL key is set to HYDROVALVE. The pressure drop and the critical flow rate are calculated using the choke model.) The volume fractions of flow field i Pressure drop over the orifice See Cv to area conversion for the details of the conversion from Cv to orifice area. Combining equations (p) and (q). (p). Setting CD=1. or multiphase flow. Ao.) Valve sizing coefficient (gal/min / psi 1/2) Specific gravity (-). Valves can be inserted anywhere in the pipeline. For HENRYFAUSKE the entropy will be integrated from the enthalpy and density data in the thermo tables. the key OPENING will set the valve opening. connect a controller to the input signal terminal INPSIG. but in some cases. See Selmer-Olsen et al. It is also possible to use the HYDROVALVE (MODEL key) to simulate a gas valve. To control the valve flow in the choke. A discharge coefficient. To limit the rate of change in valve position. The given OPENING can be constant. Otherwise. Framo pump The FRAMOPUMP keyword is used to model a Framo helicoaxial pump. If Cv data are available.840 kg/m3) Fluid density at reference conditions Setting ∆POrifice = ∆PSizing and solving for Cv or orifice area (AOrifice): (c) Above we have assumed that the orifice equation is given with the same units as the sizing equation. for limitations in the choke model /34/. When using the Equilibrium or Henry-Fauske equilibrium model (EQUILIBRIUMMODEL = HENRYFAUSKE or EQUILIBRIUM) make sure the entropy is given in the thermo tables. and specify the Cv vs. Set CLOSINGTIME/ OPENINGTIME or STROKETIME. Methods and assumptions Pump model The Framo multiphase pump is a Helico-axial design that can operate from 0-100% gas volume fractions. If Cg data are available. Choose which valve model to use from available information in data sheet etc. Consider using the EQUILIBRIUMMODEL option HENRYFAUSKE or EQUILIBRIUM for two/three-phase simulations with flashing fluids. m. eliminating transients from slug flow and hence minimise the dynamic loading effects. It is possible to tune both the choke and valve model. Otherwise use EQUILIBRIUMMODEL = FROZEN. or the pressure drop over it. The Framo flow mixer (patented) in which the fluid is mixed into a homogeneous mixture. License requirements The Framo pump is part of the Multiphase Pump Module that requires a separate license. Further. use the choke model. OLGA 5 does not have this restriction. When connected. and inserting the reference water density we get the following equation: (e) Limitations Friction and gravity forces are neglected in the choke model. valve opening in a table. Converting to SI units: CvSI = Cv · (m3/s/Pa1/2) (d) Using SI units for the area. The choke is used when the model option HYDROVALVE (keyword MODEL) is set. See also: When to use Methods and assumptions Limitations How to use When to use When the design contains a Framo helicoaxial pump or when such a pump is considered. or a function of time. CD and maximum choke diameter must be defined for the choke. If no Cv/Gg is given. Specify the Cg vs. The valve Cv can also be described as a function of valve pressure drop (DELTAP) and valve opening. The input signal CVTUNINGSIG will scale the choke CD. which can operate from 0-100% gas volume fractions.G ρRef ρFluid Specific gravity (-) Water density at 39ºF/4ºC and 1 atmosphere (998. valve opening in a table. . The EQUILIBRIUM option might slow down the simulation. Setting STROKETIME will give CLOSINGTIME = OPENINGTIME = STROKETIME. or the valve Cv/Cg. this will slow down the simulation. use the default value. use the model option HYDROVALVE. The Framo pump module includes all the elements given in the figure below integrated with Framo standard control system. set the valve stroke time. provides stable operating conditions for the pump independent on upstream flow conditions. use the model option GASSIZING (key MODEL). it is not allowed to position a valve at the first section boundary in a flowpath next to a closed node. How to use Position the valve. If the discharge coefficient is unavailable. INPSIG will be used as the valve opening. The NPARA key will not affect the inlet valve or bypass line. choke control and a speed control. When using inlet pressure control. a dead band (CDEADBAND) is used. Recycle choke control Figure B: Recycle choke ramp and dead band example (CHOKERATE=0. This key can be used to control the pump to operate at at best efficiency point. The LIMPOW key sets a user defined limit on shaft power. Pump speed control Figure C: Speed control ramp example (SPEEDRATE=25 rpm/s) The change in pump speed is limited to a change rate (SPEEDRATE). NPARA.01 1/s and CDEADBAND=10 s) The recycle choke is controlled to keep the pump above the minimum flow limit of the pump. To avoid too frequent changes in the choke opening. the speed is manipulated to meet the inlet pressure setpoint. Pump internal control The pump control system consists of two independent control loops. . The RELDPCONTR key is for advanced users. The inlet pressure setpoint is given by the PRESSURESETPOINT key or the PRESSURESIG key. the choke movement is restricted to a user given rate of change (CHOKERATE). After the dead band. Inlet pressure control The pump speed is manipulated to meet the specified inlet pressure setpoint. The speed of the pump can be controlled setting SPEEDSETPOINT or the SPEEDSIG signal.Figure A: The Framo multiphase pump layout The LIMDP key sets user defined limit on differential pressure for the pump. the minimum position of the choke can be set (CMINOPENING). Parallel operation of multiple pumps is possible through an integer input. In order to improve controllabillity of the choke flow. See Figure A.) When the pump speed is zero. Ramp up pump to required speed. Close bypass valve. (a) where Cd is the choke discharge coefficient and Ach the choke opening area. The pipeline effect of the recycle flowline and bypass flowline is not considered. GR. Start up procedures Start up with producing well Normal start up procedure: Produce through the bypass line. DPch.Pump trip A trip can be caused by an internal violation in the model or by an user defined trip. because no pipeline is considered. The opening/closing time of the bypass choke is set by the BYSTROKETIME key. The default behaviour. When we have a trip situation the following will happen: The pump will be spun down lineary to zero rpm using the SPINDOWNRATE. and when inital conditions are used. can be overridden using the MIXERVOLUME key. The model will trip if: Minimum flow Maximum thrust load TRIPTIME is set. the user need to reset the control signals during the trip. the CV is converted to area and used in the equation a. (BYSIG will be overridden. By default the bypass line is closed. Set pump in suction pressure control Trip By default pump will not trip. The flow is calculated with a given pressure difference between the two sides of the choke. given by the characteristics file.Methods and assumptions for details on pump trip. uses a simplified choke flow calculation. PIPE & SECTIONBOUNDARY. TRIPSIG is set to 1. (VALSIG will be overridden. In order to enaple pump tripping. Limitations The recycle flow and bypass flows around the FRAMO pump are considered as flows through controlled chokes. TRIPHOLD=0. and trip actions will be enforced for TRIPHOLD seconds. and the user given control signals will be used. If TRIPHOLD>0 the trip signal. Bypass and inlet valve The inlet valve and bypass valve. It is possible to connect a bypass controller using the BYSIG signal. opening table is given insead of the choke are. The volume of the mixer. the TRIPHOLD key must be set greater than zero.) The bypass line will be opened. Open inlet valve. It is impossible to insert any component in the recycle flowline or bypass flowline. This key is used when both the steady state preprocessor is active. Initial conditions The initial speed of the pump is set using the INITIALSPEED key. How to use General setup Add the FRAMOPUMP keyword to the desired flowpath Specify pump location by one of ABSPOSITION (length). Bypass The bypass line is defined by BYDIAMETER and BYCD or BYCVTABLE. In order to get a proper startup of the pump after a trip. (SPEEDSETPOINT/SPEEDSIG and PRESSURESETPOINT/PRESSURESIG is overridden. The recycle flow can only flow from the pump downstream section to the upstream section. Pumps can not be positioned at the first or last section boundary of a flow path.) TRIPHOLD seconds after the trip the trip actions (model overrides) will be removed. . To add a check valve in the bypass line set BYCHECK to YES. can be regulated by a controller. See FramoPump . is to ignore the trip signal. or POSITION (an alias) Framo multiphase pump setup The pump is either configured by an input file (PUMPFILE) or by a reference to a library characteristics file (PUMPCHAR). Figure A: Library of Framo pump characteristics The inlet mixer is either configured by an input file (MIXERFILE) or by a reference to a generic FRAMO mixer for initial simulations. The flow. Ramp up pump untill all flow is going through the pump. the inlet valve will be closed. Each flow is calculated with the given pressure difference between the two sides of the choke and the choke upstream conditions. and the choke upstream conditions. and the bypass flow can only flow from the pump upstream section to the downstream section. If a CV vs. Standard OLGA cannot deal with single component systems if the saturation line is crossed due to the explicit coupling between volume balance and energy balance equations and the lack of a two phase region (two phase envelope) for single component systems. additional. The opening/closing time of the inlet valve is set by the STROKETIME key. One should. Multiplying this temperature difference with a certain heat or energy transfer coefficient yields an energy transfer rate that can be used to estimate the mass transfer rate. 1. are introduced in the evaporation/condensation process. The inner pipe wall surface can be superheated or subcooled as compared to the saturation temperature. The properties are evaluated at a grid of pressure/temperature values that is limited by the minimum and maximum values of pressure and temperature given in the input. Since the behavior is very case dependent. it is hard to give general guidelines on the exact amount of impurities required before standard OLGA can be expected to yield reasonable results. For other single component fluids. a default CV-opening curve will be used. For CO2. and. therefore. The evaluation of the fluid property equations is time consuming. be careful when using standard OLGA to simulate fluids consisting of 90% or more of one component. e. Besides the numerical issues. that crosses the saturation line in time or space in a pipeline. the Soave–Redlich–Kwong (SRK) cubic equation of state (Appendix 1) is used to calculate the saturation line and the physical properties of the vapor and liquid phases. for example a fluid composed predominantly of one component. 4. Generation of gas and liquid properties The equations used to calculate the H2O properties are taken from ref. the pressure of the gas and liquid phases is the same.Inlet valve The inlet valve is defined by DIAMETER and CD or CVTABLE. the single component module can only be applied to pure single component fluids. flashing or boiling of liquid will take place. In order to circumvent this limitation. An equidistant grid is used with a minimum of 50 . if the fluid temperature is higher than the saturation temperature. License requirements The Single Component Module requires a separate license. condensation of vapor takes place. H2O or CO2. At present. See also: When to use Methods and assumptions How to use When to use The single component module should be used for all single component fluids.. but with a small amount of impurities. Special options exist for H2O and CO2. The same can happen for multi component fluids with very narrow phase envelopes. or delays. Such situations might lead to surface boiling or surface condensation in cases where the liquid or gas is in direct contact with the pipe wall.g. see Figure C. the thermodynamic equations are taken from ref. RECVTABLE. The difference between the saturation temperature and the fluid temperature serves as a potential for phase mass transfer. however. Temperature dependent volume translation is applied to improve the accuracy of phase density. mass transfer term is not explicitly included. For other components. As implied by the name. but it can be accounted for by an enhanced heat transfer due to surface boiling/condensation. An asymptotic approach to equilibrium occurs where the speed at which equilibrium is reached is determined by the size of the energy transfer coefficient. it is necessary to specify input parameters to the fluid property calculations. Recycle The recycle choke is defined by RECV or a CV-opening curve. it is important to make sure that the fluid property calculations are accurate for the particular fluid composition to be simulated. When using the RECV. The transport properties are calculated through the equations given in ref. Methods and assumptions The following assumptions are made in the single component model: the gas and liquid phases have the same temperature. The numerics in standard OLGA have been designed for multi component hydrocarbon fluids. 2). if the fluid temperature is lower than the saturation temperature. 2. The resulting. Figure C: Default CV for recycle valve Single component The single component module allows for tracking of a single component. A consequence of the chosen approach is that standard OLGA become unstable when simulating single component fluids that cross the saturation line in time or space. The transport properties are determined by the corresponding state method by Pedersen (ref. for which the fluid property calculations have been hard coded into OLGA. they are only evaluated at the start of the simulation. time constants. OLGA is thus not able to simulate single component fluids with small amounts of impurities. Within this zone. vapor properties are calculated based on equations for the different regions. Pc]. less than the saturation point. the saturation line is extrapolated with the slope of the saturation line at the critical point. For pressures above 225 bar. Psat(Tlow)]. the gas and liquid properties are continuous across the fictitious gas-liquid (V–L) division line when the pressure is above the critical one. pressure at the saturation pressure corresponding to the given temperature. Liquid properties for H2O For pressures below 225 bar in region 1. For pressures above 225 bar. the gas properties in the gas region are acquired from the EOS. and up to T=676 K and P=250 bar. a buffer zone is introduced near the critical temperature as shown below.2 bar and TC=647. During the simulation.3 K. Above the critical point. In the water region. the saturation pressure. 1. To avoid numerical problems in region 3. Gas properties for a single component For pressures below the critical pressure. the vapor and water properties are continuous across the vapor-liquid (V–L) division line when the pressure is above 225 bar. All other properties are taken at the saturation temperature corresponding to the pressure. above the saturation point. TC. the liquid density derivative and thermal capacity are given the values calculated at a temperature. and saturation temperature. Gas properties for H2O For pressures below 225 bar. liquid properties are calculated from the EOS. determined by the critical pressure.r. is calculated using the density derivative w. [Thigh. Above 676 K and 250 bar. At the critical point and its vicinity. The definition of the regions is found in ref. the properties for water are extrapolated from the saturation point — the enthalpy is based on thermal capacity at the saturation temperature corresponding to a given pressure. PC and the critical temperature. [Thigh. All the other properties are evaluated at the saturation temperature. Psat(T). Below the critical point. Above the critical point. on the other hand. water properties are calculated based on equations for the different regions specified in ref. at a given grid point (P. the water properties equations found in ref. Saturation line for H2O Below the critical point. (PC. at a given grid point (P. Tsat(P). linear interpolation is used to evaluate the properties in between grid points. Saturation line for a single component The saturation line is determined by solving the equal fugacity of gas and liquid from the equation of state (EOS). 1. a straight line is used to divide the single-phase or dense-phase region into gas and liquid. All the other properties are from the saturation temperature.and maximum of 100 grid points for both pressure and temperature. even to the extent where discontinuities occur. the water properties from region 1 are used instead of those for region 3 when the pressure is below 225 bar.t. All other properties are evaluated at the saturation temperature corresponding to the vapor pressure. PC=221. In the gas region. For pressures above the critical pressure. [Tlow. steam property equations for region 2 are used for gas in the gas region. pressure at the saturation pressure corresponding to the given temperature. In the liquid region and a pressure below the critical pressure. The same procedure is used for steam (gas). and saturation temperature. the gas properties are extrapolated from the saturation point. the thermal capacity and density derivatives show extreme sensitivity to temperature and pressure changes. The buffer zone is bounded by the coordinates [Tlow.TC). Pc]. the liquid properties are extrapolated from the saturation point — the enthalpy equals the gas enthalpy minus the latent heat at the saturation temperature and the density is integrated from the vapor saturation pressure to actual pressure using the compressibility at the saturation temperature. Liquid properties for a single component For pressures below the critical pressure liquid properties are determined by the EOS in the liquid region. the boundary line between region 2 and region 3 is used as the division between gas and liquid. For pressures above the critical pressure. Therefore. Enthalpy is based on thermal capacity at the saturation temperature corresponding to the given vapor pressure and the density according to the density derivative w. Psat(T). Using this procedure. the gas density derivative and the thermal capacity are given the values calculated at a temperature. are determined from the saturation line. Thigh.r.t. Tlow. Using this procedure.T). . The density. Tsat(P). The thermal capacity and enthalpy for water are singular near the critical point.T) are determined from the saturation line. Psat(Thigh)]. for the vapor phase. gas properties are calculated based on the EOS. In the gas region. Similarly. 1 are used for water in the water region. the gas properties are extrapolated from the saturation line — the enthalpy equals the liquid enthalpy plus the latent heat at the saturation temperature corresponding to the pressure and the density is acquired by linear interpolation between the value at critical pressure and the saturation pressure. the saturation pressure. R. B. 5th Edition.P. Z. 3. Texas. K. J. Pedersen et al. it is assumed that this mass transfer occurs over a time T&psi. J. No.2) where The solution. 4. 1996 Appendix 1 The Soave–Redlich–Kwong (SRK) equation of state: (A.O’Connell: The properties of gases and liquids.Poling. The total energy available for generating gas or condensing it to obtain saturated conditions is (a) where mg = specific mass of gas [kg/m3] ml = specific mass of liquid [kg/m3] cpg = specific heat of gas [kJ/kgC] cpl = specific heat of liquid [kJ/kgC] h S V = heat transfer coefficient at inner wall surface [kJ/m2sC] = inner surface area per unit volume of pipe [1/m] = section volume [m3] The total mass transfer to obtain saturated conditions is: (b) where hsat. References 1. the pressure is given by the Antoine equation except for CO2 where the Wagner equation is used. but can be accounted for through an enhanced heat transfer at the pipe wall.. 3. Gulf Publishing Company. J. Coefficients for these equations can be found in ref. August 2007 2. Data. 25.g = enthalpy of saturated gas [kJ/kg] hsat.Flashing/Condensation The driving force for flashing of liquid or condensation of gas is the difference between the saturation temperatures and the fluid temperature. 1989. Span and W.M. Switzerland. The solution for Z can be adjusted by a volume tuning factor . McGRAW-HILL 2000. The International Association for the Properties of Water and Steam. Wagner: A New Equation of State for Carbon Dioxide Covering the Fluid Region from the Triple-Point Temperature to 1100 K at Pressures up to 800 MPa.1) where The SRK equation of state can be written on the form: (A. Revised Release on the IAPWS Industrial Formulation 1997 for the Thermodynamic Properties of Water and Steam. Chem. 6.l = enthalpy of saturated liquid [kJ/kg] In order to reduce numerical problems. Properties of Oils and Natural gases.Prausnitz. S. The effect of local boiling on a hot wall surface or condensation on a cold one are not explicitly included in the mass balance of liquid and gas. As initial guess. Phys.E. Vol. to the above equation is found by iteration. Ref. Lucerne. Houston. This yields the mass transfer rate (c) The mass transfer per time step must not be larger than the available component mass of the diminishing phase. in order to use this option.. which is the recommended slug initiation method for hydrodynamic and terrain slugging. During the simulation. and Pr = P/Pc. respectively. Level slug initiation.. or boundary conditions changing with time just as well as geometry effects. no external PVT file is needed.5) where the coefficients. 2. which initiate slugs when changes in liquid hold-up are detected from one section to another. maintain. VISX critical temperature. the key WRITEPVTFILES=[NO]/YES controls whether the program will write the single component properties that are being used to file or not. These options are: 1. How to use The single component model is activated by setting the key COMPOSITIONAL=SINGLE under the OPTIONS keyword. Methods and assumptions Initiation of level slugs . Too small values might however cause instabilities which in turn can result in nonphysical results. The slug tracking model is designed to initiate. For boundaries. H2O is set by default. at which positions to set them up. MINTEMPERATURE and MAXTEMPERATURE in SINGLEOPTIONS are used to generate a PVT tables for the single component properties. under the keyword SINGLEOPTIONS. linear interpolation between the grid points (P. The keyword SINGLEOPTIONS specifies options for COMPOSITIONAL=SINGLE. the gas fraction will be either gas or liquid. all possible single components will be treated similarly and as an "oil phase".g. This option is activated through the HYDRODYNAMIC key and requires that all slugs initiated are given as user input. the pressure of the source receiving position is used. For YES. In situations where slug flow is identified by the flow model. 3. Small values will speed up the mass transfer and thereby reduce the thermal non-equilibrium. The keys MINPRESSURE. Note that if you use COMPONENT=OTHER. Thus. many flow parameters are highly dependent on the slug pattern. See also: When to use Methods and assumptions Limitations How to use When to use The slug tracking model have two different options initiating slugs (keyword SLUGTRACKING). VOLX(2) coefficients in equation for specific heat. it is required to specify additional fluid properties. These are: viscosity tuning factor. the HOLWT and HOLHL output from that pipe is 0 and 1 respectively. CPIC(5) Also note that although it is possible to choose water as a component. hydrodynamic slugs are accounted for only in an average manner that does not give any information about slugs. An equidistant grid is used with a minimum of 50 and maximum of 100 grid points for both pressure and temperature. License requirements Slug tracking is part of the Slugtracking Module that requires a separate license. For many different components values of these coefficients can found in ref. This option is activated through the LEVEL key and is mainly to be used for well-defined start-up slugs. length. the saturation line will be written to a file <inputile>_pvt. These keys are available as time series if desired. The griding is adjusted so that a grid point is close to the critical point. Large values of the time constants will slow down the mass transfer leading to a fairly large non-equilibrium. or OTHER. physically sharp fronts in liquid hold-up are smeared out by the numerical scheme. a tab file <inputfile>_pvt. their properties. Thus.T) is applied. MW volume tuning factors. velocity. PC [bara] acentric factor. COMPONENT can have the values H2O. Hydrodynamic slugs can be initiated when OLGA predicts transitions from either stratified or annular flow to slug flow. CO2. is calculated through the equation (A. The time constants for condensation and boiling are specified by the keys TCONDENSATION and TBOILING.3) according to (A. are given through the input by CPIC(i+1). the pressure drop in a flow-path. However. all depending on the specified temperature as compared to the saturation temperature at the specified pressure.env. it is necessary to be able to explicitly account for the occurrence of slugs. respectively. Hydrodynamic slug initiation.4) where XV1 and XV2 are given through the keys VOLX(1) and VOLX(2). This means that although the holdup in a single component water simulation is 1 in a pipe. there is manual hydrodynamic slug initiation. and at which times. or how they affect the flow. CPi. Similar behaviour is to be expected from other output-variables which has an option for water.tab (fixed format) will be generated. the model gives information about position. e. i. detailed knowledge about the slugging is required since the user has to specify the number of slugs to set up. TSV. TC [C] critical pressure. The output variables TSAT. a phenomenon that is more pronounced in horizontal or near horizontal high velocity transient flow cases. this information is used to give better estimates of the actual properties of the overall flow. Under OPTIONS. TSV equals TM and PVAP equals PT for single component simulations (no partial pressure since only a single component is considered). The properties are evaluated on a grid of pressure/temperature values that is limited by the minimum and maximum values of pressure and temperature given in the input. Slug Tracking In the standard OLGA model. For sources without any given pressure. In turn. Among other things. This option is activated by the key HYDRODYNAMIC. PVAP (see output variables description) are used to retrieve the vapor data. sources and wells. and other characteristic quantities of each individual slug. Both these files can be visualized in the GUI. PSAT. MAXPRESSURE.e. In addition to these two options. Furthermore. The specific heat. and track physically sharp fronts such as those constituted by start-up slugs and hydrodynamic slugs. OMEGA molecular weight. liquid sources. CP. Other data can be obtained by specifying compositional variables. The change in hold-up might be caused by a start-up situation.(A. see Figure B. is given as the minimum number of pipe diameters between the new slug and the slug that last occupied the same section. How to use General 1. The delay constant. TRENDDATA VARIABLE=(LIQC. To avoid such discontinuities. HOL. The first slug initiated gets identification number. UG) TRENDDATA PIPE=PIPE5. Initiation of hydrodynamic slugs Figure B Schematic visualization of the initiation of a hydrodynamic slug. on the other hand. a tail is initiated.DC. If OLGA predicts slug flow (ID=3) at boundary J. 2. ACCLIQ. the minimum distance is 10 pipe diameters. HOLWT. The idle time is calculated according to (a) where D = pipe diameter [m] Ul = average liquid velocity [m/s] The default value for the delay constant is 150. all depending on the void in the neighboring sections. If the void increases and exceeds BUBBLEVOID within two upstream sections. TM. The slug frequency determines how close to an existing slug a new slug can be initiated whereas the delay constant determines the shortest time allowed between setting up two consecutive slugs at the same boundary or setting up a new slug after a slug has passed. HOLHL. but as far as slugging goes. where UB is the bubble nose velocity of the new slug. UL. ACCWAQ) The accumulated flow rates (ACCLIQ) can be used to estimate slug sizes. Plotting individual slug data is useful mainly when there are few slugs is the system. and a riser. the new slug is set up with an as short slug length as possible. VOLGBL. ACCOIQ. 3.. It is possible to plot. the results will be the same as if complex fluid had not been used. two criteria must be met before a hydrodynamic slug is initiated in a section: The distance to the closest slug must exceed a minimum distance. NSLUG) Slug identification number When initiated. Compatibility limitations At present. a hydrodynamic slug may be initiated in section J. The pipeline consists of a well. SECTION=3. Per default. . Level slug initiation may be carried out at any time in the user specified time interval given by STARTTIME and ENDTIME. or over both sections. the void increases and exceeds BUBBLEVOID within two downstream sections. SLUGVOID is used to specify the maximum void allowed in a slug whereas BUBBLEVOID determines the minimum void in a bubble. and then 1 is added for each new slug initiated. slug length. a level slug might be initiated. The idle time required before generating a new slug at any section boundary is specified through the DELAYCONSTANT key. The simulation will run. The time elapsed since a slug was either generated in or passed through the section must be larger than a specified minimum time. ID.g. QLTWT. The detection of level slugs is based on differences in the gas fraction.g. These short hydrodynamic slugs will then grow into larger slugs as they propagate through the pipe if the conditions are favorable. a transport line. Complex fluid. The combination is not allowed. etc. Add global trend to get overview of the simulation. the minimum distance is calculated as UB/Fi. Add trend and profile plot variables to see differences between running the simulation with and without slug-tracking. HT. J-1. Using the slug initiation frequency. Add the SLUGTRACKING keyword and choose a slug initiation method. If. WATC) TRENDDATA VARIABLE=(RMERR. e. When a section is found with void less than SLUGVOID. Limitations Model limitations The model currently used for hydrodynamic slug initiation uses a slug frequency and a delay constant to determine when to set up new slugs. front and tail velocities. The minimum distance between slugs is specified through the INITFREQUENCY key (slug initiation frequency. it is difficult to identify which slug to consider. e..Figure A Schematic visualization of a pipeline shut-in situation where liquid has been accumulated at low points. When OLGA predicts slug flow. VARIABLE=(QLT. Initiating a new slug implies redistribution of masses which might lead to discontinuities in pressure in inclined or vertical pipes. a front is initiated. Fi). each slug is assigned a unique identification number. When hydrodynamic slugging generates lots of slugs. it is not possible to run slug tracking in combination with Pig. QLTHL. PROFILEDATA VARIABLE=(PT. OILC. This unique number enables the possibility to follow the development of individual slugs as they move through the pipeline. Startup slugs not detected If all start-up slugs are not detected. The properties of these plots can be set through 'Slug Statistics. it is recommended that illegal sections are introduced around the process equipment. only gas will enter the pipeline. diameter. say the last 5-10 km. Slug tuning The SLUGTUNING keyword makes it possible to tune parameters in the slug model. INITFREQUENCY can be modified as well. Slugs are counted for each section. the time between two consecutive slug initiations on any given boundary or the time between a slug passes a boundary and a new slug can be set up is given by (a) where D = pipe diameter [m] Ul = average liquid velocity [m/s] Using the Shea correlation for the slug frequency (b) where D = pipe diameter [m] L = pipeline length [m] Usl = superficial liquid velocity [m/s] it is possible to get an estimate of the delay constant. This will show the instantaneous hold-up at the boundary specified. it is recommended to only allow for slugs close to the pipeline outlet. if there are large changes in pipe diameter.Illegal slug section An illegal section is a section where no slugs are initialized and through which no slugs are allowed to pass (keyword SLUGILLEGAL). PTJF.. it might be of interest to look at a statistical sample of slugs in order to get an idea of the general slug properties.out file) for each DTOUT. JSLT. is the number of pipe diameters a slug must travel before the slug model tries to initiate a new slug at the same boundary. the flow regime indicator will never indicate slug flow when slug tracking is activated. The slug statistics is generated by post-processing of the .' under the Edit menu. a summary of the slug statistics is written to the output file (. The problems are usually caused by back-flow in the riser. illegal sections should not be used to prevent such slugs from developing. VARIABLE=LSLEXP Using the OLGA GUI. add a couple of horizontal sections at the top of the riser. these variables can be used to plot slug statistics. This feature is mainly of use when there are few slugs in the system and the slugs of interest are easily identified. It is not possible to resolve the hold-up of individual slug and bubble regions inside sections. Hydrodynamic slug initiation The slug model might initiate slugs too often or too seldom as compared to the expected slug pattern. the flow regime indicator (ID) should be used with caution since the flow regime is forced to bubbly inside liquid slugs whereas it is forced to stratified in slug bubbles. However. Vertical riser at the end of a pipeline Problems might be encountered when slug tracking is activated and the pipeline has a vertical riser at the end. and sorted by slug length interval using number of pipe diameters as measure (in order to be applicable for all pipe diameters). Slug statistics is written together with some other slug information. The slug statistics information is reset in a restart. It is possible to plot properties of individual slugs using their identification number. it is possible to specify the void limits used for initializing start-up slugs. This implies that slugs cannot propagate through networks. the large number of slugs will make it virtually impossible to single out a particular slug. If possible. pipe and section is also written. one should not use the Shea correlation. If such problems are encountered. e. e. In such situations. DC. USF. the following actions might reduce them: Set the gas fraction on the outlet node equal to one. In order to visualize the hold-up of individual slugs/bubbles. VARIABLE=(LSL. See also: When to use Methods and assumptions Limitations How to use . if terrain effects are predominant. Thus.g. SECTION=10. the hold-up (HOL) in TRENDDATA or PROFILEDATA. TRENDDATA PIPE=PIPE-1. the number of slugs can become very large which in turn results in long simulation times. Thus. but these are used to calculate the section average. this can be accomplished by using the keyword SLUGILLEGAL. UST. Tuning on the delay constant should be performed such that the resulting slug frequency is in the same order of magnitude as Fsl. A slug front may enter into the illegal section. In cases where terrain effects are predominant and large slugs develop far away from the outlet. Profile plots. Flow regime When slug tracking is activated. branch. ZTSL. and slug statistics When specifying. If stability problems are encountered when using in-line process equipment together with slug-tracking. Unless the flow in the riser is expected to influence slug patterns significantly. The syntax for addressing individual slugs is TRENDDATA SLUGID=1. PTJT) Slug statistics There are usually two choices to assess slug statistics in OLGA. specify HOLEXP under TRENDDATA. The default value of 150 has been found to yield good results for a number of cases. it is important to note that the hold-up plotted is the section average. First of all the trend plot variables LSLEXP and LSBEXP show the length of a liquid slug or slug bubble currently residing at a given section boundary.. The first section in a flow-path is by default an illegal section and so is the last one. Yet again.g. set the riser pipeline sections to illegal (SLUGILLEGAL).. when modeling a separator at the end of a pipeline as a pipe with big diameter. Thus. ZFSL. It should be noted that this correlation is based on experimental data and field data for systems dominated by hydrodynamic slugging. These two plot variables represent the statistical distribution of slug and slug bubble lengths at the boundary considered. In cases with severe slugging. instabilities can be avoided by setting illegal sections on each side of such boundaries. trend plots. This is done by modifying the void limits given by the keys BUBBLEVOID and SLUGVOID. An additional table listing positions with LSLEXP containing position. If it is not possible to achieve the slug pattern sought by varying DELAYCONSTANT alone. Also for positions. Now. The table contains number of slugs per section and per slug length interval. but it will be trapped inside it until the slug tail reaches the section and the slug is removed. Furthermore. it is recommended that only the DELAYCONSTANT key is varied first. Hydrodynamic slug initiation: the delay constant The delay constant. JSLF. where plotting of LSLEXP is defined..tpl-file and is accessed by selecting the variables LSLEXP_STAT and LSBEXP_STAT in the trend plot dialog. In order to tune the model to mimic the expected pattern. With long pipelines mainly operating in the slug flow regime. if back-flow occurs at the outlet. LSB. The figure below illustrates this. sum of the superficial velocities drift velocity The slug front pressure drop is given by (b) where CDP = tuning coefficient for slug front pressure drop given by key DPFACT CDP0 = tuning coefficient for onset of slug front pressure drop given by key DPONSET Lslug = slug length f(&alpha. from which the oil phase fraction will be calculated. the actual mass flow rate into the section (positive source) or out of the section (negative source) is a fraction of the mass flow rate given as input. which is also known as a controlled mass source or source controlled by valve (SOVA). Source A source can be used to model pipeline inflow and outflow of gas and liquid. as it might cause the validation and verification of the OLGA model to no longer be valid. it is not possible to specify different sets of tuning parameters for different flow-paths. Methods and assumptions The slug tuning coefficients are multiplied by the related values calculated by OLGA. The default value for gas is -1. which means it will be read from the PVT file.. Each type of source can be either positive (flow into the pipeline) or negative (flow out of the pipeline).B. i.e.When to use The SLUGTUNING keyword is used for tuning the OLGA slug tracking model to specific sets of measurement data or sensitivity studies. Methods and assumptions Two types of sources can be specified. and this will then be set to the pressure inside the pipe section where the source is introduced. Pressure driven source (SOVA) The flow for a SOVA will be calculated from a flow equation for mass flow through an orifice. where the orifice area can be governed by a controller.l) = additional pressure drop Ucrit = cutoff velocity at which the slug front pressure drop is switched on Limitations The slug tuning coefficients are given globally. Mass source The mass source is the simplest model and has a given mass flow rate specified by the user.. the mass source and the pressure driven source. N. When the upstream/downstream pressure is given. the expansion from the given pressure to the pressure inside the pipe section will be taken into account for the temperature calculations. The exception is slug length which is interpreted directly as slug length in number of diameters. the phase fractions in the connected section will be used. For more advanced flow simulations the WELL or NEARWELL keys can be used. Note that the mass flow node covers the functionality of a mass source in the first section after a closed node. A SOVA must always specify the upstream/downstream pressure. License requirements Slug tuning is part of the Tuning Module that requires a separate license. How to use Specify the desired slug tuning coefficients and where they should be applied. Wells and nearwells are more specialized types of modelling pipeline inflow and outflow. The external pressure and temperature can be constant or given as a time series. Phase fractions can be specified in the input for a positive source. SLUGTUNING should be applied with great care. The default value for water is 0. If a controller is used.. The Taylor bubble velocity is calculated as (a) where CUB1 CUB2 C0 Umix U0 = = = = = tuning coefficient 1 given by the key UBCOEFF1 tuning coefficient 2 given by the key UBCOEFF2 distribution coefficient mixture velocity. but input flow rate may also be given as volumetric flow at standard conditions. A mass source need not specify the upstream/downstream pressure. The upstream (for positive source) or downstream (for negative source) pressure and temperature can be specified.. i. OLGA use mass flow rate for internal calculations. See also: When to use Methods and assumptions How to use When to use The SOURCE key can be used when a flow needs to be inserted into the pipeline.&rho.e. the slug tuning coefficients are global. Phase fractions for gas and water can be specified. . For a negative source. with the fraction regulated by the controller. The orifice area is calculated from: (a) where us = controller signal Valve functionality The valve-specific functionality is further described in the Valve section. GOR and volume flow of water at standard condition ( PHASE = WATER and STDFLOWRATE = ) are known. The pressure difference determines the direction of flow in or out of the pipe. use: (b) If WATERCUT. the upstream conditions and the flow area. Calculating mass flow at standard conditions The following equations show how the total mass flow is calculated from volumetric flow given at standard conditions. use: (c) If WATERCUT. where the valve has finite opening and closing time (stroke time) specified by the user. volume of gas divided by volume of liquid at standard condition Volume flow Mass flow Density ρ Indexes: tot ST g o liq w * Total At standard condition Gas phase Oil phase Liquid phase (water + oil) Water phase Equivalent phase The density in the equations below is taken from the PVT table. use: (e) If WATERCUT. volume of gas divided by volume of oil at standard condition Gas liquid ratio. For critical flow the flow rate is governed by the upstream conditions and the flow area only. Symbols used in the equations are given in the list below: wc GOR GLR Q Water cut. GOR and volume flow of gas at standard condition ( PHASE = GAS and STDFLOWRATE = ) are known.Figure A. use: . If WATERCUT. GLR and volume flow of gas at standard condition ( PHASE = GAS and STDFLOWRATE = ) are known. volume of water divided by volume of liquid at standard condition Gas oil ratio. GLR and volume flow of liquid at standard condition ( PHASE = LIQUID and STDFLOWRATE = ) are known. GOR and volume flow of liquid at standard condition ( PHASE = LIQUID and STDFLOWRATE = ) are known. GOR and volume flow of oil at standard condition ( PHASE = OIL and STDFLOWRATE = ) are known. use: (f) If WATERCUT. It is necessary that the properties at standard condition are included in the PVT table. Illustration of a pressure driven source Controlling the flow The flow area of the SOVA is governed by the control system. use: (d) If WATERCUT. For sub-critical flow the flow rate is governed by the difference between the internal and external pressures. Both sub-critical and critical flow is described. See Capabilities for further description. . Removal of gas that is not present is impossible.value from the PVT table (k) If the equivalent gas volumetric flow rate at standard condition ( PHASE = GAS. are known. MEG. or a combination of the PIPE and SECTION keys.calculated from given GOR or GLR Gas mass fraction at given pressure and temperature .e. However. either by use of the POSITION key. Each SOURCE must have a unique LABEL. Blackoil. see the Valve section. and the total mass flow will be given from the following equation on condition that GOR or GLR is greater then 1010 (infinitely in OLGA) (l) If GOR or GLR is less than 1010 the total mass flow will be calculated from the equations described earlier for PHASE = GAS with = and = . For further descriptions. With compositional models the keys FEEDMASSFLOW. Note: There are limitations on how much the value of GOR/GLR can be changed when using a PVT table. use: (i) Specified GOR or GLR will shift the values of gas mass fraction in the PVT table with use of the following equation (2 phase) (j) where Gas mass flow at given pressure and temperature Gas mass flow at standard condition . FEEDMOLEFLOW or FEEDSTDFLOW may be used. follow the steps described below. ABSPOSITION key. One can check the source input by plotting the volume flow rates through the source at standard conditions (e. wells. Pressure driven source (SOVA) The SOVA massflow is defined by the valve specific input data. STDFLOWRATE = ) and the mol weight of the total flow. When the mass flow rate is to be specified at the source temperature and pressure without compositional tracking use the key MASSFLOW.g. and nearwells) can not be 0 How to use To define a SOURCE. When the volumetric flow rate at the standard conditions is given. if a source using default GOR/GLR has no gas at the in-situ conditions. use: (h) If WATERCUT. there are certain limitations: With a closed node. one cannot give a lower GOR/GLR for this source. Mass source There are several keys available to define the mass source. use: and MOLWEIGHT = The density of the equivalent gas at standard conditions will then be calculated from ideal gas law.(g) If WATERCUT. E. Phase fractions can be given either directly with the GASFRACTION and WATERFRACTION/TOTALWATERFRACTION keys or at standard conditions with the GLR/GOR/WATERCUT keys. Compositional Tracking. Steady state pre-processor Both source types can be used with the steady state pre-processor. . The upstream/downstream PRESSURE and TEMPERATURE can be specified. Each source type is also available for use with the compositional models (i. Wax). the key STDFLOWRATE should be used. QGSTSOUR).calculated from given GOR or GLR Oil mass flow at standard condition . the sum of all flows into the adjacent section (including contributions from all sources.value from the PVT table Gas mass fraction at standard condition . All input variables can be defined as time series with the TIME key. See keyword SOURCE for more details. See keyword SOURCE for more details.g. The position along the branch must be given. See keyword SOURCE for more details. GLR and volume flow of water at standard condition ( PHASE = WATER and STDFLOWRATE = ) are known. GLR and volume flow of oil at standard condition ( PHASE = OIL and STDFLOWRATE = ) are known. etc. Iteration on the sequence 1) to 3) is performed until the change between two iterates is smaller than a tolerance. In this case initial temperature profiles must be given for all the flow components in the network. 3. See also: When to use Methods and assumptions Limitations How to use When to use The steady state pre-processor may be used in order to 1. The steady state pre-processor can sometimes fail to find a solution if flows are negative. SteamWater-HC The availability of the steam module depends on the User's licensing agreement with SPT Group. Methods and assumptions The steady state pre-processor finds a consistent solution for flow networks by iteration. Limitations The solution computed by the steady state pre-processor and the solution obtained when simulation with the dynamic solver until a steady state is achieved may not be equal. For flow networks with one or more separators the steady state pre-processor uses a simplified approach. The steady state pre-processor is primarily intended for generation of initial values for dynamic computations. temperatures. valve openings. eliminate the need for user given initial conditions 2. but may also be used as a standalone steady state tool. if the pre-processor does not converge to a reliable solution. therefore it should not be used with closed valves in the flow path or with mass sources that sum up to zero flow rate at start time. the steady state pre-processor uses the values at the start time. The temperatures along all the network components are computed. Phase transitions are computed using old values of pressures and temperatures. the pre-processor must be turned OFF (STEADYSTATE=OFF under OPTIONS). In some sensitive cases this can cause a difference in pressure.Steady State Processor The steady state pre-processor in OLGA computes a steady state solution for a pipeline or an entire flow network. This implies that the simulation must be run dynamically for some time in order to achieve a true thermal steady state solution. Choose STEADYSTATE=NOTEMP to avoid the temperature calculation. The SteamWater-HC module is an improved way of tracking when there is a considerable amount of H2O in the fluid. liquid hold-ups and flow regimes are calculated along the pipelines. old temperatures. Networks where all inlet flows and outlet pressures are known are solved by the following sequence of computations: 1. Τηε στανδαρδ ταβλε βασεδ ϖερσιον οφ τηε χοδε ασσυµεσ τηατ τηε γασ πηασε ισ αλωαψσ σατυρατεδ ωιτη στεαµ (νο µασσ βαλανχε φορ στεαµ). Steady state pressures. The steady state pre-processor cannot handle zero flow in the pipeline. Except for displacement pumps and pump battery. If input parameters (boundary conditions. Using the newly computed flows. How to use To activate the steady state pre-processor from the OLGA GUI do the following: In the property window for OPTIONS. but the pre-processor does not consider the wax phase or hydrate formation.) are given as time series. i. get a consistent initial state as a basis for dynamic simulations 3.1). temperature and hold-up profiles. and the pressure boundary conditions at the outlet. 2. The separator is treated as a simple node with mixture properties and the phase flow fractions of any phase are assumed to be equal for any of the outlets of a separator. In such cases. The steady state pre-processor has some small residual errors that are removed by the transient simulation. one can use the steady state pre-processor results. For such pipelines it is therefore recommended to set INIFLOWDIR=NEGATIVE in the BRANCH input group. For unstable systems (for instance slugging cases) the steady state pre-processor may find a solution that differs from the average value in the transient solution as there is no truly steady-state condition.e. Both merging and diverging networks can be calculated. an outer iteration is needed in addition to the one shown above. ∆οεσ νοτ . perform screening studies The steady state pre-processor can be used for flow networks with any combination of boundary conditions at inlets and outlets. new pressures are computed along all the pipelines in the network. The latter option can be useful if the pre-processor has problems finding a solution. If the inlet flows and/or outlet pressures are not known. In this case use STEADYSTATE = ON under OPTIONS and STARTTIME equal ENDTIME under INTEGRATION. it is recommended to perform a dynamic simulation with the slug tracking model (not available in OLGA 6. The combination of phase transition and inlet flows gives consistent flow rates along all the pipelines in the entire network. mass flows. or negative sources. In order to do some fast studies (screening studies). This is particularly the case for simulations with pressure or well (productivity index) as inlet boundary conditions. There are some basic limitations when not using this module: 1. The steady state pre-processor may be run with wax deposition or hydrate kinetics activated. if the flow goes from the outlet to the inlet of a pipeline. The steady state pre-processor cannot handle counter-current flow (such as for instance positive gas flow and negative liquid flow). The point model OLGAS THREE-PHASE is used in this step. and INITIALCONDITIONS must be applied to all the FLOWPATHS instead. This approach may lead to discontinuities between the steady state and dynamic solution. if the slug flow regime is detected in the simulation. Therefore. The steady state pre-processor is not as robust as the dynamic OLGA. In this iteration the initial guesses for inlet flows/outlet pressures are refined until the residuals are smaller than a given tolerance. For PID controllers the bias settings are used as the controller outputs. 2. the steady state pre-processor incorporates the effect of process equipment. Choose STEADYSTATE=ON to get a full steady state computation including calculations of temperatures. This is mainly due to the two following reasons: 1. Τηεσε εθυατιονσ αρε τιµε χονσυµινγ το σολϖε ανδ ωιλλ τηερεφορε βε υσεδ ονλψ ατ τηε σταρτ οφ α σιµυλατιον. ΟΛΓΑ χαν νοτ δεαλ ωιτη α σινγλε χοµπονεντ σψστεµ ιφ τηε σατυρατιον λινε ισ χροσσεδ. ρεφ. ιτ ισ ιµπορταντ τηατ τηε ΗΧ ΠςΤ ταβλε χονταινσ α γριδ ποιντ τηατ ισ χλοσε το τηε χριτιχαλ ποιντ ιν ορδερ το οβταιν αχχυρατε χροσσινγ οφ τηε σατυρατιον λινε. ΤΣΑΤς. Τηισ ισ δυε το τηε εξπλιχιτ χουπλινγ οφ ϖολυµε βαλανχε ανδ ενεργψ βαλανχε εθυατιονσ ανδ τηε λαχκ οφ α τωο πηασε ρεγιον (τωο πηασε ενϖελοπε) φορ α σινγλε χοµπονεντ σψστεµ.2 βαρ ανδ ΤΧ = 647. See also: When to use Methods and assumptions How to use When to use The SteamWater–HC module should be used when there is a considerable amount of water in the fluid. ΤΣΑΤΩ. . this module gives more correct water/steam properties around the critical point and also in the supercritical region. Τηε δεφινιτιον οφ τηε ρεγιονσ ισ δεσχριβεδ ιν 1. ωιλλ βε χαλχυλατεδ φροµ τηε τοταλ πρεσσυρε. Also. Generation of steam and water properties. χονδενσατιον οφ ϖαπορ ωιλλ τακε πλαχε. This is solved by introducing time constants or delays in the evaporation/condensation process. Multiplying this temperature difference with a certain heat or energy transfer coefficient gives a certain energy transfer rate that can be used to estimate the mass transfer rate. (πρεσσυρε ανδ τεµπερατυρε). Τηερε µυστ βε α γασ πηασε οτηερωισε ωατερ χαν νοτ βε εϖαπορατεδ.. Αβοϖε τηε χριτιχαλ ποιντ. Τσατ (Π). Π. 2. ΠΧ = 221. τηε βουνδαρψ λινε βετωεεν ρεγιον 2 ανδ ρεγιον 3 ισ υσεδ ασ τηε διϖισιον βετωεεν ϖαπορ ανδ λιθυιδ. εϖαπορατιον οφ ωατερ ωιλλ τακε πλαχε. ατ α γιϖεν γριδ ποιντ. How fast this approach is depends on the size of the energy transfer coefficient. ΤΜ. Τηε τηιρδ λιµιτατιον ισ ρελατεδ το τηε ωαψ τηε χονσερϖατιον εθυατιονσ αρε σολϖεδ ωιτη αν εξπλιχιτ χουπλινγ βετωεεν ϖολυµε (πρεσσυρε) βαλανχε ανδ ενεργψ (τεµπερατυρε) βαλανχε. Αβοϖε 676 Κ ανδ 250 βαρ. ςαπορ σατυρατιον τεµπερατυρε. Ιφ τηε φλυιδ τεµπερατυρε. Ιφ ΤΜ ισ ηιγηερ τηαν ΤΣΑΤς βυτ λοωερ τηαν ΤΣΑΤΩ. ανδ το 676 Κ ανδ 250 βαρ. Τηε πρεσσυρε οφ τηε ωατερ πηασε ωιλλ βε εθυαλ το τηε τοταλ πρεσσυρε. 3. License requirements SteamWater–HC is part of the Single Component Module that requires a separate license.3 Κ. Αφτερ τηε σατυρατιον ποιντσ ανδ τηε πηψσιχαλ προπερτιεσ αρε χαλχυλατεδ φορ αλλ τηε Π/Τ γριδ ποιντσ τηατ χορρεσπονδ το τηε ΠςΤ ταβλε φορ τηε ΗΧ µιξτυρε.Τ. Τηε εθυατιονσ υσεδ το χαλχυλατε τηε στεαµ ανδ ωατερ προπερτιεσ αρε τακεν φροµ ρεφ. ΤΜ.g. Methods and assumptions Τηε φολλοωινγ ασσυµπτιονσ αρε µοδε ιν τηε µοδελ: Οιλ. when simulating drying of a pipeline with hot gas. λινεαρ ιντερπολατιον βετωεεν τηε γριδ ποιντσ ισ αππλιεδ δυρινγ τηε σιµυλατιονσ.αππλψ φορ ΜΕΓ/ΜεΟΗ/ΕτΟΗ Τραχκινγ ανδ Χοµποσιτιοναλ Τραχκινγ ασ τηεψ ηαϖε α στεαµ µασσ βαλανχε. 1 Physical properties. ισ δετερµινεδ φροµ τηε σατυρατιον λινε. Τηε πρεσσυρε οφ ϖαπορ ωιλλ βε εθυαλ το τηε παρτιαλ πρεσσυρε οφ ϖαπορ ιν τηε γασ πηασε ανδ ωιλλ βε χαλχυλατεδ ασσυµινγ αν ιδεαλ µιξ οφ ϖαπορ ανδ ηψδροχαρβον γασ. In that case an asymptotic approach to equilibrium occurs. Πσατ (Τ). Ωατερ σατυρατιον τεµπερατυρε. Φορ αλλ τηε χασεσ. e. Τηισ αδδιτιοναλ µασσ τρανσφερ τερµ ωιλλ νοτ βε διρεχτλψ ινχλυδεδ βυτ χαν βε αχχουντεδ φορ βψ αν ενηανχεδ ηεατ τρανσφερ δυε το συρφαχε βοιλινγ/χονδενσατιον. or when it is important to limit the rate of boiling/evaporation/condensation. ισ ηιγηερ τηαν ΤΣΑΤΩ. ωατερ ανδ ϖαπορ (στεαµ) ωιλλ αλλ ηαϖε τηε σαµε τεµπερατυρε. ωιλλ βε χαλχυλατεδ φροµ τηε παρτιαλ πρεσσυρε οφ ϖαπορ. Τηε ονλψ σιτυατιον ωηερε τηισ λιµιτατιον ισ ρεαλ ισ ιφ ονλψ ωατερ ισ πρεσεντ ιν τηε φλυιδ ανδ τεµπερατυρε ανδ πρεσσυρε χονδιτιονσ αρε συχη τηατ τηε σατυρατιον λινε ισ χροσσεδ. 1 1. ανδ σατυρατιον τεµπερατυρε. Συχη α σιτυατιον µαψ λεαδ το συρφαχε βοιλινγ ορ συρφαχε χονδενσατιον ιν χασεσ ωηερε ωατερ ορ ϖαπορ ισ ιν διρεχτ χονταχτ ωιτη τηε πιπε ωαλλ. The difference between the saturation temperature and the fluid temperature serves as a potential for phase mass transfer. Τηε σεχονδ λιµιτατιον ισ νοτ α ρεαλ λιµιτατιον ασ τηερε ωιλλ υσυαλλψ βε σοµε ΗΧ γασ ιν σιτυατιονσ ωηερε ωατερ ισ εϖαπορατινγ. Τηε προπερτιεσ ωιλλ βε χαλχυλατεδ ατ πρεσσυρε/τεµπερατυρε ϖαλυεσ χορρεσπονδινγ το τηε πρεσσυρε/τεµπερατυρε γριδ ποιντσ σπεχιφιεδ ιν τηε ΠςΤ ταβλε πρεπαρεδ φορ τηε σιµυλατιον. Νοτε τηατ ΤΣΑΤς ωιλλ αλωαψσ βε λεσσ ορ εθυαλ το ΤΣΑΤΩ. α στραιγητ λινε ισ υσεδ το διϖιδε τηε σινγλε−πηασε ορ δενσε−πηασε ρεγιον ιντο ϖαπορ ανδ λιθυιδ. Saturation line Βελοω τηε χριτιχαλ ποιντ. τηε σατυρατιον πρεσσυρε. Ιφ ΤΜ ισ λοωερ τηαν ΤΣΑΤς. φλασηινγ ορ βοιλινγ οφ ωατερ ωιλλ τακε πλαχε. γασ. ΠΧ ανδ ΤΧ. α πρεσσυρε ιντερϖαλ λεσσ τηαν10 βαρ ανδ α τεµπερατυρε ιντερϖαλ λεσσ τηαν 10 Κ αρε ρεχοµµενδεδ ιν ορδερ το µαινταιν αχχεπταβλε αχχυραχψ οφ τηε λινεαρ ιντερπολατιον. Τηε ιννερ πιπε ωαλλ συρφαχε µαψ βε συπερηεατεδ ορ συβχοολεδ χοµπαρεδ το ΤΣΑΤΩ ορ ΤΣΑΤς. Φορ σιµυλατιον χασεσ ωηερε τηε πρεσσυρε µαψ χροσσ τηε χριτιχαλ πρεσσυρε. Ωιτη τηε πρεσενχε οφ ΗΧ−γασ ιν τηε φλυιδ. 1 1. 1 αρε υσεδ φορ ωατερ ιν τηε ωατερ ρεγιον. Ωιτη νο ΗΧ−γασ ιν τηε φλυιδ τηε παρτιαλ πρεσσυρε οφ ϖαπορ ωιλλ βε εθυαλ το τηε τοταλ πρεσσυρε ανδ νο βυλκ µασσ τρανσφερ τακεσ πλαχε υντιλ ειτηερ συβ−χοολεδ ωατερ ρεαχηεσ σατυρατιον τεµπερατυρε ορ συπερηεατεδ στεαµ χοολσ δοων βελοω σατυρατιον τεµπερατυρε. κµολεσ οφ ϖαπορ/υνιτ ϖολυµε(µ3) Μηχ = ΜΓΗΧ/ΜΩηχ. τηε ϖαπορ ανδ ωατερ προπερτιεσ αρε χοντινυουσ αχροσσ τηε ϖαπορ−λιθυιδ (ς−Λ) διϖισιον λινε ωηεν πρεσσυρε ισ αβοϖε 225 βαρ.Ωατερ προπερτιεσ: Φορ πρεσσυρεσ βελοω 225 βαρ. ΗΤΟΤς = (µγηχ∗χπγη + µληχ∗χπλη +µλωτ∗χπωτ + µγϖ∗χπϖ) ∗(ΤΜ−ΤΣΑΤς) ωηερε µγηχ = σπεχιφιχ µασσ οφ ΗΧ−γασ (κγ/µ3) µληχ = σπεχιφιχ µασσ οφ ΗΧ−λιθ (κγ/µ3) µλωτ = σπεχιφιχ µασσ οφ ωατερ (κγ/µ3) µγϖ = σπεχιφιχ µασσ οφ ϖαπορ (κγ/µ3) χπγη = σπεχιφιχ ηεατ οφ ΗΧ−γασ (Κϑ/κγΧ) χπλη = σπεχιφιχ ηεατ οφ ΗΧ−λιθ (Κϑ/κγΧ) χπωτ = σπεχιφιχ ηεατ οφ ωατερ (Κϑ/κγΧ) χπϖ = σπεχιφιχ ηεατ οφ ϖαπορ (Κϑ/κγΧ) Τηε τοταλ µασσ τρανσφερ το οβταιν σατυρατεδ χονδιτιονσ ισ: ΠΣΙςΤΟΤ = ΗΤΟΤς / ( ΗΣΑΤς − ΗΣΑΤΩ ) Ιν ορδερ το ρεδυχε νυµεριχαλ προβλεµσ ιτ ωιλλ βε ασσυµεδ τηατ τηισ µασσ τρανσφερ ωιλλ τακε α χερταιν τιµε ΤΠΣΙ. τηε ϖαπορ προπερτιεσ αρε εξτραπολατεδ φροµ τηε σατυρατιον ποιντ. Τηε εφφεχτ οφ λοχαλ βοιλινγ ον α ηοτ ωαλλ συρφαχε ορ χονδενσατιον ον α χολδ ωαλλ συρφαχε ωιλλ νοτ βε ινχλυδεδ διρεχτλψ ιν τηε µασσ βαλανχε οφ ωατερ ανδ ϖαπορ βυτ χαν βε αχχουντεδ φορ τηρουγη αν ενηανχεδ ηεατ τρανσφερ ατ τηε πιπε ωαλλ. Τηε τοταλ ενεργψ αϖαιλαβλε φορ γενερατινγ ϖαπορ ορ χονδενσινγ ϖαπορ το οβταιν σατυρατεδ χονδιτιονσ ισ ΗΤΟΤς. Ιν τηε ωατερ ρεγιον. Αλλ τηε οτηερ προπερτιεσ αρε φροµ τηε σατυρατιον τεµπερατυρε. Το αϖοιδ νυµεριχαλ προβλεµσ ιν ρεγιον 3 τηε ωατερ προπερτιεσ φροµ ρεγιον 1 ινστεαδ οφ τηοσε φορ ρεγιον 3 ωηεν τηε πρεσσυρε ισ βελοω 225 βαρ (τηε εθυατιονσ αρε ϖερψ σιµιλαρ εξχεπτ ωηεν ψου αρε χλοσερ τηαν <1Χ ανδ 0. ϖαπορ προπερτιεσ αρε χαλχυλατεδ βασεδ ον εθυατιονσ φορ τηε διφφερεντ ρεγιονσ. Τηε ϖαπορ σατυρατιον τεµπερατυρε ωιλλ βε διρεχτλψ ρελατεδ το τηε παρτιαλ πρεσσυρε οφ ϖαπορ ασσυµινγ αν ιδεαλ µιξινγ οφ ΗΧ−γασ ανδ ϖαπορ. τηε προπερτιεσ φορ ωατερ αρε εξτραπολατεδ φροµ τηε σατυρατιον ποιντ: Εντηαλπψ ισ βασεδ ον τηερµαλ χαπαχιτψ ατ σατυρατιον τεµπερατυρε χορρεσπονδινγ το α γιϖεν πρεσσυρε ανδ τηε δενσιτψ αχχορδινγ το τηε δενσιτψ δεριϖατιϖε το πρεσσυρε ατ τηε σατυρατιον πρεσσυρε χορρεσπονδινγ το α γιϖεν τεµπερατυρε. α γραδυαλ τρανσφερ οφ µασσ οφ Η2Ο ωιλλ τακε πλαχε ασ τηε παρτιαλ πρεσσυρε οφ ϖαπορ χηανγεσ. 1) Ιν τηε ϖαπορ ρεγιον. Εντηαλπψ ισ βασεδ ον τηερµαλ χαπαχιτψ ατ σατυρατιον τεµπερατυρε χορρεσπονδινγ το τηε γιϖεν ϖαπορ πρεσσυρε ανδ τηε δενσιτψ αχχορδινγ το τηε δενσιτψ δεριϖατιϖε το πρεσσυρε ατ τηε σατυρατιον πρεσσυρε χορρεσπονδινγ το τηε γιϖεν τεµπερατυρε. Τηε µασσ τρανσφερ ρατε ωιλλ τηεν βε: ΠΣΙς = ΠΣΙςΤΟΤ / ΤΠΣΙ ( κγ/ µ3σεχ ) Τηε µασσ τρανσφερ περ τιµε στεπ µυστ νοτ βε λαργερ τηαν τηε αϖαιλαβλε µασσ οφ τηε διµινισηινγ πηασε χοµπονεντ. ςαπορ προπερτιεσ: Φορ πρεσσυρεσ βελοω 225 βαρ. Αλλ τηε οτηερ προπερτιεσ αρε φροµ τηε σατυρατιον τεµπερατυρε χορρεσπονδινγ το τηε ϖαπορ πρεσσυρε. ϖαπορ προπερτψ εθυατιονσ φορ ρεγιον 2 αρε υσεδ φορ ϖαπορ ιν τηε ϖαπορ ρεγιον. ςαπορ πρεσσυρε: πρεσσυρε ωηερε ΠςΑΠ = Π∗Μϖαπ/(Μϖαπ + Μηχ) Μϖαπ = ΜΓςΑΠ/ΜΩΗ2Ο. ωατερ προπερτψ εθυατιονσ φορ ρεγιον 1 (σεε ρεφ. ωατερ προπερτιεσ αρε χαλχυλατεδ βασεδ ον εθυατιονσ φορ τηε διφφερεντ ρεγιονσ σπεχιφιεδ ιν ρεφ. Τηε σαµε ισ δονε φορ στεαµ. Τηερµαλ χαπαχιτψ ανδ εντηαλπψ φορ ωατερ ισ σινγυλαρ νεαρ τηε χριτιχαλ ποιντ. κµολεσ οφ ΗΧ γασ/υνιτ ϖολυµε(µ3) ΜΓςΑΠ = Μασσ οφ ϖαπορ/υνιτ ϖολυµε ΜΓΗΧ = Μασσ οφ ΗΧγασ/υνιτ ϖολυµε ΜΩΗ2Ο = Μολωειγητ οφ ϖαπορ = 18 κγ/κµολ ΜΩηχ = Μολωειγητ οφ ΗΧ γασ Flashing/Condensation Τηε δριϖινγ φορχε φορ φλασηινγ οφ ωατερ ορ χονδενσατιον οφ ϖαπορ ωιλλ βε τηε διφφερενχε βετωεεν τηε σατυρατιον τεµπερατυρεσ ανδ τηε φλυιδ τεµπερατυρε. Φορ πρεσσυρεσ αβοϖε 225 βαρ. . Φορ πρεσσυρεσ αβοϖε 225 βαρ.1 βαρ). Ωιτη τηισ προχεδυρε. New output variables for presenting vapor data have been implemented: TSAT.env. Figure 1 Example of an annulus configuration. Also. there will be cross sectional heat transfer between the different pipelines. It computes a three-dimensional temperature distribution by combining computation of radial and angular heat storage and heat transfer in the medium surrounding the pipelines.. it will affect the temperatures in all the other pipelines. the pressure of the source receiving position will be used.and drilling-applications. For all the cases. OLGA has three types of thermal components that also take cross-sectional heat transfer between different pipelines into account. TCONDENSATION. The Annulus model is similar to the Bundle model. the input key COMPOSITIONAL under keyword OPTIONS must be set to STEAMWATER-HC.and drilling-configurations such as the one illustrated in Figure 1 below. but it is specially designed for well and drilling configurations. Figure 1 Example of an annulus configuration. linear interpolation between the grid points is applied during the simulations. TSV. See also: When to use Methods and assumptions Limitations How to use When to use The annulus model should be used for pipeline configurations like the one shown in Figure 1 below in order to account for cross sectional heat transfer between the different pipelines. In addition to this functionality. Ρεϖισεδ Ρελεασε ον τηε ΙΑΠΩΣ Ινδυστριαλ Φορµυλατιον 1997 φορ τηε Τηερµοδψναµιχ Προπερτιεσ οφ Ωατερ ανδ Στεαµ. Σωιτζερλανδ. For simulation cases where the pressure may cross the critical pressure. In the annulus model diameters are allowed to vary in the axial direction. using the same P/T grid. For YES. respectively. The annulus model is very similar to the bundle model. For sources without any pressure given. STEAMFRACTION can be set between 0 and 1 to give both water and steam. with the one-dimensional axial computation for the pipeline fluid. If the temperature distribution in one pipeline changes.References 1. it is important that the HC PVT table contains a grid point that is close to the critical point in order to obtain accurate crossing of the saturation line. Both can be viewed in the GUI. boundaries. evaporation and boiling. but it is specially designed for well. The annulus model treat such heat couplings in a more explicit and dynamic manner than the basic OLGA model. tab files (fixed format) will be written for each HC mixture PVT table. a pressure interval less than 10 bar and a temperature interval less than 10 K are recommended in order to maintain acceptable accuracy of the linear interpolation. the saturation line will be written to a file with the name <inputile>_pvt. The Bundle model should be used for pipeline bundles when the effect of heat transfer between different pipelines is important. Other data for vapor can be obtained by specifying compositional variables. Αυγυστ 2007 How to use In order to activate the SteamWater-HC model. the specified water fraction will be either steam or liquid depending on the specified temperature compared to the water saturation temperature at the specified pressure when STEAMFRACTION is set to -1 (default). After the saturation points and the physical properties are calculated for all the P/T grid points that correspond to the PVT table for the HC mixture. TVAPORIZATION and TBOILING in keyword COMPOPTIONS can be used to specify the time constants for condensation. Thermal Components The basic functionality in OLGA computes an axial temperature distribution in pipelines taking into account radial heat transfer through pipe walls. This is useful for. For initialconditions. Small values will speed up the mass transfer thereby reducing the thermal non-equilibrium. pipeline bundles. buried pipelines and drilling configurations. Λυχερνε. The name of the file(s) will be <inputfile>_pvt_<HCfluidlabel>. e.g. Τηε Ιντερνατιοναλ Ασσοχιατιον φορ τηε Προπερτιεσ οφ Ωατερ ανδ Στεαµ.tab. The annulus model may be used to model gas-lifted wells where gas is injected into the annulus between the casing and tubing and recovered in the tubing together with the . Too small values may however cause instabilities and probably nonphysical results. PVAP (see output variables description). They are available as time series if desired by using the subkey TIME (but not for Compositional Tracking). The FEMTherm model should be used when pipeline configurations are surrounded by a solid medium. Annulus In well. PSAT. sources and wells. In OPTIONS the subkey WRITEPVTFILES=[NO]/YES controls if the program will write to file the water/steam properties that are being used. Large values will slow down the mass transfer leading to fairly large nonequilibrium. Methods and assumptions The annulus model computes temperatures in annular pipeline configurations by coupling the basic temperature computation in the axial direction to a temperature computation in the cross sectional direction. the fluid temperature and wall layer temperatures of all the enclosed pipelines are solved simultaneously. right click and choose: Add→ThermalComponent→ANNULUS In the OLGA GUI. the model is very useful when the immediate surroundings of a pipe cannot be treated as a constant thermal reservoir. 2. an annulus consists of a carrier line enclosing one or several flow-paths. grid and results (FEMTherm Viewer) More accurate discretization around the circular pipe wall (unstructured triangular mesh) Radiation is included See also: When to use Methods and assumptions Limitations How to use When to use The FEMTherm model is designed to simulate the thermal interactions between parallel pipelines enclosed in a solid medium. However. The combination of 1-dimensional fluid and wall layer temperature calculations in the axial direction and the 2-dimensional calculation in each bundle cross section results in a 3dimensional temperature field. this model is not recommended for systems where the ambient heat transfer boundary . The carrier line itself is a regular flow-path. The properties XOFFSET and YOFFSET are X. fill out the required fields. the FLOWPATH identifier have to be specified.. the model is capable of predicting the transient thermal behavior of the surrounding soil. The annulus model requires the WALL or FASTWALL temperature calculation option to be used. thus. FEMTherm FEMTherm may be used to calculate the thermal performance of the following systems: Bundled pipelines Buried pipelines Complex risers Figure A A hot water insulated and buried bundle FEMTherm covers the functionality of the Soil module implemented in earlier versions of OLGA. in which the fluid temperatures and wall layer temperatures in the whole pipeline are solved simultaneously. Flow-paths that are contained within the same annulus have to have the same section lengths and elevations. no flow-path is created by this procedure. The properties FROM and TO define the part of the flow path that is enclosed in the annulus (axial direction). The WALL or FASTWALL temperature calculation option must be specified when an annulus is present in a case.and Y-direction offsets for the FLOWPATH center from an arbitrary reference point. with several differences: Easier input: Discretization: just one value is required (MESHFINENESS) Predefined shapes (circle. The annulus model has no purpose if all U-values (overall heat transfer coefficients) and temperatures are known. A regular one-dimensional temperature calculation is performed for each pipeline. thus. the FEMTherm calculations can be time-consuming. All flow-paths contained in the same annulus must have the same reference point. The property OUTERHVALUE may be used if the heat transfer coefficient from the outer wall surface to the carrier line is known. In particular. in the OLGA GUI do the following: From the Case level. and. rectangle) in addition to a user-defined polygon Better visualization of cross section.production fluid. the following has to be repeated for each participating component: From the newly created annulus. otherwise forced/free convection will be applied. Therefore. In each cross section of the annulus. License requirements Annulus is part of the Wells Module that requires a separate license. The annulus must cover entire pipes. This is achieved by the following two-step procedure: 1.B. They refer to position labels which must be defined under Piping for the FLOWPATH. How to use To use the Annulus model. the flow-path specified have to either exist beforehand or be added to the case later. In situations with buried pipelines. No additional girding is used in the annulus model as compared to solving each pipeline thermally decoupled from each other. To populate the annulus. N. Limitations All pipelines that are contained within the same annulus must have the same section lengths and elevations. The model is also very flexible with respect to geometry definitions and is well suited for analyzing complex risers with temperature variations that are not axisymmetric. The annulus model is based on the following assumptions: The heat transfer from an outer wall surface of one pipeline to the surrounding fluid in a carrier line is based on free/forced convection unless a user given heat transfer coefficient is given. ellipse. and. right click and choose: Add→AnnulusComponents→COMPONENT In the property window for the newly created component. Pipe diameters may vary in the axial direction. ). giving the profiles of the fluid temperature along the pipeline and in the pipe WALL. Figure B: Cross section grid and concentric pipe with a single wall layer In the situation of an incompressible fluid in the pipe visualized above. . Figure A illustrates the grid system used for solving the 2-dimensional heat transfer equation in a rectangular cross section with two interior pipelines. Equation (a) describes the energy conservation of the fluid. CIRCLES. Equation (b) the energy conservation of the pipe WALL and Equation (c) the energy conservation with heat conduction in the interior of the solid medium. The combination of 1-dimensional fluid and WALL temperature equations along the pipelines and the 2-dimensional heat transfer equations for the media in each of the cross sections along the pipeline results in a 3-dimensional temperature field. 1. In addition to these. 2. a set of boundary and initial conditions are required for the calculation. The simulation model consists of stacks of such cross sections along the pipeline. equations (a) and (b) are solved for each component and for each wall layer. The temperature. i. The grid generator makes a 2D finite element mesh in accordance with the Delaunay criterion. FEMTherm establishes the thermal coupling of the pipelines and solves the 2-dimensional heat transfer equation in the solid medium surrounding the pipe WALL. OLGA solves the following equations in two steps: Energy equation for the fluid in the pipe and the heat transfer equation for the layers of the pipe WALL. RECTANGLES and POLYGONS. The finite element equation solver determines the transient 2D temperature distribution of any user defined cross section. License requirements The FEMTherm model is part of the FEMTherm Module that requires a separate license. = ( . In the more general case. ELLIPSES. which can have several shapes. . Figure A: Cross section grid In a FemTherm calculation. is the central variable in FEMTherm and the parameters in the model are: Af Tf rf Area of the pipe cross section Temperature of the fluid Density of the fluid Heat capacity of the fluid Tw rw Temperature of the first wall layer Density of the first wall layer Heat capacity of the first wall layer Aw Cross sectional area of first wall layer Flow rate of fluid Heat transfer between fluid and first layer Heat transfer between first layer and FEM domain boundary Heat flux across FEM domain boundary . giving the temperature distribution over the cross sections as well as the interaction between fluid temperatures in embedded pipes.conditions can be defined sufficiently well using the concentric wall layer model.e. Methods and assumptions FEMTherm consists of a grid generator and a Finite Element Method (FEM) equation solver. the governing equations for this system are: (a) (b) (c) . Consider the pipe cross section in Figure B. These equations are solved for each of the pipe sections along the pipelines. Figure C: Two OLGA pipes in a cross section One needs to determine the number of nodes that is required to obtain a suitable grid and time step in order to obtain numerical solutions to the heat transfer Equation (c). The wall layer temperatures are not yet known. Numerical considerations In OLGA the fluid temperature varies in the axial (z) direction only. must be evaluated for each section and each FEMTherm time step. In the cross section below. The FEMTherm model should be used with optimized spatial and temporal discretizations which gives a step-size independent solution. . (f) This can now be used to solve the vector of nodal temperatures. The linearization needed for this coupling is derived in the following manner: The ”ambient” temperature. Thus the pipe WALL outer surface (see Figure C) serves as an external boundary to the finite element equation. . . . . these integrals are evaluated once. are user-defined constants. By the linearity of the solution. By factoring out the ambient temperature. however. The numerical accuracy is strongly dependent on the number of internal nodes (N) between external boundaries. . . decoupled from the temperature calculations in the pipes. and is a scaling of the nodal temperatures at timen. and therefore the equation system (f) is coupled to and solved simultaneously with the equations for the fluid and wall temperatures for all embedded components. Given that the temperature. as a function of the ambient temperature. The inertial term. and the temperature in the last wall layer. using superposition this (h) where is a vector of nodal temperatures resulting from the boundary condition at perimeterj. . The finite element domain is discretized using linear triangular elements. two OLGA pipes are placed within a circular cross section.within the FEM domain is a linear function of the nodal temperatures. This is possible because FEMTherm operates with a fixed time step. The heat conduction in the rest of the cross section is in both spatial directions (x and y). the last wall layer temperatures of each component and the temperature at previous time step. component. of the last wall layer of each component is obtained by taking the average temperature in the FEM domain along the boundary of thei’th . is the boundary subject to non-essential boundary conditions and impose the boundary condition for the Newton’s law of cooling of external boundaries: (e) is the test function. the following system of discrete equations is obtained. The last term in this equation is used to where the heat transfer coefficient. The temperature of the fluid and the temperature of the pipe WALL are solved with the OLGA model (finite difference method) on the assumption that radial heat conduction is predominant. while the evolution in time is modeled using a backward Euler scheme. Therefore the heat conduction in the first WALL layer is always in the radial (r) direction.Conductivity of the solid interior of the bundle Density of the solid interior of the bundle Heat capacity of bundle Heat flux at the FEM domain boundary Unit outward normal at the FEM domain boundary The weak form of Equation (c) according to classical functional analysis is: (d) where is the interior of the FEM domain. and the ambient temperature. . This average temperature of discrete nodal temperatures is defined by the function (g) where can be written as: is the length of boundary i and the function is evaluated element by element along the boundary. . It is possible to include more than one radial conduction WALL layer in the model. the constantsaijcan easily be obtained from: With the exception of the term. . In the figure below we see a close-up of the region between the two pipes in Figure C for three examples of the spatial discretization. See Figure E that shows an inner OLGA WALL with two outer walls defined by SHAPE. Thus. one should determine this time constant for all the layers in a It should be noted that the thermal masses in the solid medium can be very large and it may require very long simulation times to obtain thermal equilibrium when integrating the energy balance equation. right click and choose: Add →ThermalComponent → SOLIDBUNDLE. However. and are the density. . This is in principle the procedure used in the steady state pre-processor. The results from an OLGA simulation where the FEMTherm module has been applied can be visualized using FEMTherm Viewer. Thus the grid in (c) is the only acceptable grid for high precision calculations. This is for the purpose of visualization only. or alternatively using FEMTherm Tool. if an annulus borders to a solid shape the diameter of the outermost pipeline of the annulus is not allowed to vary. in (b) N=3 and in (c) N=4. Figure A Illustration of allowable FEMTherm/SOLIDBUNDLE configurations in OLGA. For complex pipes this constant may be difficult (if not impossible) to calculate. LINES and/or FLUIDBUNDLES. The temperature is not calculated separately for these dummy nodes (e. The number N can be checked after the simulation has been performed by looking at the grid in FEMTherm Viewer. All materials are assumed to be homogeneous and isotropic. the amount of data may become exceedingly large for long simulations. Note that the FEMTherm code makes a triangle mesh also for the OLGA WALLS (radial conduction layers) and the fluid within. it is possible to switch the TEMPERATURE option from FASTWALL to WALL between restarts. In (a) N=0. By increasing the value of DTPLOT. To include a SOLIDBUNDLE/FEMTherm computation in the simulation. For very fine discretization and/or long bundle sections. The density of nodes (nodes divided by circumference) on the SHAPE with the longest circumference determines the number of nodes on all other non-POLYGON SHAPES in order to obtain a mesh with uniform node spacing. The integration in time is performed using a fixed time step (no time step control) for the temperature distribution in the cross section. but a fairly valid approximation is: (a) where . Figure E: Left: Grid visualized in FEMTherm Viewer (the fluid in the middle will also have a mesh). In the following these are referred to as bundle components. which are evenly distributed on the outer boundary of the SHAPE with the longest circumference within a SOLID BUNDLE. specific heat capacity and thermal conductivity of a pipe layer thickness pipe and use a time step that is below the smallest of these. shapes inside an outer shape are not allowed to partially overlap. the nodes in the WALL layers have the same temperature for a given radius). The plotting frequency is determined by the key DTPLOT in the SOLIDBUNDLE keyword and should be set judiciously. How to use FEMTherm is activated through the SOLIDBUNDLE keyword. To account for this. The increase in computational speed may be significant when compared to using the WALL option. we recommend that N should be at least 4 to get a good approximation for the temperature field. The MESHFINENESS[*] key in the SOLIDBUNDLE keyword sets the spatial resolution of the grid by determining the number of nodes on the outermost shape. The FEMTherm calculations are based on linear theory which assumes fixed geometry and material properties. A SOLIDBUNDLE consists of a collection of SHAPES. without using the steady state pre-processor. which is not a POLYGON. Thus. Note that the model is constructed with the use of rectangles and circular pipes only. FLOWPATHS. Multiple outer shapes as well as overlapping shapes are allowed. the amount of data may be limited. For each bundle component do the following: . Thermal calculations with the finite element method are computationally expensive and are not carried out for every single time step in OLGA. for transient analyses this option should only be used to initialize the simulations.. [*] MESHFINENESS is the number of nodes. We recommend that the time step for thermal calculations The key DELTAT in the SOLIDBUNDLE keyword should be below the smallest characteristic time constant in the system. However. Limitations All pipelines that border to a solid shape must have a constant diameter in the axial direction. The model can only handle parallel pipes and pipes of a constant diameter. The FASTWALL option is equal to setting the heat capacity parameter to zero and can be used when there are no thermal transients.Figure D: Different discretizations for the area between two OLGA pipes Due to the linear interpolation functions in the finite element calculation.g. Right: Grid used in FEMTherm calculation. or to be adjacent as shown in Figure A. the following must be done in the OLGA GUI: From the Case level. Note that no new component is created by this procedure. If this keyword is not given. right click and choose: Add → BundleComponents → COMPONENT. In the property window for the newly created bundle component. In particular. A SOLIDBUNDLE/FEMTherm simulation requires that the WALL or FASTWALL temperature calculation option is selected For every SOLIDBUNDLE a finite element triangle mesh is generated. . In this case. the grid is not very sensitive with respect to MESHFINENESS as the value of this parameter is being rounded off to multiples of 32. it will affect the temperatures in all the other pipelines. fill out the required fields. The Bundle model is based on the following assumptions: The heat transfer from an outer wall surface of one pipeline to the surrounding fluid in a carrier line is based on free/forced convection unless a user given heat transfer coefficient is given. Fluid bundle For pipeline configurations like the one shown in Figure 1 below. All components are by default placed concentric around the origin and may be independently moved to its correct location with the keys XOFFSET and YOFFSET. and that the specified component must exist beforehand or be added later. the coordinate system of the bundle cross section is decoupled from the rest of the model. If the temperature distribution in one pipeline changes. without having to adjust the pipeline geometry. They refer to position labels. The only exception to this rule is for SHAPES of type RECTANGLE and POLYGON. Methods and assumptions The bundle model computes temperatures in bundled pipelines by coupling the basic temperature computation in the axial direction to a temperature computation in the cross sectional direction. See also: When to use Methods and assumptions Limitations How to use When to use The bundle model should be used for pipeline configurations like the one seen in Figure 1 below when accuracy in temperature is important. The value of this key denotes the number of nodes on the component with the largest circumference. To give better control of the cross section. The property OUTERHVALUE may be used if the heat transfer coefficient from the outer surface of the bundle component to the carrier line is known. The higher the MESHFINENESS. The properties FROM and TO define the part of the component that is enclosed in the bundle (axial direction). The thermal computations are only affected by the relative position of one object to another. the ambient conditions defined in the HEATTRANSFER keyword in the largest flow component of the bundle is used. The combination of 1-dimensional fluid and wall layer temperature calculations in the axial direction and the 2-dimensional calculation in each bundle cross section results in a 3-dimensional temperature field. License requirements Fluid bundle is part of the FEMTherm Module that requires a separate license. there will be cross sectional heat transfer between the different pipelines. The typical values for this key is between 128 and 640. The fineness of the mesh is set by the MESHFINENESS key. but XOFFSET and YOFFSET may still be used for an additional offset. To select this parameter wisely. This is achieved by the following two-step procedure: 1. 2. the x and y coordinates of the shape are given explicitly. No additional griding is used in the bundle model as compared to solving each pipeline thermally decoupled from each other. The ambient conditions for the bundle may vary both in the vertical axis of the cross section and along the length of the bundle. Figure 1 Example of a fluid bundle configuration.From the newly created solid bundle. It is defined through the use of the AMBIENTDATA keyword. a LINE a FLUIDBUNDLE or a SHAPE must be specified. However. Figure 1 Example of a fluid bundle configuration. The bundle model treat such heat couplings in a more explicit and dynamic manner than the basic OLGA model. a reference to either a FLOWPATH. otherwise forced/free convection will be applied. The length and elevation of each section of a pipeline that is contained within a SOLIDBUNDLE must be maintained. the finer the mesh. it is recommended to read about numerical considerations in Methods and Assumptions. the fluid temperature and wall layer temperatures of all the enclosed pipelines are solved simultaneously. In each cross section of the bundle. Thermal computations Temperature is an important parameter in flow assurance analyses and is a key prediction in the analysis of phenomena such as hydrate and wax formation propensities. a homogeneous temperature is calculated for the fluid which can be multiphase. To populate the fluid bundle. CompTrack. These fluid properties are given as usual with the PVTFILE and FLUID keys. OLGA can simulate phase changing materials and give detailed modelling of the soil taking the latent heat of fusion and differences in thermal properties for frozen and unfrozen materials into account. lines. fill out the required fields. See also: When to use Limitations How to use When to use Lines are typically used in bundles. thus. The bundle model requires the WALL or FASTWALL temperature calculation option to be used.Limitations The diameters of the carrier line and all the interior pipelines have to be constant in the axial direction. it needs fluid properties as a function of both pressure and temperature. Flow-paths that are contained within the same bundle have to have the same section lengths and elevations. All pipelines that are contained within the same bundle have to have the same section lengths and elevations.. The property OUTERHVALUE may be used if the heat transfer coefficient from the outer wall surface of the bundle component to the carrier line is known. The pipe wall may comprise of multiple layers of materials of different types. In OLGA. Thus. In addition. it calculates the heat transfer across the pipe wall by determining the average temperature of each wall layer. The WALL or FASTWALL temperature calculation option must be specified when a fluid bundle is used in a case. the following has to be repeated for each participating flow component: From the newly created fluid bundle. in the OLGA GUI do the following: From the Case level. Example 1-phase fluid files are provided with the Sample cases. See also: Methods and assumptions Limitations How to use Methods and assumptions Thermal calculations for the wall rest on the assumption that radial heat conduction through the concentric walls is the dominating phenomenon. right click and choose: Add→ThermalComponent→FLUIDBUNDLE In the OLGA GUI a fluid bundle consists of a carrier line enclosing one or several flow components (flow-paths. LINE A LINE is a type of FLOWPATH for which simplified one-phase calculations are performed. right click and choose: Add→BundleComponents→COMPONENT In the property window for the newly created bundle component.B. Fill in the required fields in the property window. For further instructions on FLOWPATH properties see the keyword description for FLOWPATH. The properties FROM and TO define the part of the flow path that is enclosed in the bundle (axial direction). The former way of giving constant fluid properties with MATERIAL=FLUID is only supported in versions prior to OLGA 6. LINES can form networks but these networks must be hydrodynamically decoupled from multiphase networks. N. and. Limitations LINES cannot be connected to multiphase nodes. The heat flux may be calculated in two ways: . a reference to the flow component (FLOWPATH. Note that this also applies when running component tracking (e. and/or bundles). the component specified have to either exist beforehand or be added to the case later. Ambient conditions for an area can vary significantly in winter and summer seasons or during a day. Pipe diameters must be constant in the axial direction. for injection lines and auxiliary lines where the pipeline hydraulics may be neglected. How to use The implementation of a LINE in the OLGA GUI is as follows: From the Case level right click and choose Add → FlowComponent → FLOWPATH. LINE or FLUIDBUNDLE) have to be specified. The bundle must cover entire pipes How to use To use the Bundle model. see the keyword description of NODE for details. a reliable prediction of the temperature profile in a pipeline is important. In particular. LINES must be connected to nodes just as FLOWPATHS do. In the property window for the FLOWPATH choose LINE=YES. otherwise forced/free convection will be applied. Thus. Blackoil). no new flow component is created by this procedure. A CROSSOVER node is a node that allows flow recirculation. A LINE also takes into consideration frictional effects and will give a pressure drop along the pipeline. These nodes must also be defined as singe-phase by selecting LINE=YES or LINE=CROSSOVER in the property window for the node.g.and Y-direction offsets for the component center from an arbitrary reference point. They refer to position labels which must be defined under Piping for the FLOWPATH. This may cause freezing or melting of the soil surrounding a pipeline. All components contained in the same fluid bundle must have the same reference point. The carrier line itself is either a regular flowpath or a line. The properties XOFFSET and YOFFSET are X. temperature can influence the production capacity of a network and therefore. which are aligned concentrically. the equivalent heat transfer coefficient from the outer surface of a buried pipeline to the top of the soil can be calculated to be: (α) where: D H lsoil hsoil = outer diameter of buried pipe = distance from centre of pipe to top of soil = soil heat conductivity = overall heat transfer coefficient for soil The term cosh-1 (x) can be expressed mathematically as follows: cosh-1 (x) = ln ( x + ( x2 . above the melting point.27 kJ/kg. as a rule of thumb. If the FUISIONMULT key is different from 0. specific heat capacities and densities for each wall layer. with 10% water weight/dry soil weight. between two neighbouring layers should be 0. A finer discretisation of the wall layers may be necessary for transient calculations. Only the thickness needs to be adjusted if the thermal conductivity of the thin layer is fairly close to the conductivity of one of it's neighbours. If ELECTRICHEAT is defined in the WALL definition. The soil is assumed to have a dry density 1900 kg/m3.The heat flux through the pipe wall layers is calculated by the code with user-defined thermal conductivities. the value specified in CAPACITY is used for all temperatures above the melting point. The moist unfrozen heat capacity is 1067 J/kgC (0. The latter option will save some CPU time. not be thicker than approximately 30% of the outer radius of the layer.209 btu/lbF). a step wise function is used for heat capacity having the value equal to FUSIONMULT*CAPACITY in the phase changing region. when the heat storage in the pipe walls can be important (cool down or warm up). it is preferable to have at least three layers and define the electric heating in the middle layer. If the FUSIONMULT key is 0.1 ) 0. It is preferred to include a dynamic calculation of the temperatures of individual wall layers in a transient simulation. we use a phase changing region from -1 to 0 C. Phase changing materials The model for simulating phase changing materials accounts for latent heat of fusion and the difference in thermal properties for unfrozen and frozen materials. Figure A: Illustration of a buried pipe Buried pipelines may be modelled with the soil as the outermost wall layer. This gives: HCAPMULT = 876/1067 = 0. a good soil discretization is important in order to obtain a reliable temperature profile across the wall layer. Very thin layers. Thermal conductivity and heat capacity are given for three ranges. but should be used with care and preferably in steady state situations only. Alternatively. linear interpolation is performed between 1 and HCAPMULT.255 btu/lbF) and the frozen heat capacity is 876 J/kgC (0. The former is recommended since the heat storage capacity in the wall is often significant. δ. The latent heat of fusion is (190 kg/m3*333 kJ/kg)/(2090 kg/m3) = 30.. The thickness of the composite soil layer is based on an equivalent heat transfer coefficient for the soil for a pipeline burial of a particular depth. In the example. The change in thickness. The heat flux is determined by a user-defined overall heat transfer coefficient.4 Thermal conductivity given in CONDUCTIVITY is used directly for temperatures above the melting point. A conductivity multiplier (CONDMULT) is used for temperatures below the melting point. It is sufficient to undiscretize the wall layer for steady-state calculations. . The FUSIONMULT key takes the latent heat of fusion (additional energy added or withdrawn for a phase change) into consideration. such as paint etc. should be included in a neighbouring layer by adjusting the thickness and conductivity of that layer. Theoretically. However. A multiplier (HCAPMULT) is used below the melting point. Limitations Wall Layer Thickness The numerical solution for the temperatures in the wall layer depends on the discretisation of the layer. A wall layer should. below the melting point and in the transition zone. The first method of calculating the heat flux (where heat flux is a function of wall properties) should then always be used due to the large thermal mass of the soil. Linear interpolation is used in between.5 ) for x ³ 1 The thickness of the composite soil layer can be determined using the expression below for a known value of the soil thermal conductivity: (β) where: Rsi = inner radius of soil layer (=outer radius of pipe wall) Rso = outer radius of soil layer ksoil = input value of soil conductivity The specific heat capacity of the soil may be adjusted as follows in order to predict the transient heat transfer accurately: (χ) where: Cp input = input value of soil thermal capacity Cp soil = soil thermal capacity Heat transfer at steady state conditions depends only on the outer soil layer radius Rso and on ksoil.2 ≤ δ(i)/δ (i-1) ≤ 5 to obtain a good accuracy. while another multiplier is used below -1 C for the frozen soil. for dynamic situations.82 FUSIONMULT = (30270+1067)/1067 = 29. This gives one multiplier between -1 and 0 C to account for the latent heat of fusion. The exmple below describes how the latent heat of fusion is caluated in a situation with a wet soil material. For heat capacity. the Solid Bundle module may be used in such a situation. Production flows from wells will not contain any tracer. Further. Partitioning of tracers is not implemented in the current version. corrosion inhibitors and radioactive tracers.or corrosion inhibitors). See also: When to use Methods and assumptions Limitations How to use When to use Tracer tracking should be used when one wants a distribution in space and time of mass. TYPE must be set to PCM in MATERIAL keyword. although if large pressure differences occur between two neighbouring sections the Joule-Thompson effect may give a substantial temperature difference. wells and pipelines. Τηε τραχερσ/ινηιβιτορσ αρε ασσυµεδ το βε χαρριεδ ιν α χαρρψινγ πηασε (χονδενσατε. which. age and residence time of tracers of such small amounts that their influence on the flow is negligible. ages are divided into age groups (defined by the key AGEBOUNDARIES).How to use In the OLGA GUI the method for the temperature calculation is set from the OPTIONS card on the Case level. as well as the surrounding medium. Tracer tracking can be combined with all other modules. and pipe walls. Methods and Assumptions The Tracer Tracking model in OLGA computes a distribution in space and time of tracer mass. The following assumptions are used: Τηε πρεσενχε οφ τραχερσ ισ ασσυµεδ το ηαϖε νο εφφεχτ ον τηε φλοω. The age.and residence time-equation has an additional source term. specific heat capacities and densities for each wall layer Similar as WALL but heat storage is neglected in the wall User-defined heat transfer parameters for the chosen temperature option must be given for each pipeline. here represented by the equation for mass: Here G represents the sum of regular sources as well as the influence of entrainment and deposition of droplets. · · · It will not be possible to specify the tracer content in negative sources. Tracer tracking Tracer tracking simulations together with measurements of tracer output from real fields provide a means to obtain valuable information about flow conditions in reservoirs. Large discontinuities are often unphysical. but the tracer output variables are average values for a section. but distribution of tracer on each side of the pig might in some cases be inaccurate. e. How to use . Furthermore. If aging is on.and corrosion models to take into account the effect of the inhibitors. the required fields must be filled out. An upper and lower temperature limit for melting and freezing must be specified. but some limitations exist: • · · Tracer tracking can be combined with slug tracking. τραχερσ υσυαλλψ εξιστ ιν αµουντσ σο σµαλλ τηατ τηε εφφεχτ ον τηε φλοω οφ τηε προδυχτιον φλυιδσ ισ νεγλιγιβλε. and the average age within each group is computed. Any vaporization/condensation does not affect the tracer mass. by vaporization. the remaining tracer is removed. The tracer tracking functionality in OLGA can be used to track tracers which have such a purpose of investigation/examination. The injection flows will be treated in the same manner as negative sources. Examples of such tracers are KHI inhibitors. In the OLGA GUI under Boundary&InitialConditions for each FLOWPATH . ι. License requirements Tracer tracking is part of the Inhibitor Tracking Module that requires a separate license. Tracer tracking can be combined with pig tracking (which is a special version of slug tracking). liquid. The amount of tracer going out will be based on the concentration of the tracer in the section from which the source originates. All the inhibitors within each group are assumed to have the same age (average age). The results may be used by for instance hydrate kinetics. • It is not possible to specify an initial condition (by the keyword INITIALCONDITIONS) containing tracers. The computation of all these variables is based on simple conservation equations. In a temperature calculation the homogeneous temperature profile along the pipeline should be critically examined. Παρτιτιονινγ οφ τραχερσ/ινηιβιτορσ το οτηερ πηασεσ τηαν τηε χαρρψινγ πηασε ισ νοτ ινχλυδεδ ιν τηε χυρρεντ ϖερσιον οφ τηε µοδελ.ε. In the OPTIONS property window the TEMPERATURE can be set either to: OFF ADIABATIC UGIVEN WALL FASTWALL No temperature calculation – initial temperatures must be specified with the INITIAL keyword statement No heat transfer to surroundings A user-defined overall heat transfer coefficient is used for the entire wall The heat flux through the pipe wall layers is calculated by the code with user-defined thermal conductivities. The distribution of ages (when applicable) is divided into a given number of groups. and it can be used to track tracers of inhibitor type (for instance kinetic hydrate. residence time and age (if the key AGING=ON). Tracer functionality is not implemented in the near well module Rocx. water. one or several HEATTRANSFER cards may be added. in the case of aging. Limitations · · • The current corrosion model and hydrate kinetics model in OLGA do not take into account the inhibition effect of any tracer. In order to simulate a phase changing material. PHCHMAX and PHCHMIN. but the concentration changes. ωατερ ορ γασ).g. OLGA predicts the distribution in space and time of mass. the three multipliers for properties below the melting point and in the phase changing region must be given. but the steady state preprocessor will compute an initial steady state tracer distribution. The tracer does not follow the water vapor phase. takes into account the amount of time the tracer is subject to sub-cooling relative to an equilibrium temperature (for instance the hydrate formation temperature in case of KHI tracking). age and residence time for tracers being inserted into wells/pipelines. In the property window for each HEATTRANSFER card. Each group has a user given low and high bound of age. temperature differences can be expected depending on the thermal properties of the gas. If a section is totally emptied of the carrying phase. if there is a great difference in hold-up between two adjacent sections. License requirements The Tuning Module requires a separate license. σπεχιφψ τηε ΗΨ∆ΡΑΤΕΧΗΕΧΚ κεψωορδ. The number of entries must either be one or a multiple of the listed number of combinations of pipes. User defined dispersions and plug-in framework This framework is designed as a flexible flow assurance framework for tracking user defined dispersions and utilizing external physical models provided by the user through a DLL. Methods and assumptions The tuning coefficients are multiplied by the related values which are either calculated by OLGA or set in the input file depending on whether the tuned parameter is dynamically calculated by OLGA or case invariant. e. through an output signal terminal. PIPE and SECTION will be processed in a nested manner. The keys POSITION. See also: When to use Methods and assumptions Limitations How to use Tuning The TUNING keyword makes it possible to tune the fluid properties..g. Some output variables are available for plotting per tracer feed and per age group. phase mass transfer and entrainment of liquid droplets into the gas phase. It is not possible to specify these coefficients using the section key. The tuning coefficients AREA. DIAMETER and ROUGHNESS can only be specified for an entire pipe or an entire branch. Transmitter Transmitters are used to measure flow path variables and transmit them to controllers etc. ατ τηε λιβραρψ λεϖελ ριγητ χλιχκ ανδ χηοοσε Αδδ−>ΤΡΑΧΕΡΦΕΕ∆.The following keywords and keys must be set to use tracer tracking. TUNING should be applied with great care. How to use Specify the desired tuning coefficients and where they apply. as it might cause the validation and verification of the OLGA model to no longer be valid. In the property window for the keyword OPTIONS choose: • ΤΡΑΧΕΡΤΡΑΧΚΙΝΓ=ΟΝ Specify one TRACERFEED for each tracer: • Ιν τηε ΟΛΓΑ ΓΥΙ. geometry information. friction. See also: When to use Methods and assumptions How to use When to use The TUNING keyword can be used for adjusting the OLGA model to specific sets of measured data or for sensitivity studies. . sections or positions. In the property window for each TRACERFEED set the following keys: • • • • • • ΛΑΒΕΛ ΑΓΙΝΓ ΧΑΡΡΙΕΡΠΗΑΣΕ ΑΓΕΒΟΥΝ∆ΑΡΙΕΣ ΛΟΩΛΟΩΒΟΥΝ∆ ΗΙΓΗΛΟΩΒΟΥΝ∆ χηοοσε α λαβελ µυστ βε σετ το ΟΝ το τραχκ αγε διστριβυτιον οφ τηε τραχερ σπεχιφψ τηε φλυιδ πηασε ον ωηιχη τηε τραχερ ισ βασεδ µαψ βε σπεχιφιεδ ωηεν ΑΓΙΝΓ=ΟΝ (νυµβερσ σεπαρατεδ βψ χοµµα) αγε βελοω ΛΟΩΛΟΩΒΟΥΝ∆ ισ νοτ πλοττεδ αγε βελοω ΗΙΓΗΛΟΩΒΟΥΝ∆ ισ νοτ πλοττεδ υνδερ χερταιν χονδιτιονσ Τραχερσ µαψ βε φεδ ιντο πιπελινεσ ειτηερ ϖια α ΣΟΥΡΧΕ ορ ϖια α ΜΑΣΣΦΛΟΩ νοδε. Ιν τηε προπερτψ ωινδοω φορ α ΣΟΥΡΧΕ ορ α νοδε οφ τψπε ΜΑΣΣΦΛΟΩ σετ τηε φολλοωινγ κεψσ: • • • • • ΣΟΥΡΧΕΤΨΠΕ ΤΡΑΧΕΡΦΕΕ∆ ΤΡΑΧΕΡΜΑΣΣΦΛΟΩ ΤΡΑΧΕΡΑΓΕ ΤΡΑΧΕΡΡΕΣΙ∆ΕΝΧΕΤΙΜΕ σελεχτ ΤΡΑΧΕΡ σετ τηε ναµε οφ τηε τραχερ φεεδ ιν τηισ σουρχε/νοδε σπεχιφψ τηε τραχερ µασσ φλοω σπεχιφψ τηε αγε οφ τηε τραχερ σπεχιφψ τηε ρεσιδενχε τιµε οφ τηε τραχερ Το χοµπυτε αγινγ οφ α κινετιχ ηψδρατε ινηιβιτορ. g. oil and water) or being part of the stationary bed or wall layers. modifications of the heat transfer coefficient between the fluid and the pipe wall 6. Please refer to the "Model. Well. User defined dispersed phases are defined through the input groups UDPHASE. hydrate formation. Limitations Some default sample physical models are included in the plug-in DLL provided with the installation. The formation of the UD phases. modification of apparent viscosity due to the presence of the dispersion 4. Numerics and Programmer’s Guide for the OLGA Plug-In". The option is activated through the UDOPTIONS COMPOSITIONAL key. as e. Methods and assumptions User Defined phases (UD phases) are assumed to be either transported in one of the built-in carrying flow layers (gas. for defining a “dispersion in dispersion”. Loss. FLUID keyword. UDOPTIONS (CaseDefinition section) and UDGROUP (UDData section). These are then referred to by SOURCE and NODE (for boundary conditions) or INITIALCONDITIONS (for specifying the amount of UD phases at the start of the simulation) Plug-in DLL: Through UDOPTIONS PLUGINDLL the user may refer to a DLL to be used by the program for handling of dispersions. OPTIONS DRILLING=ON. The "Model. sand transport. Numerics and Programmer’s Guide for the OLGA Plug-In" for a detailed description of how to program a DLL with physical models to be used by OLGA. mass transfer between layers (e. please refer to the "Model. PVT properties of the new phase and optionally modification of the gas/oil/water properties 5. mass transfer between phases (e.) UDGROUP is used to define combinations of UD phases. sources and for giving initial conditions. This file is to be used by the user defined plug-in. UDPHASE defines the dispersions to be tracked. UDDISPERSION and UDPDF (in the Library section). Leak. OPTIONS WAXDEPOSITION=ON. Physical models can then be provided in a user made DLL for 1. transport between layers. The available interfaces and functionality is presented in the Plug-in Guide. are to be given in the user provided plug-in DLL. a hydrate formation model) 2. Numerics and Programmer’s Guide for the OLGA Plug-In" describes the methods applied in the sample plug-in DLL provided with the installation. a combination of hydrates and water UDPDF is used to specify size distribution functions UDOPTIONS is used for overall simulation parameters (In order to use UDOPTIONS. For further limitations.The user may through the input define new User Defined dispersed phases (“UD phases”) inside each layer and phase in the OLGA model as depicted above. See also: When to use Methods and assumptions Limitations How to use When to use The plug-in framework for user defined phases is designed for simulation of e. Pump. models for properties of the UD phases etc. Compressor. How to use Please refer to the "Model. NOTE: This option cannot be run simultaneously with the OLGA Compositional Tracking Module.g. It may be referenced by the FLOWPATH BRANCH and NODE. Phase split node. The sample cases utilize the models in this DLL. OPTIONS UDPLUGIN must be set to YES. i. CheckValve. NearWellSource. Valve. The feeds may then be referenced by nodes. These are available for test purposes only in order to illustrate the use of the framework for User Defined phases (UD phases).e. COMPOSITIONAL=ON/MEG/… . and where the user wants to utilize in house physical models coupled to OLGA. The file to be used is defined under FILES UDFILE. sand deposition to a bed or wax deposition to a wall layer) 3.g. wax deposition or other phenomena involving solid particle type dispersions. Numerics and Programmer’s Guide for the OLGA Plug-In" for a detailed description of the use of this system. Slug Tracking The system cannot be used in connection with the following models or modules: Separator. . OPTIONS TRACERTRACKING=ON Some of these limitations may be lifted in future versions. referring to a phase recognized by the models in the DLL UDDISPERSION defined a set of UDPHASEs. HeatExchanger. A separate file defining the feeds and their properties must be given under FILES UDFEEDFILE. Compatibility The plug-in framework with tracking of User Defined phases is compatible with the following models or modules: Source. Compositional UD option: The composition of a dispersed UD phase may be tracked.g. compositional calculations A sample DLL with some simple physical models is provided with the installation. PVT Properties: PVT properties for a UD phase may be given as input to a user defined plug-in. WALL At least one of these options must be given if a UD phase variable shall be plotted. If INMASSFRACTION and OUTMASSFRACTION are specified. The pre-defined phases (gas. by reference either to a UDGROUP or a UDFEED. P-SAUTER: Sauter mean for r P-NUMMOM1: Number based statistical moment for r P-NUMMOM2: Number based statistical moment for r2 P-NUMMOM3: Number based statistical moment for r3 P-BOUNUMMOM1: Flowing number based statistical moment for r P-BOUNUMMOM2: Flowing number based statistical moment for r2 P-BOUNUMMOM3: flowing number based statistical moment for r3 P-MASSMOM1: Mass based statistical moment for r P-MASSMOM2: Mass based statistical moment for r2 P-MASSMOM3: Mass based statistical moment for r3 P-STATP1: Statistical parameter – mean value P-STATP2: Statistical parameter – standard deviation P-STATP3: Statistical parameter – skewness These variables are available for regular trend and profile plots and text output. To enable these plot variables. these are used with linear interpolation 2. Furthermore. A relative range 0-19 is used. while other distributions can be given in the UD plug-in. Size distributions may be plotted using the XYTDATA definition under OUTPUT for each FLOWPATH. Pressure boundary: The mass fractions of UD phases at a pressure boundary are defined for each relevant NODE by reference either to a UDGROUP or a UDFEED. . The variables are grouped under “ParticleField” in the output variable list and cover this information for each dispersed phase: P-ACCG : Accumulated mass flow [kg/s] P-ACCQ : Accumulated volume flow [kg/s] P-G: mass flow rate [kg/s] P-HOL: volume fraction [-] P-M: specific mass [kg/m3] P-Q: volumetric flow rate [m3/s] P-U: velocity [m/s] P-US: superficial velocity [m/s] P-E0: statistical moment [kg/m6] P-E1: statistical moment [kg/m5] P-E2: statistical moment [kg/m4] P-EU0: statistical moment velocity [m/s] P-EU1: statistical moment velocity [m/s] P-EU2: statistical moment velocity [m/s] P-E0-FLOW: flowing statistical moment [kg/m6] P-E1-FLOW: flowing statistical moment [kg/m5] P-E2-FLOW: flowing statistical moment [kg/m4] P-H: Enthalpy of UD Phase [J/kg] P-CP: Specific heat of UD Phase [J/kg/K] P-RO: Density of UD Phase [kg/m3] P-DRDP: Pressure differential of UD Phase [kg/m-N] For particle size distributions the output variables below are available. starting from the bottom of the pipe. Otherwise the value in MASSFRACTION corresponding to the start time is used Plotting of output Specific output variables are available for plotting of dispersed phases. All three options can be combined. The plot interval is the same as for the TREND plots.Inflow: The inflow of UD phases is defined for each SOURCE. WATER. Selecting the variable P-SD in this statement generates a plot file with extension “xyt”. Distributions are then plotted for all vertical positions at the given point in the pipe. OLGA supports Log Normal. PHASE = <UD-PHASE> DISPERSION = <UD-DISPERSION> FLOWLAYER = ALL. cross sectional plots of particle concentration and dispersion velocity are available through the CROSSDATA definition under OUTPUT for each FLOWPATH: Concentration of dispersion (particles) from bottom to top of line along vertical diameter: P-CON Volume velocity profile from bottom to top of line along vertical diameter: U-PROFILE These data files have extension “csp” and can be plotted in the GUI. but will be added to FLOWLAYER when plotting without any specified PHASE or DISPERSION. The latter refers to a UD phase composition that must be defined in a plug-in. one or all of PHASE. The values for each UDFRACTION in the UDGROUP are used as follows: 1. Initial conditions: The initial fraction of each UDGROUP in the pipeline is given by the reference to UDFEED (for composition tracking) or UDGROUP under INITIALCONDITIONS. BED. and water) are not available for plotting of UD phase variables. Time points for plotting are specified with the Output group XYT. OIL. oil. The concentration profile will be plotted for each UD phase and the plot variables will automatically be labeled accordingly in the csp file. DISPERSION. Example plot: Different Log Normal distributions. The statistical distribution defined on UDPHASE/UDDISPERSION is used. and FLOWLAYER must be given. The option for using distribution functions (UDOPTIONS SIZEDIST = ON) must be selected. The latter refers to a UD phase composition that must be defined in a plug-in. GAS. VARIABLE=(P-M) Water The purpose of the Water model is to let the user specify the parameters and model used for oil/water dispersion viscosities and to specify the approach used to determine the water distribution between liquid and gas phases. the user assumes that there is no velocity difference between the oil and water flow fields. VARIABLE=(P_M) To plot for the total dispersion HydrateWater from all layers (including bed and wall): TRENDDATA DISPERSION=”HydrateWater”.5). … Ex 1 – Plot for whole phase/dispersion To plot for the total phase Hydrate from all layers (including bed and wall): TRENDDATA PHASE=”Hydrate”. Between a lower critical water cut (given by FWLOW) and the inversion point (given by INVERSIONWATERFRAC). Phase inversion is assumed to occur at a water cut given by the user through the key INVERSIONWATERFRAC (default value of 0.g. depending on the phase velocities and the material properties. The degree of mixing of water into oil is predicted by the standard OLGA model. VARIABLE=(P-M) Ex 3 – Plot for layers To plot for the gas layer: TRENDDATA FLOWLAYER=GAS. In this case oil and water are always assumed to flow as a homogeneous mixture with average properties. … UDDISPERSION LABEL = "HydrateWater". The degree of mixing of oil and water can vary from fully separated to fully dispersed. VARIABLE=(P-M) To plot for the phase Hydrate in the gas layer and in the bed layer (2 plots): TRENDDATA DISPERSION=”HydrateWater”. The module may also be used for sensitivity analysis with respect to dispersion e. VARIABLE=(P-M) To plot for all layers (5 plots): TRENDDATA FLOWLAYER=ALL. BED). the flow is assumed to be a water-in-oil dispersion flowing above a free water layer.Examples Given a case with the following UD phase definitions: UDPHASE LABEL = "Hydrate". . the water volume fraction at inversion point. However. See also: When to use Methods and assumptions Limitations How to use When to use Changes to the dispersion model are recommended when experimental data shows that the default options do not give a good description of the fluid. Water droplets are entrained in the oil if the water cut in the liquid film is less than the phase inversion point. FLOWLAYER=GAS. This velocity difference is termed the "slip velocity" or just "slip". By turning the water slip option off (WATERSLIP = OFF). The liquid droplets flowing in the gas phase are not included in this context. It is also possible to specify an intermediate dispersion range. and vice versa. VARIABLE=(P-M) Ex 2 – Plot for phase/dispersion in layer To plot for the phase Hydrate in the gas layer: TRENDDATA PHASE=”Hydrate”. This applies to all gas/liquid flow regimes. VARIABLE=(P-M) To plot for all phases in all layers (5 plots): TRENDDATA PHASE=”Hydrate”. but the maximum fraction of the total water stream that can be mixed into the oil is given by EMAX: (Volume flow of water in oil)/(Total volume flow of water) ≤ EMAX. water enthalpies are accounted for in the temperature calculations. FLOWLAYER=ALL. The fluid mechanical model reduces to a two-phase gas-liquid model. FLOWLAYER=(GAS. Methods and assumptions Calculation of velocity difference between water and liquid hydrocarbon ("slip velocity") Two different options can normally be used for calculating the velocity difference between liquid water and hydrocarbon liquid (we term the latter "oil" for simplicity). Pal & Rhodes correlated with experimental data. Frel (Fh or Fw depending on the inversion point) and mρελ (mρελ. Rønningsen: Another correlation for relative viscosities of an oil continuous dispersion is the correlation by Rønningsen recommended for a shear rate of 500 1/s (2003) /17/: (f) where mρελ. The equations below show the Pal & Rhodes correlations for relative viscosity of an oil continuous dispersion (mρελ.0 respectively. no such intermediate range is defined.η) and a water continuous dispersion (mρελ. Woelflin: A third option for the relative viscosity is given by Defined by WATEROPTIONS DISPMODEL = WOELFLIN.765 (Søntvedt et al. mρελ is limited upwards to 10000. Pal & Rhodes and Pal & Rhodes correlated with experimental data: One correlation for relative viscosities of liquid/liquid dispersions was developed based on a generalization of Einstein’s equation to also be valid for high concentrated dispersions. 1994).η) specified. Frel is defined with the key PHIREL. six different viscosity models can be chosen: Pal & Rhodes. A third option is also available: The user may specify a constant velocity difference between oil and water. It is still left to investigate how to discriminate between oil and water continuous dispersions.2) and BWOELFLIN (default value 2. In the present version of the model. this correlation and the correlation parameters are also applied for water continuous dispersions using the analogous quantities. the relative viscosity is given by where Here µc and µd are the viscosities for the continuous and dispersed phases. Based on pipe flow experiments on stable oil continuous emulsions for different crude oils and formation waters. Woelflin. Barnea & Mizrahi or table based model. Table based model: The final way of giving a dispersion viscosity correlation is to use the bable based model. The model is activated with WATEROPTIONS DISPMODEL = BARNEA. Barnea & Mizrahi: For the Barnea & Mizrahi correlation. Dispersion viscosities With the dispersion viscosity option turned on (DISPERSIONVISC= ON). mmix = (moil*(1-WATERCUT) + mwater* WATERCUT)*VISCMOD (g) where the tuning factor VISCMOD can be specified through input as a tabulated function of WATERCUT. and is the concentration of oil droplets in the water continuous dispersion.. The possibility to use a simple volume weighting with a tuning factor is also available. Rønningsen. Two parameters can be set with this model: AWOELFLIN (default value 4.ω): (c) (d) where is the concentration of water droplets in the oil continuous dispersion. The input is used as in this example: . respectively.5). the parameter is set equal to 0. the viscosity of the oil in water dispersion is assumed equal to the pure water viscosity.With the default values of FWLOW and EMAX. This can be defined by WATEROPTIONS DISPMODEL = INPUTVISC. The parameter is the dispersed phase volume fraction for which the relative viscosity mρελ equals 100. Equation (d) is used. With an experimental point. 0.ω or mρελ. mrel with the key VISCREL. and the inversion point with the key INVERSIONWATERFRAC. the Pal & Rhodes method in Equations (c) and Equation (d) is rearranged to calculate the value: (e) Equation (c) will then be used to calculate the water in oil dispersion viscosity.η = Relative viscosity (dispersion/oil) T = Temperature (deg C) Fw = Volume % of water dispersed in oil Above the inversion point.0 and 1. The correlation was published by Pal and Rhodes (1989) /15/ and is primarily developed for dispersions where coalescence and deposition has negligible influence on the pressure drop (and the apparent viscosity). The mixture viscosity for oil continuous dispersions (mηω) and water continuous dispersions (mωη) are expressed as: (a) (b) where mη [cP] is oil viscosity. This is a special option that should only be used with great care in special cases for tuning purposes. mω [cP] is water viscosity and mρελ [-] is relative viscosity (dispersion viscosity / viscosity of continuous phase). For oil in water dispersion. when the Rønningsen method is applied. The various mass fractions then become: Rs = 50/(50+30) = 0. source is considered to be liquid water. source.mass flow rate of total water (vapor + liquid) .7. inclusion of the inhibitor tracking option may provide more accurate calculation of the distribution of water between phases. however.0.mass flow rate of liquid water .02 Rsw = 20/(50+30+20) = 0. The user should be aware that when performing standard simulations with PVT tables there is no separate water vapour mass balance equation.6. the gas phase is assumed to be saturated with water. Therefore. WATERCUT must be given as a list ascending values for the water cut. a mass source at a specific temperature and pressure are then by definition: Rs Rswt Rswv Rsw where Rs Rswt Rswv Rsw Gtot Ghc Gw GwL Ggas Gwv = Ggas/Ghc = Gw/Gtot = Gwv/Ggas = GwL/Gtot .0. Flashing/condensation of water With the water flash option turned on for standard simulations with PVT tables (FLASHMODEL = WATER in the OPTIONS keyword) the amount of water that evaporate or condense is calculated by OLGA under the assumption that the gas phase is always saturated with water vapour.1.g.liquid water mass fraction (WATERFRACTION) .0. WATERCUT=( 0.0.4.3. Hints and tips Water fractions in sources.765).0.mass flow rate of total gas (including any water vapor) .0.g. water vapour in the gas phase is assumed to be zero and FLASHMODEL = WATER is disregarded.2. the inlet total water mass flow rate is not sufficient to saturate the gas at the water vapour mass fraction from the PVT table.WATEROPTIONS DISPMODEL=INPUTVISC.total water mass fraction (TOTALWATERFRACTION) . the water vapour will be taken into account depending on FLASHTYPE in COMPOPTIONS.source total mass flow rate . PHI100 must be given (default: PHI100 = 0. If the fluid temperature becomes sub-zero. will be set to zero.1. all water in the calculations will be free water. However. therefore.g.gas mass fraction . The relations between the various mass fractions and mass flow for e.2. PHIREL and VISCREL are required for the EXPERIMENT option (default: PHIREL = 0. the user may specify a constant velocity difference between oil and water with WATERSLIP = CONSTANT. The amount of water vapour is determined by the water vapour mass fraction from the PVT table. it is not assumed that the gas phase is saturated with water vapor. meaning that the fluid is in thermal but not in chemical equilibrium (sub-cooled water. If TOTALWATERFRACTION is set to -1. When using two-phase PVT tables in OLGA simulations. that is.mass flow rate of water vapor in the gas phase Example: Assume a flowing mixture consisting of 50 kg/s gas (saturated with water).0.1.0. Furthermore.9.5). Wax deposition .source total mass flow rate exclusive of liquid water . 30 kg/s of oil and 20 kg/s of aqueous phase.8.15. If DISPERSIONVISC = OFF. For three phase simulations.9. The pressure and temperature dependent mass fraction of water vapour in the gas phase at water saturation is determined from the fluid properties table. while with FLASHMODEL = HYDROCARBON the value is interpreted as only free water (resulting in more free water than with FLASHMODEL = WATER).1). The velocity difference is the specified by the key VELOCITYDIFFERENCE. the total water mass could be in error for cases where e. its actual value is taken from the fluid properties table. With FLASHMODEL = WATER this value is split into free water and water in gas according to the water mass fraction in gas values from the fluid table.1)\. the enthalpy and entropy are extrapolated. Finally. Dispersion viscosities The water volume fraction at inversion point is determined by the key INVERSIONWATERFRAC (default: INVERSIONWATERFRAC = 0. For multiphase transport systems where liquid accumulation could represent a problem. If water properties are calculated by OLGA itself.3. \ VISCMOD=(1. WATERFLASH has no effect on Compositional Tracking simulations.1.water vapor mass fraction (always from fluid table) . WATERSLIP=ON Note that the "Table base model" should use WATERFLASH=ON and WATERSLIP=ON. This is consistent with the 3-phase PVT tables created by PVTsim.4. the volume weighting calculation of viscosities can be tuned using the keys VISCMOD and WATERCUT. it is recommended to perform three phase flow computations with the water slip switched on.765 and VISCREL = 100).\.8.1. the viscosities are read from the fluid property file directly if WATERSLIP = ON. WATERFLASH=ON.5. oil and water are always assumed to flow as a homogeneous mixture with average properties. viscosities of liquids are weighted according to volume fraction. How to use The following sections describe how to use the keys in the WATEROPTIONS keyword. When WATERSLIP = OFF | CONSTANT. If the inhibitor tracking module is used (which uses PVT tables). MEG tracking has a water vapour mass balance equation that makes it suitable for simulating three phase systems where a detailed analysis of the water distribution is necessary (can be used with no MEG). For each value in WATERCUT a corresponding value for the viscosity tuning factor must exist in the VISCMOD key.0. If DISPMODEL = PALRHODES. Calculation of velocity difference between water and liquid hydrocarbon By default OLGA calculates the velocities of the oil and water fields separately (WATERSLIP = ON).625 Rswt = (20+1)/(50+30+20) = 0. If WATERFRACTION is specified all the water in the e. The default values for the EXPERIMENT option correspond to the standard PALRHODES model. When modeling a three-phase mixture using PVT tables where you want to include the mass transfer between the free water and the gas phase. When using compositional tracking. the gas might be dry if there is no available water.05. wells and at boundaries (when using PVT tables) are specified either as the mass fraction of liquid water relative to the total mass (flow) with the keyword WATERFRACTION or as mass fraction of total water (liquid water plus the water vapour in the gas phase) with the keyword TOTALWATERFRACTION. In some instances. in which case flashing of water is decided by FLASHTYPE in COMPOPTIONS. The water vapour mass fraction.2. internal routines are used for the calculation of water properties. Limitations The three phase flash option is only valid when a three phase fluid property file is used. the water option in OLGA must be used with FLASHMODEL = WATER.21 Rswv = 1/50 = 0. The water vapour fraction of the gas phase is taken from the fluid properties table.05. This is a special option that should only be used with great care in special cases for tuning purposes. If DISPERSIONVISC = OFF and WATERSLIP = OFF.1. If WATERSLIP = OFF.7.20 Please observe that either TOTALWATERFRACTION (Rswt) or WATERFRACTION (Rsw) can be specified for the same e.2. This option is more important for gas production systems than for "normal" oil production systems. the dispersion viscosities are calculated according to the model specified in the DISPMODEL key. not ice). let the saturated gas flow include 1 kg/s of water.1. If DISPERSIONVISC = ON.1.g. Heat balance for precipitation. the laminar velocity boundary layer is used. The format of this file is described in Wax table file. Oil viscosity is adjusted to take into account any suspended (dispersed) wax Wax precipitation and dissolution in bulk Precipitation and dissolution/melting of dispersed wax are calculated from variations of the wax component solubility with pressure and temperature. The MATZAIN model uses the laminar thermal boundary layer and an adjustment constant to enhance diffusion. The key may be applied for all deposition models. The shear stripping terms are taken from the Matzain model /12/. deposition and melting of wax. NSR is a flow regime dependent Reynolds number /12/: Where and is the oil density [kg/m3]. See also: When to use Methods and assumptions Limitations How to use When to use When case laboratory experiments indicates the presence of wax. 3. is the oil viscosity kg/(m s).The wax deposition module allows for modeling of wax precipitation and deposition of wax on the wall. Wax layer porosity (volume fraction of trapped oil in wax layer).055 and C3 = 1. Values: C2 = 0. The equation for the rate of change in wax layer thickness is as follows: [kg/(cm2s)] (b) where C2 and C3 are the constants given in /12/. License requirements The Wax Deposition Module requires a separate license. The RRR and HEATANALOGY models are using the Hayduk & Minhas correlation. or by transfer of precipitated wax due to shear. A model for shear stripping of wax is used as a wax deposition limiting effect in the MATZAIN and HEATANALOGY models. is the liquid velocity. During a system shut-in. is the change rate due to diffusion. is the oil velocity [m/s]. 4. It is assumed that the precipitation rate at the wall is much quicker than the rate of wax transported to the wall. and porosity effects. 5. Methods and assumptions The model takes into account the thermal-hydraulic effects of the wax in the following way: 1. either by diffusion of dissolved wax due to a temperature difference between fluid and wall. Wax deposited at wall 2. Production cases where low fluid temperatures occurs in the pipeline. The value is directly multiplied with the diffusion coefficients calculated by the code. when the temperature may fall under the wax appearance temperature and wax solids starts to precipitate. Gelling of the oil may occur at zero fluid velocity and sufficiently low temperatures. Mass conservation equations are solved for a. Pipe diameter and roughness for each section is adjusted depending on the thickness of wax deposited on the wall. This may cause both a reduction in effective pipe diameter and a severe increase in oil viscosity. Shear deposition effects may be included by applying the key COEFSHEAR when using the RRR or HEATANALOGY models. The boundary layer is calculated differently for the different models activated through the key MODEL. is the wax layer thickness [m].0 from /12/ is included in for the MATZAIN model only. so that all wax transported from bulk to wall immediately precipitates. Transport mechanisms from bulk to wall Wax deposition can occur in two ways. The wax file can be generated in PVTSim. The solubility variations are taken from the wax property tables. mass diffusivity (Lewis number). Wall heat transfer is adjusted to take the wax layer into account 6. The wax deposition rate due to molecular diffusion may be described by: (a) Where G is the mass transfer rate of wax deposited and D [cm2/s] is the molecular diffusion coefficient. In the RRR model. Volume change due to precipitation. Wax precipitation is calculated based on a pre-calculated wax table containing data on each of the wax forming components. making it difficult to restart the pipeline. and L [cm] is the thickness of the boundary flow layer. The HEATANALOGY model uses a laminar concentration boundary layer based on the laminar thermal layer and the ratio of thermal vs. where wax both deposits at the wall and precipitates as particles suspended in the oil. Wax deposition will be calculated for all flow paths. The constant C1 = 15. is the average density of the gas-oil mixture It is possible to adjust the constants related to the shear stripping model by using the keys SHEARMULTC2 and SHEARMULTC3. and the wax appearance temperature is within the temperature envelope encountered during pipeline operation. These are tuning parameters multiplied directly with C2 and C3 . It is possible to adjust the diffusion coefficient for the wax components by using the key DIFFCOEFFMULT. deposition and melting of wax. Wax dissolved in oil b.4. Example cases: a. φ [-]. The MATZAIN model is using the Wilke & Chang correlation. respectively. Both diameter reduction due to the wax layer at the wall and the effect of suspended wax particles on oil viscosity may significantly increase pipeline pressure drop and thereby reduce the production capacity of a pipeline. ρoil [kg/cm3] is the oil density. b. mfr [-] is the mass fraction of wax components. Wax precipitated and dispersed in oil c. The deposition rate constant K* (=COEFSHEAR) determines the volume rate of precipitated wax deposited due to shear by the following formula: . is taken into account when calculating the wax layer thickness. but different wax data can be given for each flow path. The dissolved wax concentration at the wall is adjusted when the wall surface temperature is above the dissolution temperature (found by applying DISSOLTDIFF). is the weight Limitations . These are multiplied with the D. while DISSOLTDIFF may be a constant or a function of the section pressure (through the given DISSOLPRESS). Keys: VISCMULTD. is limited to be or larger. This activates a linear ageing model where the entries for AGEINGTIME. respectively. is the oil viscosity kg/(m s). The conductivity is found by using the following equation [ref. E and F have the following values (viscosities in Pa s and shear rates in s-1) D= E= F= 18. koil is the conductivity of oil and fraction of solid wax in the wax film. 2. The total dissolution and diffusion rate of wax from wall to bulk. 4.876*106 In the PVTsim program from Calsep. . is the inner pipe diameter including the wax layer [m] The effect of ageing may also be included by using the keys AGEINGOPT=AGEING.13] (f) Where kdep is the overall thermal conductivity of the wax film.0e+12. DISSOLTDIFF and DISSOLRATE for the RRR model. The porosity of the wax layer is taken into account when calculating the thermal conductivity of the wax layer.0 and 1. The default value of DISSOLRATE is 1. 3.bulk. The resulting tuning parameters may be given directly as input to OLGA when using the Calsep viscosity model.1 7. is limited upwards by DISSOLRATE (kg/(m2s )): where is the mass diffusion rate based solely on the wax concentration differences between wall and bulk (see point 3). When Cwax. melting will occur. The instantaneous porosity equation used by the code is as follows /12/: (e) where and is the porosity (volume fraction of oil in the wax film). INITPOROSITY and HARDPOROSITY. INITPOROSITY and HARDPOROSITY are used to determine the derivative of porosity with time. the roughness due to deposited wax (keys: WAXROUGHNESS and MAXROUGHNESS) and the thermal conductivity of pure wax.Cwax. aged layer at each time step. kwax is the conductivity of pure wax (=CONDUCTIVITY in input).0). E and F parameters. is the liquid velocity [m/s].(c) Where Cwall is the volume fraction of precipitated wax in the oil at the inner wall temperature. is the oil density [kg/m3]. The dissolved wax concentration derivative with respect to temperature is found at the cloud point for the pressure in the section. The adjusted Cwax. The instantaneous porosity of wax added to the wax layer may be set as a constant (INSTPOROSITYOPT = MANUAL. The conductivity may be set manually in the input file by using CONDUCTOPT = MANUAL and set CONDUCTIVITY.bulk . WDT is the dissolution temperature: WDT = WAP + DISSOLTDIFF WAP is from the wax tables. WAXPOROSITY between 0. The parameters D. DISSOLPRESS.wall is the driving potential of the diffusion process. Wax layer properties: One may also give information about the porosity (oil volume fraction) of the wax layer. is the shear rate at the wall [1/s]. minimum and maximum limit given by MINPOROSITY and MAXPOROSITY). A is the surface area available for deposition [m2] Transport mechanisms from wall to bulk (dissolution of wax layer) Dissolution/melting of wax deposited on the wall may be activated separately through the keys DISSOLUTION. TWS is wall surface temperature. The reduction to DISSOLRATE is done so that the mass fraction of the wax components transported by diffusion is kept constant. is the shear rate. and is the average density of the wax [kg/m3]. VISCMULTF.wall > Cwax. VISCMULTE. which means that there is no limitation of the dissolution and molar diffusion rate. The melting process is calculated by the following method: 1.wall is used in the normal diffusion equations where Cwax. . The resulting viscosity. or be calculated by the code (INSTPOROSITYOPT = AUTOMATIC. AGEINGTIME. when using the key VISCOPTION = CALSEP. or it may be taken from the wax tables (CONDUCTOPT = TABLE). where Cwax is the concentration of wax. The apparent viscosity of oil with suspended wax particles is calculated as follows: (d) where is the viscosity of the oil not considering solid wax and the volume fraction of precipitated wax in the oil-wax suspension. The adjustment is as follows: is the concentration derivative with respect to temperature at the cloud point (see point 1).12 405. The current model is the same as used in PVTSIM 16. . Viscosity of wax/oil dispersions: Calculation of the viscosity of the wax/oil dispersion is done by using a model supplied by Calsep A/S. it is possible to tune the wax-oil dispersion viscosity model to measurements. The porosity is averaged over the new layer and the old. The shear rate used in the equation is limited to be 10 s-1 or larger to avoid division by zero. When generating the OLGA PVT table. which is taken into account in the model. unstable flow. oil. the inlet or bottom hole flowing pressure is calculated by adding the hydrostatic pressure drop to the pressure in the well section.1]. /12/ The required model is chosen by using the key MODEL in keyword WAXDEPOSITION. well bore. See The Wells Module for more details. The trend file and profile file are text files that can be viewed in the OLGA GUI. well testing. A scaling factor for determining the amount of wax forming components relative to a HC mixture. the gas mass fraction of the oil and gas mixture of the well fluid. The plot file is a binary file that is viewed in a separate plotting tool called the OLGA Viewer. Al. GASFRACTION. rate changes. pipeline network and facilities simulators are used to construct an analytical model of the full field production system.tpl). Step 1: Generate a wax file and an OLGA PVT table in PVTsim. A sample case for wax deposition is described in Sample: Waxdeposition. quadratic.plt) are used for plotting several variables related to wax deposition: The different was deposition variables are described in Waxdeposition Output Variables. e. If the water option is not used. How to use Input To use the wax deposition module.ppl) and plot file (*. the equilibrium gas mass fraction will be used.g. Wells Module The wells module provides the possibility of building virtual wells that can be used to analyse ”what if” case scenarios. PROFILEDATA and PLOT in the input file specifies the output from the simulation. Phase fractions For flows from the well section into the reservoir. When it is placed at the inlet. compositional tracking or the inhibitor tracking models. WATERFRACTION (or TOTALWATERFRACTION) are given. Due to the binary format this file can use a shorter plotting interval and is useful for detailed analysis. If GASFRACTION < 0 is given. The steady state pre-processor will not consider the wax phase. This is especially useful for analyzing transient well behaviour such as start-up/shut-down. however. the total mass flow is calculated with the gas mass flow fraction equal to the gas mass fraction within the well section. See also: When to use Methods and assumptions Limitations How to use When to use The Wells module is suited for the following applications: Start-up and shut down of production and well testing Complicated production from several reservoir zones Reservoir injection. the amount of wax in the inflow will be according to equilibrium (specified in the wax data file). wax) should be used. WELL and/or SOURCE to specify WAXFRACTION. . normally not have a significant effect on the properties of the oil phase. Please also see /36/ which covers different topics where the OLGA wells module could be used. Wax deposition may be calculated by using one of the three following models: RRR model /6/ HEATANALOGY model /14/ MATZAIN model. follow the steps below. TREND to print wax variables for given positions to a trend plot file OUTPUT to print wax variables for a branch at given times to an output file PROFILE to print wax variables for a branch at given times to a profile file Output The keywords TRENDDATA. apart from the viscosity of the oil/wax dispersion. or tabular are enabled by the Wells Module that requires a separate license. where a combination of reservoir. The wax phase will. OPTIONS to set WAXDEPOSITION = ON OPTIONS TEMPERATURE = WALL FILES WAXFILE to specify the file containing the wax data WAXDEPOSITION to specify wax specific data for each flow path. If all inflow boundaries have WAXFRACTION = 1 (default value). well clean-up. Step 2: Prepare the OLGA input using the following keywords. BOUNDARY.. profile file (*. Methods and assumptions Well placement options A well can be placed at the mid-point or the inlet (bottom) of the well section. The trend file (*.Note: The wax deposition model cannot be used together with the slug tracking. An Wells Module is available for well flow applications where the reservoir properties and the inflow relationships play an important role in the modeling. the bottom hole flowing pressure is equal to the pressure in the well section. It also enables a full-field integrated modelling approach. For the flow from the reservoir into the well section. The value must be in the range [0. and water mass fraction in the total mixture of the well fluid. water alternating gas injection (WAG) Analyzing cross flow between different reservoir zones Water cut limit Flow from multilateral wells Flow stability Flow assurance (hydrates) Gas lift requirements Production optimization Well test equipment sizing License requirements Production or injection flow equations other than linear. multiphase flashing (gas. liquid loading and chemical injection. as described by Matzain et. If the well is placed at the mid-point of the section. pR the reservoir pressure. B and C are constants. the negative enthalpy source will correspond to the pressure and temperature conditions in the well section. 3. and pwf the bottom hole flowing pressure. Constant B is defined as the productivity index. the flow rates are determined by a linear extrapolation using the tangent to the quadratic curve at the end point of the table. the constants A and B for the equivalent well are: A = NAi B = NBi where Ai and Bi are constants for each parallel well. B and C are constants. With the Wells Module seven new models for calculating the reservoir inflow are available. The relationship between the flow rate (or other well parameters) and the pressure difference is given by a table. Equation (g) in the Wells Module. If the linear equation is used. Tabular form (see keyword TABLE): The table input option is made to support gas and water coning. qf¥ is the steady-state flow with the bottom hole flowing pressure at time t. the constants A. When Pwf is above Plim. Linear formula: Gw = A + B( pR . and Tf is the time constant for the flow of phase f. Use one of the following procedures to construct data for the equivalent well: 1. Constant A allows for a minimum pressure difference required for the fluid to start to flow from the reservoir to the well and it must be less or equal to zero. f. The isothermal option assumes that the fluid enters the well at the reservoir temperature. The inflow model Constant productivity index. 3. Constant A represents the minimum pressure difference required for the fluid to start to flow from the well into the reservoir and it must be less than or equal to zero. Dynamic Well Inflow An option is available for simulating the dynamic characteristics of a well. If the well performance is given by a table. This model is available for all users and is described in section Constant productivity index. Tf can change with Pwf. A is the minimum pressure required for flow to start from the well into the reservoir. Options for calculating flow rate Flow from reservoir into well Two thermal options for calculating enthalpy inflow are available. 1. see The Wells Module for further information. Plim. 3. 2.f. can also be used for linear inflow. will be set to zero. Constant A allows for a minimum pressure difference required for flow to start from the reservoir to the well. the program will automatically add a zero pressure difference. If the user does not give a zero flow point in the input.WATERFRACTION should be zero (default value). as well as the time constant .pR2 where A. 2. 2. Non-linear formula: A + BGw + CGw2 = pwf2 .f. The following three options are available for specifying the relationship between the mass flow rate and the pressure difference. Pwf. there are two ways to prepare the data for these wells: Give input data for each individual well. If the user does not give a zero flow point in the input. Equation (g) in the Wells Module. Tabular form (see keyword TABLE): The table input option is made to support gas and water coning. Bi and Ci are the constants for each parallel well. the flow rate in the table is the sum of the flow rates of all the parallel wells at the same pressure difference. Note: If equivalent pipe is used and there are wells in each parallel pipe. The steady-state flow for each phase is calculated by: (b) when the flowing pressure. The following three options are available for specifying the relationship between the mass flow rate and the pressure difference (with the Wells Module seven new options are available – see The Wells Module). can also be used for linear inflow. If the non-linear equation is used. PIf. For pressure differences larger than the maximum value in the table. For these models the reservoir performance can be specified through reservoir variables or from draw-down/build-up tests from the actual well. the reservoir fluid enthalpy is calculated on the basis of reservoir temperature and reservoir pressure. B and C for the equivalent well are: A = Ai B = Bi/N C = Ci/N2 where Ai. 1. the program will automatically add a zero point at zero pressure difference.pwf ) where Gw is the mass flow rate. The interpolation and extrapolation procedure is the same as for flow from the reservoir to the well.pwf2 where A. This model is available for all users. Non-linear formula: A + BGw + CGw2 = pR2 . The inflow model Constant productivity index. Flow from the well into the reservoir For negative flow from the well to the reservoir. For pressure differences within the range of the table. The fluid temperature may change as the pressure decreases from the reservoir pressure to the pressure at the well section due to constant enthalpy expansion and flashing. If the adiabatic option is used. The relationship between the flow rate (or other well parameters) and the pressure difference is given by a table. and reservoir fluid enthalpy is calculated on the basis of reservoir temperature and well pressure. the flow rates are calculated by a polynomial interpolation of second degree. Use a single equivalent well. Linear formula: Gw = A + B( pwf . For positive well flow. is less than a given threshold pressure. N is number of parallel wells included in the equivalent well. The productivity index.pR ) where Gw is the mass flow rate into the reservoir and constant B is the injectivity index. is calculated by (a) where qf is the instantaneous flow rate for phase f. the instantaneous flow rate for each phase. a transport delay can be modelled by specifying a certain distance that the front of phase f must travel before the actual inflow can be started. This distance.o. For the negative flow. the flow rate into the well section is set to zero. Equation (b) is solved by (c) (d) As an option. Reservoir inflow In the Wells Module the reservoir performance is specified through permeability. e. The Wells Module The Wells Module is designed for well flow applications where the reservoir properties and the inflow relationships play an important role in the modelling.Numerically. or as a first estimate when the production curve for the well is not properly defined: (g) where pR is the static reservoir pressure.o. (l) . the flow rate into the well section is set to qf. The Wells Module will be especially well suited for the following applications: Start-up and shut down of production and well testing. fluid properties etc. (e) (f) If hf > hf. extension of the reservoir. hf. will be user determined. pwf is the flowing bottom hole pressure and J is the constant productivity index given by: Linear productivity (typical oil reservoir) (h) in oilfield units (stb/d/psi) where J kh n Bo re rw s Productivity index [stb/d/psi] Effective permeability x net pay [mD ft] Oil viscosity [cP] Oil formation volume factor [Rft3/Sft3] Reservoir extension [ft] Wellbore radius [ft] Mechanical skin Forchheimer and Single Forchheimer model When the full production curve can be estimated and a constant PI is not applicable a quadratic form of the relation between inflow and draw-down can be used. The transient option is only applied for positive flow (from the reservoir to the well section). for example the Forchheimer model (see ref. The different inflow performance models are presented below.g. Constant productivity index The linear form is used for the production of a typical oil reservoir. pressure can be used instead of pressure-squared. /1/): (i) where B and C are the linear and non-linear part of the productivity index respectively defined by: [psi2/(scf/d)] [psi2/(scf2/d2)] Where: T mg z re rw s D k h (j) (k) reservoir temperature [° (RESTEMPERATURE) R] gas viscosity at reservoir conditions [cP] (VISGRES) Gas z-factor at reservoir conditions (ZFACT) reservoir extension [ft] (RESEXT) wellbore radius [ft] (HOLES/2) mechanical skin [-] (SKINS) non-Darcy or turbulence skin [1/Sft3/d] (SKIND) reservoir permeability [mD] (KPERM) well effective net pay [ft] (HPAY) For high pressure gas wells with limited draw down. The reservoir inflow can be specified in a number of different ways depending on the type of reservoir simulated. Reservoir injection. the constants are assumed to be zero. or from draw-down/build-up tests from the actual well. Flow from multilateral wells. Complicated production from several reservoir zones. The transient option is switched on if one or both of the time constants are greater than zero. water alternating gas injection (WAG). in which case the Single Forchheimer equation is written: . otherwise. Analysing cross flow between different reservoir zones. In these cases the linear inflow relationship will not be sufficient alone to describe the inflow under varying flowing pressures. The initial static reservoir reference pressure is no longer applicable for specifying the inflow from the zone and a reduced reference pressure is introduced.max is the maximum oil rate when flowing bottom hole pressure equals zero. Fracture pressure When the pressure in the wellbore exceeds a certain value above the static reservoir pressure the formation will break down. and the fluid in the wellbore will flow into these fractures instead of flowing into the reservoir matrix. the reservoir reference pressure can be specified as a function of time by the user. Limitations The steady state pre-processor does not handle injection wells. That is. was traditionally used for oil-well performance in saturated oil reservoirs (see ref. but a different relationship can also be used. /1/ ).max is the theoretical maximum oil rate when flowing bottom hole pressure equals zero. when the bottom hole pressure exceeds the static reservoir pressure an inflow into the reservoir will start depending on the injectivity index. This option is for example used for pushing the gas back into the reservoir during a work-over operation. . The following two equations are therefore introduced: for (s) for where pb is the bubble point pressure. a tabulated inflow curve can be specified by the user. Backpressure and normalized backpressure equations For gas wells the following simple equation is often used for the inflow performance (see ref. The inflow into the reservoir can be specified on the same form as the well production. For the model to take these local drawdown and build-up effects into account. See the description in the beginning of this section. /1/ ). Injectivity index The injectivity index is used for modelling of flow from the wellbore into the reservoir zone of gas.where B and C are defined by: [psi/(scf/d)] (m) [psi/(scf2/d2)] where pav is defined as pav= (pR + pwf)/2. For these cases a solution with source close to 0 is found as input to the dynamic solver. When the pressure inside the wellbore exceeds this pressure small fractures will be created in the formation resulting in a significant increase in injectivity. The exponent n ranges in value from 0. The pressure required to burst the formation is called the fracture pressure. hydrocarbon liquid or water. the bottom hole flowing pressure might drop below the bubble point pressure during production. The injectivity index is adapted to specify the relation between the flow from the well into the reservoir and the pressure build-up in the well.5 to 1. By specifying the fracture pressure the user defines the maximum allowable pressure inside the wellbore. (n) Vogels equation The following IPR equation. (t) Tabulated inflow performance curve If neither of the above inflow performance curves nor the linear and non-linear option presented in this section is applicable for the reservoir. In addition. A normalised form of this equation can be used for saturated oil wells: (r) where q0. Undersaturated oil wells For oil wells producing from reservoirs with static reservoir pressure above the bubble point pressure. (o) where q0. known as Vogels equation. Variable reservoir reference pressure When a reservoir has been flowing for some time at high rates the reservoir pressure close to the well can be reduced significantly. In the Wells Module this is modelled by an "infinite" inflow into the reservoir zone. a separate linear injectivity index can be used for the oil phase or the water phase.0. where C is defined by: (p) [scf/d/psi2n] (q) This equation is often referred to as the backpressure equation. How to use . BINJ. See also: When to use Methods and assumptions How to use When to use The Zone keyword simplifies input when inflows are to be present in all control volumes in a given region of a branch. WATINJ and ZFACT.ppl) are used for plotting several Well variables (same variables for Advanced and Standard well): Mass rates for each phase (gas. When using the standard well in Olga the key GASFRACTION. HOLES. and WATERFRACTION or TOTALWATERFRACTION is the one to use since AINJ. There are several different inflow models implemented in the Wells Module e. APROD and BPROD then are mass based. QMAX.tpl) and profile file (*. BPPRESSURE. INJPREFRACFRATOR. GASINJ. The production and the injection models are specified through the keys PRODOPTION and INJOPTION with the following values available: LINEAR QUADRATIC TABULAR FORCHHEIMER (The Forchheimer model) SINGLEFORCHHEIMER (Forchheimer with pressure instead of pressure squared) VOGELS (The Vogels equation for saturated oil reservoirs) BACKPRESSURE (The Backpressure equation for oil and gas wells) NORMALIZEDBACKPR (Normalized backpressure for saturated oil wells) UNDERSATURATED (Under saturated oil wells) For advanced well inflow types the coefficients could be given directly by using the keys BINJ.g. The resulting trend file (*. i. Instead of specifying each individual inflow in each control volume. VISGRES. pressure and temperature can change. RESEXT. GEOMETRY. Vogels and Backpressure. Please refer to the Interpolation section for further details. PRODI. KPERM. With the advanced well inflow types the key GORST and WATERCUT is appropriate to use since AINJ. Please see Methods and Assumption for more information. RESPRESSURE. HPAY.. If COMPOSITIONAL = ON in OPTION then either the key FEEDMASSFRACTION or FEEDMOLEFRACTION is used. Keyword dependencies: BRANCH. a linear formula. WATERCUT is calculated from PVT table if set to -1 in the input. INJTHRESHOLD. Please refer to the individual sections to get detailed information on the various references given in the ZONE keyword. APROD and BPROD then are volume based. ISOTHERMAL. FEED Required keys: LABEL. Be aware of that you may not get as output the fractions or water cut specified for the well since this depend on that there are enough content of the specified phases in the well. Zone A zone is a region within a branch in which OLGA automatically generates inflows in each control volume based on a template definition. Which key to use for the different well flow models will be highlighted in the GUI interface.e. FRACPR. it is only affected by license requirements that apply to the inflows referenced. Forchheimer. Methods and assumptions General Given a start position and an end position. Three options are available for specifying the relationship between the mass flow rate and the pressure difference. Values from PVT table is used when GASFRACTION and TOTALWATERFRACTION is set to -1 in the input.Standard and advanced well feature There are two ways of specifying the data for flow between the reservoir and the well. In the standard well for OLGA the coefficients used in the inflow correlations is specified directly. these are automatically generated based on a template. PRODPOSTFRACFACTOR. PRODOPTION. OPTIONS. GASINJ. inflows are automatically generated in all control volumes inside the region based on a template. or you may specify traditional well/reservoir variables like permeability and net pay. The volume flow q is a function of the bottom hole pressure pwf. INJPOSTFRACFACTOR. and the computed coefficients used in the inflow correlations. BPROD. Input The keyword ”WELL” is used to define required data for calculating the flow performance of wells. PHASE. RESTEMPERATURE. BINJ. You may either specify the coefficients used in the inflow correlations directly. License requirements Zone is only implicitly affected by license requirements. If COMPOSITIONAL = BLACKOIL in OPTION then the key FEEDVOLFRACTION is used. OILINJ. Please see the keyword Well description for more details. The coefficients used in the inflow correlations may also be given directly. Reservoir inflow assumptions . a non-linear formula and a tabular form. Output The keywords TREND and PROFILE in the input file specify the output from the simulation. POSITION. oil and water) Steady-state mass rates for each phase Total mass rate for the liquid phase and all phases Cone front for each phase Enthalpy for the well Please see the Well variables for more details. CPROD and EXPONENTN or by setting the reservoir variables through using some of the keys BOOIL. fluid properties etc. SKIND. Please see Methods and Assumption description for more details. In the Wells Module the reservoir performance is specified through permeability. LOCATION (Default values can be used if specified) Either the key ABSPOSITION or POSITION or the keys PIPE and SECTION is used to locate the well. the reservoir pressure pR. INJOPTION. While most properties are assumed to be constant over a zone. The well/reservoir variables are translated into the coefficients used in the inflow correlations. VISLRES. INJECTIVITY. The Wells Module is designed for well flow applications where the reservoir properties and inflow relationships play an important role in the modeling. extension of reservoir. CINJ. SKINS. PRODPREFRACFACTOR. Peter Andersson and Magnus Nordsveen: Implementation of CO2 Corrosion Models in a Three-Phase Fluid Flow Model. For COEFTYPE=PERMETER. Rygg.VERTICAL.B. Friedmann and J. output is generated for each individual inflow that has been automatically generated in addition to the accumulated one. The third interpolation option. A. To illustrate this. IADC Well Control Conference for Europe. well-type objects are automatically generated according to a template. Automatic interpolation This option (referred to as AUTOMATIC in the input) requires that the reservoir pressure and reservoir temperature is specified at one of the zone endpoints. Bradley: Petroleum Engineering Handbook. Rydahl and H. Interpolation The zone has a number of options for specifying the reservoir pressure and reservoir temperature. ASME Symposium on Multiphase Flow in Wells and Pipelines. Magnus Nordsveen and Kjell Bendiksen: Numerical simulation of slugging in pipelines. Millheim. and F. The template is specified using the keyword RESERVOIRINFLOW under Library and is linked to ZONE through the reference key RESERVOIRINFLOW. the coefficient values need to be multiplied by a length in order to generate the value for each individual inflow. the equivalent input using COEFTYPE=PERMETER is to specify that very same coefficient to be 0. N. O. Multi-Phase Flow . Volume 31. Nyborg. Chenevert. E. A. the reservoir pressure and reservoir temperature are specified through ZONE. 1989 10. For COEFTYPE=TOTAL.B. the coefficient values are considered to correspond to the sum for all contributions within the zone.B. Here. Bourgoyne. BHR Group 1999 Multiphase ’99..K. Coefficient specification One final thing to be noted is the specification of the injection and production coefficients. corresponds to constant reservoir pressure and temperature as given through PRESSURE and TEMPERATURE. 2000) 9. TX: NACE International. ISBN 1 86058 212 5 6. M.The inflows specified generate well-type objects where the location is assumed to be in the middle of the control volume. Hovden: Implementation of CO2 corrosion models in the OLGA three-phase flow code.E. which will be described in the following. 8. May 1971. R. Furthermore. REFERENCES Referenced papers 1.P. Rønningsen Wax Deposition in offshore pipeline systems BHRGroup Multiphase Technology. Rolf Nyborg. pp. Brill: Upward Vertical Two-Phase Flow Velocity and Flow Through an Annulus. No interpolation This option (referred to as OFF in the input) means that the reservoir pressure and reservoir temperature is assumed to be constant through the entire zone. it is not possible to get data for an individual inflow. p(h). Caetano. INTERPOLATION={[OFF]. . Vertical interpolation This option (referred to as VERTICAL in the input) applies linear interpolation w. is calculated at each depth h by integrating the hydrostatic pressure of the reservoir liquid according to (a) The reservoir temperature is assumed to be constant. Taylor Bubble Rise Velocity and Flow Pattern Prediction. D.r. For each control volume between the endpoints. Slug and Annular Flow. it is assumed.K. Anaheim. Journal of Heat Transfer. ENDPRESSURE. that all reservoir properties except for the reservoir pressure and the reservoir temperature remain constant throughout the zone. M. France. Aberdeen. Furthermore. CORROSION/2000. How to use General Instead of specifying WELL keywords in numerous consecutive control volumes.T. H. L. Reservoir inflow The keyword RESERVOIRINFLOW under Library is in most parts a duplicate of the flow-path level keyword WELL. The default option. Paper No. the ZONE keyword can be used to simplify input. Interpolation There are three different kinds of interpolation implemented.050. Nordsveen. these are specified for that particular inflow object whereas their interpretation in RESERVOIRINFLOW is depending on the COEFTYPE key on ZONE. A. 301-362. automatic interpolation. CA (1992) 5. p0. Nice. R.AUTOMATIC}.Proceedings of the 4th International Conference. set ZONEDETAILS=YES in the TRENDDATA keyword. H. O. Shoham and J. Henry and H. consider a 1. drilling and well control applications.S.t. Part I: Single-Phase Friction Factor. there is no position to be specified since the positions of each respective inflow is automatically generated through the input given on ZONE. and ENDTEMPERATURE) and linear interpolation is carried out as a function of vertical depth. output is always given accumulated over the entire zone. June 1998 7. Terje Straume. OFF. Calsep: PVTSIM Method documentation: Modelling of wax formation -> Viscosity of oil-wax suspensions. J. 179-187 4. vertical depth between the reservoir pressure and reservoir temperature specified at the zone endpoints. uses a uniform temperature while the pressure is calculated through integrating the hydrostatic pressure contribution in the reservoir fluid starting at the given reference pressure. By doing so. O.F. Society of Petroleum Engineers. STARTTEMPERATURE. K. Canada.000 meter long zone. Young: Applied Drilling Engineering. 1987 2. As compared to WELL. the reservoir pressure and reservoir temperature are specified at the zone endpoints (STARTPRESSURE. Given this reference pressure. If one of the coefficients is specified to equal 50 when COEFTYPE=TOTAL. The extend of the zone is specified through the position references STARTPOSITION and ENDPOSITION. 1991 3. Society of Petroleum Engineers. Banff. please refer to the section on interpolation below.K. the pressure. orifices and short tubes. For detailed information. 48 (Houston. it is either all or nothing. Skelland: Non-Newtonian Flow and Heat Transfer. Output When specifying output variables for zones. May 1996 11.E. BHRA. Part II: Modelling Bubble. P. Nossen: Advanced well flow model used for production.B. A more advanced option is vertical interpolation. Fauske: The two-phase critical flow of one-component mixtures in nozzles. p.P. On WELL. In order to get data for the individual inflows. Rygg. J. 30. Texas.: The Dynamic Two-Phase Modeling of Offshore Live Crude Lines Under Rupture Conditions. December 28. 785-795.: Holdup predictions for wet-gas pipelines compared.M.G. Wilson. D. 34. D.C.: Estimation of the Critical Velocity in Pipeline Flow of Slurries Powder Technology. P. pp. Vol. 171-180 Rygg. Thomas. pp. Oil and Gas Journal. Handbook of natural gas engineering. 1997 .J. K.. Winkler. 1959 26. AIChE Journal.. New York. Nilsen. and Eads.. Redus. No.. Rønningsen. pp. 7th Int. 33. H. P..B. Subsea Chokes as Multiphase Flowmeters.: The properties of petroleum fluids.M. pp. presented at the 23rd annual Offshore Technology Conference. 1995 17. Glaso.: Viscosity of ’live’ water-in-crude-oil emulsions: experimental work and validation of correlations. E.: Viscosity/Concentration Relationships for Emulsions. Proc. Houston. pp. Singh. Oil & Gas Journal. P. Darby R. Reid. May 1991. and Ellul.: Correlations for Predicting Viscosity of W/O Emulsions based on North Sea Crude Oils. Hammerschmidt. 15. Vol. P. vol 1. U.A (May 16-9. Vol. 1976. of Petroleum Science and Engineering 38. 5. T. 30-35. ISBN 0-07-066525-7 24. Apte and Creek: Multiphase flow wax deposition modelling. ANIME (1958). R. M. 1990 29.: Algorithm for More Accurately Predicting Nitrogen-Charged Gas-Lift Valve Operation at High Pressures and Temperatures. SPE Production Engineering. Houston. no. GAS. SPE 18871... S. February 2001. Juan Carlos Mantecon. Rheol. on Multiphase Production. R. 14. H.. R. May 19.M. March 1969 21. 27.: The Dynamic Two-Fluid Model OLGA: Theory and Application. 1987 25.. and Rønningsen H. John M. Stein Olsen and Arne Dugstad: Corrosion under Dewing Conditions CORROSION/91.: How to predict the friction factors for flow of Bingham plastics Chemical Engineering. pp 35-47.E.R. 23-26 (2003) 18. 1967 12. Prausnitz.: Generalized Pressure-Volume-Temperature Correlations Journal of Petroleum Technology. Selmer-Olsen. 1956. S.: Bubble Point Pressure Calculation Trans. 46. A. Zhang. Soc. The Properties of Gases & Liquids Fourth Edition. Tulsa Univ. NACE. and Swerdloff W. and Dougherty. F.: Gas Hydrate Formations: A Further Study on Their Prevention and Elimination from Natural Gas Pipe Lines.. 441-446 35. Moe. Conf. Rasmussen. 7. Lasater..T. K. 31. K. 5. L. no. 2. Houston USA 13. R. Turian. 1966-1998 33. 51. US. PennWell P. BHR Group. OTC 6747. Life Cycle Design and Production Non-referenced papers describing the OLGA model: Bendiksen.. Thesis. I. I. 4th ed. White. 1981 23. March 14-18.W. A.S. San Antonio. Haugen. McGRAW-Hill 1959 32. Jan.: Effect of precipitated wax on viscosity Presentation at AIChE Spring National Meeting. C. Pedersen. 28. ISBN 0-471-30460-3 15.. Melson J..D. Vazquez and Beggs: Correlations for Fluid Physical Property Prediction M. Campbell and Company. presented at the SPE International Symposium on Oilfield Chemistry. J. and Nuland. Sydney.: Slurry Pipeline Rheology 2nd Conference on Rheology.S. F. J. 1991 19. H. Proceeding ETCE. Incropera & DeWitt: Fundamentals of Heat and Mass Transfer.L. Nagarajan: Formation and Aging of Incipient Thin Film Wax-Oil Gels. J. and Malnes. J. D. May 1980.H. O. E.. Australia. Campbell J. February 14-17. and Poling. 1999. Rønningsen. B. McCain W. and Ma.) Cannes 7-9 June 1995. Holm.John Wiley & Sons.M. R. Matzain. T. 1021-1045 (1989) 16. R. 22. Katz D.H. pp. Oistein. P. Hedne. Krieger. 36. and Sandberg. May 1939 20. Volk. SPT Group: SPE 109829: The Virtual Well: Guidelines for the Application of Dynamic Simulation to Optimise Well Operations. Malnes. SPE Paper 28968.Fogler. S. H. of Rheology. III 137-152. Hsu. Pal.: Finding surface tension of hydrocarbon liquids. Rhodes. TX. 1991) Shea. (ed. P.Venkatesan. J.: Fluid Mechanics 2nd ed.W..472.. Baker O. Gas conditioning and processing. Brill. A. Production Control at Troll Olje. 379.: A mechanism for Non-Newtonian Flow in Suspensions of Rigid Spheres Trans. Paper No. 1995) Burke.. State of the Art Review and Simulation. 477-496 Lingelem. and Assayaga. E. D. Conf. and Nossen. Cannes. pp 147-163 Hærdig. Journal of Petroleum Technology.Z. Conf.: History Matching of a North Sea Flowline Startup. 4 Mazzoni.C. S. pp. 470-476 Courbot.: Capability of the OLGA Computer Code to Simulate Measured Data From AGIP Oil Field.. J. on Multi-Phase Production. T. on Multi-Phase Production. A. A. 24. Presented at the 8th Int.S. A. P. De Toma. BHR Group Conference Series No. and Hustvedt.C. M. Cannes. and Kashou. D.Non-referenced papers describing applications of the OLGA model: Burke. Cannes. OTC 6670.. Conf. and Hawker. Keywords ABCDEFGHIJKLMNOPQRSTUVWXYZ A ANIMATE ALGEBRAICCONTROLLER AMBIENTDATA ANNULUS ASCCONTROLLER B BLACKOILCOMPONENT BLACKOILFEED BLACKOILOPTIONS BRANCH C CASCADECONTROLLER CASE CENTPUMPCURVE CENTRIFUGALPUMP CHECKVALVE COMPOPTIONS COMPRESSOR COMPONENT CORROSION D DISPLACEMENTPUMP DRILLINGFLUID DTCONTROL E ESDCONTROLLER F FEED FILES FLOWPATH FLUID FLUIDBUNDLE G GEOMETRY H HEATEXCHANGER HEATTRANSFER . BHR Group Conference Series No. OTC 8196.. M. P. Presented at the 8th Int. Washington.N. Nunes. Cannes. Houston. BHR Group Conference Series No. E. 1997. 497-512 Xu.: Determination of Slug Length Distribution by the Use of the OLGA Slug Tracking Model.F. 8-13 Nov.C. N. OTC 7744.: TOGI Multiphase Flow From Troll to Oseberg.: Simulation study and field measurement for mitigation of slugging problem in The Hudson Transportation lines. 1997. O. Symp. S. Kashou. SPE 24790. BHR Group Conference Series No. Bonuccelli. Anaheim..F. On Multiphase Flow in Wells and Pipelines. 1991) Mazzoni. BHR Group Conference Series No. R. Hall. on Multi-Phase Production. Presented at The IDAC Well Control Conference for Europe. Meland. Houston.. T. M. presented at the 28th annual Offshore Technology Conference. May 22-24.. 24. and Mai. U. Conf. U.A (May 1-4. 185-198 Hustvedt. 4. 24. 1993. Houston.D. S.. Z. pp.: A Transient Multiphase Temperature Prediction Program. A. Cannes. and Crescezi. Friedemann. October 4-7. Presented at the 6th Annual Technical Conference and Exhibition of the SPE. M.E. 1997. J.: Slug Sizing/Slug Volume Prediction.S. Cannes.. on Multi-Phase Production. and Rambaek. Gayton.: Evaluation of the dynamic flow behavior for the Petroboost system.: OLGA and WOLGA dynamic codes validation with Trecate test loop three-phase transient data. on Multi-Phase Production.C. 1992 Flaten. Aberdeen. pp.B. BHR Group Conference Series No. Presented at the 8th Int. and Moe. G. 24. N. 1993. 275-289 Klemp. Mazzei.: Solutions to Slugging Problems Using Multiphase Simulations.A (May 16-9. M. 1997. and Bonuccelli. and Bendiksen. pp.: Numerical Simulation of Slugging in Pipelines. B. M. 257-274 Rygg. Presented at the 8th Int. Cannes. on Multi-Phase Production. Presented at the 6th Int.: Operational experiences from multiphase transfer at Troll.E. G. Villa. U.G.: Advanced Well Flow Model Used for Production. J. Presented at the 8th Int.: Prevention of Severe Slugging in the Dunbar 16" Multiphase Pipeline. G. ASME Int.. 1992.D.: Dynamic simulations of multiphase flow in flowline bundles on Åsgård. presented at the 23rd annual Offshore Technology Conference.S. D. 1992 Xu. Nordsveen. pp. BHR Group Conference Series No. Conf.. May 1993. 1996) Erickson. 24. 1997. S. Conf.. Drilling and Well Control Applications. pp.. Conf. K. 1996 Straume. G. Presented at the 6th Int. on Multi-Phase Production. presented at the 27th annual Offshore Technology Conference.. A..A (May 6-9. HYDRATECHECK HYDRATECURVE HYDRATEKINETICS HYDRATEOPTIONS I INITIALCONDITIONS INTEGRATION L LEAK LOSS M MATERIAL MANUALCONTROLLER N NEARWELLSOURCE NODE NODE O OPTIONS OPTIONS OUTPUT OUTPUTDATA OVERRIDECONTROLLER P PHASESPLITNODE PIDCONTROLLER PIG PIPE PLOT POSITION PRESSUREBOOST PROFILE PROFILEDATA PSVCONTROLLER PUMP PUMPBATTERY R RESERVOIRINFLOW RESTART S SCALERCONTROLLER SELECTORCONTROLLER SEPARATOR SHAPE SIMPLIFIEDPUMP SINGLEOPTIONS SLUGILLEGAL SLUGTRACKING SLUGTUNING SOLIDBUNDLE SOURCE SOURCE STDCONTROLLER SWITCHCONTROLLER T TABLE TABLECONTROLLER TIMESERIES TOOLJOINT TRACERFEED TRANSMITTER TREND TRENDDATA TUNING U UDDISPERSIONS UDPHASE UDPDF UDOPTIONS V VALVE W . DTPLOT Link to: ANIMATE (on CaseLevel) Description Keys CASE (on CaseLevel) Description ( See also: Keys) Defines information about a simulation. . See restrictions and limitations for more information.hdfgroup. Useful links: 1. free program to view the content of HDF5 files) ANIMATE (on CaseLevel) Keys ( See also: Description ) Key Type Unit:( ) Real (s) Parameter set Default:[ ] Description Time interval between subsequent data printouts. if given more than once. CASE (on CaseLevel) Keys ( See also: Description ) Key AUTHOR DATE INFO PROJECT TITLE Type Unit:( ) String String String String String Parameter set Default:[ ] Description Author of the input file.h5".org/hdf-java-html/hdfview/ (HDFVIEW. so the generated files will have extension ".hdfgroup. The data format chosen is HDF5. DTPLOT should only be given once in the input file. Project name.WALL WATEROPTIONS WAXDEPOSITION WELL X XYT XYTDATA Z ZONE ANIMATE (on CaseLevel) Description ( See also: Keys) This keyword generates the data needed by the OLGA 3D-viewer.org/HDF5/ (HDF5 home page) 2 http://www. OLGA will use the last value given. http://www. Case title. Link to: CASE (on CaseLevel) Description Keys DTCONTROL (on CaseLevel) Description ( See also: Keys) This statement defines a switch for stability control. General information about the case. Date. g. ENDTIME EXPOSE MAXDT MAXLAGFACT Real (s) SymbolList RealList (s) Real [1.. It also defines the start value. Time-step control based on the speed of pressure waves. these are specified as additional files in the PVTFILE key. Tuning factor for pressure criterion. FILES (on CaseLevel) Keys ( See also: Description ) Key COMPRESSORFILE FEEDFILE PUMPFILE PVTFILE UDFEEDFILE UDPVTFILE WAXFILE Type Unit:( ) StringList String StringList StringList String StringList String Parameter set Default:[ ] Description Name of COMPRESSOR file(s). The file can contain several feeds. pump δατα ταβλε φιλεσ χοµπρεσσορ ταβλε φιλεσ φεεδ φιλε for the compositional φιλεσ. For definition of a restart file. Link to: FILES (on CaseLevel) Description Keys INTEGRATION (on CaseLevel) Description ( See also: Keys) This statement defines the start and end times of the simulation. however one file can contain several feeds.8] [OFF] [OFF] Description The Courant-Friedrichs-Lewy (CFL) criterion based on the flow velocity. Note: several files can be listed for COMPRESSORFILE.3] Simulation end time.8] ON | [OFF] [0.DTCONTROL (on CaseLevel) Keys ( See also: Description ) Key CFL CFLFACTOR GRADPRESSURE PREFACTOR PRESSURE SOUND_CFL Type Unit:( ) Symbol Real Symbol Real Symbol Symbol Parameter set Default:[ ] [ON] [0. INTEGRATION (on CaseLevel) Keys ( See also: Description ) Key DTSTART Type Unit:( ) Real (s) PIDCONTROLLER | ASCCONTROLLER | PSVCONTROLLER | MANUALCONTROLLER | OVERRIDECONTROLLER | SELECTORCONTROLLER | CASCADECONTROLLER | ESDCONTROLLER | LINEARCOMBINATION | TABLECONTROLLER | SCALERCONTROLLER | SWITCHCONTROLLER | Parameter set Default:[ ] Description Initial time-step.0] [0. Time-step control based on the second-order derivative of pressure w. click here. Note that only one wax table can be specified for the time being. tracking model and wax file for the wax deposition model. Time-step control based on the first-order derivative of pressure w. φιλεσ.r. time. Name of User Defined (UD) feed file (used by the plug-in module). Name of FEED file (used by the compositional tracking module). ENDCONTROLLER Symbol Label of the controller determining conditional termination of the simulation.t. A controller can be used to setup a conditional stop of the simulation before the specified end time. Link to: DTCONTROL (on CaseLevel) Description Keys FILES (on CaseLevel) Description ( See also: Keys) This statement defines the additional input files. PUMPFILE and PVTFILE. Largest time-step allowed. Maximum lagging factor (see LAGFACT output variable) to allow before the output variable LAGIND is set to 1. Name of the file(s) containing fluid properties. time. If drilling fluids are used and the fluid properties are given in files. . e. the maximum value and the minimum value of the time step. Each file can contain only one pump. States which keys should be made available as input variables on the OPC server.r. Note that only one file may be specified. Name of PUMP file(s). The files can contain several compressors each. Name of User Defined (UD) property file (used by the plug-in module) Name of the file containing the WAX table. Tuning factor for the CFL time-step. Note that only one file may be specified. The simulation stops when the signal from the controller is zero. PVT table files for fluid properties.t. walls. Set it to ON for simulation drilling process Turn on or off the use of the effect of expanding/contracting walls Mass transfer model. section lengths. ON: This option should only be used when old PVT files with too narrow pressure/temperature ranges cannot be reproduced and improved. time integration. SERVER prints server information. Any other positive number means that the simulator will slow down the simulation so it matches the factor given relative to real time. Link to: INTEGRATION (on CaseLevel) Description Keys OPTIONS (on CaseLevel) Description ( See also: Keys) This statement specifies the different calculating options to be applied in the simulation. E. Please note that it is not allowed to change any geometry data in a restart run.MAXTIME MINDT MINTIME RUNTIMESTEPAGAIN SIMULATIONSPEED STARTTIME RealList (s) RealList (s) RealList (s) Symbol Real Real (s) [0. a restart file is written at the end of the simulation. Simulation speed relative to real-time. Nodes must have the same connections. The content of the restart file can be thought of as specialized initial conditions. HYDROCARBON: Only mass transfer between gas-oil. Use with extreme care. Turns off the initial value (steady state) pre-processor or only turn off the temperature calculation in the pre-processor. Select the information to print when DEBUG = ON or LIMITED. Specify the desired temperature calculation option.001] [0. ON: Enable compositional tracking. Select correlations for determining gas volume fraction in liquid slugs. The gas and liquid (oil and water) is treated as one single homogenized phase in the pressure drop and momentum calculations. without using the RESTART keyword. The setting for component tracking (keyword OPTIONS.g.0] FALSE | [TRUE] [0] Timetable for changing MAXDT. etc. The no-slip option is implemented in both the steady state pre-processor and the dynamic code. OFF: No temperature calculation. mass transfer. Select whether or not to recompute the time-step if the first-stage solution is unsatisfactory. the pipe line. For STEAMWATER-HC and SINGLE only. DEBUG = OFF reports only essential warnings. sources. Discretization scheme used for solving the mass equations. Switch for using tracertracking Set to ON to use User Defined phases and a plugin dll Switch wax deposition model on or off. In OLGA 6 the only option is THREE. The other calculations. and output information. The restart file contains data necessary to restore the state of the simulation engine from a previous run. SINGLE: Use single-component model Turn on or off printing of time step information to standard output. OPTIONS (on CaseLevel) Keys ( See also: Description ) Key Type Unit:( ) Symbol Parameter set Default:[ ] ON | MEG | MEOH | ETOH | BLACKOIL | STEAMWATER-HC | SINGLE | | [OFF] Description OFF: No compositional tracking. COMPOSITIONAL DEBUG Symbol ON | LIMITED | [OFF] DEBUGINFO DRILLING ELASTICWALLS FLASHMODEL FLOWMODEL HYDSLUG MASSEQSCHEME SymbolList Symbol Symbol Symbol Symbol Symbol Symbol SERVER | STATE | ON | [OFF] ON | [OFF] HYDROCARBON | [WATER] OLGAHD | [OLGA] OFF | [ON] 2NDORDER | [1STORDER] NOSLIP Symbol ON | [OFF] PHASE SLUGVOID STEADYSTATE Symbol Symbol Symbol [THREE] AIR | [SINTEF] OFF | NOTEMP | [ON] TABLETOLERANCE Symbol ON | UNLIMITED | [OFF] TEMPERATURE Symbol ADIABATIC | UGIVEN | OFF | FASTWALL | [WALL] TRACERTRACKING UDPLUGIN WAXDEPOSITION WRITEPVTFILES Symbol Symbol Symbol Symbol ON | [OFF] ON | [OFF] ON | [OFF] YES | [NO] Link to: OPTIONS (on CaseLevel) Description Keys RESTART (on CaseLevel) Description ( See also: Keys) The restart statement defines a restart of the program from a previous run. UNLIMITED: This option will remove the upper an lower limits of temperature and pressure and will use the end values in the table outside the table range without extrapolation. No wall temperatures are calculated. ON: Should only be used for sensitivity simulations. either of the keys . key COMPOSITIONAL) cannot be changed. Define the number of phases to be simulated. The type of flow model to use for dynamic flow This key (HYDSLUG) makes it possible to turn off the distributed flow regimes (hydrodynamic slug flow and dispersed bubble flow). but with more information than the standard user specified initial conditions. STEAMWATER-HC: Use steam model. OFF: Slip between phases is calculated (recommended).0] [0. Simulation start time. OFF: The limits will be the ones specified in the fluid tables (recommended). ADIABATIC: No energy exchange with the walls. STATE prints information about state changes in OLGA engine. To save restart files generated at other times. MEG/MEOH/ETOH: Use Inhibitor tracking with the given component. WATER: Mass transfer between gas-oil and gas-water. WALL: Heat transfer on wall inside and outside. BLACKOIL: Use Black oil model. This means in particular that the original input file has to be read to get information about e. Adiabatic flow is assumed. OLGA will not contain a complete snapshot of the in-memory data structures as it did for versions prior to OLGA 6. wall heat conduction and heat storage is accounted for. initial values are used. but otherwise report the same as DEBUG = ON. DEBUG = LIMITED will be more silent about fluid table warnings and some informative messages. OPTIONS is a required keyword. Zero means simulate at highest possible speed. just use the fluid table. elevations and diameters. will be as for a normal simulation with slip. DEBUG = ON will report all informative messages and can slow down simulation significantly. HYDSLUG OFF will enforce stratified or annular flow (both including liquid droplets). Walls and materials must be the same. YES: PVT table file(s) and saturation line file are written for steam and single component properties. UGIVEN: Total heat transfer coefficient for the pipe-wall is given. mass conservation. Timetable for changing MINDT. Define the upper and lower limits of pressure and temperature allowed in the simulation. Smallest time-step allowed. By default. This option is used for a fast approach to steady state thermal conditions. FASTWALL: Same as option WALL except that heat storage is neglected.g all pipes must have the same number of sections. Several actions. UDFEED (on CaseLevel) Keys ( See also: Description ) Key LABEL Type Unit:( ) String Parameter set Default:[ ] [UDFEED] Description Name of user defined feed recognized by plug-in. Link to: UDFEED (on CaseLevel) Description Keys UDOPTIONS (on CaseLevel) Description ( See also: Keys) UDOPTIONS contains options for simulation of user defined dispersions like hydrates and sand. Will be sent to the plug-in. In order to use UDOPTIONS. UDFEEDs can also be defined through the UDFEEDFILE. such as activate/deactivate SLUGTRACKING. They are also referred to for output of distribution related variables. In order to run this option. APPEND: Add data to an existing restart file. entrainment/deposition and PVT properties. Example: <Number of compositions> 2 <Composition labels> FEED-1 FEED-2 Will add the FEED-1 and FEED-2 to the list of UDFEEDs available in SOURCE UDFEED etc. may be performed in a restart. modify controller settings etc. used to calculate flashing. OVERWRITE: Replace any existing restart file with the current data. RESTART (on CaseLevel) Keys ( See also: Description ) Key DTWRITE FILE READFILE READTIME WRITE WRITETIME Type Unit:( ) Real (s) String Symbol Real (s) Symbol RealList (s) APPEND | OFF | [OVERWRITE] Parameter set Default:[ ] Description Define the time interval at which to write restart data to file. When running with a user defined plug in. a plug-in DLL describing the components and containing the proper interfaces must be provided.DTWRITE or WRITETIME can be used. the name of the plug-in DLL should be given trough the key PLUGINDLL. Numerics and Programmers Guide for the OLGA Plug-In". Note that this option is not compatible with the standard Compositional Tracking Module activated through OPTIONS COMPOSITIONAL = ON. A specific time or time series when restart data is written to the restart file. The plug-in model to use. Component tracking of user defined phases can be activated by setting COMPOSITIONAL = ON. Watch out for these to catch any unintended effects in the restart run (e. SIZEDIST = ON activates handling of size distributions through tracking of statistical moments. OFF: Restart is disabled. OPTIONS UDPLUGIN must be set to YES. ON: Enable reading of the restart file. OLGA parses the file looking for the following strings: <Number of compositions> and <Composition labels> If <Number of compositions> is found the next line will be read as number of feeds (Nfeeds). In order to use UDFEED. ON | [OFF] Link to: RESTART (on CaseLevel) Description Keys UDFEED (on CaseLevel) Description ( See also: Keys) This keyword contains only a label key. Distribution functions are defined through UDPDF.g. and are referred by the UDFRACTIONs in the UDGROUP section. change valve openings. UDOPTIONS COMPOSITIONAL must be set to ON. The PLUGINMODEL key allows definition of a model type that is transported to the plug-in and can be stored for easy selection of different plug-in models by the plug-in programmer. OFF: No restart data is written to file. Furthermore a file describing the composition is needed and must be referred to with FIELD UDFEEDFILE. Discrepancies between the original and the restart case will be reported as info messages when the restart case is started. These interfaces are described in the "Model. If <Composition labels> are found the Nfeeds lines following will be read and added to the list of UDFEEDs. Time in previous simulation at which the state is read in order to restart this simulation (only one time point is allowed). The name of the restart file from which to restart the simulation. a missing source or something else that will influence results). The label is used to refer feeds recognized by the plug-in dll. UDOPTIONS (on CaseLevel) Keys ( See also: Description ) Key COMPOSITIONAL PLUGINDLL PLUGINMODEL SIZEDIST Type Unit:( ) Symbol String String Symbol ON | [OFF] Parameter set Default:[ ] ON | [OFF] Description Turn on component tracking (can not be combined with OPTIONS COMPOSITIONAL) Name of PlugIn dll. Option for activating statistical moment model . Alternative to GLR (to be used for gas feeds). The GOR should not be larger than 1000 Sm3/Sm3. Gas/oil ratio. Blackoil feed label. to blackoil component label of type gas.5 (0. Used in order to include density effect on water due to components other than salt. [] [] . oil or water) for the black oil options. Ref.0] [0. Gas specific gravity (gas density/air density). Gas or water component. Gas/oil ratio. [BOFEED] BLACKOILCOMPONENT | BLACKOILCOMPONENT | [0. The temperature corresponding to the bubble pressure. BLACKOILFEED (on CaseLevel) Keys ( See also: Description ) Key GASCOMPONENT GLR GOR LABEL LGR OGR OILCOMPONENT WATERCOMPONENT WATERCUT Type Unit:( ) Symbol Real (Sm3/Sm3) Real (Sm3/Sm3) String Real (Sm3/Sm3) Real (Sm3/Sm3) Symbol Symbol Real (-) Parameter set Default:[ ] BLACKOILCOMPONENT | Description Ref.5/(oil specific gravity)–131.5 (0. Gas specific gravity (gas density/air density).0] [0. GASSPECIFICGRAVITY has to be larger than 0. to blackoil component label of type water.5.55 is pure methane). Name of the blackoil component. Oil/gas ratio. Oil specific gravity (oil density/water density). H2SMOLEFRACTION has to be less than 10%. Mole fraction of H2S in gas at standard conditions. CO2MOLEFRACTION has to be less than 10%. BLACKOILOPTIONS (on CaseLevel) Keys ( See also: Description ) Key APIGRAVITY BUBBLEPRESS BUBBLETEMP GASSPECIFICGRAVITY GOR Type Unit:( ) Real Real (Pa) Real (C) Real Real (Sm3/Sm3) Parameter set Default:[ ] [] Description API gravity. Cannot be given if APIGRAVITY is given. Watercut.5/(oil specific gravity)–131. Liquid/gas ratio. API = 141. Gas/liquid ratio. to blackoil component label of type oil. Ref. BLACKOILCOMPONENT (on CaseLevel) Keys ( See also: Description ) Key APIGRAVITY CO2MOLEFRACTION GASSPECIFICGRAVITY H2SMOLEFRACTION LABEL N2MOLEFRACTION OILSPECIFICGRAVITY TYPE WATERSPECIFICGRAVITY Type Unit:( ) Real Real (-) Real Real (-) String Real (-) Real Symbol Real Parameter set Default:[ ] [30] [0. Water specific gravity (water density/fresh water density).5. Cannot be given if OILSPECIFICGRAVITY is given. Link to: BLACKOILCOMPONENT (on CaseLevel) Description Keys BLACKOILFEED (on CaseLevel) Description ( See also: Keys) This statement defines a black oil feed.0] [BOCOMP] [0.Link to: UDOPTIONS (on CaseLevel) Description Keys BLACKOILCOMPONENT (on CaseLevel) Description ( See also: Keys) This statement defines a component (gas. Define if the component is an oil. Alternative to GOR (to be used for gas feeds).g. Alternative to GOR.0] Link to: BLACKOILFEED (on CaseLevel) Description Keys BLACKOILOPTIONS (on CaseLevel) Description ( See also: Keys) This statement defines the black oil options. Mole fraction of CO2 in gas at standard conditions. e. MEG. Alternative to GLR.55 is pure methane).64] [0.0] Description API gravity. Bubble pressure at a given temperature. Mole fraction of N2 in gas at standard conditions. API = 141. GASSPECIFICGRAVITY has to be larger than 0.876] OIL | GAS | WATER | [1. N2MOLEFRACTION has to be less than 10%. Cannot be given if OILSPECIFICGRAVITY is given. For COMOSITIONAL=ON the components are defined in the feed file. MEG/MEOH/ETOH. This option must be used if any salt components are defined in the feed. it should preferably be set equal to the fluid density at the critical point. SIMPLETHREEPHASE is <default> if there is at least one aqueous component in the feed. Only for STEAMWATER-HC.GORMODEL OILSPECIFICGRAVITY OILVISC OILVISC-TUNING RSGO_BP-TUNING VISCPRESS VISCTEMP Symbol Real Real (N-s/m2) Symbol Symbol Real (Pa) Real (C) STANDING | BEGGS | GLASO | [LASATER] [] Correlation used to calculate the gas/oil ratio. TWOPHASE is <default> if no aqueous components are part of the feed. An error is given if the feed has been tuned to another viscosity correlation in PVTsim. When COMPOSITIONAL=ON. The components in the feed must be defined in the feed file. and the properties for each component will be taken from the feed file. The TCONDENSATION/TVAPORIZATION keys are non-equilibrium delay constants for the mass transfer from liquid phase to gas phase and vice versa. DENSITYLIMIT Real (kg/m3) FLASHTYPE Symbol TWOPHASE | SIMPLETHREEPHASE | FULLTHREEPHASE | [<default>] [1. Cannot be given if APIGRAVITY is given. Can not be used with Drilling. Time constant for mass transfer from liquid phase to gas phase (Nonequilibrium delay constant). The temperature at which the viscosity is measured. The pressure at which the viscosity is measured. CUTTING and MUD components. Used in the dense phase region. Only for STEAMWATER-HC. Feeds can also be defined directly in the feed file. The feed file is generated in PVTsim. FULLTHREEPHASE is the most time-consuming option. If VISCOSITYCORR is specified the chosen model is used for viscosity calculations for the gas and oil phases. internal routines will decide the phase (may cause instabilities when crossing bubble/dew point). Mole fractions of the components of the feed. Measured oil viscosity at a given pressure and temperature. Whether to use Corresponding state or Lohrenz-Bray-Clark correlation for viscosity correlation. the default value is no delay and each value must have a corresponding component in COMPONENT. H2O. Time constant for mass transfer from gas phase to liquid phase (Nonequilibrium delay constant). Mass fractions of the components of the feed. When COMPOSITIONAL=ON. TVAPORIZATION and TCONDENSATION changes. TWOPHASE is the simplest one and is default if no aqueous components (H2O. The default is no delay.0] TBOILING RealList (s) TCONDENSATION RealList (s) TIME RealList (s) [0. Enable tuning of RSGO (gas dissolved in oil) and Bubble point. Time points for which TBOILING. a fluid with higher density than the given value is defined as liquid and a fluid with lower density is defined as gas. MEG. the default value is no delay and each value must have a corresponding component in COMPONENT. The equilibrium state reached in the flash calculations will then be delayed for the specified components. For DRILLING=ON available components are HC. Algorithm used in flash calculations. Name of feed. In the dense phase region. The DENSITYLIMIT key can be used to specify the limit for the dense phase region density. where there are no good criteria to distinguish gas from oil. etc) are part of the feed. The FLASHTYPE key specifies the type of flash calculations to use.0] TVAPORIZATION RealList (s) VISCOSITYCORR Symbol LBC | [CORRSTATE] Link to: COMPOPTIONS (on CaseLevel) Description Keys FEED (on CaseLevel) Description ( See also: Keys) This statement defines a feed (fluid composition used in a source or at a boundary) and its components with belonging mole fractions. If used. Oil specific gravity (oil density/water density). The keys can be introduced for each component specified with the COMPONENT key. FEED (on CaseLevel) Keys ( See also: Description ) Key Type Unit:( ) SymbolList String RealList (-) RealList (-) [FEED] Parameter set Default:[ ] Description Components in feed. SIMPLETHREEPHASE is the default if there are at least one aqueous component. When COMPOSITIONAL=STEAMWATER-HC TVAPORIZATION may be defined as a time series and the default value is 1 s. in which case this is the only allowed option. Time constant for mass transfer from liquid phase to gas phase due to boiling for components in COMPONENT. A fluid with a density higher than this limit is defined as a liquid and a fluid with lower density is identified as gas. TCONDENSATION may be defined as a time series and the default value is 1 s. COMPOPTIONS (on CaseLevel) Keys ( See also: Description ) Key COMPONENT Type Unit:( ) SymbolList Parameter set Default:[ ] Description Components to specify delay constants for (defined in feed file). but provides full mixing in all phases. When COMPOSITIONAL=STEAMWATER-HC. Enable tuning of oil viscosity. (Non-equilibrium delay constant). COMPONENT LABEL MASSFRACTION MOLEFRACTION . If not used. ON | [OFF] ON | [OFF] [] [] Link to: BLACKOILOPTIONS (on CaseLevel) Description Keys COMPOPTIONS (on CaseLevel) Description ( See also: Keys) This statement specifies the different options used in the PVT routines for calculating material properties and flashing terms in the Compositional Tracking model. value zero otherwise LT – Compare current result with the next input signal (INPSIG_i). The initial current result (result from previous operation) is input signal one (INPSIG_1). Time from when the measured value is read to when it is used by the controller. value zero otherwise GE – Compare current result with the next input signal (INPSIG_i). The ASC controller has the following signal terminals: MEASRD (Required input) MODE (Optional input) SIGNAL (Optional input) SETPOINT (Optional input) ACTIVATE (Optional input) CONTR_1.N MODE SIGNAL ACTIVATE CONTR_1. return value one if current result is not equal to the next input signal. value zero otherwise LE – Compare current result with the next input signal (INPSIG_i). The controller loops over all operators given in VARIABLEFUNCTION key. see below. The operators are applied to the current result (result from previous operation) as the first operand and additional operands in terms of input signals terminals (INPSIG_i). value zero otherwise EQ – Compare current result with the next input signal (INPSIG_i). Manual output. Stroke or actuator time. The second operator will be used on the result ffor the first operation and possibley any additional INPSIG terminal. EXTERNALSIGNAL: The controller output is given by the controller connected to the SIGNAL terminal... The controller uses a non-symmetrical PID algorithm.0e10] MANUAL | EXTERNALSIGNAL | FREEZE | [AUTOMATIC] Parameter set Default:[ ] [0. AUTOMATIC: The setpoint is defined on the controller. value zero otherwise Controller type Algebraic makes use of the following signal terminals: INPSIG_1.0e10] [-1. One amplification for positive and one for negative controller error. return value one if current result is greater than next input signal. States which keys should be made available as input variables on the OPC server. The first operator vill be used on the first operand(s)=INPSIG terminal(s). Minimum output signal. Identification label for this controller.. Two amplification constants must therefore be given.N (Optional output) . return value one if current result is equal to the next input signal. MODE SymbolList OPENINGTIME STROKETIME TIME VARIABLEFUNCTION Real (s) Real (s) RealList (s) SymbolList [0] [0] ADD | SUB | MUL | DIV | GT | LT | GE | LE | EQ | NEQ | ABS | Link to: AlgebraicController Description Keys ASCController Description ( See also: Keys) The main purpose of the Anti Surge Controller (ASC) is to prevent a compressor from operating to the left of the Surge Line in a compressor performance map. value zero otherwise NEQ – Compare current result with the next input signal (INPSIG_i). return value one if current result is less than or equal to the next input signal. Time required to change valve settings or compressor speed from maximum to minimum value. For use when one or more variables are specified. Time required to change valve settings or compressor speed from minimum to maximum value. The values of the variables will be subject to the operator specified. Maximum output signal.Link to: FEED (on CaseLevel) Description Keys AlgebraicController Description ( See also: Keys) The controller type ALGEBRAIC can combine signals from other controllers using a defined set of operators. EXTERNALSETPOINT the setpoint is given by the controller connected to the SETPOINT terminal. return value one if current result is greater than or equal to the next input signal.N (Required input) (Optional input) (Optional input) (Optional input) (Optional output) AlgebraicController Keys ( See also: Description ) Key BIAS CLOSINGTIME DELAY EXPOSE LABEL MANUALOUTPUT MAXSIGNAL MINSIGNAL Type Unit:( ) Real Real (s) Real (s) SymbolList String RealList Real Real [CONTR] [1. The following unary operator has been implemented: ABS – Take the absolute value of the current result The following binary operators have been implemented: ADD – Add next input signal (INPSIG_i) to the current result SUB – Subtract next input signal (INPSIG_i) from the current result MUL – Multiply the current result with the next input signal (INPSIG_i) DIV – Divide the current result with the next input signal (INPSIG_i) GT – Compare current result with the next input signal (INPSIG_i). return value one if current result is less than next input signal. MANUAL: The controller output is given by key MANUALOUTPUT. Time series for the MANUALOUTPUT key. FREEZE the controller output is frozen (kept constant). Time required to change valve settings or compressor speed from minimum to maximum value or vice versa. The number of operands is defined by the operation.0] [0] [0.0] Description Initial output signal. Average time for the moving averaging function of the primary controller variable. For use with EXTENDED CASCADE controller. Setpoint for INACTIVEMODE=DEFAULTMODE. Coefficient in front of the derivative term of a PID controller. OLGA will go back to the previous point in time and integrate with a shorter time-step. Time required to change valve settings or compressor speed from maximum to minimum value. Identification label for this controller. INTEGRALCONST LABEL MANUALOUTPUT Real (s) String RealList [1. For use with EXTENDED CASCADE controller: Switching value for using C1 and C2. EXTERNALSIGNAL: The controller output is given by the controller connected to the SIGNAL terminal. The cascade controller is used in the inner loop of a cascade control.b. Setpoint values.. Time series for the SETPOINT key.0] [0. If the change in output exceeds this value.0s and MAXCHANGE=0. If the non-linear option is chosen.0] [10. Initial output signal. AUTOMATIC: The setpoint is defined on the controller. Time required to change valve settings or compressor speed from maximum to minimum value. this is an array as a function of the ERROR array. Coefficient in front of the integral of PID controllers. Time required to change valve settings or compressor speed from minimum to maximum value.0] MANUAL | EXTERNALSIGNAL | EXTERNALSETPOINT | FREEZE | [AUTOMATIC] MODE SymbolList NORMRANGE OPENINGTIME SAMPLETIME SETPOINT STROKETIME TIME TIMESTEPCONTROL Real Real (s) Real (s) RealList Real (s) RealList (s) Symbol OFF | [ON] [10. This restriction is used by the time-step control. If the non-linear option is chosen. For use with EXTENDED CASCADE controller: Constant C1. EXTERNALSETPOINT the setpoint is given by the controller connected to the SETPOINT terminal. Time from when the measured value is read to when it is used by the controller. Digital controller: Maximum discrepancy between the instance a sample should be taken and the actual time in the simulation in terms of a fraction of the sample time interval. Time from when the measured value is read to when it is used by the controller. States which keys should be made available as input variables on the OPC server.g.. it is the inverse of the coefficient which appears in the expression for the output signal.0] [0.ASCController Keys ( See also: Description ) Key AMP1 AMP2 BIAS CLOSINGTIME DELAY DERIVATIVECONST EXPOSE Type Unit:( ) Real Real Real Real (s) Real (s) Real (s) SymbolList [10.N (Required input) (Optional input) (Optional input) (Optional input) (Optional input) (Optional output) CascadeController Keys ( See also: Description ) Key AMPLIFICATION AVERAGETIME BIAS CLOSINGTIME CONSTONE CONSTSWITCH CONSTTWO DEFAULTINPUT DELAY Type Unit:( ) RealList Real (s) Real Real (s) Real (1/s) Real Real (1/s) Real Real (s) [0. If the non-linear . N. Coefficient in front of the derivative term of PID controllers.0] Link to: ASCController Description Keys CascadeController Description ( See also: Keys) A cascade controller (normal or extended) is a PID controller. Manual output. (E.2] MAXSIGNAL MINSIGNAL Real Real [1. Analog controller: Maximum allowed change in controller output signal from one time-step to the next.0] [10. Initial output signal.0E+10] [CONTR] MAXCHANGE Real [0. Time interval between each sampling of input. this is an array as a function of the ERROR array. For normalized controllers (used together with AMPLIFICATION).) Maximum output signal. Time required to change valve settings or compressor speed from minimum to maximum value and vice versa.0] [0. with SAMPLETIME=2. Activates digital controller option. For use with EXTENDED CASCADE controller: Constant C2. If TIMESTEPCONTROL=OFF the time step control is bypassed. Used for negative deviation from setpoint. the maximum discrepancy will be ±0. Anti Surge Controller amplification (proportional term). If STROKETIME is less than DTMIN the time step control is also bypassed. Indicates measuring range for input to controller.4s.0] Parameter set Default:[ ] Description PID amplification factor. The output of the primary controller changes the setpoint of the secondary (cascade) controller. Used for positive deviation from setpoint. A cascade controller has the following terminals: MEASRD MODE SIGNAL SETPOINT ACTIVATE CONTR_1. It represents a characteristic time.0] Parameter set Default:[ ] Description Anti Surge Controller amplification (proportional term). FREEZE the controller output is frozen (kept constant).2. Stroke or actuator time. MANUAL: The controller output is given by key MANUALOUTPUT. Minimum output signal.. 0] Description Time required to change valve settings or compressor speed from maximum to minimum value. N. Indicates measuring range for input to controller. EXTERNALSIGNAL: The controller output is given by the controller connected to the SIGNAL terminal. MANUAL: The controller output is given by key MANUALOUTPUT.4s. Activate the non-linear option for the PID.0] MANUAL | EXTERNALSIGNAL | FREEZE | [AUTOMATIC] MODE SymbolList NORMRANGE OPENINGTIME SAMPLEDT SAMPLETIME STROKETIME TIME TIMESTEPCONTROL Real Real (s) Real (s) Real (s) Real (s) RealList (s) Symbol OFF | [ON] [10.N (Required input) (Optional input) (Optional input) (Optional input) (Optional input) (Optional output) ESDController Keys ( See also: Description ) Key CLOSINGTIME DELAY EXPOSE LABEL MANUALOUTPUT Type Unit:( ) Real (s) Real (s) SymbolList String RealList [CONTR] Parameter set Default:[ ] [10. Time interval between each sampling of input.. The valve is opened again if RESET is given. Error is the deviation.0s and MAXCHANGE=0. States which keys should be made available as input variables on the OPC server. Time required to change valve settings or compressor speed from minimum to maximum value. everything is on hold.Emergency shutdown controller. Maximum output signal. and if the measured variable is below or above (depending on the OPENMODE key) the setpoint value. override controller etc. FREEZE the controller output is frozen (kept constant). Identification label for this controller. INACTIVEMODE Symbol ONHOLD | INTERLOCK | DEFAULTINPUT | NORMAL | INITIALSETPOINT INTEGRALCONST LABEL MANUALOUTPUT Real RealList (s) String RealList [1. this is an array as a function of the ERROR array. OLGA will go back to the previous point in time and integrate with a shorter time-step. Minimum setpoint for secondary controller in cascade control loop.2] MAXSETPOINT MAXSIGNAL MINSETPOINT MINSIGNAL Real Real Real Real [1.0] [0.b. If STROKETIME is less than DTMIN the time step control is also bypassed. Coefficients are given as an array of values representing each value in ERROR.) Maximum setpoint for secondary controller in cascade control loop. it is the inverse of the coefficient which appears in the expression for the output signal. It represents a characteristic time.0] ON | [OFF] option is chosen. States which keys should be made available as input variables on the OPC server. For use with EXTENDED CASCADE controller. Analog controller: Maximum allowed change in controller output signal from one time-step to the next.0] Link to: CascadeController Description Keys ESDController Description ( See also: Keys) ESD . this is an array as a function of the ERROR array. Identification label for this controller. If the change in output exceeds this value. (E. Logging time interval for the primary controller variable. Activates digital controller option. The ESD controller will send a signal intended to close a valve when the measured variable is above or below (depending on the OPENMODE key) the setpoint value. Coefficient in front of the integral of PID controllers.0] [0. Initial setpoint for extended cascade. Time required to change valve settings or compressor speed from minimum to maximum value or vice versa. For normalized controllers (used together with AMPLIFICATION).N MODE SIGNAL SETPOINT ACTIVATE CONTR_1. EXTERNALSETPOINT the setpoint is given by the controller connected to the SETPOINT terminal.. with SAMPLETIME=2. If the PID controller becomes inactive it will back calculate its integral error to match the output signal of the connected controller. The ESD controller has the following signal terminals: MEASRD_1. Minimum output signal. given in key DEFAULTINPUT.. OLGA will go back to the previous point in time and integrate with a shorter time-step. INTERLOCK: The PID controller get feedback on the output signal used from the connected controller (Selector or Override). Digital controller: Maximum discrepancy between the instance a sample should be taken and the actual time in the simulation in terms of a fraction of the sample time MAXCHANGE Real [0. Stroke or actuator time.0] [10. Digital controller: Maximum discrepancy between the instance a sample should be taken and the actual time in the simulation in terms of a fraction of the sample time interval. If the non-linear option is chosen. This restriction is used by the time-step control. If TIMESTEPCONTROL=OFF the time step control is bypassed.2] .0] [0. ONHOLD: Restore old values. The setpoint is given as a signal or a key..2. Manual output. This restriction is used by the time-step control. NORMAL: No action. Manual output.DERIVATIVECONST ERROR EXPOSE EXTENDED RealList (s) RealList SymbolList Symbol [0. DEFAULTINPUT: Compute output signal based on default input. Time series for the SETPOINT key. Specifies how the controller act when it is deactivated by a selector. the maximum discrepancy will be ±0. Select ON to use the EXTENDED CASCADE controller.0E+10] [CONTR] MAXCHANGE Real [0. Time from when the measured value is read to when it is used by the controller.g. Analog controller: Maximum allowed change in controller output signal from one time-step to the next. AUTOMATIC: The setpoint is defined on the controller. If the change in output exceeds this value. If TIMESTEPCONTROL=OFF the time step control is bypassed.) Maximum output signal. EXTERNALSETPOINT the setpoint is given by the controller connected to the SETPOINT terminal. only dependent on time.0] [0. AUTOMATIC: The setpoint is defined on the controller.2. The input signals are compared.0] OFF | [ON] interval. Time interval between each sampling of input. If RANGECHECK=ON MINSIGNAL and MAXSIGNAL will be used to limit the output signal. Setpoint values. FREEZE the controller output is frozen (kept constant).0] [0.) Maximum output signal. Time series for the SETPOINT key. with SAMPLETIME=2. The manual controller limits the setpoint with STROKETIME or CLOSINGTIME/OPENINGTIME. Stroke or actuator time. Time required to change valve settings or compressor speed from minimum to maximum value.MAXSIGNAL MINSIGNAL Real Real [1. Activates digital controller option. EXTERNALSETPOINT the setpoint is given by the controller connected to the SETPOINT terminal. Time interval between each sampling of input. Analog controller: Maximum allowed change in controller output signal from one time-step to the next. Minimum output signal. or as a setpoint signal. Time required to change valve settings or compressor speed from minimum to maximum value. MANUAL: The controller output is given by key MANUALOUTPUT.0s and MAXCHANGE=0.2.0] BELOW | [ABOVE] MODE SymbolList OPENINGTIME OPENMODE RESET SAMPLETIME SETPOINT STROKETIME TIME TIMESTEPCONTROL Real (s) Symbol RealList Real (s) RealList Real (s) RealList (s) Symbol [10. If the change in output exceeds this value.g. AUTOMATIC: The setpoint is defined on the controller. Identification label for this controller. Time required to change valve settings or compressor speed from minimum to maximum value or vice versa. EXTERNALSIGNAL: The controller output is given by the controller connected to the SIGNAL terminal. FREEZE the controller output is frozen (kept constant). (E.2] MAXSIGNAL MINSIGNAL Real Real [1.0] MANUAL | EXTERNALSIGNAL | EXTERNALSETPOINT | FREEZE | [AUTOMATIC] [10. States which keys should be made available as input variables on the OPC server. Time series for the SETPOINT key. Activates digital controller option. Time required to change valve settings or compressor speed from minimum to maximum value or vice versa...0] OFF | [ON] Link to: ManualController Description Keys OverrideController Description ( See also: Keys) An override controller is a low select or high select operator. MANUAL: The controller output is given by key MANUALOUTPUT. with SAMPLETIME=2. Setpoint values. For ESD. the maximum discrepancy will be ±0. and the . Manual output. An override controller uses any number of input signals. If TIMESTEPCONTROL=OFF the time step control is bypassed. The valve closes if the input variable gets below or exceeds the reset value depending on OPENMODE.0s and MAXCHANGE=0.0] ON | [OFF] MODE SymbolList OPENINGTIME RANGECHECK SAMPLETIME SETPOINT STROKETIME TIME TIMESTEPCONTROL Real (s) Symbol Real (s) RealList Real (s) RealList (s) Symbol [10.. (E.0] MANUAL | EXTERNALSIGNAL | EXTERNALSETPOINT | FREEZE | [AUTOMATIC] [10.g.4s. the maximum discrepancy will be ±0. If STROKETIME is less than DTMIN the time step control is also bypassed. If STROKETIME is less than DTMIN the time step control is also bypassed.0] Description Time required to change valve settings or compressor speed from maximum to minimum value. Depending on whether the valve is to close when the signal goes above or below the setpoint. A manual controller has the following signal terminals: MODE SIGNAL SETPOINT ACTIVATE CONTR. Link to: ESDController Description Keys ManualController Description ( See also: Keys) The manual controller simulates an operator. MAXCHANGE Real [0. OLGA will go back to the previous point in time and integrate with a shorter time-step.4s. Minimum output signal. It provides a valve opening directly from a user specified series. Digital controller: Maximum discrepancy between the instance a sample should be taken and the actual time in the simulation in terms of a fraction of the sample time interval. Either ABOVE or BELOW. Stroke or actuator time. The user specified series is given in the setpoint key.N (Optional input) (Optional input) (Optional input) (Optional input) (Optional output) ManualController Keys ( See also: Description ) Key CLOSINGTIME EXPOSE LABEL MANUALOUTPUT Type Unit:( ) Real (s) SymbolList String RealList [CONTR] Parameter set Default:[ ] [10. EXTERNALSIGNAL: The controller output is given by the controller connected to the SIGNAL terminal. This restriction is used by the time-step control. The PID controller has the following signal terminals: MEASRD MODE SIGNAL SETPOINT ACTIVATE WINDUP CONTR_1. Stroke or actuator time.0] [0.0] HIGH | [LOW] [10. MODE SymbolList OPENINGTIME SAMPLETIME SELECTIONMODE STROKETIME TIME Real (s) Real (s) Symbol Real (s) RealList (s) [10.. . Time required to change valve settings or compressor speed from minimum to maximum value or vice versa. integral time constants. MANUAL: The controller output is given by key MANUALOUTPUT. and derivative time constants as functions of the error input. Error is the deviation. Setpoint for INACTIVEMODE=DEFAULTMODE. States which keys should be made available as input variables on the OPC server. Coefficients are given as an array of values representing each value in ERROR.N (Optional input) (Optional input) (Optional input) (Required input) (Optional output) OverrideController Keys ( See also: Description ) Key CLOSINGTIME EXPOSE LABEL MANUALOUTPUT MAXSIGNAL MINSIGNAL Type Unit:( ) Real (s) SymbolList String RealList Real Real [CONTR] [1. EXTERNALSIGNAL: The controller output is given by the controller connected to the SIGNAL terminal. Time from when the measured value is read to when it is used by the controller.minimum/maximum (depending on the SELECTIONMODE key) input signal is chosen as the output signal from the override controller. Time series for the SETPOINT key. Time required to change valve settings or compressor speed from maximum to minimum value. this is an array as a function of the ERROR array. Activates digital controller option. everything is on hold. Key SELECTIONMODE determines the selection of minimum or maximum signal. EXTERNALSETPOINT the setpoint is given by the controller connected to the SETPOINT terminal..0] Link to: OverrideController Description Keys PIDController Description ( See also: Keys) PID (Proportional-Integral-Derivative) controllers are designed to maintain a specified value (given by a setpoint signal or key) for a measured flow variable (given as an input signal).N CONTR_1. Activate the non-linear option for the PID. Identification label for this controller.0] [10. An override controller has the following signal terminals: MODE SIGNAL ACTIVATE INPSIG_1. Minimum output signal.0] MANUAL | EXTERNALSIGNAL | FREEZE | [AUTOMATIC] Parameter set Default:[ ] [10. If the non-linear option is chosen. Coefficient in front of the derivative term of PID controllers.0] Parameter set Default:[ ] Description PID amplification factor.. States which keys should be made available as input variables on the OPC server. Time interval between each sampling of input. Specify how the controller acts when it is deactivated by a selector. The user can specify if the controller is linear or non-linear. Initial output signal. Maximum output signal. FREEZE the controller output is frozen (kept constant).N (Required input) (Optional input) (Optional input) (Optional input) (Optional input) (Optional input) (Optional output) PIDController Keys ( See also: Description ) Key AMPLIFICATION BIAS CLOSINGTIME DEFAULTINPUT DELAY DERIVATIVECONST ERROR EXPOSE Type Unit:( ) RealList Real Real (s) Real Real (s) RealList (s) RealList SymbolList [0. ONHOLD: Restore old values. If the non-linear option is chosen. AUTOMATIC: The setpoint is defined on the controller. override controller etc. If a controller is non-linear. An override controller selects either minimum or maximum of the signals from all the subcontrollers.0] Description Time required to change valve settings or compressor speed from maximum to minimum value. Time required to change valve settings or compressor speed from minimum to maximum value. the user has to give tables for specifying the amplification factors. Manual output. this is an array as a function of the ERROR array.0] [0.0] [0. Minimum output signal.0] MODE SymbolList OPENINGTIME Real (s) . FREEZE the controller output is frozen (kept constant).0] MANUAL | EXTERNALSIGNAL | EXTERNALSETPOINT | FREEZE | [AUTOMATIC] [10. The setpoint can be given as a key or as an input signal. Activates digital controller option. MANUAL: The controller output is given by key MANUALOUTPUT. If TIMESTEPCONTROL=OFF the time step control is bypassed. (E. the maximum discrepancy will be ±0. Digital controller: Maximum discrepancy between the instance a sample should be taken and the actual time in the simulation in terms of a fraction of the sample time interval. INTEGRALCONST LABEL MANUALOUTPUT RealList (s) String RealList [1. with SAMPLETIME=2.N MODE SIGNAL SETPOINT ACTIVATE CONTR_1. NORMAL: no action. Coefficient in front of the integral of PID controllers. MANUAL: The controller output is given by key MANUALOUTPUT. MAXCHANGE Real [0. Manual output. this is an array as a function of the ERROR array.b. If the change in output exceeds this value.2] MAXSIGNAL MINSIGNAL Real Real [1.2. EXTERNALSETPOINT the setpoint is given by the controller connected to the SETPOINT terminal.INACTIVEMODE Symbol ONHOLD | INTERLOCK | DEFAULTINPUT | NORMAL | INTERLOCK: The PID controller gets feedback on the output signal used from the connected controller (Selector or Override).0] [0. It represents a characteristic time.0s and MAXCHANGE=0. Time required to change valve settings or compressor speed from minimum to maximum value. If the PID controller becomes inactive it will back calculate its integral error to match the output signal of the connected controller. States which keys should be made available as input variables on the OPC server. N..0E+10] [CONTR] MAXCHANGE Real [0. Analog controller: Maximum allowed change in controller output signal from one time-step to the next.0] [0. Stroke or actuator time. EXTERNALSIGNAL: The controller output is given by the controller connected to the SIGNAL terminal. Time required to change valve settings or compressor speed from minimum to maximum value.2. given in key DEFAULTINPUT.) Maximum output signal. If the non-linear option is chosen.. Time interval between each sampling of input. EXTERNALSIGNAL: The controller output is given by the controller connected to the SIGNAL terminal. AUTOMATIC: The setpoint is defined on the controller. Minimum output signal. Manual output.2] MAXSIGNAL MINSIGNAL Real Real [1.0] [10. AUTOMATIC: The setpoint is defined on the controller. it is the inverse of the coefficient which appears in the expression for the output signal.) Maximum output signal. DEFAULTINPUT: Compute output signal based on default input. EXTERNALSETPOINT the setpoint is given by the controller connected to the SETPOINT terminal.g.0s and MAXCHANGE=0. Indicates measuring range for input to controller. Identification label for this controller. Digital controller: Maximum discrepancy between the instance a sample should be taken and the actual time in the simulation in terms of a fraction of the sample time interval. (E.4s. This restriction is used by the time-step control. OLGA will go back to the previous point in time and integrate with a shorter time-step. Setpoint values.g..0] Link to: PIDController Description Keys PSVController Description ( See also: Keys) A Pressure Safety Valve controller (PSV) opens a valve when the pressure at a specified position (given by a measured signal) is above or below (depending on SETPOINTMODE) the setpoint value... For normalized controllers (used together with AMPLIFICATION). If STROKETIME is less than DTMIN the time step control is also bypassed. This restriction is used by the time-step control.0] [0. Identification label for this controller. with SAMPLETIME=2. Time from when the measured value is read to when it is used by the controller.0] Description Time required to change valve settings or compressor speed from maximum to minimum value.N (Required input) (Optional input) (Optional input) (Optional input) (Optional input) (Optional output) PSVController Keys ( See also: Description ) Key CLOSINGTIME DELAY EXPOSE LABEL MANUALOUTPUT Type Unit:( ) Real (s) Real (s) SymbolList String RealList [CONTR] Parameter set Default:[ ] [10. the maximum discrepancy will be ±0. Time series for the SETPOINT key.0] MANUAL | EXTERNALSIGNAL | EXTERNALSETPOINT | FREEZE | [AUTOMATIC] MODE SymbolList NORMRANGE OPENINGTIME SAMPLETIME SETPOINT STROKETIME TIME TIMESTEPCONTROL Real Real (s) Real (s) RealList Real (s) RealList (s) Symbol OFF | [ON] [10. The PSV controller closes the valve when the pressure is below or above (depending on SETPOINTMODE) a specified RESET value.4s. FREEZE the controller output is frozen (kept constant). If the change in output exceeds this value. OLGA will go back to the previous point in time and integrate with a shorter time-step. Time required to change valve settings or compressor speed from minimum to maximum value or vice versa. The PSV controller has the following signal terminals: MEASRD_1. Analog controller: Maximum allowed change in controller output signal from one time-step to the next. Time required to change valve settings or compressor speed from maximum to minimum value. Any number of limits (HIGHLIMITSIG/LOWLIMITSIG) can be given.0] [0. Time interval between each sampling of input.MAXSIGNAL.0] [10.. A scaler controller has the following terminals: MEASRD CONTR_1. Maximum output signal. Link to: PSVController Description Keys ScalerController Description ( See also: Keys) The main purpose of a SCALER controller is to scale the measured signal from range LOWLIMIT.0] OFF | [ON] Either ABOVE or BELOW. A selector controller has the following signal terminals: SUBCONLOW SUBCONHIGH HIGHLIMITSIG_1. Time required to change valve settings or compressor speed from minimum to maximum value.N LOWLIMITSIG_1.LOWLIMIT)*(MAXSIGNAL-MINSIGNAL) + MINSIGNAL where Y is the measured signal. Stroke or actuator time. Then another sub-controller takes over. Depending on whether the valve is to close when the signal goes above or below the setpoint. The selector controller switches between these subcontrollers depending of the low and high limits given as input through the HIGHLIMITSIG and LOWLIMITSIG signal terminals... Activates digital controller option. Time from when the measured value is read to when it is used by the controller. and stays active until yet another limit is reached.N MODE SIGNAL ACTIVATE CONTR_1. The valve closes if the input variable gets below or exceeds the reset value depending on OPENMODE. Low limit for measured signal. Setpoint values. If STROKETIME is less than DTMIN the time step control is also bypassed.HIGHLIMIT to range MINSIGNAL.OPENMODE RESET SAMPLETIME SETPOINT STROKETIME TIME TIMESTEPCONTROL Symbol RealList Real (s) RealList Real (s) RealList (s) Symbol BELOW | [ABOVE] [10. Time series for the SETPOINT key.0] Description Initial output signal. [CONTR] [1.0] [10.N (Required input) (Optional output) ScalerController Keys ( See also: Description ) Key BIAS CLOSINGTIME DELAY EXPOSE HIGHLIMIT LABEL LOWLIMIT MAXSIGNAL MINSIGNAL OPENINGTIME STROKETIME Type Unit:( ) Real Real (s) Real (s) SymbolList Real String Real Real Real Real (s) Real (s) Parameter set Default:[ ] [0..N (Required input) (Required input) (Required input) (Required input) (Optional input) (Optional input) (Optional input) (Optional output) SelectorController Keys ( See also: Description ) Key Type Unit:( ) Parameter set Default:[ ] Description .0] [0. If TIMESTEPCONTROL=OFF the time step control is bypassed. Identification label for this controller. Output U is set: U = (Y -LOWLIMIT)/(HIGHLIMIT . States which keys should be made available as input variables on the OPC server. Time required to change valve settings or compressor speed from minimum to maximum value or vice versa. Minimum output signal.0] Link to: ScalerController Description Keys SelectorController Description ( See also: Keys) The selector controller has two sub controllers. High limit for measured signal. Time required to change valve settings or compressor speed from minimum to maximum value or vice versa. A subcontroller that is active due to a limit being reached stays active until another limit is reached. SUBCONLOW and SUBCONHIGH.0] [10... value at the MEASRD terminal. Stroke or actuator time. the controller will loop all connections and test if HIGHLIMITSIG_i > HIGHLIMIT[i] Active sub-controller at the start of the simulation.0] Time required to change valve settings or compressor speed from maximum to minimum value. Time required to change valve settings or compressor speed from minimum to maximum value or vice versa. Link to: STDController Description Keys SwitchController Description ( See also: Keys) . Mole fraction of each feed. States which keys should be made available as input variables on the OPC server. i. Time from when the measured value is read to when it is used by the controller. If multiple LOWLIMIT/LOWLIMITSIG is given. Identification label for this controller. Time required to change valve settings or compressor speed from minimum to maximum value.0] [-1. MANUAL: The controller output is given by key MANUALOUTPUT. EXTERNALSIGNAL: The controller output is given by the controller connected to the SIGNAL terminal. the GOR from the PVT table is used. Time series for the SETPOINT key. By default. the controller will loop all connections and test if LOWLIMITSIG_i < LOWLIMIT[i]. Ratio between water (including water in gas phase) and gas. Stroke or actuator time. EXTERNALSETPOINT the setpoint is given by the controller connected to the SETPOINT terminal. Time interval between each sampling of input. Σπεχιφψ τηε ωαντεδ ΓΟΡ/ΧΓΡ/ΩΓΡ/ΩΑΤΕΡΧΥΤ/ΜΟΛΩΕΙΓΗΤ. STDController Keys ( See also: Description ) Key CGR EXPOSE FEEDMASSFRACTION FEEDMOLEFRACTION FEEDNAME FEEDVOLFRACTION FLUID GLR GOR LABEL MOLWEIGHT Type Unit:( ) Real (Sm3/Sm3) SymbolList RealList (-) RealList (-) SymbolList RealList (-) Symbol Real (Sm3/Sm3) Real (Sm3/Sm3) String Real (kg/kmol) Sm3/h | Sm3/d | scf/d | MMscf/d | STB/d | STB/M | scf/s | scf/h | MSm3/d | Mscf/d | [Sm3/s] GAS | OIL | WATER | LIQUID | ALL | SlurryPvtData | [-1. Molecular weight of equivalent gas (total flow). Mass fraction of each feed.e. If a keyword based pvt-file is used.0] MANUAL | EXTERNALSIGNAL | FREEZE | [AUTOMATIC] MODE SymbolList OPENINGTIME SAMPLETIME STROKETIME TIME Real (s) Real (s) Real (s) RealList (s) [10. LOWLIMIT is compared with the LOWLIMITSIG signal input. If the signal from SUBCONHIGH is used.CLOSINGTIME DELAY EXPOSE Real (s) Real (s) SymbolList [10. the gas density at standard conditions from the PVT table is used to determine the molecular weight. Χοννεχτ τηε ΣΤ∆ Χοντρολλερ ουτπυτ τερµιναλ Χοντρ το αν ΠΙ∆ χοντρολλερ Μεασρδ τερµιναλ.0] HIGHLIMIT RealList INITIALCONTROLLER LABEL Symbol String SUBCONHIGH | SUBCONLOW | [CONTR] LOWLIMIT RealList MANUALOUTPUT MAXSIGNAL MINSIGNAL RealList Real Real [1. The default value is the equilibrium value from PVT data. numbering is not valid for this format. Water volume fraction in oil/water mixture. HIGHLIMIT is compared with the HIGHLIMITSIG signal input. Minimum output signal. If the signal from SUBCONLOW is used.0] [STD] PVTData | Parameter set Default:[ ] Description Condensate-gas ratio.0] [-1. Volume fraction of each feed given in FEEDNAME for choke model (only for Blackoil model). If multiple HIGHLIMIT/HIGHLIMITSIG is given. Label of feeds feeding to terminal nodes. Activates digital controller option. Link to: SelectorController Description Keys STDController Description ( See also: Keys) The STD Controller converts mass flow rate to volumetric flow rate at standard conditions.0 the total water fraction is taken from the fluid table. the controller will switch to the SUBCONHIGH signal if HIGHLIMITSIG > HIGHLIMIT. Maximum output signal. Name of User Defined property file used by the plug-in module. Gas/liquid volumetric flow ratio at standard conditions. Requires COMPOSITIONAL=ON or BLACKOIL under the OPTIONS keyword. By default. OUTPUTUNIT Symbol PHASE UDPVTFILE WATERCUT WGR Symbol Symbol Real (-) Real (Sm3/Sm3) The phase for which the volumetric flow rate is specified. Σπεχιφψ τηε φλυιδ ιν τηε ΦΛΥΙ∆ ορ ΦΕΕ∆ΝΑΜΕ κεψσ. FREEZE the controller output is frozen (kept constant). Unit of controller output. Identification label for this controller. States which keys should be made available as input variables on the OPC server. the controller will switch to the SUBCONLOW signal if LOWLIMITSIG < LOWLIMIT. With a value of -1.. Has to refer to a SUBCON terminal.0] [0. Label or number of fluid table to apply for the specific branch. Σετ χορρεχτ πηασε ιν ΠΗΑΣΕ κεψ. FLUID must be the same as the LABEL given in the pvt-file. AUTOMATIC: The setpoint is defined on the controller.0] [10. ανδ τηε οϖεραλλ µασσ φλοω ρατε ωιλλ βε χαλχυλατεδ. Gas/oil volumetric flow ratio at standard conditions. Manual output.0] [0. Setpoint values.0] [10] [10] TABLE | Parameter set Default:[ ] [0.N (Required input) (Optional input) (Optional input) (Optional input) (Optional input) (Optional output) SwitchController Keys ( See also: Description ) Key BIAS CLOSINGTIME DELAY EXPOSE LABEL MANUALOUTPUT MAXSIGNAL MINSIGNAL Type Unit:( ) Real Real (s) Real (s) SymbolList String RealList Real Real [CONTR] [1. Time from when the measured value is read to when it is used by the controller. Time required to change valve settings or compressor speed from minimum to maximum value or vice versa.0] MANUAL | EXTERNALSIGNAL | EXTERNALSETPOINT | FREEZE | [AUTOMATIC] [10.The main purpose of the switch controller is to switch between alternative inputs values..0] [10] [0.5 1.0] Parameter set Default:[ ] [0.5) <= SP unconstrained output A is set equal to controller at terminal INPSIG_N unconstrained output A is set equal to controller at terminal INPSIG_1 unconstrained output A is set equal to controller at terminal INPSIG_2 unconstrained output A is set equal to controller at terminal INPSIG_3 Where Ni is the number of connected input terminals INPSIG A switch controller has the following terminals: INPSIG_1. Identification label for this controller.5 <= SP < 2.0] [10. Time required to change valve settings or compressor speed from minimum to maximum value.0] Link to: SwitchController Description Keys TableController Description ( See also: Keys) A table controller uses the input signal (terminal INPSIG) as lookup variable.0] Description Initial output signal. Label of the table. Maximum output signal.5 <= SP < 3.Ni MODE SIGNAL SETPOINT ACTIVATE CONTR_1.N (Required input) (Optional output) TableController Keys ( See also: Description ) Key BIAS CLOSINGTIME DELAY EXPOSE LABEL MAXSIGNAL MINSIGNAL OPENINGTIME STROKETIME TABLE Type Unit:( ) Real Real (s) Real (s) SymbolList String Real Real Real (s) Real (s) Symbol [CONTR] [1.0] [0.. Stroke or actuator time. MODE SymbolList OPENINGTIME SETPOINT STROKETIME TIME Real (s) RealList Real (s) RealList (s) [10. Time required to change valve settings or compressor speed from maximum to minimum value. Time required to change valve settings or compressor speed from minimum to maximum value. Maximum output signal.0] Description Initial output signal. Time required to change valve settings or compressor speed from minimum to maximum value or vice versa. EXTERNALSIGNAL: The controller output is given by the controller connected to the SIGNAL terminal. Time from when the measured value is read to when it is used by the controller.0] [0. Stroke or actuator time. x. Time required to change valve settings or compressor speed from maximum to minimum value. The output of the controller is selected based on the setpoint in MODE = AUTOMATIC or SETPOINT terminal if MODE = EXTERNALSETPOINT.. Minimum output signal. Input signal x1 gives output . MANUAL: The controller output is given by key MANUALOUTPUT. Manual output. States which keys should be made available as input variables on the OPC server. Identification label for this controller. FREEZE the controller output is frozen (kept constant). The look-up function is linear interpolation. (Ni-0. The table controller has the following terminals: INPSIG CONTR_1. Time series for the SETPOINT key. AUTOMATIC: The setpoint is defined on the controller. The controller output is y = f(x). States which keys should be made available as input variables on the OPC server.5 2. EXTERNALSETPOINT the setpoint is given by the controller connected to the SETPOINT terminal. in a table.5 …. The table consist of x and y. SP < 1.0] [0. Minimum output signal. Link to: OUTPUTDATA (on ASCController) Description Keys TRENDDATA (on ASCController) Description ( See also: Keys) TRENDDATA (on ASCController) Keys ( See also: Description ) Key VARIABLE Type Unit:( ) SymbolList (ValueUnitPair) Parameter set Default:[ ] Description List of variables to be plotted. . The purpose is to calculate a correction factor for the pipe wall roughness due to the pipe upsets. Units may be specified. The TOOLJOINT keyword is part of the Wells Module. Units may be specified. Link to: TableController Description Keys OUTPUTDATA (on ASCController) Description ( See also: Keys) OUTPUTDATA (on ASCController) Keys ( See also: Description ) Key VARIABLE Type Unit:( ) SymbolList (ValueUnitPair) Parameter set Default:[ ] Description List of variables to be printed.signal y1 by table interpolation. Link to: TRENDDATA (on ASCController) Description Keys TOOLJOINT (on CaseLevel) Description ( See also: Keys) This statement defines the geometrical data for internal and external pipe upsets in the flow path. Hydrocarbon liquid plastic viscosity. Consistency factor for hydrocarbon liquid in the complex viscosity model. . used in both the complex viscosity and complex fluid model. Type of complex fluid model of the water phase. Length of upset. and in the Bingham formulation it is used as the coefficient of rigidity. Consistency factor for water phase in the complex viscosity model. In the power law formulation it is used as the consistency factor K. Whether or not to use power exponent/yield stress as function of P and T from the fluid property file in a complex fluid model. used in the complex viscosity model. Label of pipe(s) for which the wall roughness shall be adjusted. Outer diameter of annulus. Fluid model type. the power law exponent or the yield stress is given as a function of pressure and temperature in the fluid property table file specified in PVTFILE in FILES. As opposed to the complex viscosity model. simple or full (FULL = YES). Therefore. default is tool-joint number.Figure A Side view and cross section of flow path with upsets TOOLJOINT (on CaseLevel) Keys ( See also: Description ) Key D1EXUP D2INUP DD1 DD2 GEOMETRY LABEL LJOINT LUPSET PIPE Type Unit:( ) Real (m) Real (m) Real (m) Real (m) Symbol String Real (m) Real (m) SymbolList Parameter set Default:[ ] Description External upset of pipe/tubing. Due to limited testing against Newtonian data. FLUID (on CaseLevel) Keys ( See also: Description ) Key CFLUML CFLUMW CONSFL CONSFW CVISL CVISW FULL PLASTL PLASTW POWEXPL POWEXPW TYPE YIELDSTRL Type Unit:( ) Symbol Symbol Real Real Symbol Symbol Symbol Real (N-s/m2) Real (N-s/m2) Real Real Symbol Real (Pa) COMPLEXFLUID | COMPLEXVISCOSITY | [NEWTONIAN] BINGHAM | POWERLAW | HERSCHELBUCKLEY | [NEWTONIAN] BINGHAM | POWERLAW | HERSCHELBUCKLEY | [NEWTONIAN] YES | [NO] Parameter set Default:[ ] BINGHAM | POWERLAW | [NEWTONIAN] BINGHAM | POWERLAW | [NEWTONIAN] Description Type of complex fluid model of the liquid hydrocarbon phase. Internal upset in annulus/tubing. This implies that the FLUID keyword must be given above the FILES keyword in the OLGA input file since the fluid property files are read as soon as OLGA reads the FILES keyword. As soon as TYPE is set to COMPLEXFLUID the modified physical models are used. setting CFLUML = NEWTONIAN is equivalent to CFLUML = BINGHAM with YIELDSTRL = 0. GEOMETRY | [TOOLJ] Link to: TOOLJOINT (on CaseLevel) Description Keys FLUID (on CaseLevel) Description ( See also: Keys) This statement enables the use of the complex viscosity model and the complex fluid model for simulation of non-Newtonian flows and high viscosity liquids. Type of complex viscosity model of the water phase. Geometry label to where the tool-joint is located. the complex fluid model includes numerous modifications to the physical models for both separated and distributed flow taking into account the non-Newtonian behavior of the fluids. used in both the complex viscosity and complex fluid model. the power law or a Newtonian model. Yield stress for hydrocarbon liquid phase in the complex viscosity and complex fluid models. Exponent for water phase model. the complex fluid model is not recommended used on gas-condensate and oil-gas systems with oil viscosity less than 50 cp. In the simple mode the power law exponent or yield stress is given in the main input file. even if CFLUML or CFLUMW are set to NEWTONIAN. In the full mode. For the complex fluid model. Distance between upsets. In all cases the hydrocarbon liquid and/or the water viscosity part of the usual PVT file is used. Tool-joint label. Type of complex viscosity model of the liquid hydrocarbon phase. Inner diameter of annulus. and CFLUML = POWERLAW with POWEXPL = 1. Exponent for hydrocarbon liquid phase model. the fluid properties can be given in two ways. The complex fluid model The Complex Fluid module requires a separate license. The module utilizes either the Bingham. Water plastic viscosity used in the complex viscosity model. That is. These two options may be used together or separately. The slug tracking option offers full temperature calculation capabilities. the user can specify a fixed number of slugs to be set up at predefined positions and times. If HYDRODYNAMIC = ON. Accentric factor. Viscosity tuning factor. the slug front is allowed to move into the outlet section. (2) Remove SLUGTRACKING keyword. Only for SINGLECOMPONENT=OTHER. Terrain slugging will be detected in ordinary simulations without the slug tracking module. The level slug option is mostly used for startup-slugs. Void fractions in the slug bubbles. Only for SINGLECOMPONENT=OTHER. Minimum temperature for PVT table generated. Coefficients in equation for specific heat. Average values will be used in the sections. However. Only for SINGLECOMPONENT=OTHER.0] [1. CO2 and OTHER. and is specified by key COMPONENT in SINGLEOPTIONS . More details can be found in the description of the slug tracking module. (Non-equilibrium delay constant). (3) The time elapsed since the previous slug was generated in or passed this section is higher than a specified minimum time. Maximum temperature for PVT table generated. liquid will be injected into the pipeline to generate slugs of required size. the code will set up a new slug in a section whenever the set-up criteria are fulfilled. Only for SINGLECOMPONENT=OTHER.YIELDSTRW Real (Pa) Yield stress for water phase in the complex viscosity and complex fluid models. Users can specify the sections where slugs are not allowed to be generated by using SLUGILLEGAL keyword. (Non-equilibrium delay constant). Only for SINGLECOMPONENT=OTHER. Using this option. To turn off slug-tracking in a restart there are two possibilities: (1) Set both LEVEL and HYDRODYNAMIC to OFF. Molecular weight. Link to: FLUID (on CaseLevel) Description Keys SINGLEOPTIONS (on CaseLevel) Description ( See also: Keys) This statement defines options for simulation of single component systems in OLGA. End time for level slug initiation.0] [0. SINGLEOPTIONS (on CaseLevel) Keys ( See also: Description ) Key COMPONENT CPIC MAXPRESSURE MAXTEMPERATURE MINPRESSURE MINTEMPERATURE MW OMEGA PC TBOILING TC TCONDENSATION TIME VISX VOLX Type Unit:( ) Symbol RealList Real (Pa) Real (C) Real (Pa) Real (C) Real (g/mol) Real Real (Pa) RealList (s) Real (C) RealList (s) RealList (s) Real RealList [1. . These are: (1) Flow regime at the section boundary changes from separated to slug flow. and the slug tail into the inlet section. Only for SINGLECOMPONENT=OTHER. For COMPONENT equal H2O and CO2 most physical parameters are implemented in OLGA. Then the only slugs in the system will be the ones read from restart. Only for SINGLECOMPONENT=OTHER. (2) Other slug fronts are the required distance away. and the interactions between terrain and hydrodynamic slugging can be investigated using the key HYDRODYNAMIC. Option for initiating hydrodynamic slugs. No slugs in the simulation. Link to: SINGLEOPTIONS (on CaseLevel) Description Keys SLUGTRACKING (on CaseLevel) Description ( See also: Keys) This statement defines the slug tracking option.0] Parameter set Default:[ ] H2O | CO2 | OTHER | Description Name of single-component. VOIDINSLUG: Entrainment based on correlation for void in slug. turned on by specifying COMPOSITIONAL=SINGLE in keyword OPTIONS. This statement has two main sub-options for initiation of liquid slugs: the level slug option (LEVEL) and the hydrodynamic slug option (HYDRODYNAMIC). Time constant for mass transfer from gas phase to liquid phase for the component. Maximum pressure for PVT table generated. the boundary sections are automatically set to illegal for slugs by the program itself. SLUGTRACKING (on CaseLevel) Keys ( See also: Description ) Key BUBBLEVOID DELAYCONSTANT ENDTIME GASENTRAINMENT HYDRODYNAMIC INITBUBBLEVOIDS Type Unit:( ) Real (-) Real Real (s) Symbol Symbol RealList (-) NYDAL | [VOIDINSLUG] ON | MANUAL | [OFF] [1] [150] Parameter set Default:[ ] Description Minimum void required behind a level tail and ahead of a level front at initiation time Number of pipe diameters a slug needs to propagate before the next hydrodynamic slug is initiated. Volume tuning factor. Time points for which TBOILING and TCONDENSATION changes. If not given no end time restriction is enforced. Critical temperature.0] [0. while for COMPONENT=OTHER the user needs to specify these parameters in SINGLEOPTIONS. Minimum pressure for PVT table generated. Gas entrainment into slug from bubble for breaking/level front in slug tracking. If HYDRODYNAMIC = MANUAL. Slugs are not allowed to be generated at the inlet and outlet sections by default. These are H2O. NYDAL: Nydal correlation for entrainment.0] [1. Remark: The availability of the slug tracking option depends on the user’s licensing agreement with SPT Group. Critical pressure. Time constant for mass transfer from liquid phase to gas phase due to boiling for component. There are three single component systems that can be specified. The SLUGTUNING keyword may be used for adjusting the OLGA model to specific sets of measured data or for sensitivity studies.0] Link to: SLUGTUNING (on CaseLevel) Description Keys WATEROPTIONS (on CaseLevel) Description ( See also: Keys) In WATEROPTIONS several options are available for modeling the dispersion viscosity (DISPERSIONVISC) and the slip between the water and oil phases (WATERSLIP). Labels of section boundaries where slug generation zones are located. the slip between the oil and water phases must be specified with VELOCITYDIFFERENCE. Option for detecting and initiating level slugs. respectively. witch makes it possible to tune certain parameters in the slug model.0] [1. SLUGTUNING should be applied with great care. If WATERSLIP = CONSTANT. The minimum distance between two consecutive slugs is defined as (bubble vel.must be specified. the velocities of liquid hydrocarbon and water is calculated by separate momentum balance equations.0] End times for slug generation. If DISPERSIONVISC = VOLUMEAVERAGE. SLUGTUNING (on CaseLevel) Keys ( See also: Description ) Key Type Unit:( ) Real Parameter set Default:[ ] [1. PHI100 . a continuous phase is assumed (no dispersion). This keyword is available both in batch and server mode. The slug front pressure drop is set to 0 when the film velocity in the slug bubble region is larger than a certain critical velocity which can be tuned.0] SLUGLENGTH UBCOEFF1 UBCOEFF2 VOIDINSLUG VOIDINVERTSLUG Real Real Real Real Real [1e+09] [1. If DISPERSIONVISC = EXPERIMENT. Tuning coefficient 1 in Taylor bubble velocity calculation (with and without SLUGTRACKING). Has no effect for a large value of SLUGLENGTH when not SLUGTRACKING. the user may specify values for the viscosity tuning factor (VISCMOD) corresponding to given WATERCUT (volume fraction of water in the liquid phase) values. values for the dispersed phase volume fraction (PHIREL) for each given value of the relative viscosity (VISCREL) must be specified. as the validation and verification of the OLGA model may not be valid for such cases. If DISPERSIONVISC = PALRHODES./INITFREQUENCY). If WATERSLIP = ON. The relative viscosity is the viscosity of the dispersed phase divided by the viscosity of the continuous phase. If DISPERSIONVISC = WOELFLIN. Tuning coefficient for onset of slug front pressure drop (with and without SLUGTRACKING). if not given there are no restrictions. ON | [OFF] Link to: SLUGTRACKING (on CaseLevel) Description Keys SLUGTUNING (on CaseLevel) Description ( See also: Keys) This statement defines the slug tuning option. Maximum initial length of hydrodynamic slugs in number of pipe diameters. the user may specify the two parameters a (AWOELFLIN) and b (BWOELFLIN) of this relative viscosity model: No parameters are needed for the option DISPERSIONVISC = BARNEA.0] [1. The parameters available for tuning are at the moment very limited.0] Description Tuning coefficient for slug front pressure drop (with and without SLUGTRACKING).INITENDTIMES INITFREQUENCY INITLENGTH INITPERIODS INITPOSITIONS INITSLUGVOIDS INITSTARTTIMES INITZONELENGTHS LEVEL MAXNOSLUGS SLUGVOID STARTTIME RealList (s) Real (1/s) Real RealList (s) SymbolList RealList (-) RealList (s) RealList (m) Symbol Integer Real (-) Real (s) [0. DISPERSIONVISC specifies which model is used to calculate the dispersion phase viscosity. If DISPERSIONVISC= OFF. level detection is on from simulation start.dP/dz is inversly proporsional to SLUGLENGHT. for which the Barnea & Mizrahi model is used: where Here µc and µd are the viscosities for the continuous and dispersed phases. Slug length (number of diameters) in slug front pressure drop correlation for unit cell model (ignored for SLUGTRACKING). Start times for slug generation. Tuning coefficient for void in vertical slug (with and without SLUGTRACKING). Time interval between initiations of consecutive slugs. Max number of slugs allowed in the system. The maximum void allowed in a level slug at initiation time. A table based model is available using input as given in this example: . Void fraction in the liquid slug. DPFACT DPONSET Real [1. Tuning coefficient for void in horizontal slug (with and without SLUGTRACKING). The length of zones where slugs are to be generated. Tuning coefficient 2 in Taylor bubble velocity calculation (with and without SLUGTRACKING). If not given. Start time for level slug initiation.value of the dispersed phase volume fraction when the relative viscosity = 100% .0] [1. 1. Used if DISPERSIONVISC=OFF. OUTPUTDATA (on Node) Keys ( See also: Description ) Key VARIABLE Type Unit:( ) SymbolList (ValueUnitPair) Parameter set Default:[ ] Description List of variables to be printed.3. An intermediate dispersion range is introduced.1. OFF: No velocity difference.2.6.1.0. of continuous phase) is 100%.15. Watercut values corresponding to a given viscosity tuning factor (VISCMOD).0.8.0.0] [0.1.3. \ VISCMOD=(1.1).8. Relative viscosity for a given dispersed phase volume fraction (PHIREL). Viscosity tuning factors corresponding to given WATERCUT values.765] [0.2. The flowing water volume fraction inversion point (INVERSIONWATERFRAC) can be specified for any Dispersion Viscosity model.0] OFF | CONSTANT | [ON] Link to: WATEROPTIONS (on CaseLevel) Description Keys OUTPUTDATA (on Node) Description ( See also: Keys) This statement defines the node variables to be printed to the output file (*. Should be used with great care.7. WATEROPTIONS (on CaseLevel) Keys ( See also: Description ) Key AWOELFLIN BWOELFLIN DISPERSIONVISC Type Unit:( ) Real Real Symbol Parameter set Default:[ ] [4. WATERSLIP=ON Note that one should use WATERFLASH=ON and WATERSLIP=ON with this model. Dispersed phase volume fraction given the relative viscosity (VISCREL).0] [1. Define the velocity difference between the oil and water phases. WATERCUT=( 0.0.0] [0.1. Between the lower critical water cut (FWLOW. Link to: OUTPUTDATA (on Node) Description Keys TRANSMITTER (on Node) Description ( See also: Keys) .WATEROPTIONS DISPMODEL=INPUTVISC. Units may be specified.4. Used if DISPERSIONVISC=OFF.0. See Node Output Variables for available variables.0] Description Constant A in Woelflin viscosity correlation Constant B in Woelflin viscosity correlation ON: Dispersion viscosity calculated according to DISPMODEL settings. DISPMODEL EMAX ENTRAINMENTFACTOR FWLOW INVERSIONWATERFRAC PHI100 PHIREL VELOCITYDIFFERENCE VISCMOD VISCREL WATERCUT WATERSLIP Symbol Real (-) Real Real (-) Real (-) Real (-) Real (-) Real (m/s) RealList Real RealList (-) Symbol [0.5] [0.5] OFF | [ON] RONNINGSEN | EXPERIMENT | WOELFLIN | BARNEA | INPUTVISC | [PALRHODES] [1.0] [0.0.\.2.4.1)\.9. Used if DISPMODEL=EXPERIMENT.05.0. The degree of mixing of water into oil is predicted by the standard OLGA model.7.2] [2.1. Dispersed phase volume fraction when the relative viscosity (visc. Viscosity from tables for continuous phase is used if WATERSLIP = ON. ON: Oil/water slip velocity is calculated within the flow model. OFF: Viscosity volume weighting if WATERSLIP = OFF or CONSTANT. of dispersed phase/ visc.9.1. CONSTANT: A constant velocity difference between oil and water is specified. WATERFLASH=ON.0): (Volume flow of water in oil)/(Total volume flow of water) ≤ EMAX Both parameters should be defined under the WATEROPTIONS keyword. Specify which model to be used to calculate the dispersion viscosity (DISPERSIONVISC=ON). but the maximum fraction of the total water stream that can be mixed into the oil is given by EMAX (default value 1. Maximum fraction of water dispersed for FWLOW < WC < INVERSIONWATERFRAC Scaling factor for water entrainment rate from bulk to droplets Critical water fraction above which the fraction of the water dispersed into oil < EMAX Flowing water volume fraction at inversion point. default value 0.5.05.out).0.0. Used if DISPMODEL=EXPERIMENT.2.1.0) and the inversion point (given by INVERSIONWATERFRAC) the flow is assumed to be a water-in-oil dispersion flowing above a free water layer. Flowpath Keys ( See also: Description ) Key FLUIDTYPE INFO LABEL LINE Type Unit:( ) Symbol String String Symbol Parameter set Default:[ ] GAS | OIL | WATER | Description The phase of the fluid flowing in the single-phase line. Link to: TRANSMITTER (on Node) Description Keys TRENDDATA (on Node) Description ( See also: Keys) This statement defines the trend data to be plotted for nodes. Unit may be specified. the several controllers can receive the output signal from one transmitter. YES: Use a single-phase fluid in the flowline. YES | [NO] Link to: Flowpath Description Keys . If several different output signals are needed form the same position. The signals can be received by a controller. Link to: TRENDDATA (on Node) Description Keys Flowpath Description ( See also: Keys) This statement defines the label of the flow path. NO: Three-phase flow. process equipment. For information purposes only. However.This keyword is used to define output signals from flowpath. Controllers that receive these measured values use them to calculate new signals which in turn are used to regulate e. TRENDDATA (on Node) Keys ( See also: Description ) Key VARIABLE Type Unit:( ) SymbolList (ValueUnitPair) Parameter set Default:[ ] Description List of variables to be plotted. The location is only used graphically to position the transmitter along the flowpath. node. General information about the flowpath. add a transmitter to the flowpath at a dummy location (use a valid absolute position or pipe/section). Note: If a branch variable is to be controlled.g. Network component label (if nothing is given the NC tag is used). fluid pressure in the flowpath (PT) or liquid level in the separator (LIQLV). Variable to be transmitted. For available variables see Node Output Variables. add a transmitter per output signal. A trend plot is a time series plot for a specified variable. Units may be specified.g. separator and phase split node. TRANSMITTER (on Node) Keys ( See also: Description ) Key LABEL VARIABLE Type Unit:( ) String Symbol (ValueUnitPair) Parameter set Default:[ ] [TM] 2048 | Description Transmitter Terminal label. The signals are defined through the variable key e. a valve opening (see Controllers). PIPE (on Flowpath) Keys ( See also: Description ) Key Type Unit:( ) Real (m2) Parameter set Default:[ ] Description Total cross-sectional flow area in case of equivalent pipes. If the temperature option is WALL or FASTWALL in OPTIONS. Pipe data such as geometrical data: elevation.e.. Defines whether the initial guess on the flow direction for a branch should be positive or negative. A pipe is one straight part of a pipeline. BRANCH (on Flowpath) Keys ( See also: Description ) Key Type Unit:( ) Symbol Symbol Parameter set Default:[ ] PVTData | GEOMETRY | Description Label or number of the fluid table to apply for this branch. Equivalent pipe means one single pipe representing a number of equal parallel pipes with a correct total flow area. The pipes belonging to this geometry must be defined sequentially after the geometry statement by use of the PIPE-keyword for each pipe.BRANCH (on Flowpath) Description ( See also: Keys) This statements defines a grouping of pipes by reference to a GEOMETRY. GEOMETRY (on Flowpath) Keys ( See also: Description ) Key LABEL XSTART YSTART ZSTART Type Unit:( ) String Real (m) Real (m) Real (m) Parameter set Default:[ ] [GEOM] [0] [0] [0] Description Geometry label x-coordinate of the starting point of the geometry y-coordinate of the starting point of the geometry z-coordinate of the starting point of the geometry Link to: GEOMETRY (on Flowpath) Description Keys PIPE (on Flowpath) Description ( See also: Keys) This statement defines the pipe elements in a geometry. If a keyword based pvt-file is used. AREA . FLUID GEOMETRY INIFLOWDIR UDPVTFILE Symbol Symbol NEGATIVE | [POSITIVE] UDPvtData | Link to: BRANCH (on Flowpath) Description Keys GEOMETRY (on Flowpath) Description ( See also: Keys) This statement defines the geometry label and the co-ordinates of the starting point for a branch. Name of User Defined (UD) property file used by the plugin module. numbering is not valid for this format. FLUID has to be the LABEL given in the pvt-file. Changing the direction might avoid a crash in the preprocessor or result in a solution closer to the transient steady state solution. Preprocessor input. a WALL for the pipe must be specified. Only one geometry is allowed in each BRANCH statement. roughness. Label of GEOMETRY keyword. diameter. i. number and length of sections for discretization are specified. Positive direction refers to direction of increasing section number. "1-4"). The total flow area in the equivalent pipe will correspond to this number of original parallel pipes.g. Pipe label. PIPE and SECTION should not be used.DIAMETER ELEVATION IDIAMETER LABEL LENGTH LSEGMENT NEQUIPIPE NSEGMENT ODIAMETER ROUGHNESS WALL XEND YEND ZEND Real (m) Real (m) Real (m) String Real (m) RealList (m) Integer Integer Real (m) Real (m) Symbol Real (m) Real (m) Real (m) [PIPE] WALL | [0] Hydraulic diameter of the pipe. "1") or as a number range (e. Total number of pipes represented in the equivalent pipe. Position label. End point elevation relative to starting point of the pipe. Length of the pipe. Check valve label. Zero for internal flow. It may either specify a distance from flow path inlet (ABSPOSITION). Outer diameter for internal pipe for annulus flow. Distance from branch inlet. CHECKVALVE (on Flowpath) Keys ( See also: Description ) Key ABSPOSITION DIRECTION LABEL PIPE POSITION SECTIONBOUNDARY Type Unit:( ) Real (m) Symbol String Symbol Symbol Integer NEGATIVE | [POSITIVE] [CHECK] PIPE | POSITION | Parameter set Default:[ ] Description Absolute position. Link to: PIPE (on Flowpath) Description Keys POSITION (on Flowpath) Description ( See also: Keys) This statement specifies a position along the pipeline. Pipe number or pipe label where the check valve is located. z-coordinate of the pipe end. If this is defined. Link to: CHECKVALVE (on Flowpath) Description Keys CENTRIFUGALPUMP (on Flowpath) . Equivalent to the pipe's inner diameter for normal pipe flow. Section boundary number of position. Link to: POSITION (on Flowpath) Description Keys CHECKVALVE (on Flowpath) Description ( See also: Keys) Defines a check valve in the pipeline. Inner diameter of external pipe for annulus flow. Distance from branch inlet. or a reference to a pipe and a section-volume/boundary number. y-coordinate of the pipe end. Position label where the source is located. x-coordinate of the pipe end. Number of sections in the pipe. POSITION (on Flowpath) Keys ( See also: Description ) Key ABSPOSITION LABEL PIPE SECTION SECTIONBOUNDARY Type Unit:( ) Real (m) String Symbol Integer Integer Parameter set Default:[ ] [POS] PIPE | Description Absolute position. Pipe labels cannot be formatted as a number (e. Absolute roughness of the pipe wall. Section number of position. Allows flow only in the defined flow direction. Section lengths. Pipe label. Section boundary number where the checkvalve is located. Allowed direction. Label of the wall used.g. void fraction at pump inlet. Distance from branch inlet.0] <None> | YES | [NO] PIPE | POSITION | [0. If YES: The input data deviate too much from the pump laws.MINSPEED) Here MAXSPEED is the maximum pump speed (defined by user). The setpoint specifies the required N (MAXSPEED > N > MINSPEED) (2). [CENTRIFUGALPUMP] [30. Each curve interpolated in model speed. head. the pump flow rate can be expressed as the difference between the theoretical flow rate and the back flow rate. . Note that a pump cannot be defined at the first or last section boundary of a pipeline. Controlled manually by specifying time and speed series in the controller definition. Pump pressure increase at rated conditions. List of CENTPUMPCURVEs. Maximum recycle mass flow rate. Minimum recycle mass flow rate. Minimum pump speed.7] Parameter set Default:[ ] Description Absolute position. The following options are available for controlling the pump speed: (1). this value will be used to increase or decrease the pump speed.0] [0.0] [0. Mechanical efficiency. Section boundary number where the pump is located. The setpoint specifies the required N (MAXSPEED > N > MINSPEED) (2).0] <None> | SINGLEPHASE | [TWOPHASE] [900] [0. CENTRIFUGALPUMP (on Flowpath) Keys ( See also: Description ) Key ABSPOSITION ACCECOEFF BYDIAMETER CURVEMODE CURVES DENSITYR DPRATED EFFIMECH FLOWRATED HEADRATED LABEL MAXPOWER MAXRECYCLE MAXSPEED MINRECYCLE MINSPEED ONECURVEPERSPEED PIPE POSITION POWERRATED RECDIAMETER RECPHASE SECTIONBOUNDARY SPEEDR TABLE TORQMAX TORQR Type Unit:( ) Real (m) Real (rad/s2) Real (m) Symbol SymbolList Real (kg/m3) Real (bar) Real Real (m3/s) Real (m) String Real (kW) Real (kg/s) Real (rpm) Real (kg/s) Real (rpm) Symbol Symbol Symbol Real (kW) Real (m) Symbol Integer Real (rpm) Symbol Real (Nm) Real (Nm) CentrifugalData | [3000. If other curves shall be used they must be given with the TABLE keyword. The following options are available for controlling the pump speed: (1). MINSPEED is the minimum pump speed (defined by user) and u the signal from the controller. Rated pump shaft power. Rated pump speed. CALCMULTIPLIERS: Calculate two phase multipliers and use default fully degraded head. If other table values shall be used they must be given with the TABLE keyword. Create one curve per GVF and interpolate using model GVF. and all curve data is combined in one homologous curve.0] [0. Pipe label for pump location. Rated pump head. Maximum pump speed. and only the single phase curves will be used. Regulated by a physical parameter. CALCMULTANDDEGRADEDHEAD: Calculate two phase multipliers and calculate fully degraded head from largest GVF. Name of the tables of pump back flow data or pump characteristic data. ∆P. inlet gas volume fraction αI. Maximum shaft power allowed. or the CURVES keyword. A default table is included in the code. Curve input mode for centrifugal pump.0] [0. INTERPOLATEINGVF: Don't use two phase multiplier. MINSPEED is the minimum pump speed (defined by user) and u the signal from the controller.The pump curve data. pressure increase across the pump. the pressure increase over the pump. A valve can be located at the centrifugal pump section boundary for controlling flow through the pump.0] <None> | GAS | LIQUID | WATER | [MIXTURE] TWOPHASEOPTION Symbol <None> | CALCMULTANDDEGRADEDHEAD | INTERPOLATEINGVF | [CALCMULTIPLIERS] <None> | NO | [YES] USEPHASEMULT Symbol Link to: CENTRIFUGALPUMP (on Flowpath) Description Keys DISPLACEMENTPUMP (on Flowpath) Description ( See also: Keys) For the displacement pump.MINSPEED) Here MAXSPEED is the maximum pump speed (defined by user). Diameter of the valve in the bypass flow line. The speed is calculated by N = MINSPEED + u (MAXSPEED . (No extrapolation) If NO: The two phase multiliers will be set to zero. The transient pump characteristics for a centrifugal pump presented in the form of four quadrant curves. flow efficiency given in the CENTPUMPCURVE will be automatically converted to a homologous table used by the centrifugal pump model. These are based on experimental data and are representative for centrifugal pumps. Maximum motor torque allowed. Controlled manually by specifying time and speed series in the controller definition. For a given pump the theoretical rate is proportional to pump speed. CURVES referes to CENTPUMPCURVEs given in the library. The four quadrant curves are converted to a simpler form by the development of homologous curves where the head and torque ratios (actual value to rated value) are functions of the pump speed and flow rate ratios. Note that a pump cannot be defined at the first or last section boundary of a pipeline. Pump speed acceleration. Regulated by a physical parameter. The back flow is tabulated as a function of pump speed. pump speed N. Rated pump density.Description ( See also: Keys) For the centrifugal pump. A complete default set of homologous curves is tabulated in the code. If YES: The two phase multipliers will be used. liquid kinetic viscosity and pressure at pump inlet. Phase of recycle flow. If NO: the pump is assumed to follow the pump laws. and the pump inlet pressure PI. When recycle flow is over or below the limits. The speed is calculated by N = MINSPEED + u (MAXSPEED . Label of the pump. is dependent on the flow rate Q. Rated pump hydraulic torque. Choke diameter for recycle flow. and one homologous curve is generated per speed. Position where pump is located. Rated pump flow. DISPLACEMENTPUMP (on Flowpath) Keys ( See also: Description ) Key ABSPOSITION ACCECOEFF ACOEFFICIENT BCOEFFICIENT BYDIAMETER LABEL MAXRECYCLE MAXSPEED MDISSIPATION MINRECYCLE MINSPEED PIPE POSITION PREFSPEED RECDIAMETER RECPHASE SECTIONBOUNDARY SPECAPACITY TABLE VDISSIPATION Type Unit:( ) Real (m) Real (rad/s2) Real Real Real (m) String Real (kg/s) Real (rpm) Real (W) Real (kg/s) Real (rpm) Symbol Symbol Real (rpm) Real (m) Symbol Integer Real (m3/R) Symbol Real (W) [0.0] [1.6] [1.6] [0.0] [DISP-PUMP] [30.0] [0.0] [0.0] [0.0] PIPE | POSITION | [3000] [0.0] <None> | GAS | LIQUID | WATER | [MIXTURE] Parameter set Default:[ ] Description Absolute position. Distance from branch inlet. Pump speed acceleration. When recycle flow is over or below the limits, this value will be used to increase or decrease the pump speed. Experimentally determined exponent for calculating the mechanical friction loss. Experimentally determined exponent for calculating the viscous friction loss. Diameter of the valve in the bypass flow line. Label of the pump. Maximum recycle mass flow rate. Maximum pump speed. Mechanical dissipation at nominal speed. Minimum recycle mass flow rate. Minimum pump speed. Pipe label for pump location. Position where pump is located. Pump reference speed. Choke diameter for recycle flow. Phase of recycle flow. Section boundary number where the pump is located. Pump specific volumetric capacity, Qspc. Name of the tables of pump back flow data or pump characteristic data. Viscous dissipation at nominal speed. CentrifugalData | [0.0] Link to: DISPLACEMENTPUMP (on Flowpath) Description Keys COMPRESSOR (on Flowpath) Description ( See also: Keys) Describes the configuration of a compressor in the system. The compressor is represented through its characteristics which give pressure increase and temperature as a function of flow and rotating speed (RPM). Note that the compressor characteristics are given in a separate file. It is possible to specify characteristics for more than one compressor. Each of the characteristics is assigned to a label, which is referred to in the COMPRESSOR statement. The compressor RPM is governed by the compressor speed controller: RPM = RPMmin + urpm × (RPMmax - RPMmin) where urpm = output signal from compressor speed controller The recirculation is governed by the anti surge controller (ASC). Note that a compressor cannot be defined at the first or last section boundary of a pipeline. COMPRESSOR (on Flowpath) Keys ( See also: Description ) Key ABSPOSITION CD COMPRDATA COOLCAPACITY COOLER DIAMETER LABEL MAXRPM MINRPM PIPE POSITION SECTIONBOUNDARY SECURITYFACTOR TEMPERATURE TIME Type Unit:( ) Real (m) Real Symbol Real (W) Symbol Real (m) String Real (rpm) Real (rpm) Symbol Symbol Integer Real RealList (C) RealList (s) ON | [OFF] [COMPR] Parameter set Default:[ ] [0.84] CompressorData | Description Absolute position. Distance from branch inlet. Discharge coefficient of valve/choke in recycle loop. Name of compressor data. This refers to a label in the compressor characteristics file. Maximum heat transfer rate from fluid flowing through the heat exchanger in the recycle loop. Switch for turning on or off heat exchanger in recycle loop. Orifice diameter of valve/choke in recycle loop. Label of the compressor. Maximum RPM. Minimum RPM. Number/name of pipe where compressor is located. Position of the compressor. If POSITION is defined, PIPE and SECTIONBOUNDARY should not be used. Section boundary number where compressor is located. Security factor (e.g. 1.2 implies that the min. flow is 120% of surge rate). Temperature values out of heat exchanger. Number of temperature values must correspond to the number of times given in the TIME-key. Time series for temperature out of heat exchanger. PIPE | POSITION | Link to: COMPRESSOR (on Flowpath) Description Keys FRAMOPUMP (on Flowpath) Description ( See also: Keys) The Framo multiphase pump is a Helico-axial design that can operate from 0-100% gas volume fractions. The Framo flow mixer (patented) in which the fluid is mixed into a homogeneous mixture, provides stable operating conditions for the pump independent on upstream flow conditions, eliminating transients from slug flow and hence minimize the dynamic loading effects. The Framo pump module in Olga includes all the elements given in the figure below integrated with Framo standard control system. This will represent a typical Framo subsea multiphase pumping system. Figure A: The Framo multiphase pump layout The characteristics of the Framo multiphase pump is defined through a data file. A list of 13 common configurations are available in PUMPCHAR keyword. It is also possible to use characteristic files for other configurations using the PUMPFILE keyword. These data files must be prepared by Framo. The characteristics of the inlet mixer can be defined in the same manner using the MIXERCHAR (library of mixer configurations) and MIXERFILE. The recycle flow control is integrated in the pump module, and only the minimum recycle valve opening can be controlled by the user. The Framo multiphase pump can be controlled by either speed (SPEEDSETPOINT) or inlet pressure (PRESSURESETPOINT). FRAMOPUMP (on Flowpath) Keys ( See also: Description ) Key ABSPOSITION BYCD BYCHECK BYCVTABLE BYDIAMETER BYSTROKETIME CD CDEADBAND CHOKERATE CMINOPENING CTIME CVTABLE DIAMETER INITIALREPOS INITIALSPEED LABEL LIMDP LIMPOW MAXSPEED MIXERCHAR MIXERFILE MIXERVOLUME NPARA PIPE POSITION PRESSURESETPOINT PUMPCHAR PUMPFILE RECV RECVTABLE RELDPCONTR SECTIONBOUNDARY SPEEDRATE SPEEDSETPOINT SPINDOWNRATE STROKETIME TIME TRIPHOLD TRIPTIME Type Unit:( ) Real (m) Real Symbol Symbol Real (m) Real (s) Real Real (s) Real (1/s) RealList (%) RealList (s) Symbol Real (m) Real (%) Real (rpm) String Real (Pa) Real (W) Real (rpm) Symbol String Real (m3) Real Symbol Symbol RealList (Pa) Symbol String Real Symbol RealList (%) Integer Real (rpm/s) RealList (rpm) Real (rpm/s) Real (s) RealList (s) RealList (s) Real (s) Parameter set Default:[ ] [0.84] YES | [NO] TABLE | [0.0] [10.0] [0.84] [5] [0.01] [0.0] [0.0] TABLE | [0.0] [PUMP] Description Absolute position. Distance from branch inlet. Discharge coefficient. Set to YES if the bypass line is checked. Label of table for bypass valve characteristics. Diameter of the valve in the bypass flow line. Stroke time of valve. Discharge coefficient. Choke dead time before opening/closing Change rate for recycle choke control. Minimum choke opening Time series when RELDPCONTR and CMINOPENING is to be modified. Label of table for valve characteristics. Maximum valve diameter. Initial recycle choke position Initial pump speed Label of the pump. Input limit of differential pressure Available shaft power Maximum speed of selected pump. Automatically set when a pump input file is chosen. Reference to mixer characteristics. The name of the file containing the mixer characteristics. Volume of mixer. Number of pumps in parallel operation Pipe label for pump location. Position where pump is located. Suction pressure setpoint PUMP_FRAMO_PUMPCHAR | Reference to pump characteristics. The name of the file containing the pump characteristics. Recycle valve sizing coeff. Label of table for recycle valve characteristics. Recycle control relative to minimum and maximum pressure. Section boundary number where the pump is located. [25] Change rate for speed control. Speed setpoint [100] [10.0] [0.0] [0.0] Rate of speed change at trip. Stroke time of valve. Time series when PSET, SPEEDSET and TRIPHOLD is to be modified. The tripped state will be maintained for this many seconds. Default, TRIPHOLD=0.0, the trip signal will be reset and the pump will never trip. Time when pump trip [0.0] PUMP_FRAMO_MIXERCHAR | [1] PIPE | POSITION | TABLE | Link to: FRAMOPUMP (on Flowpath) Description Keys HEATEXCHANGER (on Flowpath) Description ( See also: Keys) This statement describes the effects of a heat exchanger. There are two types of heat exchangers; setpoint and controlled. The setpoint heat exchanger is represented as an ideal loss. The heat exchanged is equal to the enthalpy difference corresponding to the difference between the inlet temperature and a user specified outlet temperature of the heat exchanger. The controlled heat exchanger does not know the outlet temperature and does not calculate the heat exchanged. Instead it uses a controller to specify the effect to be used. The controller signal (which should be between 0 and 1) is the fraction of the heat exchangers maximum capacity. A controller signal of 1 implies that the heat exchanger uses its maximum capacity. Note that a heat exchanger cannot be defined at the first or last section boundary of the pipeline. HEATEXCHANGER (on Flowpath) Keys ( See also: Description ) Key ABSPOSITION CAPACITY LABEL PIPE POSITION SECTION TEMPERATURE TIME TYPE Type Unit:( ) Real (m) Real (W) String Symbol Symbol Integer RealList (C) RealList (s) Symbol CONTROLLED | [SETPOINT] [HEATEX] PIPE | POSITION | Parameter set Default:[ ] Description Absolute position. Distance from branch inlet. Maximum heat exchanger capacity. Positive value is for heating and negative value for cooling. Heat exchanger label. Number/name of the pipe where heat exchanger is located. Position of the heat exchanger. If POSITION is defined, PIPE and SECTIONBOUNDARY should not be used. Section number where the heat exchanger is located. Heat exchanger outlet temperature set points. Time series in temperature set point table. Heat exchanger type. Link to: HEATEXCHANGER (on Flowpath) Description Keys LEAK (on Flowpath) Description ( See also: Keys) This statement specifies a negative mass source (mass out of the pipe). The leak is positioned in the middle of the section that is specified. Both sub-critical and critical flow is modelled. It can be used to model a valve or rupture where the mass out of the pipe is removed from the simulated system, that is, the mass is lost to the surroundings. Backflow is not allowed for the LEAK, that is, there will be no backflow if section pressure is lower than the backpressure. The LEAK has one optional input terminal, INPSIG. INPSIG scales the LEAK flow area. LEAK (on Flowpath) Keys ( See also: Description ) Key ABSPOSITION ALFA BACKPRESSURE BELLOWSPRESSURE CD CF CHECKVALVE DIAMETER EQUILIBRIUMMODEL GASLIFTTABLES GLVOPERATION LABEL PHASE PIPE POSITION R REFTEMPERATURE SECTION TABLE TEMPDEPENDENCY Type Unit:( ) Real (m) Real RealList (Pa) Real (Pa) Real Real (-) Symbol Real (m) Symbol SymbolList Symbol String Symbol Symbol Symbol Real Real (C) Integer SymbolList Symbol ON | [OFF] PRODOPERATED | [INJOPERATED] [LEAK] <None> | GAS | LIQUID | PIPE | POSITION | HENRYFAUSKE | EQUILIBRIUM | [FROZEN] [0.84] Parameter set Default:[ ] Description Absolute position. Distance from branch inlet. For TEMPDEPENDENCY=ON. Constant used for a temperature dependent GLV. 0 means that the bellows temperature equals the injection temperature, 1 means the production temperature, and interpolation for <0,1>. Leak back pressure For TEMPDEPENDENCY=ON. Pressure in GLV bellows (dome) at REFTEMPERATURE, used for a temperature dependent GLV. Leak discharge coefficient. Used only in pressure driven source. Ratio between gas and liquid sizing coefficient. Check valve active on the leak valve: NO: No check valve, YES: Check valve present to stop backflow Maximum equivalent diameter of leak area Equilibrium model used in the choke model. FROZEN - No mass transfer. HENRYFAUSKE - Partial equilibrium. EQUILIBRIUM - Gas/liquid equilibrium. Names of tables (defined in keyword TABLE) that define the curves of a GLV. For TEMPDEPENDENCY=ON. Specify whether a GLV is operated by injection pressure or production pressure. Used for a temperature dependent GLV. Label of the leak. Predominant phase. Used with valve characteristics. Number/name of pipe where leak is located. Position of the leak. If POSITION or ABSPOSITION is defined, PIPE and SECTION should not be used. For TEMPDEPENDENCY=ON. Geometry factor used for a temperature dependent GLV. For TEMPDEPENDENCY=ON. The temperature for which the gas lift response curve is defined. Section number where the leak is located. Label of table containing valve characteristics. Specify the temperature dependency of a GLV. OFF: No temperature dependency. ON: Temperature dependency for a nitrogen charged bellow. Sub-keys ALFA, BELLOWPRESSURE, GLVOPERATION, R and REFTEMPERATURE must be specified. If YES, thermal equilibrium between gas and liquid is assumed, otherwise the YES | [NO] THERMALPHASEEQ TIME TOPOSITION Symbol RealList (s) Symbol YES | [NO] POSITION | gas is expanded isentropical while the liquid is isothermal. Only used in HYDROVALVE. The Henry-Fauske model assues isothermal liquid and isentropic expansion og the gas. This option is therefore inavailable when CRITFLOWMODEL=HENRYFAUSKE. The time series for the leak back pressure Refer to position the leak is targeted to. Link to: LEAK (on Flowpath) Description Keys LOSS (on Flowpath) Description ( See also: Keys) This statement defines pressure loss due to valves, bends, contractions, expansions or other obstructions in or between pipes. The expansion pressure recovery that is always included in OLGA is: The contraction pressure loss that is always included in OLGA is: The additional loss specified by the user for positive flow is: The additional loss specified by the user for negative flow is: Figure A An illustration of the use of loss coefficients for contraction and expansion. LOSS (on Flowpath) Keys ( See also: Description ) Key ABSPOSITION LABEL NEGCOEFF PIPE POSCOEFF POSITION SECTIONBOUNDARY Type Unit:( ) Real (m) String Real Symbol Real Symbol Integer [LOSS] PIPE | POSITION | Parameter set Default:[ ] Description Absolute position where the pressure loss is located. Distance from branch inlet. Loss label. Loss coefficient when the flow is in negative direction. Pipe label with pressure loss. Loss coefficient when the flow is in positive direction. Position where the pressure loss is located. Section boundary where pressure loss is located. Link to: LOSS (on Flowpath) Description Keys PRESSUREBOOST (on Flowpath) Description ( See also: Keys) A constant pressure increase is used for modeling the behavior of a pump. An constant isentropic efficiency is used to model the heat added to the fluid from the pump. The PRESSUREBOOST pump has one optional input terminal, INPSIG. INPSIG scales the pressure increase between 0 and DELTAPRESSURE. PRESSUREBOOST (on Flowpath) Keys ( See also: Description ) Key ABSPOSITION DELTAPRESSURE EFFICIENCY LABEL Type Unit:( ) Real (m) Real (Pa) Real (-) String Parameter set Default:[ ] Description Absolute position. Distance from branch inlet. Pressure increase over pump. Isentropic efficiency. Must be between 10% and 100%. Label of the pump. [1] [BOOST] PIPE POSITION SECTIONBOUNDARY Symbol Symbol Integer PIPE | POSITION | Pipe label for pump location. Position where pump is located. Section boundary number where the pump is located. Link to: PRESSUREBOOST (on Flowpath) Description Keys PUMPBATTERY (on Flowpath) Description ( See also: Keys) The pump battery is used for pumping drilling fluid, e.g. muds in a drilling operation. The purpose is to get an overall estimate of pump power needed as well as the volume of mud pumped. The volume delivered iby the pump is proportional to the rate of pump strokes. (a) where QP PFAC SPES = = = Volume delivered by the pump battery Pumping factor Strokes per time unit The pump rate is normally controlled by the following set of controllers: Controller on the maximum hydraulic horsepower allowed Controller on the maximum pump rate Controller on the minimum pump rate Controller on the maximum pump pressure allowed If either one of these controllers is set into action the pump rate is reduced automatically. The number of controllers can be extended above the number shown above and different variables (e.g. fluid rate, inflow rate) can be used to control the pumps. The following options are available for controlling the pump speed: (1). Controlled manually by specifying time and speed series in the controller definition. The setpoint specifies the required N (MAXSPEED > N > MINSPEED) (2). Regulated by a physical parameter. The speed is calculated by N = MINSPEED + u (MAXSPEED - MINSPEED) Here MAXSPEED is the maximum pump speed (defined by user), MINSPEED is the minimum pump speed (defined by user) and u the signal from the controller. Note that a pump cannot be defined at the first or last section boundary of a pipeline. PUMPBATTERY (on Flowpath) Keys ( See also: Description ) Key ABSPOSITION HPMAX LABEL MAXCAPACITY MAXPRESSURE MAXSPEED MINCAPACITY MINSPEED PIPE POSITION SECTIONBOUNDARY Type Unit:( ) Real (m) Real (W) String Real (m3/s) Real (Pa) Real (rpm) Real (m3/s) Real (rpm) Symbol Symbol Integer Parameter set Default:[ ] Description Absolute position. Distance from branch inlet. Maximum hydraulic horsepower for each single pump in the pump battery. Label of the pump. Maximum flow capacity. Maximum downstream pressure. Maximum pump speed. Minimum flow capacity. Minimum pump speed. Pipe label for pump location. Position where pump is located. Section boundary number where the pump is located. [PUMPBATTERY] [0.0] PIPE | POSITION | Link to: PUMPBATTERY (on Flowpath) Description Keys SIMPLIFIEDPUMP (on Flowpath) Description ( See also: Keys) A simplified description of a centrifugal pump is used for modeling the behavior of a centrifugal pump around an operational point. Simple algebraic expressions are used to calculate pressure increase over the pump and pump efficiency. The following options are available for controlling the pump speed: (1). Controlled manually by specifying time and speed series in the controller definition. The setpoint specifies the required N (MAXSPEED > N > MINSPEED) (2). Regulated by a physical parameter. The speed is calculated by N = MINSPEED + u (MAXSPEED - MINSPEED) Here MAXSPEED is the maximum pump speed (defined by user), MINSPEED is the minimum pump speed (defined by user) and u the signal from the controller. Note that a pump cannot be defined at the first or last section boundary of a pipeline. Relative change in pump efficiency with pump speed. [0. Section boundary number where the transmitter is located. Rated pump density. Adiabatic efficiency of pump at rated conditions. Valve where the transmitter is located. If DENSITYR = 0. add a transmitter to the flowpath at a dummy location (use a valid absolute position or pipe/section). Displacement pump where the transmitter is located.g.0] [0.0] [0. GASSIZING is a implementation of the gas sizing equation given in Valve . HeatExchanger where the transmitter is located. Centrifugal pump where the transmitter is located. Source where the transmitter is located. the effect of rated density on the pressure increase is neglected Pump pressure increase at rated conditions. If several different output signals are needed form the same position. Pipe name where the transmitter is located. The signals can be received by a controller. Note: if the unit is not specified. TRANSMITTER (on Flowpath) Keys ( See also: Description ) Key ABSPOSITION CENTRIFUGALPUMP CHECKVALVE COMPRESSOR DISPLACEMENTPUMP FRAMOPUMP HEATEXCHANGER LABEL LEAK NEARWELLSOURCE PIPE PRESSUREBOOST PUMPBATTERY SECTION SECTIONBOUNDARY SIMPLIFIEDPUMP SOURCE VALVE VARIABLE WELL ZONE Type Unit:( ) Real (m) Symbol Symbol Symbol Symbol Symbol Symbol String Symbol Symbol Symbol Symbol Symbol Integer Integer Symbol Symbol Symbol Symbol (ValueUnitPair) Symbol Symbol CENTRIFUGALPUMP | CHECKVALVE | COMPRESSOR | DISPLACEMENTPUMP | FRAMOPUMP | HEATEXCHANGER | [TM] LEAK | NEARWELLSOURCE | PIPE | PRESSUREBOOST | PUMPBATTERY | Parameter set Default:[ ] Description Absolute position. Relative change in pump pressure increase with flow rate. Distance from branch inlet. Rated pump speed. add a transmitter per output signal. or it can be driven by a controller. Name of variable to be transmitted. The GASSIZING option requires gas valve characteristics given by the TABLE key. Label of the pump. separator and phase split node. process equipment. Rated pump flow. Distance from branch inlet. Simplified pump where the transmitter is located. Section number where the transmitter is located. 2. fluid pressure in the flowpath (PT) or liquid level in the separator (LIQLV). Compressor where the transmitter is located. liquid valves and gas valves. Checkvalve where the transmitter is located. The signals are defined through the variable key e.0] PIPE | POSITION | Link to: SIMPLIFIEDPUMP (on Flowpath) Description Keys TRANSMITTER (on Flowpath) Description ( See also: Keys) This keyword is used to define output signals from flowpath. The position of the valve can be specified in 3 ways: 1. Well where the transmitter is located. Controllers that receive these measured values use them to calculate new signals which in turn are used to regulate e. or from a table with valve characteristics. Model selection is done with the MODEL key. by referring to a pipe and a section boundary number by referring to a pre-defined position by specifying the distance from the left end of the branch (absolute position) The valve performance is either obtained from a discharge coefficient and the maximum choke diameter.0] [900] Description Absolute position.g. Note: If a branch variable is to be controlled. Section boundary number where the pump is located.7] [0. Pump battery where the transmitter is located.5] [SIMPLIFIEDPUMP] [0. Relative reduction in pump efficiency with gas volume fraction. NearWellSource where the transmitter is located. Pressure boost where the transmitter is located.Methods and assumptions. Relative change in pump efficiency with pump speed. Name of transmitter Leak where the transmitter is located.0] [0. The location is only used graphically to position the transmitter along the flowpath. HYDROVALVE can be used to simulate chokes. Pipe label for pump location. Relative change in pump pressure increase with pump speed. Maximum pump speed. The relative opening of the valve can be prescribed as a function of time. node. There are two valve models (GASSIZING and HYDROVALVE). Mechanical efficiency. Framo pump where the transmitter is located. Position where pump is located. Zone where the transmitter is located. SI units will be used. a valve opening (see Controllers). . However. Minimum pump speed.0] [0. SIMPLIFIEDPUMP | SOURCE | VALVE | 2| WELL | ZONE | Link to: TRANSMITTER (on Flowpath) Description Keys VALVE (on Flowpath) Description ( See also: Keys) Here data for valves and chokes are defined.SIMPLIFIEDPUMP (on Flowpath) Keys ( See also: Description ) Key ABSPOSITION DCOEFF1 DCOEFF2 DCOEFF3 DENSITYR DPRATED ECOEFF1 ECOEFF2 ECOEFF3 EFFIMECH EFFRATED FLOWRATED LABEL MAXSPEED MINSPEED PIPE POSITION SECTIONBOUNDARY SPEEDR Type Unit:( ) Real (m) Real (1/rpm) Real (1/m3/s) Real Real (kg/m3) Real (bar) Real (1/rpm) Real (1/m3/s) Real Real Real Real (m3/s) String Real (rpm) Real (rpm) Symbol Symbol Integer Real (rpm) Parameter set Default:[ ] [0. Relative reduction in pump pressure increase with gas volume fraction. the several controllers can receive the output signal from one transmitter.0] [0. 3. The interpolation is then based on either horizontal length. Mean heat transfer coefficient on outer wall surface. 0. If HOUTEROPTION is AIR. Valve model. GASSIZING can only be used to simulate valves with gas characteristics. In addition to this one of the following three options must be used: 1. respectively. The temperature of the surroundings must be given. Density of ambient fluid. Overall heat transfer coefficient at the inlet of the first pipe in a pipeline section where interpolation is used for overall heat transfer coefficient. EQUILIBRIUM .0] AIR | WATER | OTHER | [HGIVEN] . Discharge coefficient. Thermal conductivity of ambient fluid. or vertical depth.023 W/mK is used. If HOUTEROPTION is WATER. two values (lengthinterpolated) or given explicitly for each section. If HOUTEROPTION is WATER. Position where the valve is located. 0. thermal equilibrium between gas and liquid is assumed. The type of flow through the valve.VALVE (on Flowpath) Keys ( See also: Description ) Key ABSPOSITION CD CF CR DIAMETER EQUILIBRIUMMODEL EXPOSE LABEL MODEL OPENING PHASE PIPE POSITION RECOVERY SECTIONBOUNDARY SLIPMODEL STROKETIME TABLE THERMALPHASEEQ TIME Type Unit:( ) Real (m) Real (-) Real Real (-) Real (m) Symbol SymbolList String Symbol RealList Symbol Symbol Symbol Symbol Integer Symbol Real (s) SymbolList Symbol RealList (s) <None> | CHISHOLM | [NOSLIP] [0. Ratio between gas and liquid sizing coefficient. 1000 kg/m3 is used.29 kg/m3 is used. Thermal expansion coefficient of ambient fluid. For the default option. the overall heat transfer coefficient is calculated and the keyword WALL have to be specified. States which keys should be made available as input variables on the OPC server. If YES. Input can either be a single value (constant along range of sections). Option for ambient heat transfer coefficient. Maximum valve diameter. Label of table for valve characteristics. actual length. the fluid velocity. FROZEN . Input can either be a single value (constant along range of sections). Four different interpolation options are available. Only used in HYDROVALVE.56 W/mK is used. Distance from branch inlet. Slip model for choke throat. use LIQUID. requires TEMPERATURE=WALL in OPTIONS) 3. The VELOCITY can be specified for HOUTEROPTION=AIR or WATER. If HOUTEROPTION is AIR. If HOUTEROPTION is WATER. <None> | YES | [NO] [0. Only used in HYDROVALVE. The interpolation is performed between these points using the distance between section midpoints to achieve a linear temperature profile with respect to the distance along the pipeline.0] Link to: VALVE (on Flowpath) Description Keys HEATTRANSFER (on Flowpath) Description ( See also: Keys) This statement specifies the heat transfer data for the pipe walls. Specify overall heat transfer coefficient: UVALUE (requires TEMPERATURE=UGIVEN in OPTIONS) 2. If this value is defined PIPE and SECTIONBOUNDARY should not be used.No mass transfer. the user can specify start and end ambient temperature and OLGA will perform an interpolation along the pipeline. Time series for valve opening table. Velocity and fluid properties have to be given only if a user specified fluid is used (HOUTEROPTION=OTHER). the ambient temperature is given by the user for the midpoint of the first and last section. will be used. 1000 J/KG-K is used. HEATTRANSFER (on Flowpath) Keys ( See also: Description ) Key Type Unit:( ) RealList (J/kg-C) Parameter set Default:[ ] Description Heat capacity of ambient fluid. 4186 J/KG-K is used. otherwise the default values 4 m/s and 1 m/s. Default is valve number. Enable/disable the pressure recovery downstream valve.Partial equilibrium. Default values are applied for all other properties when HOUTEROPTION=AIR or WATER. otherwise the gas is expanded isentropical while the liquid is isothermal. Input can either be a single value (constant along range of sections). Specify properties of the ambient fluid (HOUTEROPTION=OTHER / WATER / AIR.0] [VALVE] GASSIZING | [HYDROVALVE] [1. two values (lengthinterpolated) or given explicitly for each section. If HOUTEROPTION is WATER. and VERTICAL. Pipe label where the valve is located. and fluid properties such as density and viscosity. Stroke time of the valve. 21E-5 1/C is used. Input can either be a single value (constant along range of sections). Cv/Cg include recovery and this option will therefore be unavailable when using the TABLE key.Gas/liquid equilibrium. the ambient temperature is specified at the inlet and outlet boundaries (INTAMBIENT and OUTTAMBIENT). If HOUTEROPTION is AIR. requires TEMPERATURE=WALL in OPTIONS) For options 2 and 3. If option 3 is used. For the options HORIZONTAL.0] <None> | GAS | LIQUID | PIPE | POSITION | <None> | NO | [YES] Parameter set Default:[ ] [0. Ambient temperature at the inlet of the first pipe in a branch where CAPACITY CONDUCTIVITY RealList (W/m-C) DENSITY RealList (kg/m3) EXPANSION RealList (1/C) HAMBIENT HMININNERWALL HOUTEROPTION INHAMBIENT INTAMBIENT RealList (W/m2-C) RealList (W/m2-C) Symbol Real (W/m2-C) Real (C) [0.0] <None> | HENRYFAUSKE | EQUILIBRIUM | [FROZEN] Description Absolute position. If HOUTEROPTION is AIR. the ambient heat transfer coefficient is a function of the pipe diameter. In order to simplify the input of the ambient temperature distribution along a predefined pipeline section. HENRYFAUSKE .' Relative openings in the valve opening timetable. Recovery tuning. Minimum inner heat transfer coefficient on inner wall surface. 34E-4 1/C is used.84] [1. 1. HYDROMODEL is used for chokes and valves with liquid/gas characteristics. SECTIONWISE. For two or three phase flow. LENGTH. Equilibrium model used in the choke model. Section boundary number where the valve is located. two values (length-interpolated) or given explicitly for each section. Input can either be a single value (constant along range of sections) or given explicitly for each section. 1 gives maximum recovery and 0 gives zero recovery. two values (lengthinterpolated) or given explicitly for each section. Valve label. Specify ambient heat transfer coefficient: HAMBIENT (HOUTEROPTION=HGIVEN. Only used in HYDROVALVE. Viscosity of ambient fluid. Void fraction at the inlet to the first pipe in a branch where interpolation is used. Pipe label or pipe number (single or continuous range in the form x-y). STEADYSTATE=OFF (initial conditions not calculated by steady state pre-processor): User defines the pressure. There are several ways to define initial data. OLGA can perform interpolation along pre-defined flow path segments. Three different interpolation options are available. The default is zero mass of h20 component is in the gas phase. Fraction of total mass of h2o component in the gas phase inlet to the first pipe in a pipeline section where interpolation is used. This implies that the simulation must be run for some time in order to achieve a steady state solution. Label(s) of initial feed(s) to be used for calculating the local fluid compositions in the pipe(s)/section(s). Input can either be a single value (constant along range of sections) or given explicitly for each section. Requires COMPOSITIONAL=ON/BLACKOIL or DRILLING=ON under the OPTIONS keyword. Ambient temperature at the outlet of the last pipe in a pipeline section where interpolation is used for ambient temperature. Note that this key also introduces the unit of the function. 1. INITIALCONDITIONS (on Flowpath) Keys ( See also: Description ) Key BEDFORMATION FEEDMASSFRACTION FEEDMOLEFRACTION Type Unit:( ) RealList (kg/m) RealList (-) RealList (-) Parameter set Default:[ ] [0. 1E-3 N-s/m2 is used. Overall heat transfer coefficient at the outlet of the last pipe in a pipeline section where interpolation is used for overall heat transfer coefficient. default is 4 m/s. A list means mixing of feeds. and water volume fraction in the liquid phase for all sections in each flow path. STEADYSTATE=NOTEMP (initial temperature not calculated by steady state pre-processor): User defines the temperature for all sections in each flow path. Volume fraction of each feed given in FEEDNAME (only for blackoil model). Type of interpolation used to calculate the initial conditions. temperature.0] Description The amount of bed initially deposited in each section Mass fraction of each feed given in FEEDNAME. default is 1 m/s. Temperature at the inlet to the first pipe in a branch where interpolation is used. In order to simplify the input for certain initial condition variables. 2. For STEADYSTATE=ON or NOTEMP.0] [0.0] <None> | HORIZONTAL | VERTICAL | [LENGTH] [0. depending on the key STEADYSTATE in the OPTIONS statement: 1. Mass fraction of inhibitor in water phase at the inlet to the first pipe in a pipeline section where interpolation is used. Speed of ambient fluid.0] [0. Void fraction at the outlet of the last pipe in a branch section where interpolation is used. TAMBSERIESFACTOR UVALUE RealList RealList (W/m2-C) [1] VELOCITY RealList (m/s) VISCOSITY RealList (N-s/m2) Link to: HEATTRANSFER (on Flowpath) Description Keys INITIALCONDITIONS (on Flowpath) Description ( See also: Keys) This statement defines initial conditions for the dynamic calculation. Type of interpolation used to calculate the ambient temperature and outer heat transfer coefficient. Compositional tracking input such as FEEDMOLEFRACTION can be given for all settings of STEADYSTATE (in OPTIONS). The value of each time series is scaled with a corresponding factor in TAMBSERIESFACTOR and added as an increment to the temperature defined in TAMBIENT or INTAMBIENT and OUTTAMBIENT. The variable is specified at the inlet and outlet of the pipeline segment. HORIZONTAL.0] [0. List of reference to TIMESERIES keywords. If HOUTEROPTION is WATER. Section number. the given FEEDMOLEFRACTION will be an initial input to the steady state pre-processor. mass flow. LENGTH is the default option. two values (length-interpolated) or given explicitly for each section. The initial conditions are given flow path-. two values (lengthinterpolated) or given explicitly for each section. Mass fraction of inhibitor in water phase in each section. Input can either be a single value (constant along range of sections). If HOUTEROPTION is AIR. pipe. Temperature at the outlet of the last pipe in a branch where interpolation is used. Watercut at the inlet to the first pipe in a branch where interpolation is used. and the interpolation is performed based on horizontal length. The total mass flow is defined at section boundaries while the remaining parameters are given for section volumes. LENGTH and VERTICAL. Mass fraction of inhibitor in water phase at the outlet of the last pipe in a pipeline section where interpolation is used.or section-wise. Total mass flow at each section boundaries.0] [0. If HOUTEROPTION is AIR.0] . Input can either be a single value (constant along range of sections). FEEDNAME FEEDVOLFRACTION INHIBFRACTION ININHIBFRACTION INPRESSURE INSTEAMFRACTION INTEMPERATURE INTERPOLATION INVOIDFRACTION INWATERCUT MASSFLOW OUTINHIBFRACTION OUTPRESSURE OUTSTEAMFRACTION OUTTEMPERATURE OUTVOIDFRACTION SymbolList RealList (-) RealList (-) Real (-) Real (Pa) Real (-) Real (C) Symbol Real (-) Real (-) RealList (kg/s) Real (-) Real (Pa) Real (-) Real (C) Real (-) [0. Overall heat transfer coefficient given by user based on the inner pipe diameter. Pressure at the inlet to the first pipe in a branch where interpolation is used. The default is zero mass of h20 component is in the gas phase. actual length or vertical depth along the pipeline. Mole fraction of each feed given in FEEDNAME. If HOUTEROPTION is WATER. Can not be used with Drilling. The latter option can be useful if the pre-processor has problems finding a solution.INTERPOLATION OUTHAMBIENT OUTTAMBIENT PIPE SECTION TAMBIENT Symbol Real (W/m2-C) Real (C) SymbolList IntegerList RealList (C) <None> | LENGTH | HORIZONTAL | VERTICAL | [SECTIONWISE] [ALL] TAMBIENTSERIES SymbolList (C) interpolation is used for ambient temperature.8E-5 N-s/m2 is used. gas volume fraction. List of factors to be used to scale ambient temperature time series in TAMBIENTSERIES. Pressure at the outlet of the last pipe in a branch where interpolation is used Fraction of total mass of h2o component in the gas phase outlet to the last pipe in a pipeline section where interpolation is used. Note that the outer heat transfer coefficient is only affected by the INTERPOLATION key when HOUTEROPTION = HGIVEN. Ambient temperature. dynamic gas and water coning. Position label for where the well is located. Fraction of total mass of h2o component in the gas phase.0] Link to: INITIALCONDITIONS (on Flowpath) Description Keys NEARWELLSOURCE (on Flowpath) Description ( See also: Keys) This input definition specifies the data for a NEARWELLSOURCE which links OLGA to the near-wellbore reservoir simulator Rocx developed by IFE. etc. Rocx can be run as a standalone tool. You may either specify the coefficients used in the inflow correlations directly. Rocx writes both formatted and binary industry standard Eclipse output files for post processing (3D visualization). Initial temperature in each section. The default is zero mass of h20 component is in the gas phase. The user must therefore discretize both grids in such a way that this is satisfied. This input file is edited with the ROCX GUI. the well/reservoir variables are translated into the coefficients used in the inflow correlations. Please refer to the ”Rocx User Manual” for how to define a proper input file for the Rocx simulator. Initial pressure in each section. OLGA delivers boundary conditions to Rocx. [0. Labels of User Defined (UD) feeds. Near Well Source label. which means it is not allowed to split the flow from one Rocx boundary into two or more OLGA sections. Observe that the linear coefficient BPROD can not be zero if the well is located in the first (inlet) section of a flow path. Section number for REFPRESSURE. there can be several near-well sources. Name of boundary in OLGA Rocx. Internal dependencies of keys: either BRANCH = 1 PIPE = 1 SECTION = 1 or POSITION = POSITION-1 end ! Alphanumeric values are only ! given as samples . This option is only available with the Wells Module. But for one OLGA section. The amount of wall initially deposited in each section Initial watercut in each section. Rocx reads a separate input file describing the reservoir properties. Pipe number for well. This is a useful way to obtain a suitable condition for the reservoir before initiating a coupled (and more time consuming) simulation. Typical examples are well shut-in and start-up. There are two ways of specifying the data for flow between the reservoir and the well. Pipe label or pipe number (single or continuous range in the form x-y). cross flow between layers. Section number. Dynamic phenomena not accurately predicted or even not seen with the steadystate inflow performance relationship model (WELL) may therefore be simulated in a more realistic way.OUTWATERCUT PIPE PRESSURE REFPIPE REFPRESSURE REFSECTION SECTION STEAMFRACTION TEMPERATURE UDFEED UDGROUP VOIDFRACTION WALLFORMATION WATERCUT Real (-) SymbolList RealList (Pa) Symbol Real (Pa) Integer IntegerList RealList (-) RealList (C) Symbol SymbolList RealList (-) RealList (kg/m) RealList (-) UDData | [0. Link to: NEARWELLSOURCE (on Flowpath) Description Keys WELL (on Flowpath) Description ( See also: Keys) The well statement is used to define required data for calculating the flow performance of wells. The User Defined (UD) group to use Initial void fraction in each section. Pipe label for REFPRESSURE. When you use the latter. Reference pressure used if no pressure boundary condition is used. Limitations OLGA Rocx is not compatible with these fluid property models o Compositional option o Black oil module Other limitations on the Rocx reservoir simulator are given in the ”Rocx User Manual”. Definition of the file with restart data for Rocx should be given in the Rocx input file. or by reference to a defined POSITION. and the production from (or injection into) the reservoir is received by OLGA from Rocx as mass rate for each phase. Name of input filename for boundary in OLGA Rocx. To be given for one section only. Section number for well. There is no automatic check of the correspondence in positioning and size between numerical sections in OLGA and boundary grid blocks in Rocx. The feeds must be defined by the UDFEEDFILE in FILES. NEARWELLSOURCE (on Flowpath) Keys ( See also: Description ) Key ABSPOSITION LABEL PIPE POSITION RESBOUNDNAME ROCX SECTION Type Unit:( ) Real (m) String Symbol Symbol String String Integer Parameter set Default:[ ] [NWSOUR] PIPE | POSITION | Description Absolute position. Each Rocx boundary label can only be refereed once. RESBOUNDNAME must refer to a boundary label defined in the Rocx input file. or you may specify traditional well/reservoir variables like permeability and net pay. The file name should be given under the key ROCX under FILES.0] [0. Input The position of the NEARWELLSOURCE is given by referring to the distance from the inlet of the branch (ABSPOSITION). a pipe and a section number. Rocx may be set up to read the same PVT data file as OLGA. Distance from branch inlet. The flow area at the wellbore and near-wellbore interface is calculated based on the Rocx grid block rather than the corresponding OLGA numerical section. boundary conditions and initial conditions. Rocx may be run with the RESTART option.0] [ALL] PIPE | Watercut at the outlet of the last pipe in a branch section where interpolation is used. Areas for use The link provides coupled transient simulation of near-wellbore reservoir flow and well flow. 0 [kg/s] BPROD = 0.E-9 [psi-d2/scf2] else if INJOPTION = BACKPRESSURE. then GASDIS = [0. then AINJ = 0.0 [kg/s] BINJ = 0.6 [psi2-d/scf] CPROD = 1.8 [kg/Sm3] ROLST = 700 [kg/Sm3] GORST = 1000 [Sm3/Sm3] VISGRES = 0. then APROD = 0.E-9 [psi-d2/scf2] else if PRODOPTION = BACKPRESSURE.0] [-] ROGST = [from PVT tables] [kg/Sm3] ROLST = [from PVT tables] [kg/Sm3] GORST = [from PVT tables] [kg/Sm3] if INJOPTION = FORCHHEIMER.0] [s] WATDIS = [0.0] [m] GASPLIMIT = [RESPRESSURE] [Pa] GFRTC = [0. then PRODTABLE = TABLE-2 If phase front transient is to be simulated. then BPROD = 0.E-9 [psi2-d2/scf2] else if PRODOPTION = SINGLEFORCHHEIMER. then INJTABLE = TABLE-1 end if If PRODOPTION = LINEAR. then BINJ = 0.0] [m] OILPLIMIT = [RESPRESSURE] [Pa] OFRTC = [0.0] [-] If INJOPTION = LINEAR. then EXPONENTN = 1 CPROD = 1 [scf/d/psi2] end if If you want to use well/reservoir variables: WATERCUT = [0.E-4 [psi-d/scf] CPROD = 1.8 [kg/Sm3] ROLST = 700 [kg/Sm3] GORST = 1000 [Sm3/Sm3] VISLRES = 0.5 in SKINS = 3 end else if INJOPTION = FORCHHEIMER.6 [psi2-d/scf] CINJ = 1.2 cP BOOIL = 1.0 [Pa2] BPROD = 0. then FRACPR = 1000 bara ROGST = 0.E-4 [psi-d/scf] CINJ = 1.0 [Pa2-s/kg] CINJ = 0. then either INJECTIVITY = 240 stb/d/Psi FRACPR = 1000 bar ROGST = 0.3354E08 [Pa2-s2/kg2] else if INJOPTION = TABULAR. then BPROD = 1.0 [Pa2-s/kg] CPROD = 0.If you want to use the coefficients directly for standard inflow types: either WATERFRACTION = [0. then APROD = 0.1E-5 [kg/s/Pa] else if PRODOPTION = QUADRATIC.0] end end if GASFRACTION = -1 If INJOPTION = LINEAR.0] [s] end if end if If you want to use the coefficients directly for Advanced Well inflow types: WATERCUT = [0.03 cP ZFACT = 1 KPERM = 20 mD HPAY = 20 [m] . then AINJ = 0.0] [s] OILDIS = [0.0] [m] WATPLIMIT = [RESPRESSURE] [Pa] WFRTC = [0.3354E08 [Pa2-s2/kg2] else if PRODOPTION = TABULAR. then BINJ = 1.4 KPERM = 20 mD HPAY = 20 [m] RESEXT = 1000 [m] HOLES = 8.E-9 [psi2-d2/scf2] else if INJOPTION = SINGLEFORCHHEIMER.1E-5 [kg/s/Pa] else if INJOPTION = QUADRATIC.0 [Pa2] BINJ = 0.8 [kg/Sm3] ROLST = 700 [kg/Sm3] GORST = 1000 [Sm3/Sm3] PHASE = [OIL] or FRACPR = 1000 bar ROGST = 0.0] or TOTALWATERFRACTION = [0. then EXPONENTN = 1 CINJ = 1 [scf/d/psi2] end if if PRODOPTION = FORCHHEIMER. 01 EXPONENTN = 1 else if INJOPTION = NORMALIZEDBACKPR. then FRACPR = 1000 bara ROGST = 0.4 KPERM = 20 mD HPAY = 20 [m] RESEXT = 1000 [m] HOLES = 8.5 in SKINS = 3 SKIND = 0.8 [kg/Sm3] ROLST = 700 [kg/Sm3] GORST = 1000 [Sm3/Sm3] QMAX = 10 000 Sm3/d else if INJOPTION = BACKPRESSURE.8 [kg/Sm3] ROLST = 700 [kg/Sm3] GORST = 1000 [Sm3/Sm3] VISGRES = 0.03 cP ZFACT = 1 KPERM = 20 mD HPAY = 20 [m] RESEXT = 1000 [m] HOLES = 8.2 cP BOOIL = 1.8 [kg/Sm3] ROLST = 700 [kg/Sm3] GORST = 1000 [Sm3/Sm3] VISLRES = 0. then FRACPR = 1000 bara ROGST = 0.8 [kg/Sm3] ROLST = 700 [kg/Sm3] GORST = 1000 [Sm3/Sm3] VISLRES = 0.01 else if INJOPTION = SINGLEFORCHHEIMER. then FRACPR = 1000 bara ROGST = 0.03 cP ZFACT = 1 KPERM = 20 mD . then FRACPR = 1000 bara ROGST = 0.01 else if INJOPTION = VOGELS. then FRACPR = 1000 bara ROGST = 0.8 [kg/Sm3] ROLST = 700 [kg/Sm3] GORST = 1000 [Sm3/Sm3] VISGRES = 0.03 cP ZFACT = 1 KPERM = 20 mD HPAY = 20 [m] RESEXT = 1000 [m] HOLES = 8.03 cP ZFACT = 1 KPERM = 20 mD HPAY = 20 [m] RESEXT = 1000 [m] HOLES = 8.4 KPERM = 20 mD HPAY = 20 [m] RESEXT = 1000 [m] HOLES = 8.5 in SKINS = 3 end else if PRODOPTION = FORCHHEIMER.8 [kg/Sm3] ROLST = 700 [kg/Sm3] GORST = 1000 [Sm3/Sm3] PHASE = [OIL] or FRACPR = 1000 bara ROGST = 0.8 [kg/Sm3] ROLST = 700 [kg/Sm3] GORST = 1000 [Sm3/Sm3] VISGRES = 0.5 in SKINS = 3 SKIND = 0. then FRACPR = 1000 bara ROGST = 0.RESEXT = 1000 [m] HOLES = 8.8 [kg/Sm3] ROLST = 700 [kg/Sm3] GORST = 1000 [Sm3/Sm3] VISGRES = 0.5 in SKINS = 3 BPPRESSURE = 600 bar end if If the user wants to define a specific linear injectivity index for one or more of the phases GASINJ = 100 stb/d/Psi OILINJ = 100 stb/d/Psi WATINJ = 180 stb/d/Psi end if If PRODOPTION = LINEAR.2 cP BOOIL = 1.01 else if PRODOPTION = SINGLEFORCHHEIMER.8 [kg/Sm3] ROLST = 700 [kg/Sm3] GORST = 1000 [Sm3/Sm3] QMAX = 10 000 Sm3/d EXPONENTN = 1 PHASE = [OIL] else if INJOPTION = UNDERSATURATED.5 in SKINS = 3 SKIND = 0. then either PRODI = 240 stb/d/Psi FRACPR = 1000 bara ROGST = 0.5 in SKINS = 3 SKIND = 0. then FRACPR = 1000 bara ROGST = 0. scf/d/psi2n for Backpressure. psi-d2/scf2 for Single Forchheimer. Given at in situ conditions . Given at in situ conditions . FEEDMOLEFRACTION and FEEDVOLFRACTION. Unit: kg/s for the linear formula. Positive coefficient C in well flow equation. 0. Injectivity index for linear inflow equation. FEED1(T2). psi2-d2/scf2 for Forchheimer. then TIME = (0. Given at in situ conditions . psi2-d/scf for Forchheimer. By default. FEED-2(T1). Unit: Pa2-s2/kg2 for the non-linear formula. 0. psi2-d2/scf2 for Forchheimer.3. Pa2 for the non-linear formula. 0. then FRACPR = 1000 bara ROGST = 0.5.7.uses gas mass fraction from the PVT table to calculate the split between the phases. Pa2-s/kg for the non-linear formula. Productivity index for linear inflow equation.3) or FEEDMOLEFRACTION = (0.5.8 [kg/Sm3] ROLST = 700 [kg/Sm3] GORST = 1000 [Sm3/Sm3] QMAX = 10 000 Sm3/d EXPONENTN = 1 PHASE = [OIL] else if PRODOPTION = UNDERSATURATED. BO-2) FEEDVOLFRACTION = [1. CGR from the PVT table is used.5) end or if COMPOSITIONAL = BLACKOIL in OPTIONS. the array is a function of both feed and time as shown below. 0. psi2-d/scf for Forchheimer.8 [kg/Sm3] ROLST = 700 [kg/Sm3] GORST = 1000 [Sm3/Sm3] QMAX = 10 000 Sm3/d else if PRODOPTION = BACKPRESSURE.6. Unit: Pa2-s2/kg2 for the nonlinear formula. 0. Less than zero if a minimum pressure difference is required for fluid flow from well into reservoir.uses gas mass fraction from the PVT table to calculate the split between the phases. Positive coefficient B in well flow equation.HPAY = 20 [m] RESEXT = 1000 [m] HOLES = 8.4 KPERM = 20 mD HPAY = 20 [m] RESEXT = 1000 [m] HOLES = 8. Unit: kg/s/Pa for the linear formula. then FRACPR = 1000 bara ROGST = 0. scf/d/psi2n for Backpressure (dependent on EXPONENTN).8 [kg/Sm3] ROLST = 700 [kg/Sm3] GORST = 1000 [Sm3/Sm3] VISGRES = 0.2 cP BOOIL = 1. Negative coefficient B in well flow equation.0.0. psi-d/scf for Single Forchheimer. 5) h FEEDNAME = (BO-1. Given at in situ conditions . 0. 0. FEED-2(T2)) WELL (on Flowpath) Keys ( See also: Description ) Key ABSPOSITION Type Unit:( ) Real (m) Parameter set Default:[ ] Description Absolute position. Positive coefficient A in well flow equation. Negative coefficient A in well flow equation.4. Unit: kg/s/Pa for the linear formula. Distance from branch inlet.01 EXPONENTN = 1 else if PRODOPTION = NORMALIZEDBACKPR. Less than zero if a minimum pressure difference is required for fluid flow from reservoir into well. 0. Pa2-s/kg for the non-linear formula.uses gas mass fraction from the PVT table to calculate the split between the phases. see note below) TIME = (0.8 [kg/Sm3] ROLST = 700 [kg/Sm3] GORST = 1000 [Sm3/Sm3] VISLRES = 0.0] Condensate-gas ratio. Negative coefficient C in well flow equation. 0. FEED-3) either FEEDMASSFRACTION = (0.5 in SKINS = 3 BPPRESSURE = 600 bar end if If COMPOSITIONAL = ON in OPTION.01 else if PRODOPTION = VOGELS.uses gas mass fraction from the PVT table to calculate the split between the phases.03 cP ZFACT = 1 KPERM = 20 mD HPAY = 20 [m] RESEXT = 1000 [m] HOLES = 8. psi-d/scf for Single Forchheimer. Unit: kg/s for the linear formula. FEEDMASSFRACTION = FEED-1 (T1). 5) h FEEDNAME = (FEED-1. then (multiple time and feeds. then FRACPR = 1000 bara ROGST = 0.7. then FRACPR = 1000 bara ROGST = 0. Pa2 for the non-linear formula.5 in SKINS = 3 SKIND = 0. AINJ RealList APROD RealList BINJ RealList BOOIL BPPRESSURE Real RealList (Pa) BPROD RealList CGR CINJ RealList (Sm3/Sm3) RealList CPROD RealList . Oil formation volume factor Bubble point pressure at reservoir temperature for Undersaturated oil wells.5 in SKINS = 3 SKIND = 0. psi-d2/scf2 for Single Forchheimer.5] endif Note: For the subkeys FEEDMASSFRACTION. [-1. If BH pressure has been above fracture pressure this is a multiplier when BH pressure is above INJTHRESHOLD as well. otherwise. Normally given in (1/MMSCF/d). Mass fraction of each feed.0] [-1. Distance oil front has to travel before it reaches the well bore. Volume fraction of each feed given in FEEDNAME (only for blackoil model).0] Negative well flow equation type. Requires COMPOSITIONAL=ON or BLACKOIL under the OPTIONS keyword.EXPONENTN EXPOSE FEEDMASSFRACTION FEEDMOLEFRACTION RealList SymbolList RealList (-) RealList (-) [1. PIPE. If BH pressure has been above fracture pressure the injection rate multiplied by the INJPOSTFRACFACTOR will be used when the BH pressure is above INJTHRESHOLD. Effective permeability. Note that this key can only be specified branchwise. Normally given in (Sm3/d/bar). The table variables must be given at reservoir conditions. the mass of H2O component is distributed between the gas phase and the water phase according to the vapor pressure of H2O in the gas phase.0] TABLE | NO | [YES] [WELL] BOTTOM | [MIDDLE] <None> | GAS | OIL | WATER | LIQUID | PIPE | POSITION | PRODOPTION Symbol LINEAR | QUADRATIC | SINGLEFORCHHEIMER | FORCHHEIMER | BACKPRESSURE | UNDERSATURATED | VOGELS | TABULAR | NORMALIZEDBACKPR | [1. Requires PRODOPTION=TABULAR. Linear injectivity index for oil entering the well section. GOR from the PVT table is used. Linear injectivity index for gas entering the well section. Reservoir extension.0] [-1. Fraction of total mass of H2O component in the gas phase. Given at std conditions . Gas/oil volumetric ratio.0] [1. By default value from PVT table is used. Time constant for the oil front movement. Maximum flow in Vogels and Normalized Backpressure inflow equation. Requires PRODOPTION=TABULAR.0] . Pressure. Reservoir pressure. Multiplier for injection rate when BH pressure is below fracture pressure.0] Multiplier for production rate after the reservoir is fractured. FEEDNAME SymbolList FEEDVOLFRACTION FRACPR GASDIS GASFRACTION GASINJ GASPLIMIT GFRTC GORST HOLES HPAY INJECTIVITY RealList (-) RealList (Pa) Real (m) RealList (-) RealList (Sm3/s/Pa) Real (Pa) Real (s) RealList (Sm3/Sm3) RealList (m) RealList (m) RealList (Sm3/s/Pa) [-1.0] TABLE | Positive well flow equation type.5 and 1. Fracture pressure. Turbulent non-darcy skin. A list of both positive and negative values is not allowed. The phase for which productivity index or absolute open flow rate is given. INJPOSTFRACFACTOR Real Multiplier for injection rate when BH pressure is above fracture pressure. BOTTOM if the reservoir pressure given is at the bottom of the zone. PRODPOSTFRACFACTOR PRODPREFRACFACTOR PRODTABLE QMAX RESEXT RESPRESSURE RESTEMPERATURE ROGST ROLST SECTION SKIND SKINS Real Real Symbol RealList (Sm3/s) RealList (m) RealList (Pa) RealList (C) Real (kg/Sm3) Real (kg/Sm3) Integer RealList (1/Sm3/s) RealList [-1.0] INJOPTION Symbol LINEAR | QUADRATIC | SINGLEFORCHHEIMER | FORCHHEIMER | BACKPRESSURE | UNDERSATURATED | VOGELS | TABULAR | NORMALIZEDBACKPR | [1. Normally given in inches (in). Normally given in (Sm3/d/bar). Turn on or off isothermal.0. Oil density at standard conditions. A list of both positive and negative STEAMFRACTION RealList (-) [-1. Hole size (diameter). INJPREFRACFACTOR INJTABLE INJTHRESHOLD ISOTHERMAL KPERM LABEL LOCATION OFRTC OILDIS OILINJ OILPLIMIT PHASE PIPE POSITION PRODI Real Symbol RealList (Pa) Symbol RealList (mD) String Symbol Real (s) Real (m) RealList (Sm3/s/Pa) Real (Pa) Symbol Symbol Symbol RealList (Sm3/s/Pa) [1. -1 indicates equilibrium. Table reference for negative well flow performance.0] Constant in Backpressure inflow equation. States which keys should be made available as input variables on the OPC server. If POSITION is defined. BRANCH. If the BH pressure has been above fracture pressure this is a multiplier only below INJTHRESHOLD. Label of initial feed to be used for calculating local fluid compositions in the branch (from feed file and FEED keyword). Net pay from inflow zone. Well location in the well section. Multiplier for production rate before the reservoir is fractured. Reservoir temperature. A list means mixing of feeds for each section in the branch. Requires PRODOPTION=TABULAR. Used when the well parameters are given for conditions after the reservoir is fractured. Gas mass fraction in the gas+oil mixture for positive flow. Option for supporting coning. Table reference for positive flow performance. Mechanical damage skin. Distance gas front has to travel before it reaches the well bore. Time constant for the gas front movement. The table variables must be given at reservoir conditions. Well label. Requires PRODOPTION=TABULAR. It normally varies between 0. Pressure at which the gas front will be at the well bore at steady-state conditions. Requires PRODOPTION=TABULAR. Pipe number for well. Normally given in (Sm3/d/bar). Use when the well parameters are given for conditions before the reservoir is fractured. Given at std conditions .uses GOR from the PVT table (or the specified GORST) and the PHASE to calculate the split between the phases. Mole fraction of each feed. Position where the well is located. Productivity index for linear inflow equation. Section number for well. By default value from PVT table is used. Option for supporting coning.uses GOR from the PVT table (or the specified GORST) and the PHASE to calculate the split between the phases. By default. MIDDLE if the reservoir pressure at the middle of the zone is specified. Gas density at standard conditions. Requires PRODOPTION=TABULAR. Injectivity.0] [0. the mass of H2O component is in the gas phase if the temperature is greater than the saturation temperature. By default (=-1). and SECTION should not be used. Pressure at which the oil front will be at the well bore at steady-state conditions. Pressure at the start of the well zone Temperature at the start of the well zone Reservoir temperature at specified location INTERPOLATION Symbol VERTICAL | AUTOMATIC | [OFF] LABEL PRESSURE RESERVOIRINFLOW STARTPOSITION STARTPRESSURE STARTTEMPERATURE TEMPERATURE String RealList (Pa) Symbol Symbol RealList (Pa) RealList (C) RealList (C) [ZONE] RESERVOIRINFLOW | POSITION | Link to: ZONE (on Flowpath) Description Keys CROSSDATA (on Flowpath) . Scaling factor for determining the amount of wax forming components relative to HC mixture.0] [1] values is not allowed. On global level: TRENDDATA VARIABLE=GGWELL (will plot GGWELL for all ZONES) On flowpath level: TRENDDATA ZONE=ALL.TIME RealList (s) [0. If INTERPOLATION=VERTICAL. With a value of –1. Viscosity of oil reservoir conditions. Reservoir pressure at specified location Reference to template specifying the properties of the automatically generated inflows. Watercut at standard conditions. Linear injectivity index for water entering the well section. 1 means that the amount of wax forming components is equal to the values from the wax table. even if the water option is available. All plot variables for WELL will also be available for ZONE.0] WFRTC WGR ZFACT Real (s) RealList (Sm3/Sm3) Real [-1. Either this key or WATERFRACTION can be specified.0] WAXFRACTION RealList (-) [1. The value must be in the range [0. Mass fraction of total water in the in the total fluid mixture of the reservoir. VERTICAL: reservoir temperature and reservoir pressure are given by vertical interpolation between end points.and endposition of the ZONE. Note that the value actually used by the program is interpolated between the values specified by the time table. ZONEDETAILS=YES (will plot GTWELL for all ZONES and for all inflow points in the ZONE) ZONE (on Flowpath) Keys ( See also: Description ) Key COEFTYPE ENDPOSITION ENDPRESSURE ENDTEMPERATURE Type Unit:( ) Symbol Symbol RealList (Pa) RealList (C) Parameter set Default:[ ] PERMETER | [TOTAL] POSITION | Description TOTAL: Production and injection coefficents are given for the entire well zone. Pressures between start. If ENDPOSITION is defined. These will be used for the whole zone. Gas compressibility factor. This means that reservoir inflow points will be created in all pipeline sections in the ZONE. By default. Requires PRODOPTION=TABULAR. Well zone label. Position where the well zone ends. Either this key or TOTALWATERFRACTION can be specified. Pressure at which the water front will be at the well bore at steady-state conditions. This key can only be used if water option is available. respectively. WGR from the PVT table is used. Ratio between water (including water in gas phase) and gas. Requires PRODOPTION=TABULAR. This key can only be used if water option is available.or END-values of pressure and temperature must be given.0 the total water fraction is taken from the fluid table. the total water fraction is taken from the fluid table. OFF: constant reservoir pressure and temperature given by PRESSURE and TEMPERATURE. ENDPIPE and ENDSECTION should not be used. PERMETER: Production and injection parameters are given per meter. this key is ignored if GASFRACTION<0 (the water fraction in the source section is used). For outflow.and endposition will then be computed using the hydrostatic gradient. Requires PRODOPTION=TABULAR. Time constant for the water front movement. Mass fraction of free water in the total flow mixture of the reservoir. This key can only be used if water option is available.1]. Position where the well zone begins. By default value from PVT table is used. Normally given in (Sm3/d/bar). Requires WAXDEPOSITION=ON under the OPTIONS keyword and access to the wax deposition module.0] [-1] [-1] WATERCUT WATERFRACTION WATINJ WATPLIMIT RealList (-) RealList (-) RealList (Sm3/s/Pa) Real (Pa) [-1. The ZONE keyword refers to a RESERVOIRINFLOW keyword in which reservoir inflow data must be given. Link to: WELL (on Flowpath) Description Keys ZONE (on Flowpath) Description ( See also: Keys) The ZONE keyword defines an area between two positions in the PIPELINE (STARTPOSITION AND ENDPOSITION). If INTERPOLATION=OFF. Non-zero values are ignored for twophase simulations. either START. PRESSURE and TEMPERATURE must be given. STARTPIPE and STARTSECTION should not be used. VARIABLE=GTWELL. STARTPRESSURE and STARTTEMPERATURE as well as ENDPRESSURE and ENDTEMPERATURE must be given. The reservoir pressure and temperature will then be interpolated in the sections between STARTPOSITION and ENDPOSITION. Pressure at the end of the well zone Temperature at the end of the well zone Type of interpolation used to calculate the zone properties. If INTERPOLATION=AUTOMATIC. If STARTPOSITION is defined. The pressure and temperature is specified at either the zone start or end position. Distance water front has to travel before it reaches the well bore. With a value of -1. Time series when the reservoir conditions are to be changed. By default value from PVT table is used. A ZONE with reference to a RESERVOIRINFLOW is equivalent to specification of one WELL keyword for each section between the start.0] TOTALWATERFRACTION VISGRES VISLRES WATDIS RealList (-) Real (Ns/m2) Real (Ns/m2) Real (m) [-1. AUTOMATIC: constant reservoir temperature whereas the reservoir pressure varies hydrostatically. Viscosity of gas reservoir conditions. Absolute position. available components are HC.g. For compositional models the names of the available components are given in the feed file. CUTTING and MUD components. e. e. User Defined (UD) dispersion names. The plot interval is the same as for the TREND plots. ALL | GAS | OIL | WATER | BED | WALL | Flowing layers Wall layer numbers for plotting of wall temperatures. Variables to be written to the profile plot file. H2O. Using the Inhibitor tracking module. Component names. MEG/MEOH/ETOH. available components are HC.Description ( See also: Keys) Cross sectional plots of particle concentration and dispersion velocity are available: Concentration of dispersion (particles) from bottom to top of line along vertical diameter: P-CON Volume velocity profile from bottom to top of line along vertical diameter: U-PROFILE These data files have extension "csp" and can be plotted in the GUI. H2O and MEG/MEOH/ETOH. Kinetic hydrate inhibitor (KHI). Wall layer number for plotting of wall temperatures. Link to: CROSSDATA (on Flowpath) Description Keys PROFILEDATA (on Flowpath) Description ( See also: Keys) This statement defines profile plot variables along the pipeline at specified time points. The concentration profile will be plotted for each UD phase. 1 is the innermost one. Tracer label that the tracer type variables are plotted for. Using DRILLING=ON under OPTIONS. Kinetic hydrate inhibitor (KHI).out). Section numbers where the variables will be plotted. OUTPUTDATA (on Flowpath) Keys ( See also: Description ) Key AGEGROUPID Type Unit:( ) IntegerList Parameter set Default:[ ] Description Age group for plotting inhibitors variables with aging effect. available components are HC. User Defined (UD) dispersion names. available components are HC. Using DRILLING=ON under OPTIONS. User Defined (UD) phase names. labels where the variables will be plotted. Layer no. Units may be included in the list.g. 1 is the innermost one. PROFILEDATA (on Flowpath) Keys ( See also: Description ) Key AGEGROUPID Type Unit:( ) IntegerList Parameter set Default:[ ] Description Age group for plotting inhibitors variables with aging effect. Distance from branch inlet. Layer no. ALL | GAS | OIL | WATER | BED | WALL | Flowing layers Array element index of HYKPLIST. Component names. CUTTING and MUD components. H2O. COMPONENT SymbolList DISPERSION FLOWLAYER HYKPID LAYER PHASE TRACERFEED VARIABLE SymbolList SymbolList IntegerList IntegerList SymbolList SymbolList SymbolList (ValueUnitPair) Link to: PROFILEDATA (on Flowpath) Description Keys OUTPUTDATA (on Flowpath) Description ( See also: Keys) This statement defines the variables to be printed to the output file (*. Global variables are not available on this level. COMPONENT SymbolList DISPERSION FLOWLAYER LAYER SymbolList SymbolList IntegerList . MEG/MEOH/ETOH. Units should not be used. For compositional models the names of the available components are given in the feed file. For available profile variables see Output Variables. CROSSDATA (on Flowpath) Keys ( See also: Description ) Key ABSPOSITION PIPE POSITION SECTION VARIABLE Type Unit:( ) RealList (m) SymbolList SymbolList IntegerList SymbolList (ValueUnitPair) Parameter set Default:[ ] Description Pipeline position where the variable will be plotted. and the plot variables will automatically be labeled accordingly in the csp file. Pipe numbers or labels where the variables will be plotted. H2O and MEG/MEOH/ETOH. Using the Inhibitor tracking module. List of variables to be plotted. Layer no. List of variables to be plotted. Global and branch variables are not available on this level. Component names. 1 is the innermost one. Link to: OUTPUTDATA (on Flowpath) Description Keys TRENDDATA (on Flowpath) Description ( See also: Keys) This statement defines the trend data to be plotted. Tracer label that the tracer type variables are plotted for. Valve for which the variable is to be plotted. Checkvalve for which the variable is to be plotted.PHASE PIPE SECTION TRACERFEED VARIABLE SymbolList SymbolList IntegerList SymbolList SymbolList (ValueUnitPair) User Defined (UD) phase names. User Defined (UD) dispersion names. Well for which the variable is to be plotted. Absolute position. Units should not be used. Simplified pump for which the variable is to be plotted. Section numbers where the variables will be plotted. A trend plot is a time series plot for a specified variable. HeatExchanger for which the variable is to be plotted. User Defined (UD) phase names. Pig for which the variable is to be plotted. Section or section boundary numbers where the variables will be printed. Tracer label that the tracer type variables are plotted for. Pressure boost for which the variable is to be plotted. Units may be included in the list. Section or section boundary numbers where the variables will be plotted. Array element index of HYKPLIST. Displacement pump for which the variable is to be plotted. Source for which the variable is to be plotted. List of variables to be printed. Unique identity defining a slug or a pig. Wall layer number for plotting of wall temperatures. Kinetic hydrate inhibitor (KHI). Absolute position. labels where the variables will be plotted. MEG/MEOH/ETOH. ALL | GAS | OIL | WATER | BED | WALL | Flowing layers Framo pump for which the variable is to be plotted. Switch telling whether to store trend data for all autogenerated sources/wells within zones COMPONENT SymbolList COMPRESSOR DISPERSION DISPLACEMENTPUMP FLOWLAYER FRAMOPUMP HEATEXCHANGER HYKPID LAYER LEAK NEARWELLSOURCE PHASE PIG PIPE POSITION PRESSUREBOOST PUMPBATTERY SECTION SIMPLIFIEDPUMP SLUGID SOURCE TRACERFEED VALVE VARIABLE WELL ZONE ZONEDETAILS SymbolList SymbolList SymbolList SymbolList SymbolList SymbolList IntegerList IntegerList SymbolList SymbolList SymbolList SymbolList SymbolList SymbolList SymbolList SymbolList IntegerList SymbolList IntegerList SymbolList SymbolList SymbolList SymbolList (ValueUnitPair) SymbolList SymbolList Symbol [0] YES | [NO] Link to: TRENDDATA (on Flowpath) Description Keys XYTDATA (on Flowpath) Description ( See also: Keys) Size distributions may be plotted using the XYTDATA definition. available components are HC. XYTDATA (on Flowpath) Keys ( See also: Description ) Key ABSPOSITION PIPE POSITION SECTION VARIABLE Type Unit:( ) RealList (m) SymbolList SymbolList IntegerList SymbolList (ValueUnitPair) Parameter set Default:[ ] Description Pipeline position where the variable will be plotted. TRENDDATA (on Flowpath) Keys ( See also: Description ) Key ABSPOSITION AGEGROUPID CENTRIFUGALPUMP CHECKVALVE Type Unit:( ) RealList (m) IntegerList SymbolList SymbolList Parameter set Default:[ ] Description Pipeline position where the variable will be plotted. For compositional models the names of the available components are given in the feed file. CUTTING and MUD components. Distance from branch inlet. List of variables to be plotted. H2O. H2O and MEG/MEOH/ETOH. Centrifugal pump for which the variable is to be plotted. Selecting the variable P-SD in this statement generates a plot file with extension "xyt". Well for which the variable is to be plotted. Age group for plotting inhibitors variables with aging effect. NearWellSource for which the variable is to be plotted. Using DRILLING=ON under OPTIONS. Time points for plotting are specified with the Output group XYT. Pump battery for which the variable is to be plotted. Labels of specified positions where the variables will be plotted. available components are HC. e. Distance from branch inlet.g. Pipe numbers or labels where the variables will be plotted. Compressor for which the variable is to be plotted. Leak for which the variable is to be plotted. . For available variables see Output Variables. Pipe numbers or labels where the variables will be plotted. Using the Inhibitor tracking module. Units may be specified. Pipe numbers or labels where the variables will be printed. t. Time-step control based on the speed of pressure waves. the output variable PCO2 can be read and PCO2MAX can be set to the PCO2 value in the section where gas is formed. Whether or not to calculate the pH for condensed water saturated with ion carbonate. Inhibitor (not glycol) efficiency in %. It is only used in the corrosion module to detect if water droplets are wetting the wall. water wetting is detected by the corrosion module regardless of the water cut set as the wetting limit. if a simulation shows single phase liquid flow. Pipe numbers or labels where the criteria changes will be applied. Requires access to the corrosion module. Alternatively.0] Parameter set Default:[ ] [0. If the liquid film watercut is higher than this value. the larger of the two resulting reduction factors is used.8] [OFF] [OFF] Link to: DTCONTROL (on Flowpath) Description Keys . The Courant-Friedrichs-Lewy (CFL) criterion based on the flow velocity. Time-step control based on the second-order derivative of pressure w. The effect of glycol and an additional inhibitor (through INHIBITOREFFICIENCY) depends on the model used. If Inhibitor tracking is used. a new simulation should be performed with the correct PTMAX set to the pressure in the section where gas is formed.r. Has to be given as watercut in %. INHIBITOREFFICIENCY=100% means no corrosion. the water droplets will wet the wall. while for the de Waard models the product of the two factors is used. Absolute position. That is.0] IONICSTRENGTH MODEL PCO2MAX PHSAT PTMAX Real SymbolList Real (Pa) Symbol Real (Pa) [0. Adjust the CFL time-step. the glycol fraction will be calculated. even if no continuous water film is present. Time-step control based on the first-order derivative of pressure w.0] Link to: CORROSION (on Flowpath) Description Keys DTCONTROL (on Flowpath) Description ( See also: Keys) This statement defines a switch for stability control. Maximum CO2 partial pressure in single phase liquid flow. [0. The corrosion module cannot be applied together with the wax deposition module. If the corrosion rate in single phase liquid flow is to be calculated correctly.0] [ALL] [1000000] [OFF] WCWET Real [30. DTCONTROL (on Flowpath) Keys ( See also: Description ) Key ABSPOSITION CFL CFLFACTOR GRADPRESSURE PIPE POSITION PREFACTOR PRESSURE SECTION SOUND_CFL Type Unit:( ) RealList (m) Symbol Real Symbol SymbolList SymbolList Real Symbol IntegerList Symbol [ON] [0. MODEL2: Top of Line corrosion model.8] ON | [OFF] Parameter set Default:[ ] Description Pipeline position where the criteria changes will be applied. CORROSION (on Flowpath) Keys ( See also: Description ) Key BICARBONATE CO2FRACTION GLYCOLFRACTION Type Unit:( ) Real Real Real [0. See restrictions and limitations for more information.Link to: XYTDATA (on Flowpath) Description Keys CORROSION (on Flowpath) Description ( See also: Keys) This statement is used to define corrosion module input parameters. time. Section numbers where the criteria changes will be applied. MODEL1: NORSOK. MODEL3: de Waard 95. If a continuous water film is predicted by the flow model. Mole percentage of CO2 in gas phase (ratio of CO2 partial pressure to total pressure in %). Bubble point pressure from which the CO2 partial pressure for a single phase liquid flow will be calculated. Total ionic strength in Molar (M=mol/l). PTMAX must be set equal to the pressure in the pipeline where gas is formed (bubble point pressure). Water droplet wall wetting limit. Tuning factor for pressure criterion. Only used if Inhibitor tracking is not used. Distance from branch inlet.r. INHIBITOREFFICIENCY Real [0. It has no influence on the flow conditions. For the NORSOK model.0] Description Bicarbonate (HCO3-) concentration in water given in Molar (M=mol/l). Labels of specified positions where the criteria changes will be applied. time.t. Glycol concentration in weight-% in a glycol/water mixture. Which model to use. HYDRATECHECK (on Flowpath) Description ( See also: Keys) This keyword can be used to specify a set of hydrate formation curves and how these should be treated in the flowpath. See also: HYDRATECHECK HYDRATECHECK (on Flowpath) Keys ( See also: Description ) Key HAMCONST HAMMERSCHMIDT Type Unit:( ) Real (C) Symbol Parameter set Default:[ ] [1297] ON | [OFF] Description Constant in Hammerschmidt equation. Note that unit is delta temperature. Switch for activating the Hammerschmidt formula for computing hydrate temperature curves for different inhibitor concentrations. Can only be used with a single hydrate curve without any specified inhibitor concentration (i.e. INHIBITORCONC=0). Labels of the HYDRATECURVEs (from Library) that shall be used in this flowpath. Name of file with inhibitor corrections to hydrate equilibrium. With PRESSOVERRIDE the limit for the difference between hydrate and section pressure, DPHYD (default -50 bar), can be changed. Such sections are not used when calculating the maximum DPHYD in a branch. With TEMPOVERRIDE the limit for the difference between hydrate and section temperature, DTHYD (default -50 C), can be changed. Such sections are not used when calculating the maximum DTHYD in a branch. Label of tracer feed. Requires TRACERTRACKING = ON under the OPTIONS keyword. If given the hydrate temperature will be corrected according to INHIBITORFILE. Hydrates will not form in sections with less water than the waterlimit (default = 0). HYDRATECURVE INHIBITORFILE PRESSOVERRIDE SymbolList String Real (Pa) [-5000000] TEMPOVERRIDE Real (C) [-50] TRACERFEED WATERLIMIT Symbol Real (-) TRACERFEED | [0] Link to: HYDRATECHECK (on Flowpath) Description Keys HYDRATEKINETICS (on Flowpath) Description ( See also: Keys) The hydrate kinetics module combines the hydrate kinetics and rheological model developed by Colorado School of Mines with the flow equations of the OLGA model. The hydrate kinetics model determines the amount of gas and water consumed by hydrate formation and the effective viscosity of the hydrate particle laden oil phase. The flow model integrates the mass consumption rate to obtain the amount of hydrate phase and uses the effective viscosity for the flow calculations. The model is still in the research phase, and the initial emphasis has been on flowing liquid dominated systems with excess of water and gas for hydrate formation. Future versions will likely also address gas dominated systems and include deposition mechanisms. Special care should be taken when using the model since the model has only been validated against limited data sets. Further, it is not designed for shut-in and depressurization studies. HYDRATEKINETICS (on Flowpath) Keys ( See also: Description ) Key COIL CWATER DRIFTFLUX Type Unit:( ) Real Real Symbol Parameter set Default:[ ] [1.0] [0.0] YES | [NO] Description Weighting factor for hydrate velocity related to oil velocity Weighting factor for hydrate velocity related to water velocity NO: Use OLGA flow model. YES: Forces the gas velocity to be proportional to the liquid velocity, and the keys VELOCITYRATIO and DRIFTVELOCITY become active. DRIFTVELOCITY is a constant slip velocity of the gas. Used when DRIFTFLUX = YES. gas velocity = VELOCITYRATIO times liquid velocity + DRIFTVELOCITY FOGEXPONENT is used to adjust the gas-liquid interface friction. The scaling factor for the interfacial friction is equal to the viscosity ratio of the oil phase raised to the power of FOGEXPONENT. NO: Use OLGA oil/water dispersion model. YES: Force all of oil or water to be dispersed in water or oil depending on inversion point. The inversion point can be adjusted through the WATEROPTIONS keyword. File containing methane concentration in oil. Type of hydrate model. KINETIC should be used in most cases. Two prototype models are available from Colorado School of Mines: TRANSPORT and COLDFLOW. KINETIC calculates the rate of hydrate formation using a chemical kinetics equation based on the temperature driving force. TRANSPORT accounts for mass and heat transfer resistances in the calculation of the hydrate formation rate. COLDFLOW adapted transport model for simulation of the stabilized flow concept. Type of hydrate structure. Structure I tends to enclathrate smaller natural gas molecules such as methane, whereas structure II tends to enclathrate larger natural gas molecules such as propane (Sloan and Koh, 2008) Subcooling (given as temperature difference) from hydrate equilibrium before nucleation. Default 6.5 F. Distribution coefficient for gas velocity. Used when DRIFTFLUX = YES DRIFTVELOCITY Real (m/s) [0] FOGEXPONENT Real [0] FULLDISPERSION METHANECONCFILE Symbol String YES | [NO] MODEL Symbol KINETIC | TRANSPORT | COLDFLOW | STRUCTURE SUBCOOLING VELOCITYRATIO Symbol Real (C) Real SI | [SII] [3.611111] [1] Link to: HYDRATEKINETICS (on Flowpath) Description Keys HYDRATEOPTIONS (on Flowpath) Description ( See also: Keys) HYDRATEOPTIONS (on Flowpath) Keys ( See also: Description ) Key Type Unit:( ) Symbol Symbol Symbol Parameter set Default:[ ] YES | [NO] YES | [NO] YES | [NO] Description [NO] Constant adhesion force between hydrate particles, FATTRACTION. [YES] Adhesion force between hydrate particles is calculated as a function of temperature. NO: Use MEANDIAMETER. YES: Use diameter calculated by CSM. NO: Surface area for hydrate formation is calculated by OLGA. (Recommended for Kinetic model) YES: Surface area for hydrate formation is calculated internally in CSM code based on the particle diameter. (Recommended for Transport model) Diffusivity of methane through hydrate shell. For cold flow model: Diffusivity of methane in water. Constant adhesion force between hydrate particles. Mass fraction of hydrate guest molecules in gas phase Heat capacity of hydrate particles. Heat generated by hydrate formation, or heat consumed by hydrate dissociation. Scaling factor for first kinetic reaction coefficient. Suggested value for oildominated systems is 0.002, for gas-dominated systems is 1. Scaling factor for the second reaction coefficient Mean droplet diameter Not in use Mass fraction of hydrate guest molecules in oil phase NO: The routines embedded in the OLGA executable are used. YES: csmhyddll.dll is used. This dll must exist together with the OLGA executable. CSMFATTRACTION CSMPARTICLEDIAMETER CSMSURFAREA DIFFUSIVITY FATTRACTION GASGUESTFRACTION HEATCAPACITY HEATFORMATION K1SCALINGFACTOR K2SCALINGFACTOR MEANDIAMETER OCCUPANCY OILGUESTFRACTION USEDLL Real (m2/s) Real (mN/m) Real (-) Real (J/kg-C) Real (J/kg) Real Real Real (m) Real Real (-) Symbol [1.0e-16] [50.0] [1] [1.0] [1.0] [4.0e-5] [0] YES | [NO] Link to: HYDRATEOPTIONS (on Flowpath) Description Keys PIG (on Flowpath) Description ( See also: Keys) This statement defines the pig option. The pig keyword should be used when the user wants to simulate a pig or plug in the pipeline. The pig is inserted at LAUNCHPOSITION and taken out when it reaches either the TRAPPOSITION or a boundary NODE. TRAPPOSITION can be in the same flowpath as LAUNCHPOSITION or in a different flowpath. When the pig comes to an internal NODE or SEPARATOR it will take the path with the highest volume flow. The path the pig takes in a network can be overridden by the ROUTING key. If the TRAPPOSITION is specified in a different flowpath than LAUNCHPOSITION and the pig does not reach the TRAPPOSITION (because highest volume flow or ROUTING does not take it there) the pig is taken out when it reaches a boundary node. Τηε κεψσ ΛΙΝΕΑΡΦΡΙΧ, ΘΥΑ∆ΡΑΤΙΧΦΡΙΧ ανδ ΣΤΑΤΙΧΦΟΡΧΕ αρε τηε υσυαλ ωαψ το δεφινε τηε φριχτιον οφ τηε πιγ. The keys LEAKAGEFACTOR, LEAKDPCOEF or LEAKOPENING are used to specify the leakage in the propagation direction of the pig. Τηε κεψ ∆ΙΑΜΕΤΕΡ ισ υσεδ το χαλχυλατε τηε λιθυιδ βαχκφλοω αρουνδ τηε πιγ. PIG (on Flowpath) Keys ( See also: Description ) Key Type Unit:( ) Real (m) Real (s) String Symbol Parameter set Default:[ ] Description Pig diameter NOTE! If no diameter is given, the diameter of the pig is set to the inner pipe diameter minus 4 times the wall roughness. This implies that leakage between the pig and the wall will occur Pig launch time. Pig label, default is pig number. Position for pig launch. The pig is launched downstream of the section boundary closest to the launch position. Pig leakage factor. Leakage factor at 0 corresponds to no fluid leaking past pig, and 1.0 corresponds to all fluid leaking past pig. When not given for the hydrate model, the program will calculate the leakage factor from the cross sectional area. Pressure loss coefficient measured by letting the fluid flow past a pig that is fixed to the pipe wall. Described in section 2.2.6 Leakage opening relative to pipe cross section area. Linear friction factor coefficient for fluid friction of fluid film between pig and pipe wall. Pig mass. Wax cutting efficiency, see eq. for breaking force in sec. 2.2.6. Only available with the wax module. Quadratic friction factor coefficient for fluid friction of fluid film between pig and pipe wall. Name of branches a pig passes from the launch position to trap position. This key is optional. If not given, a pig goes to the branch that has the highest volumetric flowrate out of the node the pig enters. When given, the launch branch name must be the first in the list. Force necessary to tear pig loose from the wall. When turned on the slug in front of the pig is generated and tracked, else no slug is set up in front of the pig. Activating this key requires access to the slugtracking module. Position for pig trap. The pig is trapped at the boundary closest to the trap position. Trap position is optional and if not given, the pig is removed when it exits through a terminal node. DIAMETER INSERTTIME LABEL LAUNCHPOSITION [PIG] LEAKAGEFACTOR Real (-) LEAKDPCOEF LEAKOPENING LINEARFRIC MASS PGWXFORMFAC QUADRATICFRIC Real Real (-) Real (Ns/m) Real (kg) Real (-) Real (Ns2/m2) [1E199] [0.0] [10] [140] [0.0] [0.0] ROUTING STATICFORCE TRACKSLUG SymbolList Real (N) Symbol [1000.0] ON | [OFF] TRAPPOSITION Symbol POSITION | WALLFRICTION WPPLASTVISC Real (Ns/m) Real (N-s/m2) [1000.0] [-1] WPPOROSITY Real (-) [-1] Factor for wall friction between pig and pipe. Plastic viscosity of wax plug in front of pig. The wax plug is assumed to exhibit Bingham fluid behavior. –1 implies using internal model for estimating the plastic viscosity. See 2.2.6 for further details. Only available with the wax module. Porosity of wax plug in front of pig. Used for wax plug friction calculation. Default value –1 implies that the porosity of the wax wall layer is used for the wax plug. A value = 1 implies that no wax plug friction will be applied. Yield stress of wax plug in front of pig. The wax plug is assumed to exhibit Bingham fluid behavior. –1 implies using internal model for estimating the yield stress. See 2.2.6 for further details. Only available with the wax module. Coefficient C in wax breaking force equation, see eq. in sec. 2.2.6. Only available with the wax module. Wax removal efficiency. Only available with the wax module. Yield stress of wax layer on the wall. –1 imples that the internal yieldstress correlation is used, see sec. 2.2.6. Only available with the wax module. WPYIELDSTRESS WXBRFCOEF WXRMEFF WXYIELDSTR Real (Pa) Real (-) Real (-) Real (Pa) [-1] [0.0] [1.0] [-1] Link to: PIG (on Flowpath) Description Keys SLUGILLEGAL (on Flowpath) Description ( See also: Keys) SLUGILLEGAL is part of the SLUGTRACKING keyword. Slugs are not allowed to be generated at illegal sections. A slug front or tail may propagate into an illegal section, but it will not propagate through it. The first and the last section in a pipeline are by definition illegal sections. This means that slugs do not propagate through a network. The user may add extra illegal section by using the SLUGILLEGAL keyword. This may speed up the simulation or make the simulation more robust. More info on when to use illegal sections can be found under SLUGTRACKING MODULE. SLUGILLEGAL (on Flowpath) Keys ( See also: Description ) Key Type Unit:( ) Parameter set Default:[ ] Description Specify whether or not slugs are allowed in sections defined by PIPE and SECTION. OFF: Slugs are allowed. Used for sections where illegal sections previously have been switched on. ON: Slugs are not allowed to be generated. Slugs generated elsewhere may move into the section, but are not allowed to pass through this section. The slugs will be destroyed when both the front and tail are within the section. Pipe numbers/pipe labels for illegal sections. Define the positions of illegal sections. If this option is used, sub-keys PIPE and SECTION should not be used. Section numbers for illegal sections. ILLEGALSECTION Symbol OFF | [ON] PIPE POSITION SECTION Symbol SymbolList IntegerList PIPE | Link to: SLUGILLEGAL (on Flowpath) Description Keys SLUGTRACKING (on Flowpath) Description ( See also: Keys) This statement defines the slug tracking option. This statement has two main sub-options for initiation of liquid slugs: the level slug option (LEVEL) and the hydrodynamic slug option (HYDRODYNAMIC). These two options may be used together or separately. Terrain slugging will be detected in ordinary simulations without the slug tracking module, and the interactions between terrain and hydrodynamic slugging can be investigated using the key HYDRODYNAMIC. The level slug option is mostly used for startup-slugs. If HYDRODYNAMIC = ON, the code will set up a new slug in a section whenever the set-up criteria are fulfilled. These are: (1) Flow regime at the section boundary changes from separated to slug flow. (2) Other slug fronts are the required distance away. (3) The time elapsed since the previous slug was generated in or passed this section is higher than a specified minimum time. If HYDRODYNAMIC = MANUAL, the user can specify a fixed number of slugs to be set up at predefined positions and times. Using this option, liquid will be injected into the pipeline to generate slugs of required size. Slugs are not allowed to be generated at the inlet and outlet sections by default. That is, the boundary sections are automatically set to illegal for slugs by the program itself. However, the slug front is allowed to move into the outlet section, and the slug tail into the inlet section. Users can specify the sections where slugs are not allowed to be generated by using SLUGILLEGAL keyword. The slug tracking option offers full temperature calculation capabilities. Remark: The availability of the slug tracking option depends on the user’s licensing agreement with SPT Group. To turn off slug-tracking in a restart there are two possibilities: (1) Set both LEVEL and HYDRODYNAMIC to OFF. Then the only slugs in the system will be the ones read from restart. (2) Remove SLUGTRACKING keyword. Average values will be used in the sections. No slugs in the simulation. More details can be found in the description of the slug tracking module. SLUGTRACKING (on Flowpath) Keys ( See also: Description ) Key BUBBLEVOID DELAYCONSTANT Type Unit:( ) Real (-) Real [150] Parameter set Default:[ ] Description Minimum void required behind a level tail and ahead of a level front at initiation time Number of pipe diameters a slug needs to propagate before the next hydrodynamic slug is initiated. ENDTIME GASENTRAINMENT HYDRODYNAMIC INITBUBBLEVOIDS INITENDTIMES INITFREQUENCY INITLENGTH INITPERIODS INITPOSITIONS INITSLUGVOIDS INITSTARTTIMES INITZONELENGTHS LEVEL MAXNOSLUGS SLUGVOID STARTTIME Real (s) Symbol Symbol RealList (-) RealList (s) Real (1/s) Real RealList (s) SymbolList RealList (-) RealList (s) RealList (m) Symbol Integer Real (-) Real (s) NYDAL | [VOIDINSLUG] ON | MANUAL | [OFF] [1] [0.0] End time for level slug initiation. If not given no end time restriction is enforced. Gas entrainment into slug from bubble for breaking/level front in slug tracking. NYDAL: Nydal correlation for entrainment. VOIDINSLUG: Entrainment based on correlation for void in slug. Option for initiating hydrodynamic slugs. Void fractions in the slug bubbles. End times for slug generation. The minimum distance between two consecutive slugs is defined as (bubble vel./INITFREQUENCY). Maximum initial length of hydrodynamic slugs in number of pipe diameters. Time interval between initiations of consecutive slugs. Labels of section boundaries where slug generation zones are located. Void fraction in the liquid slug. Start times for slug generation. The length of zones where slugs are to be generated. Option for detecting and initiating level slugs. Max number of slugs allowed in the system, if not given there are no restrictions. The maximum void allowed in a level slug at initiation time. Start time for level slug initiation. If not given, level detection is on from simulation start. ON | [OFF] Link to: SLUGTRACKING (on Flowpath) Description Keys TUNING (on Flowpath) Description ( See also: Keys) This statement defines the tuning option, witch makes it possible to tune certain parameters in the model. The parameters available for tuning are at the moment very limited. The TUNING keyword may be used for adjusting the OLGA model to specific sets of measured data or for sensitivity studies. TUNING should be applied with great care, as the validation and verification of the OLGA model may not be valid for such cases. TUNING (on Flowpath) Keys ( See also: Description ) Key ANGLEDIAMPOWER ANGLESCALE AREA CAPPOW DIAMETER DIAMPOWER ENTRAINMENT GASDENSITY GASVISC GROUGHNESS KTAHIGTFAC KTALOWTFAC KTGGRAVFAC KTGSMTHFAC KTGWAVYFAC LAM_LGI LAM_WOI LIQHCFAC MASSTRANSFER OILDENSITY OILVISC PIPE POSITION Type Unit:( ) RealList RealList RealList RealList RealList RealList RealList RealList RealList Real RealList RealList RealList RealList RealList RealList RealList RealList RealList RealList RealList SymbolList SymbolList Parameter set Default:[ ] [1.0] [0.0] [1.0] [0.5] [1.0] [1.0] [1.0] [1.0] [1.0] [1.0] [1.0] [1.0] [1.0] [1.0] [1.0] [1.0] [1.0] [1.0] [1.0] [1.0] [1.0] [ALL] Description Power of diameter scaling in inclination sensitive part of droplet entrainment function Scaling of inclination sensitive part in droplet entrainment function Tuning coefficient for AREA in PIPE (used for equivalent pipes). NOTE: Cannot be applied on individual sections. Pipe level and higher is allowed. Power of capillary number used in wavy turbulence parameter for gas Tuning coefficient for diameter. NOTE: Cannot be applied on individual sections. Pipe level and higher is allowed. Power of diameter scaling in constant part of droplet entrainment function Tuning coefficient for entrainment rate of liquid droplets in gas Tuning coefficient for gas density Tuning coefficient for gas viscosity Tuning coefficient for roughness from droplets. Scaling of turbulence parameter 2 for liquid Scaling of turbulence parameter 1 for liquid Scaling of gravity dominated turbulence parameter for gas Scaling of smooth turbulence parameter for gas Scaling of wavy turbulence parameter gas Tuning coefficient for interfacial friction factor between liquid and gas Tuning coefficient for interfacial friction factor between oil and water Tuning coefficient for liquid hydrocarbon fraction of total hydrocarbon mass (1Rsg)/(1-RsgRsw). This option will only work with non-compositional modules. Tuning coefficient for mass transfer between gas and oil. Tuning coefficient for oil density Tuning coefficient for oil viscosity Pipe numbers or labels where the tuning parameters will be applied. Positions where the tuning parameters will be applied. If this key is defined, PIPE and SECTION can not be used in the same keyword statement. Maximum of laminar and turbulent friction factor will be used for Reynold's number higher than REHIGH, and an interpolated value will be used for Re between RELOW and REHIGH. Can be applied on individual sections, pipes and branches. Laminar friction factor will be used for Reynold's number lower than RELOW, and an interpolated value will be used for Re between RELOW and REHIGH. Can be applied on individual sections, pipes and branches. Tuning coefficient for inner wall roughness. NOTE: Cannot be applied on individual sections. Pipe level and higher is allowed. Section or section boundary numbers where the tuning parameters will be applied. Tuning coefficient for gas/liquid surface tension Tuning coefficient for ambient temperature. Scaling of void fraction in oil film Scaling of void fraction in water film Tuning coefficient for water density Tuning coefficient for water viscosity Higher limit for Weber number when blending liquid turbulence parameters 1 and 2 REHIGH RealList [3000] RELOW ROUGHNESS SECTION SIGGL TAMBIENT VOIDINOIL VOIDINWATER WATERDENSITY WATERVISC WEMAX RealList RealList RealList RealList RealList RealList RealList RealList RealList RealList [2300] [1.0] [1.0] [1.0] [1.0] [1.0] [1.0] [1.0] [200.0] WEMIN WETFRACTION RealList RealList [100.0] [1.0] Lower limit for Weber number when blending liquid turbulence parameters 1 and 2 Scaling of fraction of wall wetted by droplets Link to: TUNING (on Flowpath) Description Keys WAXDEPOSITION (on Flowpath) Description ( See also: Keys) This group is used to define input parameters for the wax deposition module. Wax deposition is defined for all flow paths, that is, all flow paths must have assigned a wax table. If multiple wax tables are used in a network, the fluid properties must be generated in a specific manner. The derivative of wax porosity (if POROSITYOPTION=AGEING) is defined in this manner: (INITPOROSITY-HARDPOROSITY)/AGEINGTIME Full temperature calculation (OPTIONS TEMPERATURE = WALL) is necessary when simulating wax deposition. Remarks:The availability of the wax deposition option depends on the user's licensing agreement with SPT Group. The wax deposition module cannot be applied together with the slug tracking or corrosion modules. The wax file is generated in PVTsim. WAXDEPOSITION (on Flowpath) Keys ( See also: Description ) Key Type Unit:( ) Parameter set Default:[ ] Description Options for treatment of porosity of deposited wax as function of time. If CONSTANT, no aging mechanism is activated. The porosity will either be directly given by WAXPOROSITY or an average value calculated by OLGA . If AGEING, INITPOROSITY, HARDPOROSITY and AGEINGTIME will be used to find change in porosity with time. New deposits will still have the porosity according to WAXPOROSITY settings. If INITPOROSITY is to be used as porosity values of new deposits, WAXPOROSITY must be set to the same values. Time for reduction of porosity from INITPOROSITY to HARDPOROSITY. Used to describe change in porosity with time due to aging. Shear deposition rate constant for deposition of precipitated wax. Pure paraffin wax thermal conductivity. Branch-wise input. Currently not available. Options for pure wax thermal conductivity. TABLE: The wax conductivity is taken from the wax tables. MANUAL: The conductivity is given through the key CONDUCTIVITY. Currently not available. Linear multiplier for modification of the component specific diffusion coefficients given in the wax-table. Pressures at which the values of DISSOLTDIFF apply. The melting/dissolve table (defined by DISSOLRATE, DISSOLTDIFF and DISSOLPRESS) will apply to all branches referred to in the BRANCH list. If different tables are wanted, separate WAXDEPOSITON statements must be given for each branch. Linear interpolation between table values. NOTE! Works only for MODEL=RRR. Maximum melting/diffusion rate. Applied for all branches given in keyword. Works only for MODEL=RRR. Difference between dissolution temperature and wax appearance temperature as function of pressure. The melting/dissolve table (defined by DISSOLRATE, DISSOLTDIFF and DISSOLPRESS) will apply to all branches referred to in the BRANCH list. If different tables are wanted, separate WAXDEPOSITON statements must be given for each branch. Linear interpolation between table values. Works only for MODEL=RRR. Switch for turning on/off dissolution. Only applicable with RRR model. Lower value of porosity after the given ageing period through AGEINGTIME. Has the following purposes: 1. To calculate change in porosity with time due to ageing. 2. Giving lower limit for porosity in the case of ageing when INSTPOROSITYOPT = MANUAL. When INSTPOROSITYOPT = AUTOMATIC, the lower limit for the porosity is given by MINPOROSITY, and HARDPOROSITY is only used for calculating the porosity change rate. HARDPOROSITY must be equal to or larger than MINPOROSITY. Initial porosity of deposited wax, used only for describing change in porosity with time due to ageing. Options for calculating instantaneous porosity of deposited wax. MANUAL: A constant value is used, given by WAXPOROSITY. AUTOMATIC: The porosity will be calculated by the internal flow dependent model. The keys MINPOROSITY and MAXPOROSITY are used to determine the minimum and maximum limits for the porosity. The wax porosity may be changing with changing flow conditions, and the average porosity seen at a given point may be different from the instantaneous porosity given by the internal porosity model. The maximum limit for the calculated porosity is given by this key. Used when INSTPOROSITYOPT=AUTOMATIC. The porosity of new deposits is calculated by OLGA and an volume averaging of the porosity of new and old layers will be performed. Maximum wax layer roughness allowed. The minimum limit for the calculated porosity is given by this key. Used when INSTPOROSITYOPT=AUTOMATIC. The porosity of new deposits is calculated by OLGA and an volume averaging of the porosity of new and old layers will be performed. Wax deposition model. Tuning multiplier for empirical constant C2 in MATZAIN wax deposition model. Tuning multiplier for empirical constant C3 in MATZAIN wax deposition model. AGEINGOPT Symbol AGEING | [CONSTANT] AGEINGTIME COEFSHEAR CONDUCTIVITY CONDUCTOPT DIFFCOEFFMULT RealList (d) RealList (kg/m2) RealList (W/m-K) Symbol RealList [7] [0.0] [0.242] TABLE | [MANUAL] [1.0] DISSOLPRESS RealList (Pa) DISSOLRATE RealList (kg/s-m2) [1.e+12] DISSOLTDIFF RealList (C) [0.0] DISSOLUTION Symbol ON | [OFF] HARDPOROSITY RealList (-) [0.2] INITPOROSITY RealList (-) [0.8] INSTPOROSITYOPT Symbol MANUAL | [AUTOMATIC] MAXPOROSITY MAXROUGHNESS MINPOROSITY RealList (-) RealList (m) RealList (-) [0.8] [1.0E6] [0.2] MATZAIN | HEATANALOGY | [RRR] [1.0] [1.0] MODEL SHEARMULTC2 SHEARMULTC3 Symbol Real Real e. Use the PHASE key to refer directly to a UDPHASE defined in the Library section of the input. Giving more than one value. WAXPOROSITY WAXROUGHNESS WAXTABLE RealList (-) RealList (-) SymbolList [0. mass sources and for nodes with pressure boundary condition. Volume fractions of precipitated wax dispersed in oil corresponding to the viscosity multiplier values given in VISMULTIPLIER. UDGroup Keys ( See also: Description ) Key LABEL Type Unit:( ) String Parameter set Default:[ ] Description Network component label (if nothing is given the NC tag is used). Linear interpolation between table values. this input group defines how the defined dispersions are to enter the pre-defined phases in initial conditions. oil. If these are also specified in the wax-table (see userguide). while all may be used for the initial conditions. water).0] VISCMULTE Real [1.0] VISCMULTF Real [1.6] [0. NOTE: For initial conditions giving the user defined phase mass fractions in a bed/wall. Limited by MAXROUGHNESS. Currently not available. If these are also specified in the wax-table (see userguide). oil. bed and wall). separate WAXDEPOSITON statements must be given for each branch. user-specified values for the multiplier will override those in the wax-table file. Ratio of viscosity of wax/oil dispersion to oil viscosity. or 2. Linear interpolation between table values. If these are also specified in the wax-table (see userguide). Fraction of wax layer thickness that is interpreted as wax layer roughness (i. Name of wax table. Currently not available.VISCMULTD Real [1.0] WAXVOLFRACTION RealList (-) Link to: WAXDEPOSITION (on Flowpath) Description Keys UDGroup Description ( See also: Keys) Located under the GroupData section. UDGROUP can be referred to by SOURCE. Corresponding to the wax volume fractions given in WAXVOLFRACTION. water. CALSEP: Use internal model. UDFRACTIONMASSFRACTION defines the mass fraction of the dispersion relative to the total mass of the corresponding carrying layer. If different tables are wanted. Tuning multiplier for the “E” parameter in the internal non-newtonian viscosity correlation. Only used when VISCOPTION = CALSEP. Porosity of new deposits in wax layer. Tuning multiplier for the “F” parameter in the internal non-newtonian viscosity correlation. Link to: UDGroup Description Keys UDFRACTION (on UDGroup) Description ( See also: Keys) UDFRACTION specifying the mass fraction of a given user defined phase in a given layer (gas. user-specified values for the multiplier will override those in the wax-table file. The SOURCE and the NODE use the fractions in the three flowing layers (gas. INITIALCONDITIONS and NODE. If different tables are wanted. bed and wall) within a UDGROUP. The distribution is defined together phase properties on the library input UDPHASE or UDDISPERSION. The viscosity multiplier table (defined by VISMULTIPLIER and WAXVOLFRACTION) will apply to all branches referred to in the BRANCH list.0] VISCOPTION Symbol [CALSEP] VISMULTIPLIER RealList (-) Tuning multiplier for the “D” parameter in the internal non-newtonian viscosity correlation. the UDGROUP referenced must have MASSFRACTION > 0 for LAYER = BED/WALL. UDFRACTION (on UDGroup) Keys ( See also: Description ) Key DISPERSION Type Unit:( ) Symbol Parameter set Default:[ ] UDDISPERSION | Description User Defined (UD) dispersions that will mix with the predefined phase(s) . Only used when VISCOPTION = CALSEP. Option for calculating the wax/oil dispersion viscosity TABULAR: Currently not available. each specifying the mass fraction of a given user defined phase in a given layer (gas. it must be implemented in a plug-in dll. user-specified values for the multiplier will override those in the wax-table file. Used when INSTPOROSITYOPT=MANUAL. The value between the given time points is determined through interpolation. the input is interpreted as a time series and the number of values should correspond to the time points given under UDFRACTION TIME. oil. If a different distribution than LogNormal is to be used. UDFRACTION PDF is used to select the momentums/paramaters to be used for the size distribution. separate WAXDEPOSITON statements must be given for each branch. VISCOPTION must be selected for the whole system of branches. The viscosity multiplier table (defined by VISMULTIPLIER and WAXVOLFRACTION) will apply to all branches referred to in the BRANCH list. The dispersed phase to be tracked in this carrying phase can be referred to in two ways: 1. The UDGROUP is composed by a set of UDFRACTIONs. wall roughness). Use the DISPERSION key to refer to a UDDISPERSION defined in the Library section of the input. Only used when VISCOPTION = CALSEP. Each unique combination should be defined as a separate UDGROUP. water. volumetric inlet flow given for two different speeds Two applications are intended: Singel phase mode . oil. Linear interpolation is used for list of values. volumetric inlet flow (Figur 1) and pump efficiency vs. [0] [PUMPCURVE] Link to: CENTPUMPCURVE (on Library) Description Keys DRILLINGFLUID (on Library) . head generated by pump vs. Link to: UDFRACTION (on UDGroup) Description Keys CENTPUMPCURVE (on Library) Description ( See also: Keys) The centrifugal pump curve take data commonly available in centrifugal pump data sheets. Ex. volumetric inlet flow (Figur 2). Volumetric flow rate through pump. Linear interpolation is used for list of values. Inlet density.Create one CENTPUMPCURVE per inlet gas volumetric fraction The CENTPUMPCURVES should be used with the centrifugal pump. Pump efficiency. Linear interpolation is used for list of values. Pump shaft power. Pump head.LAYER MASSFRACTION PDF PHASE TIME Symbol RealList (-) Symbol Symbol RealList (s) <None> | GAS | OIL | WATER | BED | WALL | UDPDF | UDPHASE | The layer the User Defined (UD) phase/dispersion will flow in (gas. Linear interpolation is used for list of values. water) or be deposited in (bed.Create one CENTPUMPCURVE per pump speed Two phase mode . Pump speed. wall) Mass fraction in layer Mass based particle distribution function User Defined (UD) phases that will mix with the predifined phase(s) The time points for the mass fractions. Pump torque. volumetric inlet flow given for two different speeds Figure 2: Pump efficiency vs. Centrifugal pump curve label. Inlet gas volumetric fraction. Linear interpolation is used for list of values. CENTPUMPCURVE (on Library) Keys ( See also: Description ) Key DELTAP DENSITY EFFICIENCY GVF HEAD LABEL POWER SPEED TORQUE VOLUMEFLOW Type Unit:( ) RealList (Pa) Real (kg/m3) RealList (-) Real (-) RealList (m) String RealList (kW) RealList (rpm) RealList (Nm) RealList (m3/h) Parameter set Default:[ ] Description Pump differential pressure. Linear interpolation is used for list of values. Linear interpolation is used for list of values. Figure 1: Head generated by pump vs. The inhibitor component must be defined in the feed file. The label of this hydrate curve. By default the first column is for temperature and the second for pressures. the power law exponent or yield stress is read when the heading contains the strings "POWEXPW" or "YIELDSTRW" respectively. the power law exponent or yield stress is read when the heading contains the strings "POWEXPL" or "YIELDSTRL" respectively. They do not replace any of the phases. Hydrate formation pressure for each given temperature point.0] PVTData | [DRILLINGFLUID] Description Density of cutting particles. Temperature points defining the hydrate curve. DEG and TEG. For water-based mud. DRILLINGFLUID (on Library) Keys ( See also: Description ) Key CUTDENSITY FLUIDTABLE LABEL MAXDENSITY MAXVISCOSITY MINDENSITY MINVISCOSITY TYPE VISCOSITYBCONST VISCOSITYCCONST Type Unit:( ) Real (kg/m3) Symbol String Real (kg/m3) Real (N-s/m2) Real (kg/m3) Real (N-s/m2) Symbol Real Real WATERMUD | OILMUD | GASMUD | Parameter set Default:[ ] [2100. For oil-based mud. The minimum density of the drilling fluid to be used in the entire drilling process. Drilling fluid label. The inhibitor component to use with the hydrate curve. The viscosity must be given at standard conditions. Get the fluid properties for the drilling fluid from a separate fluid property file. the Young's modulus of elasticity (EMOD) can be used by OLGA to compute the flexibility of the pipe WALL. pipeline coating. The following types are allowed: WATER. Label or number of fluid table in PVT file. The temperature points have to be unique and entered in increasing order. Must be specified when FROMFILE=YES. They are treated as extra fluids and are tracked through the pipeline. and GAS. This keyword requires access to the Wells Module. see (Complex Fluid Module). 2. The pressure points have be unique and entered in increasing order. The densisty must be given at standard conditions. The density and viscosity used at the inlet is given in SOURCE or NODE. See also: HYDRATECHECK HYDRATECURVE (on Library) Keys ( See also: Description ) Key Type Unit:( ) SymbolList (ValueUnitPair) Symbol String Real (-) Symbol String RealList (Pa) RealList (C) [0] InhibitorCompData | [HYD] Parameter set Default:[ ] TEMPERATURE | PRESSURE | YES | [NO] Description Units and orders of columns of the temperature and pressure in the HYDRATEFILE.Description ( See also: Keys) This statement enables the use of drilling fluids. Inhibitor concentration (in weight percent) for a hydrate curve (default = 0). visc = visc0*exp(B/(T+C)) where visc0 is given in SOURCE and/or NODE. The fluid property file must then have an appropriate string in the header of the file: string "GASMUD" if gas phase is used as drilling fluid string "OILMUD” if oil phase is used as drilling fluid string "WATERMUD" if water phase is used as drilling fluid Non-Newtonian rheology is applied if the PVT table contains the rheology parameters yield stress or power law exponent. visc = visc0*exp(B/(T+C)) where visc0 is given in SOURCE and/or NODE. COLUMNHEADER FROMFILE HYDRATEFILE INHIBCONC INHIBITOR LABEL PRESSURE TEMPERATURE Link to: HYDRATECURVE (on Library) Description Keys MATERIAL (on Library) Description ( See also: Keys) This statement specifies physical properties of the materials associated with WALLS (pipe wall. NO: The hydrate curve is specified using the keys PRESSURE and TEMPERATURE. YES: The hydrate dissociation curve is to be read from a data file. For both types of mud the power law exponent and/or the yield stress should then be given in the file as a function of pressure and temperature. When the elastic wall option is used. Link to: DRILLINGFLUID (on Library) Description Keys HYDRATECURVE (on Library) Description ( See also: Keys) This keyword defines a hydrate formation curve to be used with the HYDRATECHECK keyword. The fluid properties of a drilling fluid can be given in two different ways: 1. The nonNewtonian models Bingham and Power law are used to modify the viscosity of the drilling fluid as for the complex viscosity option. The name of the file containing hydrate temperature as a function of pressure or vice versa. Define the range of density and viscosity at standard conditions for a drilling fluid. possible selections are: EtOH. MeOH. The density must be given at standard conditions. The maximum density of the drilling fluid to be used in the entire drilling process. C constant in the Vogel viscosity model for water based muds. A combination of 1) and 2) can not be used in the same case. The maximum viscosity of the drilling fluid to be used in the entire drilling process. Global value that only should be set once. For Compositional Tracking only. The main purpose of the material is to define the heat transfer properties in thermal computations. The minimum viscosity of the drilling fluid to be used in the entire drilling process. MEG. . Type of drilling fluid. The viscosity must be given at standard conditions. B constant in the Vogel viscosity model for water based muds. insulation and soil) and SHAPES (FEMTherm). OIL. If the fluid is a gas at low pressure (< 100 bar) natural convection will have less influence on the heat transfer rate and radiation will become important as well. By choosing TYPE = FLUID. Between temperature points. The viscosity and expansion coefficient of the fluid must then be given. Emissivity of outer surface of fluid layer. then AINJ = 0. You may either specify the coefficients used in the inflow correlations directly. Thermal conductivity of the material. while the heat capacity is set to FUSIONMULT*CAPACITY. the conductivity is linearly interpolated. SOLID: Normal wall layer material. Material label. Heat capacity multiplier between PHCHMIN and PHCHMAX used to model latent heat of fusion. Between PHCMIN and PHCMAX. Yes: Radiation across fluid layer.0 [kg/s] BINJ = 0. This is the default model in OLGA. will generate ether one well or a number of wells with the same reservoir characteristics.1e11 Pa). TYPE = FLUID: If a fluid is enclosed between two concentric cylinders. When this model is chosen. If FUSIONMULT is 0. Conductivity multiplier below PHCHMIN. TYPE = TEMPDEPENDENT: This is a generic. (High emissivity means low reflectivity). the multiplier is linearly interpolated from CONDMULT to 1. Material density. it is important to capture the effect of both temperature dependent material properties as well as the latent heat of fusion. FLUID: Stagnant fluid material. the well/reservoir variables are translated into the coefficients used in the inflow correlations. When the temperature is below PHCHMIN. For the inertial terms. Used to compute the radial flexibility of the pipe (typical value for steel: 2. Upper temperature limit for phase change region Lower temperature limit for phase change region NO: No radiation across fluid layer. the conductivity used is CONDMULT*CONDUCTIVITY and the heat capacity is set to HCAPMULT*CAPACITY. The heat transfer rate due to radiation is negligible if one or both of the emissivities are small. the CONDUCTIVITY.3354E08 [Pa2-s2/kg2] else if INJOPTION = TABULAR. Observe that the linear coefficient BPROD can not be zero if the well is located in the first (inlet) section of a flow path. the heat capacity multiplier is linearly interpolated from HCAPMULT to 1 between PHCMIN and PHCMAX. This option is only available with the Wells Module. Heat capacity multiplier below PHCHMIN Emissivity of inner surface of fluid layer. Radiation is included in heat transfer calculation by setting RADIATION = YES. Stefan-Boltzmann's law for long concentric cylinders is used to calculate the heat transfer rate. MATERIAL (on Library) Keys ( See also: Description ) Key CAPACITY CONDMULT CONDUCTIVITY DENSITY EMOD EXPANSION FUSIONMULT HCAPMULT INNEREMISSIVITY LABEL OUTEREMISSIVITY PHCHMAX PHCHMIN RADIATION TEMPERATURE Type Unit:( ) RealList (J/kgC) Real RealList (W/mC) RealList (kg/m3) Real (Pa) Real (1/C) Real Real Real String Real Real (C) Real (C) Symbol RealList (C) <None> | FLUID | PCM | TEMPDEPENDENT | [SOLID] [0] [MAT] [0] Parameter set Default:[ ] Description Thermal capacity of the material. This model is designed to provide a simplified input option for this type of simulations.0] end end if GASFRACTION = -1 If INJOPTION = LINEAR.1E-5 [kg/s/Pa] else if INJOPTION = QUADRATIC. where each entry corresponds to a temperature point in the key TEMPERATURE. temperature dependent model. CAPACITY and DENSITY can be given as lists. natural convection will be significant for the heat transfer rate. This model is only valid in WALLS. The equations solved are that of heat transfer in solid medium. Expansion coefficient of fluid layer.0 [Pa2-s/kg] CINJ = 0. the conductivity is linearly interpolated between CONDMULT*CONDUCTIVITY and CONDUCTIVITY. then AINJ = 0. or you may specify traditional well/reservoir variables like permeability and net pay. then INJTABLE = TABLE-1 end if . the product of the heat capacity and density is linearly interpolated. Used only if TYPE = TEMPDEPENDENT Type of wall material. CONDUCTIVITY and DENSITY.0 [Pa2] BINJ = 0.0] or TOTALWATERFRACTION = [0. TEMPDEPENDENT: Temperature dependent solid material (heat transfer properties tabulated as a function of TEMPERATURE). Using the RESERVOIRINFLOW keyword together with the ZONE keyword on flowpath. When you use the latter. OLGA will also include the effect of natural convection. Temperature points for interpolating CAPACITY. Young's modulus of elasticity. CONDUCTIVITY and CAPACITY is used directly. Internal dependencies of keys: ! Alphanumeric values are only ! given as samples If you want to use the coefficients directly for standard inflow types: either WATERFRACTION = [0. In this region. INNEREMISSIVITY and OUTEREMISSIVITY must then be specified. This keyword is very similar to the WELL keyword on flowpath. There are two ways of specifying the data for flow between the reservoir and the well. TYPE = PCM: In situations with freezing/thawing materials. PCM: Phase changing material. The phase change is assumed to occur when the temperature is in the region PHCHMIN < T < PHCHMAX and the latent heat of fusion is accounted for with the heat capacity multiplier FUSIONMULT. Above PHCHMAX. Dynamic viscosity of fluid material YES | [NO] TYPE VISCOSITY Symbol Real (N-s/m2) Link to: MATERIAL (on Library) Description Keys RESERVOIRINFLOW (on Library) Description ( See also: Keys) The RESERVOIRINFLOW keyword is used to define required data for calculating the flow performance of wells.OLGA has four types of material models for heat transfer computations: TYPE = SOLID: A simple model with constant thermal properties. then BINJ = 1.01 else if INJOPTION = VOGELS.4 KPERM = 20 mD HPAY = 20 [m] RESEXT = 1000 [m] HOLES = 8. then either INJECTIVITY = 240 stb/d/Psi FRACPR = 1000 bar ROGST = 0. then FRACPR = 1000 bara ROGST = 0. then BINJ = 0.0] [m] GASPLIMIT = [RESPRESSURE] [Pa] GFRTC = [0.E-4 [psi-d/scf] CINJ = 1. then FRACPR = 1000 bara ROGST = 0.E-4 [psi-d/scf] CPROD = 1.8 [kg/Sm3] ROLST = 700 [kg/Sm3] GORST = 1000 [Sm3/Sm3] VISLRES = 0.5 in SKINS = 3 SKIND = 0.3354E08 [Pa2-s2/kg2] else if PRODOPTION = TABULAR. then APROD = 0.E-9 [psi2-d2/scf2] else if PRODOPTION = SINGLEFORCHHEIMER.8 [kg/Sm3] ROLST = 700 [kg/Sm3] GORST = 1000 [Sm3/Sm3] VISGRES = 0. then BPROD = 1. then EXPONENTN = 1 CPROD = 1 [scf/d/psi2] end if If you want to use well/reservoir variables: WATERCUT = [0.8 [kg/Sm3] ROLST = 700 [kg/Sm3] .1E-5 [kg/s/Pa] else if PRODOPTION = QUADRATIC. then EXPONENTN = 1 CINJ = 1 [scf/d/psi2] end if if PRODOPTION = FORCHHEIMER.0 [Pa2-s/kg] CPROD = 0.0] [m] OILPLIMIT = [RESPRESSURE] [Pa] OFRTC = [0.0 [kg/s] BPROD = 0.0] [-] ROGST = [from PVT tables] [kg/Sm3] ROLST = [from PVT tables] [kg/Sm3] GORST = [from PVT tables] [kg/Sm3] if INJOPTION = FORCHHEIMER.2 cP BOOIL = 1.03 cP ZFACT = 1 KPERM = 20 mD HPAY = 20 [m] RESEXT = 1000 [m] HOLES = 8.5 in SKINS = 3 SKIND = 0.6 [psi2-d/scf] CINJ = 1.0] [s] end if end if If you want to use the coefficients directly for Advanced Well inflow types: WATERCUT = [0.0 [Pa2] BPROD = 0.01 else if INJOPTION = SINGLEFORCHHEIMER.0] [s] WATDIS = [0.0] [-] If INJOPTION = LINEAR. then PRODTABLE = TABLE-2 If phase front transient is to be simulated. then FRACPR = 1000 bara ROGST = 0.0] [m] WATPLIMIT = [RESPRESSURE] [Pa] WFRTC = [0.E-9 [psi-d2/scf2] else if INJOPTION = BACKPRESSURE.E-9 [psi-d2/scf2] else if PRODOPTION = BACKPRESSURE.If PRODOPTION = LINEAR.6 [psi2-d/scf] CPROD = 1.5 in SKINS = 3 end else if INJOPTION = FORCHHEIMER. then GASDIS = [0.0] [s] OILDIS = [0.8 [kg/Sm3] ROLST = 700 [kg/Sm3] GORST = 1000 [Sm3/Sm3] VISGRES = 0. then APROD = 0.8 [kg/Sm3] ROLST = 700 [kg/Sm3] GORST = 1000 [Sm3/Sm3] PHASE = [OIL] or FRACPR = 1000 bar ROGST = 0.03 cP ZFACT = 1 KPERM = 20 mD HPAY = 20 [m] RESEXT = 1000 [m] HOLES = 8. then BPROD = 0.E-9 [psi2-d2/scf2] else if INJOPTION = SINGLEFORCHHEIMER. 4 KPERM = 20 mD HPAY = 20 [m] RESEXT = 1000 [m] HOLES = 8.8 [kg/Sm3] ROLST = 700 [kg/Sm3] GORST = 1000 [Sm3/Sm3] VISGRES = 0.03 cP ZFACT = 1 KPERM = 20 mD HPAY = 20 [m] RESEXT = 1000 [m] . then either PRODI = 240 stb/d/Psi FRACPR = 1000 bara ROGST = 0. then FRACPR = 1000 bara ROGST = 0.5 in SKINS = 3 SKIND = 0. then FRACPR = 1000 bara ROGST = 0.01 else if PRODOPTION = SINGLEFORCHHEIMER.5 in SKINS = 3 BPPRESSURE = 600 bar end if If the user wants to define a specific linear injectivity index for one or more of the phases GASINJ = 100 stb/d/Psi OILINJ = 100 stb/d/Psi WATINJ = 180 stb/d/Psi end if If PRODOPTION = LINEAR.2 cP BOOIL = 1.03 cP ZFACT = 1 KPERM = 20 mD HPAY = 20 [m] RESEXT = 1000 [m] HOLES = 8.8 [kg/Sm3] ROLST = 700 [kg/Sm3] GORST = 1000 [Sm3/Sm3] VISGRES = 0.8 [kg/Sm3] ROLST = 700 [kg/Sm3] GORST = 1000 [Sm3/Sm3] QMAX = 10 000 Sm3/d EXPONENTN = 1 PHASE = [OIL] else if INJOPTION = UNDERSATURATED.GORST = 1000 [Sm3/Sm3] QMAX = 10 000 Sm3/d else if INJOPTION = BACKPRESSURE. then FRACPR = 1000 bara ROGST = 0.8 [kg/Sm3] ROLST = 700 [kg/Sm3] GORST = 1000 [Sm3/Sm3] QMAX = 10 000 Sm3/d else if PRODOPTION = BACKPRESSURE. then FRACPR = 1000 bara ROGST = 0.03 cP ZFACT = 1 KPERM = 20 mD HPAY = 20 [m] RESEXT = 1000 [m] HOLES = 8.8 [kg/Sm3] ROLST = 700 [kg/Sm3] GORST = 1000 [Sm3/Sm3] VISLRES = 0.2 cP BOOIL = 1.5 in SKINS = 3 SKIND = 0.03 cP ZFACT = 1 KPERM = 20 mD HPAY = 20 [m] RESEXT = 1000 [m] HOLES = 8.8 [kg/Sm3] ROLST = 700 [kg/Sm3] GORST = 1000 [Sm3/Sm3] VISGRES = 0.4 KPERM = 20 mD HPAY = 20 [m] RESEXT = 1000 [m] HOLES = 8.8 [kg/Sm3] ROLST = 700 [kg/Sm3] GORST = 1000 [Sm3/Sm3] VISGRES = 0.01 EXPONENTN = 1 else if INJOPTION = NORMALIZEDBACKPR.8 [kg/Sm3] ROLST = 700 [kg/Sm3] GORST = 1000 [Sm3/Sm3] PHASE = [OIL] or FRACPR = 1000 bara ROGST = 0. then FRACPR = 1000 bara ROGST = 0.5 in SKINS = 3 end else if PRODOPTION = FORCHHEIMER.5 in SKINS = 3 SKIND = 0.8 [kg/Sm3] ROLST = 700 [kg/Sm3] GORST = 1000 [Sm3/Sm3] VISLRES = 0.01 else if PRODOPTION = VOGELS. then FRACPR = 1000 bara ROGST = 0. then FRACPR = 1000 bara ROGST = 0. Note that this key can only be specified branchwise. Gas mass fraction in the gas+oil mixture for positive flow. Unit: kg/s for the linear formula.uses gas mass fraction from the PVT table to calculate the split between the phases. then FRACPR = 1000 bara ROGST = 0. Volume fraction of each feed given in FEEDNAME (only for blackoil model). 0. 5) h FEEDNAME = (BO-1. Mole fraction of each feed. [-1. Given at in situ conditions . Negative coefficient C in well flow equation.8 [kg/Sm3] ROLST = 700 [kg/Sm3] GORST = 1000 [Sm3/Sm3] VISLRES = 0.8 [kg/Sm3] ROLST = 700 [kg/Sm3] GORST = 1000 [Sm3/Sm3] QMAX = 10 000 Sm3/d EXPONENTN = 1 PHASE = [OIL] else if PRODOPTION = UNDERSATURATED.4 KPERM = 20 mD HPAY = 20 [m] RESEXT = 1000 [m] HOLES = 8.uses gas mass fraction from the PVT table to calculate the split between the phases. It normally varies between 0.5. Unit: kg/s/Pa for the linear formula.3. then (multiple time and feeds.2 cP BOOIL = 1. A list means mixing of feeds for each section in the branch. Fracture pressure. psi2-d/scf for Forchheimer.uses gas mass fraction from the PVT table to calculate the split between the phases. Label of initial feed to be used for calculating local fluid compositions in the branch (from feed file and FEED keyword).6. 0. Oil formation volume factor Bubble point pressure at reservoir temperature for Undersaturated oil wells. Positive coefficient A in well flow equation. Given at in situ conditions . A list of both positive and negative values is not allowed. Pa2-s/kg for the non-linear formula.0] [-1. psi2-d/scf for Forchheimer. CGR from the PVT table is used. FEED-3) either FEEDMASSFRACTION = (0.5 in SKINS = 3 SKIND = 0. FEEDMASSFRACTION = FEED-1 (T1). Injectivity index for linear inflow equation. psi2-d2/scf2 for Single Forchheimer. Mass fraction of each feed. Constant in Backpressure inflow equation. psi2-d2/scf2 for Forchheimer. then FRACPR = 1000 bara ROGST = 0.0] Condensate-gas ratio.HOLES = 8. Positive coefficient B in well flow equation.0. FEED-2(T2)) RESERVOIRINFLOW (on Library) Keys ( See also: Description ) Key Type Unit:( ) Parameter set Default:[ ] Description Negative coefficient A in well flow equation. Pressure at which the gas front will be at the well bore at steady-state conditions. Normally given in (Sm3/d/bar).5 in SKINS = 3 BPPRESSURE = 600 bar end if If COMPOSITIONAL = ON in OPTION. psi-d/scf for Single Forchheimer.7. 0. 0. scf/d/psi2n for Backpressure.0. then TIME = (0. FEEDMOLEFRACTION and FEEDVOLFRACTION. Unit: kg/s/Pa for the linear formula.0] FEEDNAME SymbolList FEEDVOLFRACTION FRACPR GASDIS GASFRACTION GASINJ GASPLIMIT RealList (-) RealList (Pa) Real (m) RealList (-) RealList (Sm3/s/Pa) Real (Pa) [0. Pa2 for the non-linear formula. Less than zero if a minimum pressure difference is required for fluid flow from reservoir into well. AINJ RealList APROD RealList BINJ RealList BOOIL BPPRESSURE Real RealList (Pa) BPROD RealList CGR CINJ RealList (Sm3/Sm3) RealList CPROD EXPONENTN FEEDMASSFRACTION FEEDMOLEFRACTION RealList RealList RealList (-) RealList (-) [1. Distance gas front has to travel before it reaches the well bore. BO-2) FEEDVOLFRACTION = [1. 5) h FEEDNAME = (FEED-1.7. By default. Requires PRODOPTION=TABULAR. Pa2-s/kg for the non-linear formula.uses gas mass fraction from the PVT table to calculate the split between the phases. Unit: Pa2-s2/kg2 for the nonlinear formula. FEED-2(T1).5] endif Note: For the subkeys FEEDMASSFRACTION. Unit: kg/s for the linear formula.3) or FEEDMOLEFRACTION = (0. Negative coefficient B in well flow equation. psi-d/scf for Single Forchheimer. Linear injectivity index for gas entering the well section.0. Positive coefficient C in well flow equation.5 and 1. psi2-d2/scf2 for Single Forchheimer. Given at in situ conditions . 0. scf/d/psi2n for Backpressure. 0.5. 0.01 EXPONENTN = 1 else if PRODOPTION = NORMALIZEDBACKPR. the array is a function of both feed and time as shown below. 0. see note below) TIME = (0. 0. Pa2 for the non-linear formula. Given at in situ conditions .4. Less than zero if a minimum pressure difference is required for fluid flow from well into reservoir.5) end or if COMPOSITIONAL = BLACKOIL in OPTIONS. Unit: Pa2-s2/kg2 for the non-linear formula. FEED1(T2). Productivity index for linear inflow equation. Requires COMPOSITIONAL=ON or BLACKOIL under the OPTIONS keyword.0] . Requires PRODOPTION=TABULAR. psi2-d2/scf2 for Forchheimer. -1 indicates equilibrium. With a value of -1. Fraction of total mass of H2O component in the gas phase. Requires PRODOPTION=TABULAR. GOR from the PVT table is used. With a value of –1. otherwise. Normally given in inches (in). For outflow. the total water fraction is taken from the fluid table. Gas density at standard conditions. Either this key or TOTALWATERFRACTION can be specified. Requires PRODOPTION=TABULAR. Turbulent non-darcy skin.0] . Used when the well parameters are given for conditions after the reservoir is fractured. Maximum flow in Vogels and Normalized Backpressure inflow equation.0] [-1] [-1] WATERCUT WATERFRACTION WATINJ WATPLIMIT RealList (-) RealList (-) RealList (Sm3/s/Pa) Real (Pa) [-1. INJOPTION Symbol Negative well flow equation type. Distance oil front has to travel before it reaches the well bore. Reservoir extension.0] WFRTC WGR Real (s) RealList (Sm3/Sm3) [-1. Watercut at standard conditions. this key is ignored if GASFRACTION<0 (the water fraction in the source section is used). By default value from PVT table is used. Requires PRODOPTION=TABULAR. By default. By default value from PVT table is used. Viscosity of oil reservoir conditions. A list of both positive and negative values is not allowed. 1 means that the amount of wax forming components is equal to the values from the wax table. Time constant for the water front movement. By default value from PVT table is used. the mass of H2O component is in the gas phase if the temperature is greater than the saturation temperature. the mass of H2O component is distributed between the gas phase and the water phase according to the vapor pressure of H2O in the gas phase. This key can only be used if water option is available. Viscosity of gas reservoir conditions.0] TIME RealList (s) [0. Note that the value actually used by the program is interpolated between the values specified by the time table. Given at std conditions . Water-gas ratio. Pressure at which the water front will be at the well bore at steady-state conditions. Requires PRODOPTION=TABULAR. Reservoir inflow label Time constant for the oil front movement. Given at std conditions .uses GOR from the PVT table (or the specified GORST) and the PHASE to calculate the split between the phases. The value must be in the range [0. Productivity index for linear inflow equation. Injectivity.0] [1. Pressure at which the oil front will be at the well bore at steady-state conditions. Requires WAXDEPOSITION=ON under the OPTIONS keyword and access to the wax deposition module. Time series when the reservoir conditions are to be changed. Table reference for positive flow performance. Normally given in (Sm3/d/bar). Turn on or off isothermal. Gas/oil volumetric ratio. Requires PRODOPTION=TABULAR.GFRTC GORST HOLES HPAY INJECTIVITY Real (s) RealList (Sm3/Sm3) RealList (m) RealList (m) RealList (Sm3/s/Pa) LINEAR | QUADRATIC | SINGLEFORCHHEIMER | FORCHHEIMER | BACKPRESSURE | UNDERSATURATED | VOGELS | TABULAR | NORMALIZEDBACKPR | [1.0] [-1. Mass fraction of total water in the in the total fluid mixture of the reservoir.0 the total water fraction is taken from the fluid table. If BH pressure has been above fracture pressure the injection rate multiplied by the INJPOSTFRACFACTOR will be used when the BH pressure is above INJTHRESHOLD.0] Multiplier for production rate after the reservoir is fractured. By default value from PVT table is used. <None> | GAS | WATER | LIQUID | [OIL] PRODOPTION Symbol LINEAR | QUADRATIC | SINGLEFORCHHEIMER | FORCHHEIMER | BACKPRESSURE | UNDERSATURATED | VOGELS | TABULAR | NORMALIZEDBACKPR | [1. Non-zero values are ignored for twophase simulations. Distance water front has to travel before it reaches the well bore. Normally given in (Sm3/d/bar). Linear injectivity index for water entering the well section. Mechanical damage skin.0] WAXFRACTION RealList [1. Either this key or WATERFRACTION can be specified. Requires PRODOPTION=TABULAR. Pressure. The table variables must be given at reservoir conditions. STEAMFRACTION RealList (-) [-1.0] Time constant for the gas front movement. If the BH pressure has been above fracture pressure this is a multiplier only below INJTHRESHOLD. This key can only be used if water option is available. Hole size (diameter). Scaling factor for determining the amount of wax forming components relative to HC mixture.0] [-1.1]. The table variables must be given at reservoir conditions.uses GOR from the PVT table (or the specified GORST) and the PHASE to calculate the split between the phases. Table reference for negative well flow performance. Option for supporting coning. By default (=-1).0] TABLE | NO | [YES] [RESERVOIRINFLOW] Multiplier for injection rate when BH pressure is above fracture pressure. Option for supporting coning. WGR from the PVT table is used. If BH pressure has been above fracture pressure this is a multiplier when BH pressure is above INJTHRESHOLD as well. Normally given in (1/MMSCF/d). Linear injectivity index for oil entering the well section. Effective permeability. This key can only be used if water option is available. Requires PRODOPTION=TABULAR. Normally given in (Sm3/d/bar). Multiplier for production rate before the reservoir is fractured. PRODPOSTFRACFACTOR PRODPREFRACFACTOR PRODTABLE QMAX RESEXT ROGST ROLST SKIND SKINS Real Real Symbol RealList (Sm3/s) RealList (m) Real (kg/Sm3) Real (kg/Sm3) RealList (1/Sm3/s) RealList [-1. Mass fraction of free water in the total flow mixture of the reservoir. The phase for which productivity index or absolute open flow rate is given.0] TABLE | Positive well flow equation type.0] TOTALWATERFRACTION VISGRES VISLRES WATDIS RealList (-) Real (Ns/m2) Real (Ns/m2) Real (m) [-1. even if the water option is available. By default. Multiplier for injection rate when BH pressure is below fracture pressure. Oil density at standard conditions. Net pay from inflow zone. Use when the well parameters are given for conditions before the reservoir is fractured. INJPOSTFRACFACTOR Real INJPREFRACFACTOR INJTABLE INJTHRESHOLD ISOTHERMAL KPERM LABEL OFRTC OILDIS OILINJ OILPLIMIT PHASE PRODI Real Symbol RealList (Pa) Symbol RealList (mD) String Real (s) Real (m) RealList (Sm3/s/Pa) Real (Pa) Symbol RealList (Sm3/s/Pa) [1. Name of x variable Independent variable name OPENING Real (-) POINT TABLE XLOOKUPVARIABLE XVARIABLE RealList Symbol Symbol SymbolList (ValueUnitPair) SymbolList (ValueUnitPair) TABLE | XVAR | [YVAR] NOTGIVEN | OPEN | DELTAP | LEVEL | PRODUCTIONPRESSURE | NOTGIVEN | CV | FLOW | GASFL | LIQFL | PILIQ | WATFR | OILTC | GASTC | WATTC | STDGASFLOW | VOLUME | YVARIABLE Dependent variable name Link to: TABLE (on Library) Description Keys TIMESERIES (on Library) Description ( See also: Keys) The TIMESERIES keyword is a generic function of time. SHAPE (on Library) Keys ( See also: Description ) Key LABEL MATERIAL RADIUS TYPE X_LOWER_LEFT X_UPPER_RIGHT XPOINTS Y_LOWER_LEFT Y_UPPER_RIGHT YPOINTS Type Unit:( ) String Symbol Real (m) Symbol Real (m) Real (m) RealList (m) Real (m) Real (m) RealList (m) Parameter set Default:[ ] [SHAPE] MATERIAL | <None> | CIRCLE | RECTANGLE | POLYGON | Description Name of shape. x-coordinate of the upper right corner of the rectangle. This means that it can be used for different physical properties.ZFACT Real [1] Gas compressibility factor. y-coordinate of the upper right corner of the rectangle. Define the list of values of both independent and dependent variables in the table (x1. y-coordinates of the polygon points. The shape keyword is being used for solid bundles.t. Table where XLOOKUPVARIABLE input is sampled. Radius of the circle. Link to: SHAPE (on Library) Description Keys TABLE (on Library) Description ( See also: Keys) This statement defines a function in tabular form either valve sizing coefficient or well flow parameters. POLYGON. TIMESERIES (on Library) Keys ( See also: Description ) Key AMPLITUDE Type Unit:( ) Real <None> | SEQUENTIAL | [ADDITIVE] Parameter set Default:[ ] Description Amplitude of the sine function This key determines how the time series in SERIESREF are combined. The time series functionality is implemented for ambient temperature. Table label. RECTANGLE. The transition from one to the next is defined in the keys TRANSITIONTIME and TRANSITION. both DELTAP and OPENING. normal point series can be used. x-coordinate of the lower left corner of the rectangle. x2. There is a built in sine function. Polygon points have to be specified counter clockwise. If ADDITIVE is COMBINETYPE Symbol . Name/label of solid inside the shape. and in addition a combination of these are possible. y2.). This functionality is only valid for valves with PHASE=LIQUID. y1. the time series are combined in sequence according to the order in which they are defined. Type of shape. Turn on look-up function. The material inside the shape is being described with the MATERIAL keyword.. Instead of defining one OPEN-CV table for a valve. TABLE (on Library) Keys ( See also: Description ) Key INJECTIONPRESSURE LABEL LOOKUP Type Unit:( ) Real (Pa) String Symbol Parameter set Default:[ ] [TABLE] ON | [OFF] Description Injection pressure at which the GLV curve is defined. ELLIPSE. Polygon points have to be specified counter clockwise. When using SEQUENTIAL. . Define the opening for which DELTAP-CV relationship is valid. one can instead define a list of DELTAP-CV tables. x-coordinates of the polygon. Link to: RESERVOIRINFLOW (on Library) Description Keys SHAPE (on Library) Description ( See also: Keys) This keyword describes the external contour of a material. soil temperature and radiation. The type of the shape can be one of the following: CIRCLE. and the CV for the valve is found by interpolating w. CIRCLEs are automatically placed in the origin. y-coordinate of the lower left corner of the rectangle..r. N AGEBOUNDARIES give N+1 age groups. Gas/liquid phase transfer will not affect the KHI amounts in the carrying phase. If this key is set to ON. Switch for activating aging effect on. If this key is not given. If PERIODIC = OFF. Scaling factor for each time series in SERIESREF. residence time and age are tracked through the pipeline system. Type of interpolation between each point in time. KHI will not follow any vaporization to the gas phase. the function will be smooth.0] Link to: TRACERFEED (on Library) Description Keys UDDISPERSION (on Library) Description ( See also: Keys) This keyword is used for combinations of user defined dispersions (or dispersions in dispersions). Points in time for every given value in the key SERIES This key is used to define the phase shift of the sine function. <None> | ON | [OFF] [0] <None> | STEP | [LINEAR] TYPE Symbol <None> | POINTS | COMBINE | [SINE] Link to: TIMESERIES (on Library) Description Keys TRACERFEED (on Library) Description ( See also: Keys) This statement defines a feed of tracer. a factor of 1 is used. the values are simply added. oil and water. PREDEFPHASES is used to include one or more of the built in phases gas. List of User Defined (UD) phases Link to: UDDISPERSION (on Library) Description Keys . one above the highest boundary. the function will be repeated. The tracer mass. Series of function values at corresponding times defined in key TIME List of TIMESERIES labels to be used. If it is set to a quarter period. Label of timeseries The time it takes for the sine function to start repeating itself. the last value will be used for the remainder of the simulation when the time exceeds the defined range. An example is the combination of hydrates and water in a hydrate slurry. To use TRACERFEED. Option for type of time series. AGEBOUNDARIES AGING CARRIERPHASE HIGHLOWBOUND LABEL LOWLOWBOUND Real (-) String Real (-) [0. Tracer feed label. The user defined phases to be included must be listed under UDPHASES. Note that circular references are not allowed. TRACERFEED (on Library) Keys ( See also: Description ) Key Type Unit:( ) RealList (s) Symbol Symbol ON | [OFF] GAS | OIL | [WATER] Parameter set Default:[ ] Description Boundaries of age groups [s]. Type of transition from one time series in SERIESREF to the next. Realizations of distributions are defined through UDPDF. however. and N-1 groups bounded by the N boundaries. only the concentrations. It is possible to make the plug-in module support other distributions. one below the lowest boundary. One user defined dispersion should be defined for each such combination. When used for tracking a tracer with aging effect. Carrying phase of the inhibitor. Tracers are. the difference between the first and last point is used to determine the period of the function.0] [TFEED] [0. If PERIODIC = ON. TRACERFEEDs may be referenced in a SOURCE or MASSFLOW node. The type “LogNormal” is default. This key is used to determine the points in time when the transition from one time series in SERIESREF to the next occur. for instance a feed of kinetic hydrate inhibitor or corrosion inhibitor. a distribution in age groups may be chosen. Other distribution types may be defined in the plug-in referred to under UDOPTIONS PLUGINDLL. a cosine function is created. assumed to be present in such small concentrations that they do not influence the hydraulics. otherwise the key AGING should be set to OFF. STATISTICALDISTRIBUTION is used to give the name of the distribution function type. the key TRACERTRACKING must be set to ON under the OPTIONS keyword.FACTOR INTERPOLATION LABEL PERIOD PERIODIC SERIES SERIESREF TIME TIME0 TRANSITION TRANSITIONTIME RealList Symbol String Real (s) Symbol RealList SymbolList RealList (s) Real (s) Symbol RealList (s) [1] <None> | STEP | [LINEAR] [TIMESERIES] used. UDDISPERSION (on Library) Keys ( See also: Description ) Key LABEL PREDEFPHASES STATISTICALDISTRIBUTION UDPHASES Type Unit:( ) String SymbolList String SymbolList Parameter set Default:[ ] [UDDISPERSION] GAS | OIL | WATER | [LogNormal] Description Name dispersion phase List of predefined phases Distribution function to use for statistical moments. OLGA support LogNormal. Age output variables are set to zero if (tracer mass)/(tracer mass + carrier phase mass) of the requested feed/age group is lower than this value and the ratio hasn't been above HIGHLOWBOUND since it was lower than LOWLOWBOUND. If the first and last value of the function are equal. Age output variables are set to zero if (tracer mass)/(tracer mass + carrier phase mass) of the requested feed/age group is lower than this value. Other distribution types may be defined in the plug-in referred to under UDOPTIONS PLUGINDLL.0] [UDPHASE] Description Thermal capacity of the new phase.e. The PDF parameters may be characterized in two ways: 1. Heated walls can only be used together with TEMPERATURE = WALL. specified by the keys "MATERIAL" and "THICKNESS". Each material layer can be divided into sub layers either by specifying each sub layer as a new material layer or by automatic discretization of the material layers by the use of the key "DISCRETIZATION". asphaltenes. Here STATMOMRn should be the nth root of the mass based moment for the radius to the power n. STATMOMR2 and STATMOMR3. Distribution function to use for statistical moments. Input (M3)^(1/3) with unit category length. i.g. this setting will be overridden by the moments. OLGA support LogNormal. The user defined phase could e. If a size distribution is to be applied. Realizations of distributions are defined through UDPDF. M3 is moment for R^3. Note that for the default PFD type (Log Normal). Currently only particle (solid). M2 is moment for R^2. STATISTICALDISTRIBUTION is used to give the name of the distribution function type. It is possible to make the plug-in module support other distributions. since this is a two-parameter distribution. The heat sources may vary along the pipelines by specifying different walls along the line. STANDARDDEVIATION and SKEWNESS for the particle radius or 2. A combination of walls having constant power supply and no power supplied at all can be specified in the same OLGA case. UDPDF (on Library) Keys ( See also: Description ) Key LABEL MEAN SKEWNESS STANDARDDEVIATION STATMOMR1 STATMOMR2 STATMOMR3 Type Unit:( ) String Real (m) Real Real (m) Real (m) Real (m) Real (m) Parameter set Default:[ ] [UDPDF] Description Name of mass based Probability Distribution Function (PDF) Mean value for the mass based distribution Skewness for the mass based distribution Standard deviation for the mass based distribution Statistical moment M1 for R^1 Square root of statistical moment M2. The pipe wall may consist of different material layers. the heat per unit length supplied to the wall is constant along the pipe having this specific wall. The value of the HEATCAPACITY is use for thermal calculations. Heat can be provided to a user specified wall layer in each wall. In the wall statement the user specifies the wall layer geometry and the name of the wall. Each wall in OLGA may contain only one heat source. The related functional form is specific to each User Defined phase/dispersion and is specified under UDPHASE/UDDISPERSION.UDPDF (on Library) Description ( See also: Keys) UDPDF defines the parameters in a specific Probability Distribution Function (PDF) used for describing distributions of particle size. User Defined Phase label. PARTDIAMETER defines the particle diameter of the user defined phase. PARTDENSITY is the density of the user defined phase. Constant heat or heat varying with time. Diameter of the particles. Density of the particles. Input (M2)^(1/2) with unit category length. These data are required if the TEMPERATURE option is "WALL" or "FASTWALL" in OPTIONS. UDPHASE (on Library) Keys ( See also: Description ) Key HEATCAPACITY LABEL PARTDENSITY PARTDIAMETER STATISTICALDISTRIBUTION TYPE Type Unit:( ) Real (J/kg-C) String Real (kg/m3) Real (mm) String Symbol Parameter set Default:[ ] [0. Using standard statistical parameters MEAN. [LogNormal] [PARTICLE] Link to: UDPHASE (on Library) Description Keys WALL (on Library) Description ( See also: Keys) This statement specifies the wall data for pipes. User defined phases/dispersions may then be assigned a size distribution parameters by referring to a PDF for each UDFRACTION under the UDGROUP in question. only the two first input parameters are used. Using mass based statistical moments STATMOMR1. The type “LogNormal” is default. Link to: UDPDF (on Library) Description Keys UDPHASE (on Library) Description ( See also: Keys) UDPHASE is the basic building block for defining and tracking new user defined phases. Cube root of statistical moment M3. TYPE is at present limited to PARTICLE (solid dispersion). wax or hydrate slurry. The third is calculated accordingly. The user also specifies the required data if the walls are to be heated. Type of phase. a type of sand. WALL (on Library) Keys ( See also: Description ) . rn. Pipe's inner diameter. Instants in time when the plot interval is changed. Maximum ratio of outer to inner radius of sub-layers. This value is used throughout the entire simulation. It is possible to specify either time points for output (TIME) or a time interval for output (DTOUT). It is also possible to specify different time intervals for output using a combination of TIME and DTOUT. If this key is not given. Cut off ratio for material elasticity in adjacent wall layers. Only the global variables are available on this level.out) which can be opened in a text editor. Power per unit length for the electric heating time series.Key Type Unit:( ) Parameter set Default:[ ] PIDCONTROLLER | ASCCONTROLLER | PSVCONTROLLER | MANUALCONTROLLER | OVERRIDECONTROLLER | SELECTORCONTROLLER | CASCADECONTROLLER | ESDCONTROLLER | LINEARCOMBINATION | TABLECONTROLLER | [OFF] <None> | ON | [OFF] ON | [OFF] [0. Enable plotting to file Link to: OUTPUT (on CaseLevel) Description Keys OUTPUTDATA (on CaseLevel) Description ( See also: Keys) This statement defines the variables to be printed to the output file (*.1] Description CONTROLLERLABEL Symbol Name of controller for electric heating DISCRETIZATION ELASTIC ELECTRICHEAT ERATIOMIN INNERDIAMETER SymbolList Symbol Symbol Real (-) Real (m) KAPPA Real (1/Pa) Switch on or off auto-discretization for each wall material layer. The information is saved as an output file (*. Time interval(s) between subsequent printings of output. OLGA will calculate the flexibility based on the pipe wall geometry and Young's modulus of elasticity (EMOD) of the materials. LABEL MATERIAL MAXNOLAYERS MAXRATIO POWER POWERCONTROL POWERMAX THICKNESS TIME WALLAYER String SymbolList IntegerList RealList (-) RealList (W/m) Symbol Real (W/m) RealList (m) RealList (s) Integer [WALL] [2] ON | [OFF] [0. Time series when POWER is to be modified. OUTPUT (on CaseLevel) Keys ( See also: Description ) Key COLUMNS DTOUT TIME WRITEFILE Type Unit:( ) Integer RealList (s) RealList (s) Symbol [0. this and all subsequent layers will be ignored in the calculation of the total wall elasticity.0] Link to: WALL (on Library) Description Keys OUTPUT (on CaseLevel) Description ( See also: Keys) This statement defines the time intervals for when the variables defined in OUTPUTDATA is reported. Thickness of each wall layer. Radial flexibility of pipe (increase in area for a unit change in pressure relative to area of pipe). If TIME is not specified or only contains one value. . The time interval is changed at the times specified in TIME. Switch power control on or off. power per unit length for electric heating if it is restricted by a control system. only one value must be given for DTOUT. Wall layer for electric heating. Calculate the effect of contraction/expansion of wall in pressure equation Switch electric heating on or off. Names of the materials that constitutes the wall layers.0] OFF | [ON] Parameter set Default:[ ] [4] Description Number of variable columns per page. If the Young's modulus of the material in a wall layer is less than ERATIOMIN times the Young's modulus of the material in the inside wall layer. This key can be used to override the value calculated by OLGA. Maximum number of sub-layers allowed for each of the layers. Flowing layers User Defined (UD) phase names. Must not be greater than 6. Label of the wall. Max. OUTPUTDATA (on CaseLevel) Keys ( See also: Description ) Key DISPERSION FLOWLAYER PHASE Type Unit:( ) SymbolList SymbolList SymbolList ALL | GAS | OIL | WATER | BED | WALL | Parameter set Default:[ ] Description User Defined (UD) dispersion names.out). 0] OFF | [ON] Description Time interval between subsequent printouts to the profile plot file. the stand-alone tool FEMThermTool can be used for both 2D thermal computation in a cross section and visualisation of the triangular grid generated when using the FEMTherm module. Instants in time when the plot interval is changed. List of variable names to be plotted.0] Description Time interval between subsequent printouts of the plot variables. In addition to the OLGA GUI graphical package.osi) are available for visualisation of results. Plot files: The graphical presentation of results should be considered the primary source to an understanding of the calculated state in the pipeline.plt and . The trend plot file and the profile plot file are in ASCII format.VARIABLE SymbolList (ValueUnitPair) List of variable names to be printed. . The ASCII format files can be used to interface the results from OLGA with any graphical package the user might have access to. The . PROFILE (on CaseLevel) Keys ( See also: Description ) Key DTPLOT DTTIME TIME WRITEFILE Type Unit:( ) RealList (s) RealList (s) RealList (s) Symbol Parameter set Default:[ ] [0.. Flow path variables defined on this level will be reported for all flow paths. variables from different groups can be defined on the same line. Also. Instants in time when data is written to the profile plot file. For available profile variables see Output Variables. Units may be specified. PLOT (on CaseLevel) Keys ( See also: Description ) Key DTPLOT TIME VARIABLE WRITEFILE Type Unit:( ) RealList (s) RealList (s) SymbolList (ValueUnitPair) Symbol OFF | [ON] Parameter set Default:[ ] [0. Enable plotting to file Link to: PROFILE (on CaseLevel) Description Keys PROFILEDATA (on CaseLevel) Description ( See also: Keys) This statement defines profile plot variables along the pipeline at specified time points. A graphical package is supplied as part of the OLGA GUI. Both the trend plot file and the profile plot file consist of a heading and the time and variables specified with the keyword statement TREND and PROFILE in the input file (extension inp). Points in time when the plot interval is changed. Units may be included in the list. the stand-alone tools OLGA Viewer (. Enable plotting to file Link to: PLOT (on CaseLevel) Description Keys PROFILE (on CaseLevel) Description ( See also: Keys) This statement defines either time points (TIME) or a time interval (DTPLOT) for the profile plot variables.plt files) and FEMTherm Viewer (.b.osi files are in binary format. N. Link to: OUTPUTDATA (on CaseLevel) Description Keys PLOT (on CaseLevel) Description ( See also: Keys) This statement defines the time interval (DTPLOT) for the plot variables. i. List of variable names to be plotted.e. CUTTING and MUD components. A list of NPLOT values refers to the time points given in TIME. Instants in time when the plot interval is changed. User Defined (UD) dispersion names. User Defined (UD) phase names. directly as a set of time points (TIME) or as a set of time intervals changing at specified time points (combination of DTPLOT and TIME). TREND (on CaseLevel) Keys ( See also: Description ) Key Type Unit:( ) RealList (s) IntegerList RealList (s) Symbol [0. Wall layer numbers for plotting of wall temperatures. H2O. User Defined (UD) phase names. if given more than once. Using DRILLING=ON under OPTIONS. For compositional models the names of the available components are given in the feed file. A trend plot is a time series plot for a specified variable. Link to: TRENDDATA (on CaseLevel) Description Keys . Only global and branch variables are available on this level..g. Number of data points. ALL | GAS | OIL | WATER | BED | WALL | Flowing layers Array element index of HYKPLIST. Units may be specified. available components are HC. the sample period will be DTIME/NPLOT. available components are HC. OLGA will use the last value given. MEG/MEOH/ETOH. Flowing layers Array element index of HYKPLIST.PROFILEDATA (on CaseLevel) Keys ( See also: Description ) Key AGEGROUPID Type Unit:( ) IntegerList Parameter set Default:[ ] Description Age group for plotting inhibitors variables with aging effect. Units may be specified. H2O and MEG/MEOH/ETOH. COMPONENT SymbolList DISPERSION FLOWLAYER HYKPID LAYER PHASE TRACERFEED VARIABLE SymbolList SymbolList IntegerList IntegerList SymbolList SymbolList SymbolList (ValueUnitPair) Link to: PROFILEDATA (on CaseLevel) Description Keys TREND (on CaseLevel) Description ( See also: Keys) This statement defines the time interval for trend plotting.0] OFF | [ON] Parameter set Default:[ ] Description Time interval between subsequent trend variable printouts. Kinetic hydrate inhibitor (KHI). Tracer label that the tracer type variables are plotted for. e. DTPLOT should only be given once in the input file. The time intervals may be given as single time interval (DTPLOT). TRENDDATA (on CaseLevel) Keys ( See also: Description ) Key DISPERSION FLOWLAYER HYKPID PHASE VARIABLE Type Unit:( ) SymbolList SymbolList Integer SymbolList SymbolList (ValueUnitPair) ALL | GAS | OIL | WATER | BED | WALL | Parameter set Default:[ ] Description User Defined (UD) dispersion names. Layer no. Enable plotting to file DTPLOT NPLOT TIME WRITEFILE Link to: TREND (on CaseLevel) Description Keys TRENDDATA (on CaseLevel) Description ( See also: Keys) This statement defines the trend data to be plotted. List of variable names to be plotted. 1 is the innermost one. Component names. Using the Inhibitor tracking module. . FLUID must be the same as the LABEL given in the pvt-file. LIQUID. … DRYGAS _N outlets PhaseSplitNode Keys ( See also: Description ) Key FEEDMASSFRACTION FEEDMOLEFRACTION FEEDNAME FEEDVOLFRACTION FLUID INFO INHIBFRACTION LABEL PRESSURE Type Unit:( ) RealList (-) RealList (-) SymbolList RealList (-) Symbol String Real (-) String Real (Pa) [0. General information about the PhaseSplitNode. STEAMFRACTION Real (-) [-1.01] Parameter set Default:[ ] Description Sample period for obtaining variable values. A list of both positive and negative values is not allowed. … MIXTURE _N inlets and outlets GAS_1. It has six different types of terminals: GAS. Requires COMPOSITIONAL=ON or BLACKOIL under the OPTIONS keyword. the mass of H2O component is in the gas phase if the temperature is greater than the saturation temperature. Initial temperature when using INITIALCONDITIONS. Gas volume fraction when using INITIALCONDITIONS. WATER. otherwise. Label or number of PVT table to apply for the specific branch. If a keyword based pvt-file is used. The sample period is calculated as DTIME / NPLOT. Initial pressure when using INITIALCONDITIONS. Network component label (if nothing is given the NC tag is used). A list of values for NPLOT refers to the time points given in TIME.0] TEMPERATURE VOIDFRACTION VOLUME Real (C) Real (-) Real (m3) [-1] .0] PVTData | Parameter set Default:[ ] Description Mass fraction of each feed. Volume fraction of each feed given in FEEDNAME for choke model (only for Blackoil model).. numbering is not valid for this format.gas +droplets . but the phase distributions for the outgoing branches can be specified.. DRYGAS and MIXTURE. Fraction of total mass of H2O component in the gas phase.oil and water bulk .XYT (on CaseLevel) Description ( See also: Keys) XYT (on CaseLevel) Keys ( See also: Description ) Key Type Unit:( ) RealList (s) IntegerList RealList (s) Real (m) [0. OIL. Terminal = GAS Terminal = OIL Terminal = WATER Terminal = LIQUID Terminal = DRYGAS Terminal = MIXTURE . If specified volume is less than or equal to 0. DTPLOT should only be given once in the input file. … GAS_N outlets OIL_1.gas only . Label of feeds feeding to terminal nodes. Specify –1 for OLGA to use the equilibrium values from the fluid property tables.oil bulk . …WATER_N outlets LIQUID_1. the mass of H2O component is distributed between the gas phase and the water phase according to the vapor pressure of H2O in the gas phase. The phase split node has an arbitrary number of inlets/outlets. i.0] [0. Volume of PhaseSplitNode. By default (=-1).water bulk . Mole fraction of each feed.e. If it is given more than once. …OIL_N outlets WATER_1.all phases within the node itself(default) The following connections are defined: · · · · · • MIXTURE_1.. Mass fraction of inhibitor in the water phase. Time points when the plot interval is changed Maximum value plotted on the abscissa (x-coordinate) DTPLOT NPLOT TIME XMAX Link to: XYT (on CaseLevel) Description Keys PhaseSplitNode Description ( See also: Keys) The phase split node behaves as something in-between the internal network node and the network separator. Number data points for plotting. LIQUID_N outlets DRYGAS _1. OLGA will only use the last one. . There are no level controls and separator efficiencies included. For information purposes only. one oil-outlet and one water-outlet to pipes. x-coordinate of node in network. the following outlets are defined: GAS_1.. If a keyword based pvt-file is used. Gas/liquid separation efficiency. For a two phase separator. Time constant for separation of oil from water. y-coordinate (vertical axis) of node in network. Pipelines downstream of network separators.. using the VALVE keyword. Label of the table where the relation between level (height) in the separator and volume of the separator is given. Time constant for separation of water from oil.0] [0. Mole fraction of each feed. Used for 3D graphics only. Label of feeds used to initialize separator. Valves. Two phase separators must have connected at least one gas-outlet and one oil-outlet to pipes.0] [0.) Liquid volume fraction when the efficiency is reduced. The initial water level. All valves must be defined on the outgoing branches..0] [0] [0] [0] OLGA will estimate the volume (see User's manual). If the water level exceeds this value water will be drained together with oil through the oil drain.. Used for 3D graphics only TABLE | [0. Used for 3D graphics only z-coordinate of separator in network. FLUID must be the same as the LABEL given in the pvt-file. the water level limit for when the water will be drained together with the oil can be specified by the keys: HHWATHOLDUP or HHWATLEVEL Separator Keys ( See also: Description ) Key DIAMETER EFFHIGH EFFICIENCY EFFLOW FEEDMASSFRACTION FEEDMOLEFRACTION FEEDNAME FEEDVOLFRACTION FLUID HHWATHOLDUP HHWATLEVEL INITOILLEVEL INITPRESSURE INITTEMPERATURE INITWATLEVEL LABEL LENGTH LEVELTABLE OILTCONST ORIENTATION PHASE SURFACEAREA TAMBIENT TIME UVALUE WATTCONST X Y Z Type Unit:( ) Real (m) Real (-) Real (-) Real (-) RealList (-) RealList (-) SymbolList RealList (-) Symbol Real (-) Real (m) Real (m) Real (Pa) Real (C) Real (m) String Real (m) Symbol Real (s) Symbol Symbol Real (m2) RealList (C) RealList (s) Real (W/m2-C) Real (s) Real (m) Real (m) Real (m) [0. See Separator Output Variables for available variables.e. z-coordinate of node in network. Requires COMPOSITIONAL=ON or BLACKOIL under the OPTIONS keyword. WATER_N outlets 3. The initial oil level. Mass fraction of each feed.. Used for 3D graphics only y-coordinate (vertical axis) of separator in network. Model description and user guidelines: 1. Levels used by a network separator. OIL_N outlets (Use OIL_2 to model emergency outlet) For a three-phase separator.. GAS_N outlets (Use Gas_2 to model flare outlet) OIL_1. Separator type: The separator may be horizontal or vertical.. Moreover. Number of phases separated in the separator..0] <None> | VERTICAL | HORIZONTAL | TWO | THREE | [0. Link to: PhaseSplitNode Description Keys Separator Description ( See also: Keys) The network separator model in OLGA is not intended to accurately model separation phenomena. The network separators have no internal valves. Used for 3D graphics only. Overall heat transfer coefficient given by user based on inner pipe diameter. The network separators have arbitrary number of outlets. Three phase separators must have connected at least one gas-outlet. Water level upper limit.995] [1. Initial watercut when using INITIALCONDITIONS. . (One minus the volume fraction of liquid droplets in the gas outlet stream. numbering is not valid for this format. Separator length. Label or number of fluid table to apply for the separator. Time series for specified boundary values. two-phase of three-phase. Initial pressure. and set critical levels for oil and water drainage. If the water hold-up exceeds this value water will be drained together with oil through the oil drain. .0] PVTData | [0.... Surface area of the separator. 4. The separator levels are controlled by the valves and controllers in the outlet branches.0] [0] [0] [0] Link to: Separator Description Keys OUTPUTDATA (on Separator) Description ( See also: Keys) This statement defines the separator variables to be printed to the output file (*. x-coordinate of separator in network. but is meant to include the influence of a separator on transient pipeline dynamics.995] Parameter set Default:[ ] Description Separator diameter. 2. . GAS_N outlets OIL_1. . i. Liquid volume fraction when the efficiency goes toward zero and the separator is treated as a normal section.WATERCUT X Y Z Real (-) Real (m) Real (m) Real (m) [0. .. OIL_N outlets WATER_1. Water hold-up upper limit. .0] [0. Volume fraction of each feed given in FEEDNAME for choke model (only for Blackoil model). Initial temperature. Ambient temperature. Network component label (if nothing is given the NC tag is used). Orientation of the separator.out). The user can define the separation efficiency (gas/liquid and oil/water). Used for 3D graphics only. the following outlets are defined: GAS_1. Link to: TRENDDATA (on Separator) Description Keys . Link to: TRANSMITTER (on Separator) Description Keys TRENDDATA (on Separator) Description ( See also: Keys) This statement defines the trend data to be plotted for separators. the several controllers can receive the output signal from one transmitter. The location is only used graphically to position the transmitter along the flowpath. Link to: OUTPUTDATA (on Separator) Description Keys TRANSMITTER (on Separator) Description ( See also: Keys) This keyword is used to define output signals from flowpath. A trend plot is a time series plot for a specified variable. The signals can be received by a controller. TRENDDATA (on Separator) Keys ( See also: Description ) Key VARIABLE Type Unit:( ) SymbolList (ValueUnitPair) Parameter set Default:[ ] Description List of variables to be plotted. separator and phase split node. TRANSMITTER (on Separator) Keys ( See also: Description ) Key LABEL VARIABLE Type Unit:( ) String Symbol (ValueUnitPair) Parameter set Default:[ ] [TM] 4096 | Description Transmitter Terminal label. Controllers that receive these measured values use them to calculate new signals which in turn are used to regulate e. add a transmitter per output signal. Variable to be transmitted. fluid pressure in the flowpath (PT) or liquid level in the separator (LIQLV). Unit may be specified.g. For available variables see Separator Output Variables. Units may be specified. node. Note: If a branch variable is to be controlled. a valve opening (see Controllers). Units may be specified. However. process equipment.g. The signals are defined through the variable key e. If several different output signals are needed form the same position. add a transmitter to the flowpath at a dummy location (use a valid absolute position or pipe/section).OUTPUTDATA (on Separator) Keys ( See also: Description ) Key VARIABLE Type Unit:( ) SymbolList (ValueUnitPair) Parameter set Default:[ ] Description List of variables to be printed. The servername should be a single word. Simulator mode. it will wait whenever it catches up with the external clock. Link to: Annulus Description Keys . Flowing layers User Defined (UD) phase names. 'Simulator' means a free-running simulator operating on its own. OPC-wise this means the naming hierarchy is: SERVERNAME.MODELNAME. Link to: SERVERDATA (on CaseLevel) Description Keys SERVEROPTIONS (on CaseLevel) Description ( See also: Keys) This statement activates and specifies the different settings for the OLGA OPC Server. This is the name of the total model. SIMULATORMODE Symbol EXTERNAL | [SIMULATOR] Link to: SERVEROPTIONS (on CaseLevel) Description Keys Annulus Description ( See also: Keys) Annulus is a network component.* The OPC server name. Must be ON if later playback for reproducibility of simulation results should be possible The model or submodel name OLGA namespace name.MODULENAME. See also ANNULUS COMPONENT Keys Annulus Keys ( See also: Description ) Key LABEL Type Unit:( ) String Parameter set Default:[ ] Description Network component label (if nothing is given the NC tag is used). with no spaces (' ') or dots ('. 'External' means that the simulator will try to keep synchronized with the ticking of the external clock. All submodels are logically attached beneath this name. Units may be specified.SERVERDATA (on CaseLevel) Description ( See also: Keys) SERVERDATA (on CaseLevel) Keys ( See also: Description ) Key DISPERSION DTPLOT FLOWLAYER PHASE VARIABLE Type Unit:( ) SymbolList Real (s) SymbolList SymbolList SymbolList (ValueUnitPair) Parameter set Default:[ ] [0] ALL | GAS | OIL | WATER | BED | WALL | Description User Defined (UD) dispersion names. See ANNULUS COMPONENT for more description. Turns on or off logging of external inputs to the simulator.'). Interval for update of server data. SERVEROPTIONS (on CaseLevel) Keys ( See also: Description ) Key EXPOSE INPUTLOG MODELNAME MODULENAME SERVERNAME Type Unit:( ) SymbolList Symbol String String String [Sim] [OLGAOPCServer] ON | [OFF] Parameter set Default:[ ] Description States which keys should be made available as input variables on the OPC server. List of variable names to be plotted. COMPONENT (on Annulus) Description ( See also: Keys) This statement defines the configuration of pipes which are bundled together and have thermal interaction. Gas-lifted wells are typical examples, where gas is injected in the annulus between the casing and tubing while the production fluid together with the injected gas is produced in the tubing. COMPONENT (on Annulus) Keys ( See also: Description ) Key FLOWPATH FROM OUTERHVALUE TO XOFFSET YOFFSET Type Unit:( ) Symbol Symbol Real (W/m2-C) Symbol Real (m) Real (m) POSITION | [0.0] [0.0] Parameter set Default:[ ] FLOWPATH | POSITION | Description Label of a FLOWPATH that resides inside the BUNDLE. Label of the POSITION on the FLOWPATH where it enters the BUNDLE. Heat transfer coefficient at the wall surface of a branch to the bulk fluid in the carrier line. Forced/free convection will be applied if this key is not defined. Label of the POSITION on the FLOWPATH where it exits the BUNDLE. The component's displacement along the x-axis relative to the center of the bundle. The component's displacement along the y-axis relative to the center of the bundle. Link to: COMPONENT (on Annulus) Description Keys FluidBundle Description ( See also: Keys) FLUIDBUNDLE is a network component. See FLUIDBUNDLE COMPONENT for details. See also FLUIDBUNDLE COMPONENT Keys FluidBundle Keys ( See also: Description ) Key LABEL Type Unit:( ) String Parameter set Default:[ ] Description Network component label (if nothing is given the NC tag is used). Link to: FluidBundle Description Keys COMPONENT (on FluidBundle) Description ( See also: Keys) This keyword defines a carrier line that encloses one or several FLOWPATHS, LINES and/or FLUIDBUNDLES. The carrier line itself must be specified as either a FLOWPATH or a LINE. The length and elevation of each pipe section contained in the bundle must be maintained. Pipe diameters must be constant in the axial direction. The effects of heat transfer between all the pipelines will be accounted for. A LINE is a FLOWPATH for which simplified one-phase calculations are performed. It is activated by choosing LINE=YES as a parameter for a FLOWPATH. FLOWPATHS must be connected to nodes when the sub key LINE=YES. The CROSSOVER functionality must be set up explicitly with nodes of type CROSSOVER with a specified reference pressure and boost pressure. The outer heat transfer coefficients and the ambient temperatures used by the Fluid Bundle are the values given for the outermost pipeline. The outer surface heat transfer coefficient for each OLGA FLOWPATH can be calculated by the code or specified by the user. If calculated by the code the forced/free convection on the outer surface will be taken into account. The user can specify the outer surface heat transfer coefficient by the sub key OUTERHVALUE. See also FLUIDBUNDLE COMPONENT Keys COMPONENT (on FluidBundle) Keys ( See also: Description ) Key FLOWPATH FLUIDBUNDLE FROM LINE OUTERHVALUE TO XOFFSET YOFFSET Type Unit:( ) Symbol Symbol Symbol Symbol Real (W/m2-C) Symbol Real (m) Real (m) POSITION | [0.0] [0.0] Parameter set Default:[ ] FLOWPATH | FLUIDBUNDLE | POSITION | FLOWPATH | Description Label of a FLOWPATH that resides inside the BUNDLE. Label of a bundle that resides inside the BUNDLE. Label of the POSITION on the FLOWPATH where it enters the BUNDLE. Label of a line (FLOWPATH) that resides inside the BUNDLE. Heat transfer coefficient at the wall surface of a branch to the bulk fluid in the carrier line. Forced/free convection will be applied if this key is not defined. Label of the POSITION on the FLOWPATH where it exits the BUNDLE. The component's displacement along the x-axis relative to the center of the bundle. The component's displacement along the y-axis relative to the center of the bundle. Link to: COMPONENT (on FluidBundle) Description Keys SolidBundle Description ( See also: Keys) This network component stores all information that is required to configure a solid bundle. This may be done by either editing the keywords and keys directly, or through the Bundle Editor in the GUI. Associated keywords: COMPONENT AMBIENTDATA TRENDDATA PROFILEDATA Example - Buried pipeline In the following example, a (partially) buried pipeline is modelled. The pipe is assumed to have a centre line, y , located 25 cm below the soil surface. The air temperature is c measured to be 25 ° C and the soil temperature 1 m under the ground is 20 ° C. The soil temperature re ading is assumed to be uninfluenced by the presence of the pipe. 1. Start by adding a COMPONENT and associate the flowpath to this. A natural choice for the soil surface is y = 0, so the pipe must be moved down 25 cm. This is done by setting YOFFSET = -25 cm for this COMPONENT. 2. The soil is modelled by using a rectangular SHAPE with an associated soil MATERIAL. We assume that the effect of the pipe on the soil temperature is negligible at a distance of approximately 1.5 m to each side and 2 m down. The parameters for the shape then becomes: X_LOWER_LEFT = -1.5 m, Y_LOWER_LEFT = -2 m, X_UPPER_RIGHT = 1.5 m, Y_UPPER_RIGHT = 0 m. 3. Finally, the ambient conditions must be specified. In this case we can use a single AMBIENTDATA with TYPE = SIMPLEBURIED. Above ground we have air at 25 ° C, thus HOUTEROPTION = AIR and TAMBIENT = 25 C. We have positioned the soil surface at y = 0 m, so SOILSURFACELEVEL = 0 m. The soil temperature is set by specifying SOILTEMPERATURE = 20 C and SOILTEMPLEVEL = -1 m. COMMENTS: In this example, the OLGA WALL is in contact with both air and the solid SHAPE. Due to the potentially large temperature difference between the top and botom of the pipe, it may be advisable to remove some of the outer wall layers from the OLGA WALL and use one or more SHAPES to model the wall layers. This is done by simply creating a circular SHAPE with the outer radius of the wall layer. Please note that the order of the SHAPE COMPONENTS are important and that the wall layer COMPONENT must be defined after the rectangular soil COMPONENT. Otherwise, the wall layer COMPONENT will be hidden by the soil COMPONENT. The vertical boundaries of the soil above SOILTEMPLEVEL was modelled using the default NOFLUX option for SOILVERTBOUND. This option assumes that there naturally is no heat flux across these boundaries. However, if the boundaries are too close to the pipe, the temperature in the soil may be overestimated. A better choice may then be to use the FIXEDTEMP option. This will force the temperature to be equal to the SOILTEMPERATURE on these boundaries SolidBundle Keys ( See also: Description ) Key DELTAT Type Unit:( ) Real (s) Parameter set Default:[ ] Description Time-step in thermal calculations. DTPLOT LABEL MESHFINENESS PLOTTING Real (s) String Integer Symbol [32] OFF | [ON] Time-step for saving thermal data. Network component label (if nothing is given the NC tag is used). The number of nodes on the largest SHAPE in the SOLIDBUNDLE. The higher the number the finer the mesh. Minimum value is 32 and it will always be rounded down to nearest multiple of 32. Key for turning ON/OFF detailed plot of Finite Element results in .osi file Link to: SolidBundle Description Keys AMBIENTDATA (on SolidBundle) Description ( See also: Keys) AMBIENTDATA (on SolidBundle) Keys ( See also: Description ) Key Type Unit:( ) RealList (J/kg-C) Parameter set Default:[ ] Description Heat capacity of ambient fluid. If HOUTEROPTION is AIR, 1000 J/KG-K is used. If HOUTEROPTION is WATER, 4186 J/KG-K is used. Input can either be a single value (constant along bundle length), two values (lengthinterpolated) or given explicitly for each section. Thermal conductivity of ambient fluid. If HOUTEROPTION is AIR, 0.023 W/mK is used. If HOUTEROPTION is WATER, 0.56 W/mK is used. Input can either be a single value (constant along bundle length), two values (lengthinterpolated) or given explicitly for each section. Density of ambient fluid. If HOUTEROPTION is AIR, 1.29 kg/m3 is used. If HOUTEROPTION is WATER, 1000 kg/m3 is used. Input can either be a single value (constant along bundle length), two values (length-interpolated) or given explicitly for each section. The emissivity is a measure of the ability of a material to emit heat by radiation. It is given as the ratio of energy radiated by a particular material to energy radiated by a black body at the same temperature. Thermal expansion coefficient of ambient fluid. If HOUTEROPTION is AIR, 34E-4 1/C is used. If HOUTEROPTION is WATER, 21E-5 1/C is used. Input can either be a single value (constant along bundle length), two values (length-interpolated) or given explicitly for each section. Mean heat transfer coefficient on outer wall surface. Input can either be a single value (constant along bundle length) or given explicitly for each section. Option for ambient heat transfer coefficient. Overall heat transfer coefficient at the inlet of the first pipe in a pipeline section where interpolation is used for overall heat transfer coefficient. Ambient temperature at the inlet of the first pipe in a branch where interpolation is used for ambient temperature. Type of interpolation used to calculate the ambient temperature and outer heat transfer coefficient. Note that the outer heat transfer coefficient is only affected by the INTERPOLATION key when HOUTEROPTION = HGIVEN. Overall heat transfer coefficient at the outlet of the last pipe in a pipeline section where interpolation is used for overall heat transfer coefficient. Ambient temperature at the outlet of the last pipe in a pipeline section where interpolation is used for ambient temperature. Heat flux into solid due to external radiation. List of reference to TIMESERIES keywords. The value of each time series is scaled with a corresponding factor in RADIATIONSERIESFACTOR and added to the heat flux defined in RADIATION. List of factors to be used to scale heat radiation time series in RADIATIONSERIES. Vertical level that defines the surface of the soil (SIMPLEBURIED only). At and above this level, ambient conditions given in the "Radiation", "Heat transfer coefficient", "Ambient temperature" and "Outer heat transfer coefficient" groups apply. Conditions specified in "Soil data" apply below this level. Temperature at SOILTEMPLEVEL (or lowest vertical position of cross section if SOILTEMPLEVEL is not given). If SOILTEMPERATURE is not given, TAMBIENT is used (TAMBIENTSERIES is not used). Input can either be a single value (constant along bundle length), two values (length-interpolated) or given explicitly for each section. Vertical level where the soil temperature is given. If this key is not given, the lowest vertical position of the cross section is used. List of reference to TIMESERIES keywords. The value of each time series is scaled with a corresponding factor in SOILTEMPSERIESFACTOR and added as a temperature increment to the temperature defined in SOILTEMPERATURE. List of factors to be used to scale soil temperature time series in SOILTEMPSERIES. Ambient conditions for boundaries between SOILSURFACELEVEL and SOILTEMPLEVEL. When NOFLUX is used, there is no heat flow across external boundaries. For FIXEDTEMP, the temperature is determined by SOILTEMPERATURE. FIXEDTEMP is always used for boundaries at or below SOILTEMPLEVEL. Ambient temperature. Input can either be a single value (constant along bundle length) or given explicitly for each section. List of reference to TIMESERIES keywords. The value of each time series is scaled with a corresponding factor in TAMBSERIESFACTOR and added as an increment to the temperature defined in TAMBIENT or INTAMBIENT and OUTTAMBIENT. List of factors to be used to scale ambient temperature time series in TAMBIENTSERIES. Note that this key also introduces the unit of the function. Type of ambient data input. If TYPE = VERTICALPOINTS, ambient heat transfer coefficient, ambient temperature, radiation and emissivity will be linearly interpolated in the vertical axis between AMBIENTDATA definitions. For TYPE = SIMPLEBURIED, only a single AMBIENTDATA can be defined CAPACITY CONDUCTIVITY RealList (W/m-C) DENSITY RealList (kg/m3) EMISSIVITY Real (-) [0] EXPANSION RealList (1/C) HAMBIENT HOUTEROPTION INHAMBIENT INTAMBIENT INTERPOLATION OUTHAMBIENT OUTTAMBIENT RADIATION RADIATIONSERIES RADIATIONSERIESFACTOR RealList (W/m2-C) Symbol Real (W/m2-C) Real (C) Symbol Real (W/m2-C) Real (C) RealList (W/m2) SymbolList RealList [1] [0] <None> | LENGTH | | HORIZONTAL | VERTICAL | [SECTIONWISE] <None> | AIR | WATER | OTHER | [HGIVEN] SOILSURFACELEVEL Real (m) [0] SOILTEMPERATURE RealList (C) SOILTEMPLEVEL Real (m) SOILTEMPSERIES SymbolList SOILTEMPSERIESFACTOR RealList [1] SOILVERTBOUND Symbol <None> | FIXEDTEMP | [NOFLUX] TAMBIENT RealList (C) TAMBIENTSERIES SymbolList TAMBSERIESFACTOR RealList [1] <None> | SIMPLEBURIED | [VERTICALPOINTS] TYPE Symbol VELOCITY RealList (m/s) VERTPOS Real (m) [0] VISCOSITY RealList (N-s/m2) but different ambient conditions are used for boundaries that are below or above SOILSURFACELEVEL. Speed of ambient fluid. If HOUTEROPTION is AIR, default is 4 m/s. If HOUTEROPTION is WATER, default is 1 m/s. Input can either be a single value (constant along bundle length), two values (length-interpolated) or given explicitly for each section. Vertical position of given ambient conditions. Used only if TYPE = VERTICALPOINTS. Ambient heat transfer coefficient, ambient temperature, radiation and emissivity will be linearly interpolated in the vertical axis between AMBIENTDATA definitions. Viscosity of ambient fluid. If HOUTEROPTION is AIR, 1.8E-5 N-s/m2 is used. If HOUTEROPTION is WATER, 1E-3 N-s/m2 is used. Input can either be a single value (constant along bundle length), two values (length-interpolated) or given explicitly for each section. Link to: AMBIENTDATA (on SolidBundle) Description Keys COMPONENT (on SolidBundle) Description ( See also: Keys) The COMPONENT keyword is used to define the geometric layout of the SOLIDBUNDLE cross section. The keyword has a reference to a geometric object and an offset from the origin (XOFFSET and YOFFSET). The following objects may be placed within a solid bundle: · SHAPE · Line · FLUIDBUNDLE · BRANCH When using FLUIDBUNDLE or BRANCH (flow components), the POSITION keyword must be used in order to define the start and end pipe between which the solid bundle applies. Please note a pipe wall is not allowed to intersect another pipe wall. However, a SHAPE may intersect another SHAPE or a pipe wall, unless it has already been placed in the interior of another shape. The cross section of the bundle is the union of all SHAPES and flow components. When two objects intersect, the following rules are used: Intersecting SHAPES: If the first SHAPE is defined in COMPONENT[i] and the second in COMPONENT[j] (i < j), the SHAPE in COMPONENT[j] will have the highest rank and it will remain unchanged. For the SHAPE in COMPONENT[i], the intersecting area will be removed. Intersecting SHAPE and flow components: Flow components always has infinite rank COMPONENT (on SolidBundle) Keys ( See also: Description ) Key ANNULUS FLOWPATH FLUIDBUNDLE FROM LINE OUTERHVALUE SHAPE TO XOFFSET YOFFSET Type Unit:( ) Symbol Symbol Symbol Symbol Symbol Real (W/m2-C) Symbol Symbol Real (m) Real (m) SHAPE | POSITION | [0.0] [0.0] Parameter set Default:[ ] ANNULUS | FLOWPATH | FLUIDBUNDLE | POSITION | FLOWPATH | Description Label of an annulus that reside inside the BUNDLE. Label of a FLOWPATH that resides inside the BUNDLE. Label of a bundle that resides inside the BUNDLE. Label of the POSITION on the FLOWPATH where it enters the BUNDLE. Label of a line (FLOWPATH) that resides inside the BUNDLE. Heat transfer coefficient at the wall surface of a branch to the bulk fluid in the carrier line. Forced/free convection will be applied if this key is not defined. Label of a shape that reside inside the BUNDLE. The SHAPE with the largest circumference is automatically the outer surface of BUNDLE. Label of the POSITION on the FLOWPATH where it exits the BUNDLE. The component's displacement along the x-axis relative to the center of the bundle. The component's displacement along the y-axis relative to the center of the bundle. Link to: COMPONENT (on SolidBundle) Description Keys PROFILEDATA (on SolidBundle) Description ( See also: Keys) PROFILEDATA (on SolidBundle) Keys ( See also: Description ) Key VARIABLE XPOS YPOS Type Unit:( ) SymbolList (ValueUnitPair) RealList (m) RealList (m) Parameter set Default:[ ] [TBUNXY] Description List of variables to be plotted. List of X coordinates where the variables are plotted List of Y coordinates where the variables are plotted Link to: PROFILEDATA (on SolidBundle) Description Keys TRENDDATA (on SolidBundle) Description ( See also: Keys) TRENDDATA (on SolidBundle) Keys ( See also: Description ) Key ABSPOSITION SECTIONNUMBER VARIABLE XPOS YPOS Type Unit:( ) RealList (m) IntegerList SymbolList (ValueUnitPair) RealList (m) RealList (m) Parameter set Default:[ ] Description Position where the variable will be plotted. Absolute position. Distance from bundle start position Section numbers in bundle definition where the variables will be plotted. List of variables to be plotted. List of X coordinates where the variables are plotted List of Y coordinates where the variables are plotted [TBUNXY] Link to: TRENDDATA (on SolidBundle) Description Keys Output Variables The variables belonging to a section in the pipeline are divided between boundary variables and volume variables. This is due to the staggered mesh used in the numeric solution of the problem, where some variables are computed at the section boundaries (boundary variables) while others are computed in the middle of the section (volume variables). Branch variables will give quantities, relating to the branch, such as, for instance, liquid content. Global variables will give quantities relating to the total system, such as total mass in the system, or relating to the integration, such as the time step. In addition to the variables describing the pipeline, we have variables describing the process equipment, such as compressors, sources etc. All variables listed can be written to the trend plot data file. Variables defined as boundary or volume variables can also be written to the profile plot data file. The abbreviations for the use of the variables (in the «Use as» column in the listing) are as follows: O: TP: PP: C: S: Printed output variable (to be specified with keyword OUTPUT). Trend plot variable (to be specified with keyword TREND). Profile plot variable (to be specified with keyword PROFILE). Controller signal input variable (to be specified as the controlled variable for a controller, input group CONTROLLER). Only for server output Variables belonging to different groups cannot be specified together in the input for trend plotting (except the boundary and volume variable groups). A new TRENDDATA entry has to be specified for each variable group. Boundary Variables Description ( See also: Variables) WCST,GORST, QGST, QLST, QOST and QWST are given at standard conditions (60 oF, 1 atm). A single stage flash from in-situ to standard conditions has been performed, that is, mass transfer between the phases from in-situ to standard conditions is taken into account. The gas is not dehydrated unless WATERFLASH = OFF. For table-based simulations, OLGA uses the gas mass fractions and densities from the fluid property file to perform the conversion.Note: These variables are CPU demanding for Compositional Tracking simulations since a flash must be performed for each section and time they are plotted, and should be used with care. Erosional Velocity ratio The erosional velocity ratio (EVR) defined in API RP-14E is: EVR = C-1(EVRVACTUAL)(EVRRHOMIX)1/2 where EVRVACTUAL =|Usg| + |Usl| + |Usd|, EVRRHOMIX = [ g|Usg| + l(|Usl| + |Usd)|]/(|Usg|+|Usl| + |Usd|), and C = 100 for U in ft/s and in Lb/ft3 C = 121.99 for U in m/s and in kg/m3 Here |Usg|, |Usl| and |Usd| denote the absolute value of the superficial velocity for gas, liquid film and liquid droplets respectively. Similarly liquid density. g and l denote the gas and Boundary Variables ( See also: Description) Use as Boundary Variables Name Units Definition O|TP|PP|C ACCGAG KG Accumulated gas mass flow 2=Annular. -1= not applicable. 4=Bubble.O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C ACCGAQ ACCGT ACCLIG ACCLIQ ACCOIG ACCOIQ ACCWAG ACCWAQ CFLFACT DPZ_GRAV_FACTOR DPZA DPZF DPZG DS DUG DUL EVR EVRRHOMIX EVRVACTUAL FRRG FRRH FRRW GASMFRBOUN GD GDHL GDWT GG GL GLHL GLRST GLT GLTHL GLTWT GLWT GLWV GLWVT GORST GT HOLHLNS HOLNS HOLWTNS HTOT ID IDWHBUB IDWHSEP IDWHSLU IKH INHIBMFRBOUN LAMTURB_GAS LAMTURB_OIL LAMTURB_WATER MDHLCONV MDHLSLOPE MDWTCONV MDWTSLOPE MGCONV MGSLOPE MLHLCONV MLHLSLOPE MLWTCONV MLWTSLOPE PSID PSIE QD QDHL QDWT QG QGST QL QLHL QLST QLT QLTHL QLTWT QLWT QOST QT QWST REGIMETYPE M3 KG KG M3 KG M3 KG M3 NoUnit PA/M PA/M PA/M NoUnit M/S2 M/S2 NoUnit KG/M3-S M/S KG/M3-S KG/M3-S KG/M3-S KG/S KG/S KG/S KG/S KG/S KG/S SM3/SM3 KG/S KG/S KG/S KG/S KG/S KG/S SM3/SM3 KG/S W NoUnit NoUnit NoUnit NoUnit NoUnit KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3-S KG/M3-S M3/S M3/S M3/S M3/S SM3/S M3/S M3/S SM3/S M3/S M3/S M3/S M3/S SM3/S M3/S SM3/S NoUnit Accumulated gas volume flow Accumulated total mass flow Accumulated liquid mass flow Accumulated liquid volume flow Accumulated oil mass flow Accumulated oil volume flow Accumulated water mass flow Accumulated water volume flow Local CFL factor Factor describing the gravity domination of the flow Additional pressure drop gradient Frictional pressure drop gradient Gravitational pressure drop gradient Distribution slip ratio Time derivative of gas velocity Time derivative of liquid velocity Erosional velocity ratio Mixed density used in calculation of erosional velocity ratio Actual volume flux used in calculation of erosional velocity ratio. Oil/water flowregime indicator for slug bubble: 0=Stratified smooth. Gas wall drift friction factor Oil wall drift friction factor Water wall drift friction factor Gas mass fraction at boundary Droplet mass flow Mass flow rate of oil in droplet field Mass flow rate of water in droplet field Gas mass flow Liquid bulk mass flow Mass flow rate of oil in film Gas/liquid ratio at standard conditions Total liquid mass flow Mass flow rate of oil Mass flow rate of water excluding vapour Mass flow rate of water in film Mass flow rate of water vapour Total mass flow rate of water including Vapour Gas/oil ratio at standard conditions Total mass flow No-slip oil volume fraction No-slip liquid volume fraction No-slip water volume fraction Total Enthalpy flow rate Flow regime: 1=Stratified. 1=Stratified wavy. 1=LiquidSlug. 1=Stratified wavy. 1=Stratified wavy. 2=SlugBubble . 2=Dispersed. Inviscid Kelvin-Helmoltz factor Inhibitor mass fraction in water at boundary Blending parameter between laminar and turbulent flow. -1= not applicable. 2=Dispersed. 3=Slug. Oil/water flowregime indicator for separated flow: 0=Stratified smooth. gas layer Blending parameter between laminar and turbulent flow. Oil/water flowregime indicator for slug: 0=Stratified smooth. water layer Specific convective mass of oil droplets Specific mass adjustment of oil droplets Specific convective mass of water droplets Specific mass adjustment of water droplets Specific convective mass of gas Specific mass adjustment of gas Specific convective mass of oil in film Specific mass adjustment of oil in film Specific convective mass of water in film Specific mass adjustment of water in film Deposition rate Entrainment rate Droplet volume flow Volumetric flow rate oil droplets Volumetric flow rate water droplets Gas volume flow Gas volume flow at standard conditions Liquid bulk volume flow Volumetric flow rate oil film Liquid volume flow at standard conditions Total liquid volume flow Volumetric flow rate oil Volumetric flow rate water Volumetric flow rate water film Oil volume flow at standard conditions Total volume flow Water volume flow at standard conditions Slug-trac regime: 0=Free. 2=Dispersed. oil layer Blending parameter between laminar and turbulent flow. -1= not applicable. max. gas side Turbulence parameter gas-oil interface. wall shear stress Turbulence parameter gas-oil interface.O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C SHRHL SHRWT SLAG SLAI SLAIGHL SLAIHLWT SLAIWTG SLAL SLALHL SLALWT SLGH SLGW SLHG SLWG STDROG STDROHL STDROWT TAUWG TAUWHL TAUWWT TC_GH TC_HG TC_HW TC_WH TINHIBMFRBOUN TRBPAR_CAP TRBPAR_FROUD TRBPAR_REYG TRBPAR_REYH TRBPAR_REYI TRBPAR_WEB TWATMFRBOUN UD UDHL UDO UDWT UG UHLCONT UL ULHL ULWT UO USD USDHL USDWT USG USL USLHL USLT USLTHL USLTWT USLWT USTOT UWTCONT VKH WATMFRBOUN WCST WD WDHL WDWT WG WL WLHL WLWT WTOT 1/s 1/s KG/M3-S KG/M3-S KG/M3-S KG/M3-S KG/M3-S KG/M3-S KG/M3-S KG/M3-S KG/M3-S KG/M3-S KG/M3-S KG/M3-S KG/M3 KG/M3 KG/M3 PA PA PA M/S M/S M/S M/S M/S M/S M/S M/S M/S M/S M/S M/S M/S M/S M/S M/S M/S M/S M/S M/S M/S M/S NoUnit KG/S-M2 KG/S-M2 KG/S-M2 KG/S-M2 KG/S-M2 KG/S-M2 KG/S-M2 KG/S-M2 Oil film .shear strain rate Gas friction coefficient Interfacial friction coefficient Gas/oil film interfacial friction factor Oil film/water film interfacial friction factor Water film/gas interfacial friction factor Liquid friction coefficient Oil film wall friction factor Water film wall friction factor Oil wall friction due to gas Water wall friction due to gas Gas wall friction due to oil Gas wall friction due to water Standard gas density Standard oil density Standard water density Gas . oil side Turbulence parameter oil-water interface. wall shear stress Water film .max.shear strain rate Water film . wall shear stress Oil film . oil side Turbulence parameter oil-water interface. water side Inhibitor mass fraction in water+vapour at boundary Capilary number from the TURBPAR routine Froud number from the TURBPAR routine Reynolds number for gas layer from the TURBPAR routine Reynolds number for oil layer from the TURBPAR routine Reynolds number for gas oil interface from the TURBPAR routine Weber number from the TURBPAR routine Total water mass fraction at boundary Droplet velocity Oil droplet velocity Relative velocity droplets Water droplet velocity Gas velocity Oil continuous velocity Average liquid film velocity Oil film velocity Water film velocity Relative velocity Superficial velocity total liquid droplets Superficial oil droplet velocity Superficial water droplet velocity Superficial velocity gas Superficial velocity total liquid film Superficial oil film velocity Superficial velocity liquid (USL+USD) Superficial velocity oil Superficial velocity water Superficial water film velocity Total volume flux Water continuous velocity Viscous Kelvin-Helmoltz factor Water mass fraction at boundary Water cut at standard conditions Droplet mass flux Mass flux of oil in droplet field Mass flux of water in droplet field Gas mass flux Liquid mass flux Mass flux of oil in film Mass flux of water in film Total mass flux Link to: Boundary Variables Description Variables Branch Variables Description ( See also: Variables) Branch Variables ( See also: Description) Use as Branch Variables Name Units Definition O|TP|C|GTP DPABR PA Additional pressure drop .max. O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP DPBR DPFBR DPGBR DTBR GASC GASCFR GASCST GASIN GASMASS GASOUT INHIBMASS LIQBC LIQC LIQCFR LIQDC LIQIN LIQMASS LIQOUT MASOUT MASSIN MAXPTBR MAXPTBRCT MAXPTPOS MAXTMBR MAXTMBRCT MAXTMPOS MDPHYD MDPPOS MDTHYD MDTPOS MEANPTBRCT MEANTMBRCT MINPTBR MINPTBRCT MINPTPOS MINTMBR MINTMBRCT MINTMPOS OILBC OILC OILCFR OILCST OILDC OILIN OILMASS OILOUT RGASIN RGASOUT RLIQIN RLIQOUT RMASIN RMASOUT ROILIN ROILOUT RWATIN RWATOUT RWINHIBTOT WATBC WATC WATCFR WATCST WATDC WATIN WATMASS WATOUT PA PA PA C M3 M3 KG KG KG KG M3 M3 M3 KG KG KG KG KG PA PA M C C M PA M C M PA C PA PA M C C M M3 M3 M3 M3 KG KG KG KG KG KG KG KG KG KG KG KG KG M3 M3 M3 M3 KG KG KG Total pressure drop Frictional pressure drop Gravitational pressure drop Total temperature drop (inlet minus outlet) in branch Gas content in branch Gas volume fraction in branch Gas content in branch converted to standard conditions Accumulated gas flow inlet boundary Gas mass in branch Accumulated gas flow outlet boundary Total mass of inhibitor in branch Liquid bulk content in branch Total liquid content in branch Liquid volume fraction in branch Liquid droplet content in branch Accumulated liquid flow inlet boundary Total liquid mass in branch Accumulated liquid flow outlet boundary Accumulated mass flow outlet boundary Accumulated mass flow inlet boundary Maximum pressure in branch since start Maximum pressure in branch at current time Distance from branch inlet where maximum pressure since start occurs Maximum temperature in branch since start Maximum temperature in branch at current time Distance from branch inlet where maximum temperature since start occurs Maximum difference between section and hydrate pressure since last write Distance where section and hydrate pressure differs most since last write Maximum difference between hydrate and section temp since last write Distance where section and hydrate temperature differs most since last write Mean pressure in branch at current time Mean temperature in branch at current time Minimum pressure in branch since start Minimum pressure in branch at current time Distance from branch inlet where minimum pressure since start occurs Minimum temperature in branch since start Minimum temperature in branch at current time Distance from branch inlet where minimum temperature since start occurs Oil film content in branch Total oil content in branch Oil volume fraction in branch Total oil content in branch converted to standard conditions Oil droplet content in branch Accumulated oil flow inlet boundary Total oil mass in branch Accumulated oil flow outlet boundary Accumulated gas flow after restart at inlet boundary Accumulated gas flow after restart at outlet boundary Accumulated liquid flow after restart at inlet boundary Accumulated liquid flow after restart at outlet boundary Accumulated mass flow after restart at inlet boundary Accumulated mass flow after restart at outlet boundary Accumulated oil flow after restart at inlet boundary Accumulated oil flow after restart at outlet boundary Accumulated water flow after restart at inlet boundary Accumulated water flow after restart at outlet boundary Total mass fraction in water phase in branch for inhibitor Water film content in branch Total water content in branch Water volume fraction in branch Total water content in branch converted to standard conditions Water droplet content in branch Accumulated water flow inlet boundary Total water mass in branch Accumulated water flow outlet boundary Link to: Branch Variables Description Variables Bundle Variables Description ( See also: Variables) Bundle variables can only be used when a SOLIDBUNDLE. a FLUIDBUNDLE or an ANNULUS is given Bundle Variables ( See also: Description) Use as Bundle Variables Name Units Definition . BNDL BNDL HAMBBUN TBUNXY W/M2-C C Ambient heat transfer coefficient at specified position in bundle Temperature at specified position in bundle Link to: Bundle Variables Description Variables Check valve Variables Description ( See also: Variables) Check valve Variables ( See also: Description) Use as Check valve Variables Name Units Definition O|TP|C|GTP CHECK NoUnit Check valve position: 0=open 1=closed Link to: Check valve Variables Description Variables Compositional Variables Description ( See also: Variables) Compositional variables can only be used when compositional mass equations are used. ETOH. GLTWTLEAK is the same variable as CGWLEAK 2. MEG. GLTWTWELL is only available when using inhibitor tracking (MEG. GLTWTSOUR. This means when the COMPOSITIONAL key in the OPTIONS keyword is either ON. GLTWTSOUR is the same variable as CGWSOUR 3. MEOH or ETOH) Compositional Variables ( See also: Description) Use as Boundary Variables Name Units Definition TP|PP TP|PP TP|PP TP|PP TP|PP TP|PP TP|PP TP|PP Branch Variables CGDH CGDW CGG CGHT CGLH CGLW CGWT PTG KG/S KG/S KG/S KG/S KG/S KG/S KG/S Pa Component mass rate in oil droplets Component mass rate in water droplets Component mass rate in gas phase Component mass rate in oil phase Component mass rate in oil film Component mass rate in water film Component mass rate in water phase Partial pressure in gas phase TP|GTP Leak Variables CMTOT KG Total mass in branch TP|GTP TP|GTP CGGLEAK CGHLEAK KG/S KG/S Leak mass rate in gas phase Leak mass rate in oil phase . GLTWTWELL is the same variable as CGWWELL GLTWTLEAK. BLACKOIL or STEAMWATER-HC When compositional variables can be used are: 1. MEOH. mass) in water phase Mole weight of gas phase Mole weight of oil phase .mass) in gas phase (Equilibrium mass .TP|GTP TP|GTP TP|GTP TP|GTP TP|GTP TP|GTP TP|GTP TP|GTP TP|GTP TP|GTP TP|GTP Separator Variables CGTLEAK CGWLEAK GLTWTLEAK XGLEAK XGMLEAK XHLEAK XHMLEAK XWLEAK XWMLEAK ZLEAK ZMLEAK KG/S KG/S KG/S - Leak mass rate in all phases Leak mass rate in water phase Leak mass rate in water phase Leak mole fraction in gas phase Leak mass fraction in gas phase Leak mole fraction in oil phase Leak mass fraction in oil phase Leak mole fraction in water phase Leak mass fraction in water phase Leak mole fraction in all phases Leak mass fraction in all phases NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS Source Variables CAEDLM CAEDOM CAEDWM CAGOGM CAGOLM CAGOOM CAGOTM CAGOWM CAODLM CAODOM CAODWM CATDGM CATDLM CATDOM CATDTM CATDWM CAWDLM CAWDOM CAWDWM CEDLMF CEDOMF CEDWMF CGOGMF CGOLMF CGOOMF CGOTMF CGOWMF CODLMF CODOMF CODWMF CTDGMF CTDLMF CTDOMF CTDTMF CTDWMF CWDLMF CWDOMF CWDWMF KG KG KG KG KG KG KG KG KG KG KG KG KG KG KG KG KG KG KG KG/S KG/S KG/S KG/S KG/S KG/S KG/S KG/S KG/S KG/S KG/S KG/S KG/S KG/S KG/S KG/S KG/S KG/S KG/S ACCUMULATED EMERGENCY DRAIN LIQUID MASS FLOW ACCUMULATED EMERGENCY DRAIN OIL MASS FLOW ACCUMULATED EMERGENCY DRAIN WATER MASS FLOW ACCUMULATED GAS OUTLET GAS MASS FLOW ACCUMULATED GAS OUTLET LIQUID MASS FLOW ACCUMULATED GAS OUTLET OIL MASS FLOW ACCUMULATED GAS OUTLET TOTAL MASS FLOW ACCUMULATED GAS OUTLET WATER MASS FLOW ACCUMULATED OIL DRAIN LIQUID MASS FLOW ACCUMULATED OIL DRAIN OIL MASS FLOW ACCUMULATED OIL DRAIN WATER MASS FLOW ACCUMULATED TOTAL DRAIN GAS MASS FLOW ACCUMULATED TOTAL DRAIN LIQUID MASS FLOW ACCUMULATED TOTAL DRAIN OIL MASS FLOW ACCUMULATED TOTAL DRAIN TOTAL MASS FLOW ACCUMULATED TOTAL DRAIN WATER MASS FLOW ACCUMULATED WATER DRAIN LIQUID MASS FLOW ACCUMULATED WATER DRAIN OIL MASS FLOW ACCUMULATED WATER DRAIN WATER MASS FLOW EMERGENCY DRAIN LIQUID MASS FLOW EMERGENCY DRAIN OIL MASS FLOW EMERGENCY DRAIN WATER MASS FLOW GAS OUTLET GAS MASS FLOW GAS OUTLET TOTAL LIQUID MASS FLOW GAS OUTLET OIL MASS FLOW GAS OUTLET TOTAL MASS FLOW GAS OUTLET WATER MASS FLOW OIL DRAIN LIQUID MASS FLOW OIL DRAIN OIL MASS FLOW OIL DRAIN WATER MASS FLOW TOTAL DRAIN GAS MASS FLOW TOTAL DRAIN LIQUID MASS FLOW TOTAL DRAIN OIL MASS FLOW TOTAL DRAIN TOTAL MASS FLOW TOTAL DRAIN WATER MASS FLOW WATER DRAIN LIQUID MASS FLOW WATER DRAIN OIL MASS FLOW WATER DRAIN WATER MASS FLOW TP|GTP TP|GTP TP|GTP TP|GTP TP|GTP TP|GTP TP|GTP TP|GTP TP|GTP TP|GTP TP|GTP TP|GTP TP|GTP Volume Variables CGGSOUR CGHSOUR CGTSOUR CGWSOUR GLTWTSOUR XGMSOUR XGSOUR XHMSOUR XHSOUR XWMSOUR XWSOUR ZMSOUR ZSOUR KG/S KG/S KG/S KG/S NoUnit - Source mass rate in gas phase Source mass rate in oil phase Source mass rate in all phases Source mass rate in water phase Source mass rate in water phase Source mass fraction in gas phase Source mole fraction in gas phase Source mass fraction in oil phase Source mole fraction in oil phase Source mass fraction in water phase Source mole fraction in water phase Source mass fraction in all phases Source mole fraction in all phases TP|PP TP|PP TP|PP TP|PP TP|PP TP|PP TP|PP TP|PP TP|PP TP|PP TP|PP TP|PP TP|PP TP|PP CGPSI CHPSI CMG CMHD CMHL CMWD CMWL CWPSI DMGE DMHE DMWE MWGAS MWOIL KG/M3-S KG/M3-S KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3-S KG/M3 KG/M3 KG/M3 KG/KMOL KG/KMOL Mass rate of flashing to gas phase Mass rate of flashing to oil phase Mass in gas phase Mass in oil droplets Mass in oil film Mass in water droplets Mass in water film Mass rate of flashing to water phase (Equilibrium mass .mass) in oil phase (Equilibrium mass . This means when the COMPOSITIONAL key in the OPTIONS keyword is either ON. In addition to this the SLUIGTRACKING keyword has to have been given. Compositional SlugTracking Variables ( See also: Description) Use as Boundary Variables Name Units Definition TP|PP TP|PP TP|PP TP|PP TP|PP Slug Variables CMGEXP CMHDEXP CMHLEXP CMWDEXP CMWLEXP KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 Component mass in gas phase of slug (no slug: CMG) Component mass in oil droplets of slug (no slug: CMHD) Component mass in oil film of slug (no slug: CMHL) Component mass in water droplets of slug (no slug: CMWD) Component mass in water film of slug (no slug: CMWL) TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP CMGFSB CMGFSL CMGTSB CMGTSL CMHDFSB CMHDFSL CMHDTSB CMHDTSL CMHLFSB CMHLFSL CMHLTSB CMHLTSL CMWDFSB CMWDFSL CMWDTSB CMWDTSL CMWLFSB CMWLFSL CMWLTSB CMWLTSL KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 Component mass in gas phase ahead of slug front Component mass in gas phase behind slug front Component mass in gas phase behind slug tail Component mass in gas phase ahead of slug tail Component mass in oil droplets ahead of slug front Component mass in oil droplets behind slug front Component mass in oil droplets behind slug tail Component mass in oil droplets ahead of slug tail Component mass in oil film ahead of slug front Component mass in oil film behind slug front Component mass in oil film behind slug tail Component mass in oil film ahead of slug tail Component mass in water droplets ahead of slug front Component mass in water droplets behind slug front Component mass in water droplets behind slug tail Component mass in water droplets ahead of slug tail Component mass in water film ahead of slug front Component mass in water film behind slug front Component mass in water film behind slug tail Component mass in water film ahead of slug tail Link to: Compositional SlugTracking Variables Description Variables Compressor Variables Description ( See also: Variables) . MEOH. BLACKOIL or STEAMWATER-HC.TP|PP TP|PP TP|PP TP|PP TP|PP TP|PP TP|PP TP|PP TP|PP TP|PP TP|PP TP|PP TP|PP TP|PP Well Variables MWWAT XG XGE XGM XGME XH XHE XHM XHME XW XWE XWM XWME Z ZM KG/KMOL - Mole weight of water phase Mole fraction of gas phase Equilibrium mole weight in gas phase Mass fraction in gas phase Equilibrium mole weight of gas phase Mole fraction of oil phase Equilibrium mole weight of gas phase Mass fraction in oil phase Equilibrium mass fraction in oil phase Mole fraction in water phase Equilibrium mole fraction in water phase Mass fraction in water phase Equilibrium mass fraction in water phase Total molar composition Total mass composition TP|GTP TP|GTP TP|GTP TP|GTP TP|GTP TP|GTP TP|GTP TP|GTP TP|GTP TP|GTP TP|GTP TP|GTP TP|GTP CGGWELL CGHWELL CGTWELL CGWWELL GLTWTWELL XGMWELL XGWELL XHMWELL XHWELL XWMWELL XWWELL ZMWELL ZWELL KG/S KG/S KG/S KG/S KG/S - Well mass rate in gas phase Well mass rate in oil phase Well mass rate in all phases Well mass rate in water phase Well mass rate in water phase Well mass fraction in gas phase Well mole fraction in gas phase Well mass fraction in oil phase Well mole fraction in oil phase Well mass fraction in water phase Well mole fraction in water phase Well mass fraction in all phases Well mole fraction in all phases Link to: Compositional Variables Description Variables Compositional SlugTracking Variables Description ( See also: Variables) Compositional Slugtracking variables can only be used when compositional mass equations are used. MEG. ETOH. 001 1000 1/FLOWRATE 1/LENGTH . 5=Freeze Moving averaged of primary controller variable Controller rate limited signal Controller saturated signal Setpoint of extended cascade controller Controller setpoint variable Link to: Controller Variables Description Variables List of Units and Conversion Factors Quantity Unit name Conversion to the first unit.Compressor Variables ( See also: Description) Use as Compressor Variables Name Units Definition O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP DHRCOO GCOMP GREC HCOMP HREC QGSURGE RPM W KG/S KG/S W W M3/S RPM Compressor recycle heat exchanger Enthalpy Compressor mass flow rate Compressor recycle mass flow rate Compressor enthalpy Compressor recycle enthalpy Corrected compressor surge flow Compressor speed Link to: Compressor Variables Description Variables Controller Variables Description ( See also: Variables) Controller Variables ( See also: Description) Use as Controller Variables Name Units Definition GTP|NC GTP|NC GTP|NC GTP|NC GTP|NC GTP|NC GTP|NC GTP|NC GTP|NC GTP|NC GTP|NC ACTIVATED CONTR ERRVAR INTGVAR MEASVAR MODE PMCAS RATELIMITED SATURATED SETPOINT SETPVAR NoUnit NoUnit NoUnit NoUnit NoUnit NoUnit NoUnit NoUnit NoUnit NoUnit NoUnit Controller activate signal Controller output Controller error signal Controller integral signal Controller measured variable Controller mode: 1=Automatic.28083989501312 100 6.21371192237334E-04 0.358 3. multiply by 1/ANGULAR_VELOCITY 1/rpm s M h d 1/m3/s 1/ft3/s 1/m3/h 1/ft3/h 1/bbl/d 1/m3/d 1/bbl/M 1/m 1/ft 1/cm 1/miles 1/km 1/mm 0.016667 60 1440 35.3107 3600 127119 543396 86400 377. 4=External setpoint. 2=Manual. 3=External signal. 187 4.0001 0.10471975511966 1.187 DYNAMIC_VISCOSITY ENTHALPY ENTHALPY/MASS ENTHALPY/MOL ENTHALPY/MOL-TEMP ENTHALPY/VOLUME .09290304 0.000001 86400 0.61457291804931 ANGULAR_ACCELERATION ANGULAR_VELOCITY AREA CGR 5.187 2.05 0.0254 1/STDFLOWRATE ACCELERATION ANGLE 57.187 37260 4.1/PRESSURE_DIFFERENCE 1/Pa 1/atm 1/bar 1/psi 1/KP/cm2 1/kPa 1/kgf/cm2 1/Sm3/s 1/MSm3/s 1/Sm3/d 1/MSm3/d 1/scf/d 1/MMscf/d 1/scf/s m/s2 ft/s2 cm/s2 in/s2 degree deg rad rad/s2 R/s2 rpm/s rpm/M rpm rad/s 1/s m2 ft2 cm2 in2 Sm3/Sm3 stb/scf m3/m3 scf/scf stb/mmscf mm/y kg/m3 lb/ft3 g/cm3 lb/in3 kg/m-N s2/m2 kg/m3-K kg/m3-C kg/m3-s m2/s cm2/s N-s/m2 lb/ft-h CP kg/m-h J Btu cal J/kg Btu/lb cal/kg J/mol Btu/lbmol cal/mol J/mol-K Btu/lbmol-R J/m3 Btu/ft3 cal/m3 9.0187328248672 1000 27680.61457291804931E-06 CORROSION_RATE DENSITY 16.00064516 5.0864 3050000 3.28318530717959 0.74532925199433E-03 9.001 0.326 4.001 1.45032632342277E-04 1.0001 0.0283 0.3703213706 DENSITY/PRESSURE DENSITY/TEMPERATURE DENSITY/TIME DIFFUSION_COEFFICIENT 0.0004134 0.187 2326 4.00001 1.86923266716013E-06 0.0002778 1055 4.01 0.54929658551372 60 0.3048 0.2957795130823 6.01971621297793E-05 0.01971621297793E-05 0. 000025806 0.574 0.000011574 0.01 1.819 4.187 4187 4.187 0.15740740740741E-05 2.00001 9.84012731481481E-06 1.0254 HEAT_TRANS.028316846592 2.937076616 3461 1000 1000 10000 11360 1635000 0.000001 0.0283169 0.77777777777778E-04 0.64978333333333E-03 0.000001 0.00027778 0./LENGTH HEATFLUX KINEMATIC_VISCOSITY LENGTH .ENTROPY J/K Btu/R cal/K J/kg-K Btu/lb-R cal/kg-K J/kg-C J/mol-K Btu/lbmol-R cal/mol-K J/m3-K Btu/ft3-R cal/m3-K N dyn kgf lbf % 1/s 1/M 1/h Hz Ns/m Sm3/s Sm3/h Sm3/d scf/d MMscf/d STB/d STB/M scf/s scf/h MSm3/d Mscf/d m3 ft3 cm3 L USgal bbl m3/s ft3/s m3/h ft3/h bbl/d m3/d bbl/m Sm3/Sm3 scf/STB m3/m3 scf/scf mmscf/stb W/m Btu/s-ft kW/m W/m2 kW/m2 W/cm2 Btu/ft2-s Btu/in2-s m2/s CST ft2/hr in2/s m ft cm in 1899 4.002651 0.001 0.01 0.77777777777778E-04 ENTROPY/VOLUME FORCE FRACTION FREQUENCY FRICTION_FACTOR GAS_STDFLOWRATE 0.0000018401 0.158987 0.028316846592 0.32774 0.00000786579072 1.178107937076616 GAS_VOLUME GAS_VOLUME/TIME GOR 178107.00000032774 0.187 ENTROPY/MASS ENTROPY/MOL 4187 4.00064516 0.3048 0.66666666666667E-02 2.000327778 0.0000078667 11.003786 0.4482 0.187 37260 4. 00000786579072 11.028316846592 0.15740740740741E-05 0.4536 2.1 0.4536 0.001 0.07639104167097E-02 1.000065788 453.5500031000062 0.028316846592 0.001 2.84012731481481E-06 2.64978333333333E-03 LIQ_STDFLOWRATE LIQ_VOLUME LIQ_VOLUME/TIME LOGARITHMIC_FRICTION_FACTOR MASS 0.4536 MASS/AREA MASS/LENGTH MASS/TIME MASS/TIME-AREA MASS/TIME-PRESSURE MOL MOL/MASS MOL/VOLUME MOLAR_RATE .03937 1.77777777777778E-04 1.000001 0.02835 1000 0.77777777777778E-04 0.00032774128 0.344 1000 0.MILES km mm Sm3/s Sm3/h Sm3/d scf/d MMscf/d STB/d STB/M scf/s scf/h MSm3/d Mscf/d m3 ft3 cm3 L USgal bbl m3/s ft3/s m3/h ft3/h bbl/d m3/d bbl/m N/m2 kg lb g oz t kg/m2 g/m2 g/cm2 kg/ft2 g/ft2 g/in2 kg/m g/m g/cm g/ft g/in lb/ft lb/in kg/s lb/s kg/h lb/h kg/s-m2 kg/s-cm2 lb/s-m2 kg/h-m2 lb/h-m2 kg/s-Pa lb/s-psi mol lbmol kmol mol/kg lbmol/lb mol/g mol/m3 lbmol/ft3 mol/cm3 mol/L kmol/s lbmol/s 1609.001 0.64978333333333E-03 0.000126 10000 0.001 10 10.488 17.6 1000 1000 1000 16020 1000000 1000 0.4536 0.00027778 0.858 0.84012731481481E-06 1.00328084 0.158987 0.000126 0.15740740740741E-05 2.001 0.00000032774128 0.028316846592 2.003786 0.77777777777778E-04 0.00000786579072 1.32774128 1.7639104167097 1.5740740740741 0. 5 15200.3910761155 100000 6895 101325 100000 6895 101325 100000 98066.028316846592 .5 1000 6895 100000 98066.69987158227 0.8 4186.01667 0.5 22621.34 POWER POWER/LENGHT POWERS_OF_TEN PRESSURE PRESSURE/DISTANCE PRESSURE/TIME PRESSURE_DIFFERENCE PRESSURE-TIME/MASS QUADRATIC_FRICTION_FACTOR RATE_PER_UNIT_TIME 0.5 1000 6895 100000 98066.001 52550 100000000 mol/m4 lbmol/ft4 mol/cm4 mol/m3-K kg/kmol lb/lbmol kg/mol g/mol mD D W hp Btu/h kW W/m hp/m Btu/h*m kW/m k M G T Pa bara psia atm bar KP/cm2 kPa psig barg kgf/cm2 Pa/m psi/ft Pa/s bar/s psi/s atm/s Pa bara psia atm bar KP/cm2 kPa psig barg kgf/cm2 Pa-s/kg psi-s/lb Ns2/m2 s M h d SPGR API Rm3/Sm3 m3/R ft3/R J/kg-C J/kg-K Btu/lbm-R Btu/lbm-F Sm3 SCF MOLDEN/TEMPERATURE MOLECULAR_WEIGHT 1000 PERMEABILITY 1000 745.69987158227 0.0002778 0.5 RELATIVE_DENSITY RESVOLUME/STDVOLUME SPECIFIC_CAPACITY 0.02832 SPECIFIC_HEAT 4186.2931 1000 1000 1000000 1000000000 1000000000000 100000 6895 101325 100000 98066.8 0.2931 1000 745.mol/s MOLCONC/METER 0.00001157 131. 77777777777778E-04 8.59 172.46666666666667E-05 0.846592 28.001163 1.678 0.8 1.3048 2.555555555555556 SURFACE_TENSION TEMPERATURE TEMPERATURE/TIME TEMPERATURE_DIFFERENCE 0.6126684303351E-05 0.555555555555556 THERMAL_CONDUCTANCE 5.000001 0.158987 565.000000000047533 0.44704 0.00006243 0.555555555555556 0.001 0.47 52.001163 THERMAL_CONDUCTIVITY 1.8 60 3600 86400 60 1.316846592 0.001 0.555555555555556 0.56 STATMASS_E0 STATMASS_E1 STATMASS_E2 STD_DENSITY STDFLOWRATE/PRESSURE 0.00000000026687 0.24269104761905E-02 0.731 0.555555555555556 0.001 3.001 0.000001 0.44704 6.000001 0.35582 0.STANDARD_VOLUME Scm3 SL Sgal MMscf Mscf Sbbl kg/m6 lb/ft6 kg/m5 lb/ft5 kg/m4 lb/ft4 kg/Sm3 Sm3/s/Pa Sm3/d/bar scf/d/psi STB/d/psi N/m dyne/cm mN/m C R K F C/s R/s K/s C R K F W/m2-C W/m2-K Btu/ft2-h-F cal/m2-h-C W/m-K W/m-C Btu/ft-h-R cal/m-h-K 1/C 1/R 1/K 1/F s M h d 1/rpm Nm ft-lb m/s ft/s m/h ft/h mph miles/h m3/kg ft3/lb cm3/g in3/lb m3/mol ft3/lbmol cm3/mol L/mol m3/R ft3/R m3 0.00000000011574 0.028316846592 THERMAL_EXPANSION TIME TORQUE VELOCITY VOLUME/MASS VOLUME/MOL VOLUME/REVOLUTION .003786 28316. WAX_VOLUME ft3 cm3 L USgal bbl 0.028316846592 0.000001 0.001 0.003786 0.158987 Corrosion Variables Description ( See also: Variables) Corrosion variables can only be used when the CORROSION keyword is given. Corrosion Variables ( See also: Description) Use as Volume Variables Name Units Definition O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C COBICARB CONDRATE CORR1 CORR2 CORR3 CORRW1 CORRW2 CORRW3 GLYCOL INHIB IONIC PCO2 PH1 PH2 PH3 SOLFE NoUnit KG/S-M2 MM/Y MM/Y MM/Y MM/Y MM/Y MM/Y NoUnit NoUnit NoUnit PA NoUnit NoUnit NoUnit NoUnit Bicarbonate concentration (Molar) Conden.rate in pipe upper half Corrosion rate Corrosion rate Corrosion rate Corr. rate, full water wet. Corr. rate, full water wet. Corr. rate, full water wet. Glycol concentration Inhibitor efficiency Ionic strength concentration (Molar) Partial pressure of CO2 pH for model 1 pH for model 2 pH for model 3 Saturated iron concentration in PPM Link to: Corrosion Variables Description Variables Drilling Variables Description ( See also: Variables) Drilling variables can only be used when DRILLING=ON in the OPTIONS keyword. Drilling Variables ( See also: Description) Use as Boundary Variables Name Units Definition O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C Volume Variables DRLFROGSTD GDOMUD GDPH2O GDPHC GDWMUD GGGMUD GGOMUD GGPH2O GGPHC GGWMUD GLOMUD GLPH2O GLPHC GLTPH2O GLTPHC GLWMUD GTOMUD GTPH2O GTPHC GTWMUD KG/M3 KG/S KG/S KG/S KG/S KG/S KG/S KG/S KG/S KG/S KG/S KG/S KG/S KG/S KG/S KG/S KG/S KG/S KG/S KG/S Flowing standard gas density Mass flow rate of oil-based mud in droplet Mass flow rate of produced water in droplet Mass flow rate of produced hc in droplet Mass flow rate of water-based mud in droplet Mass flow rate of gas-based mud Mass flow rate of oil-based mud in gas phase Mass flow rate of produced water in gas phase Mass flow rate of produced hc in gas phase Mass flow rate of water-based mud in gas phase Mass flow rate of oil-based mud in film Mass flow rate of produced water in film Mass flow rate of produced hc in film Mass flow rate of produced water in film and droplets Mass flow rate of produced hydrocarbons in film and droplets Mass flow rate of water-based mud in film Total mass flow rate of oil-based mud Total mass flow rate of produced water Total mass flow rate of produced hc Total mass flow rate of water-based mud O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C MDOMUD MDPH2O MDPHC MDWMUD MFAMUD MFGMUD MFOMUD MFPH2O KG/M3 KG/M3 KG/M3 KG/M3 - Specific mass of oil-based mud in droplet Specific mass of produced water in droplet Specific mass of produced hc in droplet Specific mass of water-based mud in droplet Mass fraction of all muds in total mass Mass fraction of gas-based mud in total mass Mass fraction of oil-based mud in total mass Mass fraction of produced water in total mass O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C MFPHC MFWMUD MGGMUD MGOMUD MGPH2O MGPHC MGWMUD MLOMUD MLPH2O MLPHC MLWMUD MTAMUD MTOMUD MTPH2O MTPHC MTWMUD KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 Mass fraction of produced hc in total mass Mass fraction of water-based mud in total mass Specific mass of gas-based mud Specific mass of oil-based mud in gas phase Specific mass of produced water in gas phase Specific mass of produced hc in gas phase Specific mass of water-based mud in gas phase Specific mass of oil-based mud in film Specific mass of produced water in film Specific mass of produced hc in film Specific mass of water-based mud in film Specific mass of all muds Specific mass of oil-based mud Specific mass of produced water Specific mass of produced hc Specific mass of water-based mud Link to: Drilling Variables Description Variables Global Variables Description ( See also: Variables) Global Variables ( See also: Description) Use as Global Variables Name Units Definition O|TP|C|GTP GTO|GTP GTO|GTP O|TP|C|GTP GTO|GTP GTO|GTP GTO|GTP GTO|GTP GTO|GTP GTO|GTP O|TP|C|GTP GTO|GTP GTO|GTP GTO|GTP GTO|GTP GTO|GTP GTO|GTP GTO|GTP GTO|GTP GTO|GTP GTO|GTP GTO|GTP GTO|GTP ABSMASSERR HT HTCRIT HTCRITSEC LAGFACT LAGIND NINTGR REDEL REERR RELGT RELMASSERR RETOT RETOT0 RMDEL RMERR RMLGT RMOUT RMTOT RMTOT0 SIMTIME SPEED TIME VOLGBL KG S NoUnit NoUnit NoUnit NoUnit NoUnit J NoUnit J J KG KG KG KG 1 NoUnit S - Absolute mass error Time step The current criterion used to limit the time step Section causing time step limitation Lag (drift) factor compared to reference clock expressed in number of timesteps. Lag indicator for detecting simulation is lagging compared to a reference clock. Goes to 1 when output variable LAGFACT > INTEGRATION.MAXLAGFACT, else it remains at zero. Number of time steps Relative changes of energy from start Accumulated energy balance error Total amount of energy Relative mass error Total amount of energy time integrated Initial total amount of energy Relative changes of mass from start Accumulated mass balance error Total amount of mass Cumulative mass release pipeline exit Total amount of mass time integrated Initial total amount of mass Simulated time in true time Simulation speed relative to real-time speed Simulated time Global max volume error since last write Link to: Global Variables Description Variables Heat exchanger Variables Description ( See also: Variables) Heat exchanger Variables ( See also: Description) Use as Heat exchanger Variables Name Units Definition O|TP|C|GTP DHCOOL W Heat exchanger enthalpy Link to: Heat exchanger Variables Description Variables Hydrate kinetics Variables Description ( See also: Variables) Hydrate Kinetics variables can only be used when the HYDRATEKINETICS keyword is given. Hydrate kinetics Variables ( See also: Description) Use as Boundary Variables Name Units Definition O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C Branch Variables GLHYD SRATEHYD UHYD WLHYD KG/S 1/S M/S KG/S-M2 Hydrate mass flow Shear rate used for hydrate kinetic model Hydrate slurry velocity Hydrate mass flux O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP Volume Variables MASSHYD MDPHYDC MDPPOSC MDTHYDC MDTPOSC VOLHYD KG PA M C M M3 Hydrate mass in branch Current maximum difference between section and hydrate pressure Current distance where section and hydrate pressure differs most Current maximum difference between hydrate and section temperature Current distance where section and hydrate temperature differs most Hydrate volume in branch O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C BEHYD CPHYD GASRATE HHYD HYDFRAC HYDMASS HYDPT HYDTM HYKPLIST NPARTICLE PSIHYD SAREA VISRATIO J/KG-C KG/M3-S J/KG KG/M3 PA C NoUnit NoUnit KG/M3-S 1/M - Hydrate volume fraction Specific heat of hydrate phase Hydrate gas consumption rate Hydrate enthalpy Hydrate volume fraction in slurry Specific hydrate mass Hydrate formation pressure Hydrate formation temperature CSMHYK parameter Number of hydrate monomer particles Hydrate formation rate per unit volume Hydrate formation area per per unit volume Hydrate slurry viscosity ratio Link to: Hydrate kinetics Variables Description Variables Inhibitor Variables Description ( See also: Variables) Inhibitor variables can only be used when COMPOSITIONAL key in the OPTIONS keyword is MEG, MEOH or ETOH. Inhibitor Variables ( See also: Description) Use as Branch Variables Name Units Definition TP/C/GTP INHIBMASS KG Total mass of inhibitor in branch Link to: Inhibitor Variables Description Variables Leak Variables Description ( See also: Variables) QGSTLK, QLSTLK, QOSTLK and QWSTLK are given at standard conditions (60 oF, 1 atm). A single stage flash from in-situ to standard conditions has been performed, that is, mass transfer between the phases from in-situ to standard conditions is taken into account. The gas is not dehydrated unless WATERFLASH = OFF. For table-based simulations, OLGA uses the gas mass fractions and densities from the fluid property file to perform the conversion. Note: These variables are CPU demanding for Compositional Tracking simulations since a flash must be performed for each section and time they are plotted, and should be used with care. Leak Variables ( See also: Description) Use as Leak Variables Name Units Definition O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP ACGLK ACGLKEX ACHLLK ACHLLKEX ACMLK ACQGLKEX ACQOLKEX ACQWLKEX ACWTLK ACWTLKEX DPPROD GGLEAK GGLKEX GLHLLK GLLEAK GLLKEX GLVTEMP GLWTLK GOLKEX GTLEAK GWLKEX HLEAK LMLEAK PTLEAK PTLKUP QGLKEX QGSTLK QLSTLK QOLKEX QOSTLK QTLKEX QWLKEX QWSTLK TLEAEX TLEAK WLLEAK KG KG KG KG KG M3 M3 M3 KG KG PA KG/S KG/S KG/S KG/S KG/S C KG/S KG/S KG/S KG/S W KG PA PA M3/S SM3/S SM3/S M3/S SM3/S M3/S M3/S SM3/S C C KG/S-M2 Leakage accumulated released gas mass upstream Leakage accumulated released gas mass downstream Leakage accumulated released oil mass upstream Leakage accumulated released oil mass downstream Leakage accumulated released mass Accumulated gas volume downstream of leakage Accumulated oil volume downstream of leakage Accumulated water volume downstream of leakage Leakage accumulated released water mass upstream Leakage accumulated released water mass downstream GLV change in opening production pressure Gas mass flow upstream of leakage Gas mass flow downstream of leakage Oil mass flow upstream of leakage Liquid mass flow upstream of leakage Liquid mass flow downstream of leakage GLV bellows temperature Water mass flow upstream of leakage Oil mass flow downstream of leakage Leakage total mass flow rate Water mass flow downstream of leakage Leakage enthalpy Leakage accumulated released liquid mass upstream Leakage downstream pressure Leak upstream pressure Gas volume flow rate downstream of leakage Leak gas volume flow at standard conditions Leak liquid volume flow at standard conditions Oil volume flow rate downstream of leakage Leak oil volume flow at standard conditions Total volume flow rate downstream of leakage Water volume flow rate downstream of leakage Leak water volume flow at standard conditions Fluid temperature downstream of leakage Fluid temperature upstream of leakage Leakage liquid mass flux Link to: Leak Variables Description Variables Node Variables Description ( See also: Variables) In addition to the NODE variables are many VOLUME variables available for the node Node Variables ( See also: Description) Use as Node Variables Name Units Definition NN NN NN NN NN NN NN NN NN NN NN NN DGGDPB DGLTHLDPB DGLTWTDPB DPBDGG DPBDGLTHL DPBDGLTWT GGBOU GLTHLBOU GLTWTBOU GTBOU PTBOU TMBOU kg/s-Pa kg/s-Pa kg/s-Pa Pa-s/kg Pa-s/kg Pa-s/kg KG/S KG/S KG/S KG/S PA C Gas mass flow derivative w.r.t. pressure Oil mass flow derivative w.r.t. pressure Water mass flow derivative w.r.t. pressure Pressure derivative w.r.t. gas mass flow Pressure derivative w.r.t. oil mass flow Pressure derivative w.r.t. water mass flow Gas mass flow Oil mass flow Water mass flow Total mass flow Pressure Fluid temperature Link to: Node Variables Description Variables ParticleField Variables Description ( See also: Variables) ParticleField Variables ( See also: Description) Use as Boundary Variables Name Units Definition O|TP|PP O|TP|PP O|TP|PP TP|PP TP|PP TP|PP O|TP|PP O|TP|PP O|TP|PP O|TP|PP O|TP|PP O|TP|PP O|TP|PP Mass Variables P-BOUNUMMOM1 P-BOUNUMMOM2 P-BOUNUMMOM3 P-E0-FLOW P-E1-FLOW P-E2-FLOW P-EU0 P-EU1 P-EU2 P-G P-Q P-U P-US M M2 M3 NoUnit NoUnit NoUnit M/S M/S M/S kg/s m3/s M/S m/s Number based statistical moment for r^1 Square root of number based statistical moment for r^2 Cube root of number based statistical moment for r^3 Flow of statistical moment E0(P-E0/s) Flow of statistical moment E0(P-E1/s) Flow of statistical moment E0(P-E2/s) Velocity of statistical moment E0 Velocity of statistical moment E1 Velocity of statistical moment E2 Mass flow rate Volumetric flow rate Velocity Superficial velocity O|TP|PP|NS|NN O|TP|PP|NS|NN Volume Variables P-ACCG P-ACCQ KG M3 Accumulated mass flow Accumulated volume flow O|TP|PP O|TP|PP|C O|TP|PP|C O|TP|PP CSP O|TP|PP O|TP|PP O|TP|PP O|TP|PP O|TP|PP O|TP|PP O|TP|PP O|TP|PP|NS|NN O|TP|PP O|TP|PP O|TP|PP O|TP|PP O|TP|PP O|TP|PP O|TP|PP O|TP|PP XYT O|TP|PP O|TP|PP O|TP|PP CSP DXWL HOLHTOT HOLWTOT HTKNWL P-CON P-CP P-DRDP P-E0 P-E1 P-E2 P-H P-HOL P-M P-MASSMOM1 P-MASSMOM2 P-MASSMOM3 P-NUMMOM1 P-NUMMOM2 P-NUMMOM3 P-RO P-SAUTER P-SD P-STATP1 P-STATP2 P-STATP3 U-PROFILE M W/M2-C NoUnit J/KG KG/M-N NoUnit NoUnit NoUnit J/KG-C KG/M3 M M2 M3 M M2 M3 KG/M3 M NoUnit M M NoUnit m/s Thickness of wall layer deposited at wall Oil volume fraction including all dispersions Water volume fraction including all dispersions Heat transfer coefficient of inner wall without correction for wall layer Concentration of particles along the pipe diameter Specific heat of UD Phase Pressure differential of UD Phase Statistical moment E0 Statistical moment E1 Statistical moment E2 Enthalpy of UD Phase Holdup Specific mass Mass based statistical moment for r^1 Square root of mass based statistical moment for r^2 Cube root of mass based statistical moment for r^3 Number based statistical moment for r^1 Square root of number based statistical moment for r^2 Cube root of number based statistical moment for r^3 Density of UD Phase Sauter mean diameter Particle size distribution Statistical parameter - mean value Statistical parameter - standard deviation Statistical parameter - skewness Velocity profile along the pipe diameter Link to: ParticleField Variables Description Variables ParticlePhase Variables Description ( See also: Variables) ParticlePhase Variables ( See also: Description) Use as Volume Variables Name Units Definition 1024 P-CON Concentration of particles along the pipe diameter Link to: ParticlePhase Variables Description Variables ΒΕΗΛΤΣΒ ρεπρεσεντσ τηε ηολδυπ το τηε ριγητ οφ τηε πιγ. βε α σλυγ ταιλ (πιγ το τηε λεφτ οφ τηε σλυγ) ορ βε α σλυγ φροντ (πιγ το τηε ριγητ οφ τηε σλυγ) ΤΡΕΝ∆∆ΑΤΑ ΠΙΓ=ΠΙΓ−1. Ιφ τηε πιγ ισ α σλυγ ταιλ. ΣΕΧΤΙΟΝ=5. ΒΕΗΛΤΣΒ ρεπρεσεντσ τηε ηολδυπ το τηε λεφτ οφ τηε πιγ. ςΑΡΙΑΒΛΕ=ΥΣΤ (σαµε ασ ΥΠΙΓ) ΤΡΕΝ∆ΑΤΑ ΠΙΓ=ΠΙΓ−1. Pig Variables ( See also: Description) Use as Pig Variables Name Units Definition O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP ALGL ALGR GAL GAR HOLHLL HOLHLR HOLWTL HOLWTR IDL - Void behind pig Void ahead pig Droplet fraction behind pig Droplet fraction ahead pig Oil holdup behind pig Oil holdup ahead pig Water holdup behind pig Water holdup ahead pig Flow regime behind pig (only valid without TRACKSLUG) .ParticlePhaseAndHeight Variables Description ( See also: Variables) ParticlePhaseAndHeight Variables ( See also: Description) Use as Volume Variables Name Units Definition 1024 P-SD Particle size distribution Link to: ParticlePhaseAndHeight Variables Description Variables Pig Variables Description ( See also: Variables) Αλλ τηε ϖαριαβλεσ τηατ αρε αϖαιλαβλε φορ Σλυγ τραχκινγ χαν βε υσεδ ωιτη Πιγ. ςΑΡΙΑΒΛΕ=ΗΟΛΕΞΠ Τηισ ωορκσ τηε σαµε ωαψ ασ φορ σλυγτραχκινγ. τηε ΠΙΓ µαψ βε ωιτηουτ σλυγ. νοτ αλλ οφ τηε ϖαριαβλεσ αρε ρελεϖαντ. Ιφ τηε πιγ ισ α σλυγ φροντ. Pig variable ALGL ALGR HOLHLL HOLHLR HOLWTL HOLWTR UPIG ZPIG Equivalent slugtracking variable ΑΛΤΣΒ ΑΛΤΣΛ ΒΕΗΛΤΣΒ + ΓΑΗΛΤΣΒ ΒΕΗΛΤΣΛ ΒΕΩΤΤΣΒ ΒΕΩΤΤΣΛ ΥΣΤ ΖΤΣΛ + ΓΑΩΤΤΣΒ Ωηεν τηε κεψ ΤΡΑΧΚΣΛΥΓ=ΟΝ. Τηε πιγ ϖαριαβλεσ ωιτη τηειρ εθυιϖαλεντ σλυγτραχκινγ ϖαριαβλεσ αρε λιστεδ βελοω. Ηοωεϖερ. ΤΡΕΝ∆∆ΑΤΑ ΠΙΠΕ=ΠΙΠΕ−1. ςΑΡΙΑΒΛΕ= ΒΕΗΛΤΣΒ Τηισ σηουλδ βε υσεδ ωιτη χαυτιον. For table-based simulations. that is. A single stage flash from in-situ to standard conditions has been performed. D. QOSTξD and QWSTξD (ξ = E. 2=Pigging Remaining distance for pig Averaged remaining travel time for pig Pig leakage factor Pig velocity Averaged velocity for pig Pig position in branch Pig total distance travelled Link to: Pig Variables Description Variables Pump Variables Description ( See also: Variables) Pump Variables ( See also: Description) Use as Pump Variables Name Units Definition O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP ACCTRIP GPMINFLOW GPPOW GPRECFLOW GPTHRUST GVFMIX LLMIX PUBYGG PUBYGL PUBYGT PUBYVALVOP PUMPDP PUMPGG PUMPGL PUMPGT PUMPHEAT PUMPHP PUMPQB PUMPQG PUMPQL PUMPQT PUMPSPEED PUMPTH PUMPTT PUMPVALDP PUMPVALVOP PUREGG PUREGL PUREGT PUREGW PUREQT PUREVALVOP TCM TEMPDISCH TRIP NoUnit M KG/S KG/S KG/S PA KG/S KG/S KG/S W W M3/S M3/S M3/S M3/S RPM NM W PA KG/S KG/S KG/S KG/S M3/S NoUnit C NoUnit Overall number of times the pump has tripped Minimum flow limit/total flow Used power/available power Volumetric flow in recirculation/total volumetric flow Pump pressure differential/maximum pump pressure differential Gas volume fraction in mixer Liquid level mixer Gas mass flow through bypass line Liquid mass flow through bypass line Total mass flow through bypass line Relative valve opening in bypass line Pressure difference between pump outlet and inlet Gas mass flow through the pump Liquid mass flow through the pump Total mass flow through the pump Heat added to fluid in pump Hydraulic horsepower Pump back flow (volume) Gas volume flow through the pump Liquid volume flow through the pump Total volume flow through the pump Pump speed Pump hydraulic torque Total pump power Pressure drop over valve in pump position Relative valve opening Recycle gas mass flow Recycle liquid mass flow Total recycle mass flow Recycle water mass flow Total volumetric recycle flow Relative valve opening in recycle line Choke dead band counter Temperature at pump outlet Trip signal Link to: Pump Variables Description Variables Separator Variables Description ( See also: Variables) QGSTξD. Note: These variables are CPU demanding for Compositional Tracking simulations since a flash must be performed for each section and time they are plotted. QLSTξD. The gas is not dehydrated unless WATERFLASH = OFF. 1 atm). OLGA uses the gas mass fractions and densities from the fluid property file to perform the conversion. the variables for each drain is not accurate since the flashing is performed using the PVT tables for the total composition. In addition to the SEPARATOR variables are many VOLUME variables available for the separator Separator Variables ( See also: Description) . mass transfer between the phases from in-situ to standard conditions is taken into account. and should be used with care. O and W) are given at standard conditions (60 oF. It should be noted that for simulations using PVT tables (not CompTrack).O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP IDR LIQCDOWN LIQCUP PIGM PIGSTA REMDIST REMTIME_AVRG RPIG UPIG UPIG_AVRG ZPIG ZZPIG M3 M3 KG NoUnit M S NoUnit M/S M/S M M Flow regime ahead pig (only valid without TRACKSLUG) Liquid content between plug and trap position Liquid content between launch position and plug Pig mass Pig status: 0=Not pigging. LSL. ULFSL. DPSBF. DPSB. PTJT. PTJF. BETSL. BEFSB. UGTSB. GAFSL. ULWTTSL These variables show the development of unique slugs as they pass through the pipeline. GAHLTSL. GAWTTSB. GATSB. ULTSL. LSBEXP. BEWTFSL. SLUQF. UST. ULFSB. LSB. ZTSL. QFEXP. ALFSL. BEHLTSL. BETSB. Variables for plotting properties of slugs passing at a specified section boundary: SIDEXP. DPSLF. USFEXP. JSLF. GAWTFSB. ULHLTSB. ULHLFSL. QTEXP. ULTSB. UGFSB. USF. GAFSB. ALTSB. ZSTEXP. SLUPRO 2. GAHLTSB. UGFSL. GAHLFSL. SLTYPF. Global variables: NSLUG. BEHLFSB. ULWTFSB. LSLEXP. JSLT. BEFSL. SLTYPT. BEWTFSB. BEHLTSB. ZFSL. DPSLG. ZSFEXP . ULHLTSL.Use as Separator Variables Name Units Definition NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS NS ACMDGS ACMDHL ACMDWT ACMGDGS ACMODHL ACMODWT ACMWDHL ACMWDWT ACVDGS ACVDHL ACVDWT ACVGDGS ACVODHL ACVODWT ACVWDHL ACVWDWT GGGDCONVST GNGDGS GNGDHL GNGDWT GNINDHL GNINDWT GNINGS GNINLHL GNINLWT GNODHL GNODWT GNWDHL GNWDWT GTDGS GTDHL GTDWT LIQLV OILLV PTBOTTUMN PTSEP QGSTGD QGSTOD QGSTWD QLSTGD QLSTOD QLSTWD QNGD QNOD QNWD QOSTGD QOSTOD QOSTWD QTDGS QTDHL QTDWT QWSTGD QWSTOD QWSTWD SEPEFF TMSEP WATLV KG KG KG KG KG KG KG KG M3 M3 M3 M3 M3 M3 M3 M3 SM3/S KG/S KG/S KG/S KG/S KG/S KG/S KG/S KG/S KG/S KG/S KG/S KG/S KG/S KG/S KG/S M M PA PA SM3/S SM3/S SM3/S SM3/S SM3/S SM3/S M3/S M3/S M3/S SM3/S SM3/S SM3/S M3/S M3/S M3/S SM3/S SM3/S SM3/S C M Separator: accumulated gas mass flow gas outlet Separator: accumulated total oil mass drain Separator: accumulated total water mass drain Separator: accumulated gas mass flow gas outlet Separator: accumulated oil mass flow oil drain Separator: accumulated water mass flow oil drain Separator: accumulated oil mass flow water drain Separator: accumulated water mass flow water drain Separator: accumulated gas volume flow gas outlet Separator: accumulated total oil volume drain Separator: accumulated total water volume drain Separator: accumulated gas volume flow gas outlet Separator: accumulated oil volume flow oil drain Separator: accumulated water volume flow oil drain Separator: accumulated oil volume flow water drain Separator: accumulated water volume flow water drain Separator gas train gas mass rate divided by standard conditions density Separator: gas mass flow rate gas outlet Separator: oil mass flow rate gas outlet Separator: water mass flow rate gas outlet Separator: oil droplet mass flow rate inlet Separator: water droplet mass flow rate inlet Separator: gas mass flow rate inlet Separator: oil film mass flow rate inlet Separator: water film mass flow rate inlet Separator: oil mass flow rate oil drain Separator: water mass flow rate oil drain Separator: oil mass flow rate water drain Separator: water mass flow rate water drain Separator: total gas mass flow gas outlet Separator: total oil mass drain rate Separator: total water mass drain rate Separator liquid level Separator oil level Pressure at liquid outlets Separator pressure Separator gas train gas volume flow at standard conditions Separator oil train gas volume flow at standard conditions Separator water train gas volume flow at standard conditions Separator gas train liquid volume flow at standard conditions Separator oil train liquid volume flow at standard conditions Separator water train liquid volume flow at standard conditions Separator: flow rate at gas outlet Separator: oil drain flow rate Separator: water drain flow rate Separator gas train oil volume flow at standard conditions Separator oil train oil volume flow at standard conditions Separator water train oil volume flow at standard conditions Separator: total gas volume flow gas outlet Separator: total oil volume drain rate Separator: total water volume drain rate Separator gas train water volume flow at standard conditions Separator oil train water volume flow at standard conditions Separator water train water volume flow at standard conditions Separator efficiency Separator temperature Separator water level Link to: Separator Variables Description Variables SlugTracking Variables Description ( See also: Variables) There are four main groups of slug tracking variables: 1. GAHLFSB. UGTSL. GAWTFSL. USTEXP. GAWTTSL. SLUQT. DPSL. BEWTTSB. ALTSL. Variables for plotting properties of a specific unique slug: ALFSB. BEHLFSL. ULHLFSB. ULWTFSL. 3. ULWTTSB. BEWTTSL. GATSL. UGEXP. 2 Definition sketch of void plot variables for the slug tracking option Fig. 1 Definition sketch of position and length plot variables for the slug tracking option Fig. ULEXP. BEHLEXP. ULHLEXP. 3 Definition sketch of velocity plot variables for the slug tracking option SlugTracking Variables ( See also: Description) Use as Boundary Variables Name Units Definition O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C Global Variables ALEXP BEEXP BEHLEXP BEWTEXP GAEXP GAHLEXP GAWTEXP HOLEXP HOLHLEXP HOLWTEXP LSBEXP LSLEXP QFEXP QTEXP SIDEXP SLTYPFEXP SLTYPTEXP UDEXP UDHLEXP UDWTEXP UGEXP ULEXP ULHLEXP ULWTEXP USFEXP USTEXP ZSFEXP ZSTEXP M M M/S M/S NoUnit NoUnit NoUnit M/S M/S M/S M/S M/S M/S M/S M/S M/S M M Void fraction in slug (no slug: AL) Liquid film fraction in slug (no slug: BE) Oil film fraction in slug (no slug: BEHL) Water film fraction in slug (no slug: BEWT) Liquid droplet fraction in slug (no slug: GA) Oil droplet fraction in slug (no slug: GAHL) Water droplet fraction in slug (no slug: GAWT) Liquid holdup in slug (no slug: HOL) Oil holdup in slug (no slug: HOLHL) Water holdup in slug (no slug: HOLWT) Bubble length (no slug: 0) Slug length (no slug: 0) Volume flux through slug front (no slug: 0) Volume flux through slug tail (no slug: 0) Slug identification (no slug: 0) Type of slug front Type of slug tail Droplet velocity in slug (no slug: UD) Oil droplet velocity in slug (no slug: UDHL) Water droplet velocity in slug (no slug: UDWT) Gas velocity in slug (no slug: UG) Liquid velocity in slug (no slug: UL) Oil film velocity in slug (no slug: ULHL) Water film velocity in slug (no slug: ULWT) Slug front velocity (no slug: 0) Slug tail velocity (no slug: 0) Slug front position (no slug: 0) Slug tail position (no slug: 0) GTO|GTP GTO|GTP NSLUG SLUPRO NoUnit NoUnit Total number of slugs in the pipeline Number of slugs initiated . ULWTEXP. 4. BEWTEXP. HOLEXP. BEEXP. GAEXP. UDHLEXP. UDEXP. Modified "standard" OLGA variables accounting for the effects of the slug tracking option at a specified section boundary: ALEXP. UDWTEXP Fig.These variables are nonzero only when the specified integer pipeline position is within a liquid slug. GAWTEXP. HOLHLEXP. GAHLEXP. HOLWTEXP. Slug Variables TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP TP ALFSB ALFSL ALTSB ALTSL BEFSB BEFSL BEHLFSB BEHLFSL BEHLTSB BEHLTSL BETSB BETSL BEWTFSB BEWTFSL BEWTTSB BEWTTSL DPSB DPSBF DPSL DPSLF DPSLG GAFSB GAFSL GAHLFSB GAHLFSL GAHLTSB GAHLTSL GATSB GATSL GAWTFSB GAWTFSL GAWTTSB GAWTTSL HOLFSB HOLFSL HOLHLFSB HOLHLFSL HOLHLTSB HOlHLTSL HOLTSB HOlTSL HOLWTFSB HOLWTFSL HOLWTTSB HOlWTTSL JSLF JSLT LSB LSL PTJF PTJT SID SLTYPF SLTYPT SLUQF SLUQT UDFSB UDFSL UDHLFSB UDHLFSL UDHLTSB UDHLTSL UDTSB UDTSL UDWTFSB UDWTFSL UDWTTSB UDWTTSL UGFSB UGFSL UGTSB UGTSL ULFSB ULFSL ULHLFSB ULHLFSL ULHLTSB ULHLTSL ULTSB PA/M PA/M PA/M PA/M PA/M NoUnit NoUnit M M PA PA NoUnit NoUnit NoUnit M/S M/S M/S M/S M/S M/S M/S M/S M/S M/S M/S M/S M/S M/S M/S M/S M/S M/S M/S M/S M/S M/S M/S M/S M/S Void fraction ahead of slug front Void fraction behind slug front Void fraction behind slug tail Void fraction ahead of slug tail Liquid film fraction ahead of slug front Liquid film fraction behind slug front Oil film fraction ahead of slug front Oil film fraction behind slug front Oil film fraction behind slug tail Oil film fraction ahead of slug tail Liquid film fraction behind slug tail Liquid film fraction ahead of slug tail Water film fraction ahead of slug front Water film fraction behind slug front Water film fraction behind slug tail Water film fraction ahead of slug tail Total pressure gradient in slug bubble Frictional pressure gradient in slug bubble Total pressure gradient in liquid slug Frictional pressure gradient in liquid slug Gravitational pressure gradient in liquid slug Droplet fraction ahead of slug front Droplet fraction behind of slug front Oil droplet fraction ahead of slug front Oil droplet fraction behind of slug front Oil droplet fraction behind slug tail Oil droplet fraction ahead slug tail Droplet fraction behind slug tail Droplet fraction ahead slug tail Water droplet fraction ahead of slug front Water droplet fraction behind of slug front Water droplet fraction behind slug tail Water droplet fraction ahead slug tail Liquid holdup ahead of slug front Liquid holdup behind slug front Oil holdup ahead of slug front Oil holdup behind slug front Oil holdup behind slug tail Oil holdup ahead of slug tail Liquid holdup behind slug tail Liquid holdup ahead of slug tail Water holdup ahead of slug front Water holdup behind slug front Water holdup behind slug tail Water holdup ahead of slug tail Section number of slug front Section number of slug tail Slug bubble length Slug length Pressure at slug front Pressure at slug tail Slug id Type of slug front Type of slug tail Volume flux throgh slug front Volume flux throgh slug tail Droplet velocity ahead of slug front Droplet velocity behind slug front Oil droplet velocity ahead of slug front Oil droplet velocity behind slug front Oil droplet velocity behind slug tail Oil droplet velocity ahead of slug tail Droplet velocity behind slug tail Droplet velocity ahead of slug tail Water droplet velocity ahead of slug front Water droplet velocity behind slug front Water droplet velocity behind slug tail Water droplet velocity ahead of slug tail Gas velocity ahead of slug front Gas velocity behind slug front Gas velocity behind slug tail Gas velocity ahead of slug tail Liquid velocity ahead of slug front Liquid velocity behind slug front Oil velocity ahead of slug front Oil velocity behind slug front Oil velocity behind slug tail Oil velocity ahead of slug tail Liquid velocity behind slug tail . that is. A single stage flash from in-situ to standard conditions has been performed. OLGA uses the gas mass fractions and densities from the fluid property file to perform the conversion. 1 atm). Source Variables ( See also: Description) Use as Source Variables Name Units Definition O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP DGGSDP DGLTHLSDP DGLTWTSDP DPDGGS DPDGLTHLS DPDGLTWTS GGSOUR GLHLMA GLSOUR GLWTMA GTSOUR HSOURC PTSOUR QGSTSOUR QLSTSOUR QOSTSOUR QWSTSOUR TMSOUR TSOUR USGSOU kg/s-Pa kg/s-Pa kg/s-Pa Pa-s/kg Pa-s/kg Pa-s/kg KG/S KG/S KG/S KG/S KG/S W PA SM3/S SM3/S SM3/S SM3/S C C M/S Gas mass flow derivative w.r.r.r.r. pressure Pressure derivative w.t. gas velocity Link to: Source Variables Description Variables SteamAndSingle Variables Description ( See also: Variables) Steam and single component variables can only be used when COMPOSITIONAL=STEAMWATER-HC or COMPOSITIONAL=SINGLE in the OPTIONS keyword.r. SteamAndSingle Variables ( See also: Description) Use as Volume Variables Name Units Definition O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C PSAT PVAP TSAT TSV PA PA C C Saturation pressure at fluid temperature Partial pressure of vapor Saturation temperature at system pressure Vapor temperature Link to: SteamAndSingle Variables Description Variables . pressure Water mass flow derivative w.t.t.t.r. QLSTSOUR.t. The gas is not dehydrated unless WATERFLASH = OFF. water mass flow Source gas mass rate Source oil mass rate Source liquid mass rate Source water mass rate Source mass rate Source enthalpy Valve-source pressure Source gas volume flow at standard conditions Source liquid volume flow at standard conditions Source oil volume flow at standard conditions Source water volume flow at standard conditions Valve-source temperature Source temperature Source superf. If the pressure is not given as input to the source this variable will return the pressure of the section where the source is located. oil mass flow Pressure derivative w.t. PTSOUR is the pressure specified in a pressure driven source. Note: These variables are CPU demanding for Compositional Tracking simulations since a flash must be performed for each section and time they are plotted. mass transfer between the phases from in-situ to standard conditions is taken into account. QOSTSOUR and QWSTSOUR are given at standard conditions (60 oF. gas mass flow Pressure derivative w. pressure Oil mass flow derivative w.TP TP TP TP TP TP TP TP ULTSL ULWTFSB ULWTFSL ULWTTSB ULWTTSL USF UST ZFSL ZTSL M/S M/S M/S M/S M/S M/S M/S M M Liquid velocity ahead of slug tail Water velocity ahead of slug front Water velocity behind slug front Water velocity behind slug tail Water velocity ahead of slug tail Slug front velocity Slug tail velocity Slug front position Slug tail position Link to: SlugTracking Variables Description Variables Source Variables Description ( See also: Variables) QGSTSOUR. and should be used with care. For tablebased simulations. oil carrier phase of tracer feed Mass fraction wrt. oil carrier phase of tracer age group Conc. water carrier phase of tracer feed Total mass flow rate of tracer feed Mass of tracer feed Droplet residence time of tracer feed Film residence time of tracer feed Residence time of tracer feed Specific droplet mass of tracer feed Specific film mass of tracer feed Specific mass of tracer feed Average age of tracer feed Mass fraction wrt. oil carrier phase of tracer feed Conc.wrt. wrt. water carrier phase of tracer age group TP|GTP TracerFeed Variables GSTRACER KG/S Tracer source mass flow rate O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C CONCTOTTRACEROIL CONCTOTTRACERWATER GTOTTRACER MTOTTRACER RESTIMED RESTIMEL RESTIMET SMDTOTTRACER SMLTOTTRACER SMTOTTRACER TOTAGETRACER XTOTTRACEROIL XTOTTRACERWATER KG/S KG S S S KG/M3 KG/M3 KG/M3 S - Conc. water carrier phase of tracer feed Link to: TracerTracking Variables Description Variables Valve Variables Description ( See also: Variables) Valve Variables ( See also: Description) Use as Name Units Definition . TracerTracking Variables ( See also: Description) Use as FeedAge Variables Name Units Definition O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C Source Variables AGEDTRACER AGEFTRACER AGETRACER CONCTRACEROIL CONCTRACERWATER GDHLTRACER GDTRACER GDWTTRACER GGTRACER GLHLTRACER GLTHLTRACER GLTRACER GLTTRACER GLTWTTRACER GLWTTRACER GTTRACER MDTRACER MGTRACER MLHLTRACER MLTHLTRACER MLTRACER MLTTRACER MLTWTTRACER MLWTTRACER MTRACER SMDTRACER SMGTRACER SMLHLTRACER SMLTHLTRACER SMLTRACER SMLTTRACER SMLTWTTRACER SMLWTTRACER SMTRACER XTRACEROIL XTRACERWATER S S S KG/S KG/S KG/S KG/S KG/S KG/S KG/S KG/S KG/S KG/S KG/S KG KG KG KG KG KG KG KG KG KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 - Droplet age of tracer age group Film age of tracer age group Age of tracer age group Conc. water carrier phase of tracer age group Mass flow rate of oil in droplet field of tracer age group Droplet mass flow of tracer age group Mass flow rate of water in droplet field of tracer age group Gas mass flow of tracer age group Mass flow rate of oil in film of tracer age group Mass flow rate of oil of tracer age group Liquid bulk mass flow of tracer age group Total liquid mass flow of tracer age group Mass flow rate of water excluding vapour of tracer age group Mass flow rate of water in film of tracer age group Total mass flow rate of tracer for tracer age group Droplet mass of tracer age group Mass of gas of tracer age group Mass of oil in film of tracer age group Mass of oil of tracer age group Film mass of tracer age group Total liquid mass of tracer age group Mass of water in film of tracer age group Mass of water excluding vapour of tracer age group Mass of tracer age group Specific droplet mass of tracer age group Specific mass of gas of tracer age group Specific mass of oil in film of tracer age group Specific mass oil of of tracer age group Specific film mass of tracer age group Specific total liquid mass of tracer age group Specific mass of water in film of tracer age group Specific mass of water excluding vapour of tracer age group Specific mass of tracer age group Mass fraction wrt. wrt.TracerTracking Variables Description ( See also: Variables) Tracer tracking variables can only be used when TRACERTRACKING=ON in the OPTIONS keyword. wrt. oil carrier phase of tracer age group Mass fraction wrt. Valve Variables O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP ARCH CV GCRIT GVALVE ICRIT PVALVE THROATSLIP TTHRC TVALVE TVALVEOUT UCRIT UVALVE VALSCC VALVAR VALVDP VALVOP WCRIT M2 NoUnit KG/S KG/S NoUnit PA NoUnit C C C M/S M/S NoUnit M2 PA NoUnit KG/S-M2 Choke area Valve CV (0 for chokes) Critical mass flow rate Valve mass flow Valve critical flow: 0=subcrit. 1=crit Valve pressure Slip ratio in throat (Ug/Ul) Critical temperature at throat Valve temperature Temperature at valve outlet Critical velocity at throat Valve velocity Valve sub-critical coefficient Valve flow area Subcritical pressure drop across valve Relative valve opening Critical mass flux at throat Link to: Valve Variables Description Variables Volume Variables Description ( See also: Variables) SSP gives an average speed of sound in fluid. the value is 0. Volume Variables ( See also: Description) Use as Volume Variables Name Units Definition O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|NS|NN O|TP|PP|C O|TP|PP|NS|NN O|TP|PP|NS|NN O|TP|PP|C O|TP|PP|C O|TP|PP|NS|NN O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|NS|NN O|TP|PP|NS|NN O|TP|PP|C O|TP|PP|NS|NN O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|NS|NN O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C ACCDPZA ACCDPZF ACCDPZG ACCLIQBR ACCOILBR ACCWATBR AL ANGLE BE BEHL BEHLCONT BEHLDISP BEWT BEWTCONT BEWTDISP CPG CPHL CPWT CVOL DIAM DIAMEFF DPHYD DPT DPZ DRGP DRHLDP DRWTDP DTHYD DTM ESTRESTIMEW GA GAHL GASMFR GAWT HDIAM HG HL HOL HOLHL HOLWT HTK HTKO IDIAM INCL INHIBMFR KAPPA KAPPAWALL PA PA PA M3 M3 M3 NoUnit NoUnit NoUnit NoUnit NoUnit J/KG-C J/KG-C J/KG-C NoUnit M M PA PA/S PA/M KG/M-N S2/M2 S2/M2 C C/S S M J/KG J/KG W/M2-C W/M2-C M DEGREE 1/Pa 1/Pa Integrated additional pressure drop along branch Integrated frictional pressure drop along branch Integrated gravitational pressure drop along branch Accumulated liquid volume along branch Accumulated oil volume along branch Accumulated water volume along branch Void (gas volume fraction) Pipe angle Liquid film volume fraction Oil film volume fraction Oil continuous fraction Oil dispersed in water fraction Water film volume fraction Water continuous fraction Water dispersed in oil fraction Specific heat of gas phase Specific heat of oil phase Specific heat of water phase volume error control factor Pipe diameter Effective Pipe Diameter Difference between section and hydrate pressure Time derivative of pressur Space derivative of pressure Pressure derivative of gas density Pressure derivative of oil density Pressure derivative of water density Difference between hydrate and section temperature Time derivative of temperature Residence time of water Liquid droplet volume fraction Oil droplet volume fraction Gas mass fraction relative to the mass from all phases Water droplet volume fraction Hydraulic diameter Enthalpy gas Enthalpy liquid Holdup (liquid volume fraction) Oil volume fraction Water volume fraction Heat transfer coefficient of inner wall Ambient heat transfer coefficient Inner diameter Inclination from horizontal Inhibitor mass fraction in water Compressibility of fluid Compressibility of pipe wall . However. it is only calculated if SOUND_CFL = ON in keyword DTCONTROL. Else. Waxdeposition Variables ( See also: Description) Use as Name Units Definition .O|TP|PP|C O|TP|PP|NS|NN O|TP|PP|NS|NN O|TP|PP|NS|NN O|TP|PP|NS|NN O|TP|PP|C O|TP|PP|C O|TP|PP|NS|NN O|TP|PP|NS|NN O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|NS|NN O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|NS|NN O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|NS|NN O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|NS|NN O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C MACH MD MDHL MDWT MG MHLCONT MHLDISP ML MLHL MLT MLTHL MLTWT MLWT MWTCONT MWTDISP OILMFR PSI PSIHL PSIWT PT PTMAX PTMIN Q2 QIN QM RELLENGTH ROG ROHL ROL ROWT RS RSW SECLENGTH SEG SEL SIG SSP TCONG TCONHL TCONWT TINHIBMFR TM TMMAX TMMIN TU TW TWATMFR TWS TWSO UHLDISP UWTDISP VISG VISHL VISHLEFF VISHLTAB VISL VISWT VISWTEFF VISWTTAB VOL VOLCHANGE WACBEWA WACWA WALLROUGH WATMFR WC WCWALL KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3 KG/M3-S KG/M3-S KG/M3-S PA PA PA W/M2-C W/M W/M M KG/M3 KG/M3 KG/M3 KG/M3 M J/KG-K J/KG-K N/M M/S W/M-K W/M-K W/M-K C C C C C C C M/S M/S N-S/M2 N-S/M2 N-S/M2 N-S/M2 N-S/M2 N-S/M2 N-S/M2 N-S/M2 M - Mach number Specific mass droplet Specific mass of oil droplets Specific mass of water droplets Specific mass gas Specific oil continuous mass Specific oil dispersed in water mass Specific mass liquid Specific mass of oil in film Total liquid mass Specific mass oil Specific mass water Specific mass of water in film Specific water continuous mass Specific water dispersed in oil mass Oil mass fraction relative to the mass from all phases Mass rate of flashing to gas phase Mass rate of flashing from oil phase Mass rate of flashing from water phase Pressure Maximum pressure Minimum pressure Overall heat transfer coefficient Heat transfer from inner pipe wall to fluid Heat loss per unit length from pipe wall to fluid Relative section Length from start of flowpath Density of gas Oil density Density of liquid Water density Gas mass fraction relative to hydrocarbon liquid and gas mass: (MG/ (MG+MLTHL)) from PVT table Mass fraction of water vapour in gas Section length Gas entropy Liquid entropy Surface tension Speed of sound in fluid Thermal conductivity of gas phase Thermal conductivity of oil phase Thermal conductivity of water phase Total inhibitor mass fraction in water+ vapor Fluid temperature Maximum Fluid temperature Minimum Fluid temperature Ambient temperature Temperature in center of gravity of wall (-100 C for non-existing layers) Total water mass fraction Inner wall surface temperature Outer wall surface temperature Oil dispersed in water velocity Water dispersed in oil velocity Gas viscosity Oil viscosity including wax/meg/mud effects Effective oil viscosity including dispersion effects Oil viscosity from fluid tables Liquid viscosity (no water-slip) Water viscosity including wax/meg/mud effects Effective water viscosity including dispersion effects Water viscosity from fluid tables Volume error Relative change in volume Volume fraction of free water to total liquid film Volume fraction of free water to total water in film Pipe wall roughness Water mass fraction relative to the mass from all phases Water cut (In-situ) Water cut near wall Link to: Volume Variables Description Variables Waxdeposition Variables Description ( See also: Variables) Wax deposition variables can only be used when WAXDEPOSITION=ON in the OPTIONS keyword. QLSTWELL. A single stage flash from in-situ to standard conditions has been performed. The gas is not dehydrated unless WATERFLASH = OFF. OLGA uses the gas mass fractions and densities from the fluid property file to perform the conversion. and should be used with care. For tablebased simulations. Note: The standard gas density can be given in the well input as ROGST. since ROGST is used to convert to gas mass rate and the value in the fluid property file is used to convert back to QGSTWELL (correspondingly for ROLST and QOSTWELL/QLSTWELL). but this is not used when calculating QGSTWELL.Boundary Variables O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C Branch Variables ACCGLTWL ACCGLTWS GWXDIP GWXDIS KG KG KG/S KG/S Accumulated dissolved wax mass flow Accumulated suspended wax mass flow Mass flow rate of wax dispersed in oil Mass flow rate of wax dissolved in oil O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP Pig Variables MLTWLBR MLTWSBR MTWXBR WAXMASBR WAXVOLBR KG KG KG KG M3 Mass of dissolved wax in branch Mass of suspended wax in branch Total mass of wax in branch Wax deposit mass in branch Wax deposit volume in branch O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP Volume Variables ACCPWXM ACCPWXV PIGWXBRF PIGWXPFF PIGWXPLASTV PIGWXPLEN PIGWXYIELDS KG M3 N N N-S/M2 M PA Accumulated wax mass removed from wall by pig Accumulated wax volume removed from wall by pig Pig-wax breaking force Pig-wax plug friction force Pig-wax plug plastic viscosity Pig-wax plug friction length Pig-wax plug yield stress O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C O|TP|PP|C BEWX DXWX GAWX LEWIS MWXDIP MWXDIS MWXWAL SCHMIDT TWSWX WAX_TCOND WAXAP WAXPOROSITY WXAVDC WXCDCDR WXCDIFFC WXCMCDB WXCMCDW WXDIFFC WXDR WXMPREC WXMTRW WXMTRWD M NoUnit KG/M3 KG/M3 KG/M3 NoUnit C W/M-K C M2/S 1/M M2/S NoUnit NoUnit M2/S M KG/S KG/S KG/S Volume fraction of wax dispersed in oil film Thickness of wax layer deposited at wall Volume fraction of wax dispersed in oil droplet field Lewis number Mass of wax dispersed in oil Mass of wax dissolved in oil Specific wax mass at wall Schmidt number Inner wall surface temperature adjusted for wax layer Thermal conductivity of wax film. porosity included Wax appearance temperature Wax porosity (oil volume fraction in wax film) Molar average wax diffusion coefficient Concentration gradient of dissolved wax near wall Wax component diffusion coefficient Molar concentration of dissolved wax components in bulk Molar concentration of dissolved wax near wall Apparent wax diffusion coefficient Laminar boundary layer thickness Wax mass precipitation rate Net wax mass transport rate to wall (diffusi+ shear) Wax mass transport rate to wall due to diffusion Link to: Waxdeposition Variables Description Variables Well Variables Description ( See also: Variables) QGSTWELL. Note: These variables are CPU demanding for Compositional Tracking simulations since a flash must be performed for each section and time they are plotted. Well Variables ( See also: Description) Use as Well Variables Name Units Definition O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP O|TP|C|GTP GASFRT GGSWST GGWELL GHLWST GLHLWE GLTWST GLWELL GLWTWE GTWELL GWTWST HWELL OILFRT QGSTWELL QLSTWELL QOSTWELL M KG/S KG/S KG/S KG/S KG/S KG/S KG/S KG/S KG/S W M SM3/S SM3/S SM3/S Well source gas cone front Well source steady-state gas mass flow rate Well source gas mass flow rate Well source steady-state oil mass flow rate Well source oil mass flow rate Well source steady-state liquid mass flow rate Well source liquid mass flow rate Well source water mass flow rate Well source mass flow rate Well source steady-state water mass flow rate Well source enthalpy Well source oil cone front Well gas volume flow at standard conditions Well liquid volume flow at standard conditions Well oil volume flow at standard conditions . This means that there will be a difference between the given QGSTWELL and the standard gas flowrate given by the well equations. QOSTWELL and QWSTWELL are given at standard conditions. I) Heading. as functions of reduced RPM and reduced inlet mass flow. instead of having one table for each inlet condition. compressor(I) RPMRED(K. a Rocx input file is required. compressor(I) (40 characters) PRATIO(J. a hydrate curve file might be required. RPMRED(NTABOM(I). Compressor(I) K=1. This set can be used if no pump characteristics are available.I) (-) Temperature ratio.I) Heading. through specific component data given in a feed file (Compositional Tracking) or defined in the main file (Blackoil). OLGA also requires a description of the fluid properties as a unique function of temperature and pressure.I) (kg/s) Reduced inlet mass flow. Q. compressor(I) K=1. If the OLGA Rocx module is used for simulating near wellbore. Variables: Name IDENTF NCOMTA COMPID(I) Unit Definition File identification (40 characters) (-) Number of compressors Compressor identification. . . defined below.013*105 Pa) The table values can be equidistant or non-equidistant.I) PRATIO(1. . . . compressor(I) (40 characters) Note! All characters after a blank in a character string are omitted. If pumps are used in the simulation.I) MASSRE(1.NTABOM(I) MASSRE(J. . See also Fluid properties file Compressor data file Pump data Files Wax table file Hydrate curve definition file OLGA Rocx input file Compressor data file This file contains tables of the compressor characteristics.1. the wax data are specified through a wax file. J=1.K.I) Heading. as described with the RESTART keyword.I) (r/min) Reduced RPM. .K. If a compressor is present in the pipeline. . . . Variables The definitions of reduced mass flows and reduced RPM are as follows: Reduced inlet mass flow : MASSRE = Reduced surge mass flow : MREDSU = Reduced RPM : RPMRED = G = inlet mass flow (kg/s) (kg/s) GSURGE = surge mass flow RPM = rotational speed (r/min) = normalized inlet temp = inlet temp / 288 K (-) (-) = normalized inlet pressure = inlet pressure / (1. compressor(I) NTABOM(I) (-) Number of reduced RPM points.I). MASSRE(NTABWG(I). .I) COTEXT(1. the pump characteristics are specified through a pump file. δ.NTABWG(I) COTEXT(1. or computed internally (STEAMWATERHC) A previous simulation run can be continued through the use of a restart file. These files have to be written in certain formats that are described in the following sections.I) (kg/s) Reduced surge mass flow. compressor(I) (40 characters) MREDSU(K. . . These can be given either as a fluid file. . pressure ratio table. . compressor(I) J=1.I)(-) Pressure ratio. reduced surge mass-flow table. compressor(I) K=1. temperature). .NTABOM J=1.O|TP|C|GTP O|TP|C|GTP QWSTWELL WATFRT SM3/S M Well water volume flow at standard conditions Well source water cone front Link to: Well Variables Description Variables FLUID PROPERTIES AND other DATA FILES In addition to the main file describing the simulation model. (I = 1. a file specifying the compressor characteristics is also required.I). If wax deposition is simulated.NTABOM(I). A complete set of pump characteristics is given in the code.I).NTABOM(I) Data file structure: IDENTF NCOMTA The following data is repeated for each compressor : COMPID(I) NTABWG(I) NTABOM(I) RPMRED(1. is to obtain one table for several inlet conditions (pressure. temperature ratio table.NTABOM(I). PRATIO(1. compressor(I) K=1. The reason for giving the characteristics as functions of reduced RPM and reduced inlet mass flow. .I) . compressor(I) (40 characters) TRATIO(J.NTABWG(I) COTEXT(3.NTABWG(I) COTEXT(2. NCOMTA) NTABWG(I) (-) Number of reduced mass flow points. If the possible formation of hydrate is simulated. . 14. . . 2. 20 characters. Each name may take up max.4656 1. Concentration (mol/mol) of wax components in HC mixture. oil properties should be used. • All fluids in one wax data file.I). The tables must be given in increasing order.4959 OLGA Rocx . 3. First pressure point.1. Liquid densities of wax components (kg/m3).I) MREDSU(1. the first table is for compressor number one etc. Resulting fluids with same pseudos available at bottom of fluid table from database) Use Mix to mix ”r.'C40-C50' Molecular weights (g/mol) of wax components.1. . . .NTABOM(I).1. 10. Add the inlet fluids as separate fluids. MREDSU(NTABOM(I). . . . 15 Comment lines start with an !.'C35'. 7. .3754 7. No blanks.01 . Wax phase density (kg/m3) Gas phase molecular weight (g/mol) Liquid phase molecular weight (g/mol) Wax phase molecular weight (g/mol) Enthalpy of wax (J/kg) Heat capacity of wax (J/kg K) Thermal conductivity of wax (W/m K) Second pressure point etc.6277 4. A header line must include the temperature and pressure units. which must be unique and in increasing order.4870 53. Number of pressure points. 5. . TRATIO(NTABWG(I). No more than 20 characters and no blanks. Heat of melting (J/kg) of wax components.4394 9. The wax file is generated in PVTSim. 9. Procedure for generating PVT tables in PVTSIM: 1. TRATIO(1.same pseudos” inlet fluids in proper ratios Generate OLGA and wax tables for each fluid made by ”r.5125 68.0227 77. . The table for each fluid should have the following format: 1.I) TRATIO(1.E=1. Use Fluids-> Same pseudos (Select the resulting fluids for inlets. . 4. .1369 6. The following keyword may be placed on a separate line anyplace within the lines described in point 1-14 in the list above: OIL_WAX_VISCOSITY_MULTIPLIERS D=1. .4717 41. 12.I) COTEXT(2. Example: 'C10-C20'.0003 The values for D. Ignored if PHASE = TWO. number of temperature points.9768 47. [1] Subkey not used by OLGA. 2. PRATIO(NTABWG(I).9997 60.I) Note that the number of compressor tables must equal the number of compressors. Pressure points (Pa).same pseudos” and mix. If the temperature is above the cloud point temperature. 6.I) .I). these values will override the values from the wax property file.NTABOM(I). [2] Only if PHASE = THREE. Name of table. Columns with Temperature (C) Solubility of wax component 1 (mol/mol) in oil including wax forming components Solubility of wax component 2 (mol/mol) in oil including wax forming components etc. . Wax table file This file can contain tables with the properties of the wax forming components for multiple fluids.E. .4384 11. TRATIO(NTABWG(I). VISCMULTE or VISCMULTF are given in the GUI/input file. . PRATIO(NTABWG(I). Cloud point temperatures (C) for each pressure point. NOTE! The following requirements need to be fulfilled when using multiple fluids in networks: • Same pseudo-components (number of components and lumping) for all fluids.NTABOM(I). 11.4853 32. . 8. An example hydrate definition file is shown below: TEMPERATURE (C) PRESSURE (BAR) 0. .I).002. .I) COTEXT(3. Names of wax components. F=1. Number of wax components. 4.. 3. Repeat 1-14 for next fluid 13.9738 36.7623 3. Hydrate curve definition file A hydrate curve must be defined as pairs of corresponding temperature and pressure points.I).F are the multipliers as calculated in PVTSim Note: If VISCMULTD. Component names encircled by apostrophes and separated by commas. or a file that have fluid properties as a function of temperature and pressure. It is further important that the there are no abrupt changes in property values with changing pressure and temperature. During the numerical solving process OLGA may stray outside of the 2-phase region as part of its iteration sequence before converging to a point which is inside the 2-phase region. This input file is edited with the Rocx GUI. The file may contain several feeds. 7. However. There are no specific requirements on how the properties of the non-existent phase should be generated. The user specifies a well or source with non-equilibrium inflow. This is typically done to adjust the GOR of the fluid or for simulation of gas lift. 3. Keyword based format for fluid properties This format has all the possibilities as the standard format. Feed file for compositional tracking This file is generated in PVTSim. Improve the readability of PVT table Be able to give bubble points and dew points curve to improve the accuracy close to the saturation line Use different units for the various PVT parameters Facilitate conversion between mass flow rate and volumetric flow rate at standard conditions (Not implemented yet) Be able to adapt more easily the temperature and pressure mesh to the phase envelope Make a format that is easily extendable for new parameters Provide composition information to help custom support for PVT related problems . The gas and liquid volumes in a section are then no longer well represented by the TAB file. Note that going vertically up from the critical point. That applies also if the phase the property belongs to does not exist at the pressure and temperature in question. OLGA does in certain cases use the numbers in the TAB file for the non-existent phase. The experience is that the extrapolation method is preferable. Please refer to the OLGA Rocx User Manual for how to define a proper input file for use with OLGA Rocx. The format is in principle free. 2. The file name should be given in the NEARWELLSOURCE keyword. but only one file may be referenced. OLGA considers the phase to the left (lower T) to be dense oil. There are two valid formats of the latter file. they all have to have the same format. During a shut-in the liquid in the pipeline redistributes. 2. There should be no need to view the contents of the file. This is a general limitation for labels. How this can be done is briefly described below. The format is in principle free. the user can for instance specify that there is gas present at conditions where according to the fluid file there is single phase liquid. since they in many cases in reality are used to represent fluids with slightly different composition than what the TAB file was made with. 6. SOURCE and INITIALCONDITIONS may refer to feeds defined in this file. the format is illustrated by the example below. is either a feed file with data for each component used in compositional tracking. That is. as the file will be read by the user provided DLL. so these should generally be sensible numbers rather than for instance a zero. UDFEEDFILE: File with definitions of user defined feeds to be used by the plug-in module. 5. The file can be referenced by BRANCH and NODE defining what PVT properties to be used for the user given phases in the corresponding flowpath/node. and contains data for each fluid component as well as the fluid composition (component mole fractions) for one or more feeds. For the plug-in delivered with OLGA. as the feed and component names can be chosen directly from the OLGA GUI when a feed file has been specified. Compositional: By addition of gas or condensate the phase envelope is expanded so that it passes through the P and T for which a property is to be calculated. When more than one fluid properties file is used. and some additional ones. two main approaches have been used: Extrapolation: The value and its derivative with respect to pressure at the phase boundary are used to extrapolate into the region where the property does not exist. Some examples of when the non-existent phase is used are: 1. The extrapolation of enthalpy and entropy should be consistent with thermal capacity.Rocx reads a separate input file describing the reservoir properties. and the phase to the right to be dense gas. Extrapolation of density should be consistent with the derivative of density with regard to pressure. boundary conditions and initial conditions. since the file will be read by the user provided plug-in DLL. However. The properties set for the non-existing phase must ensure that properties are continuous at the critical line so that this is a virtual transition with no actual effect. either the standard format or a keyword based format. The syntax of the file is complex. This file must be specified if UDOPTIONS COMPOSITIONAL = ON is chosen. The intension of introducing a table based format is to: 1. UDPVT FILE AND UDFEED FILE UDPVTFILE: File(s) with PVT properties to be used by the plug-in DLL. NODE. PVT properties for non-existing phase When generating an OLGA fluid properties file (TAB file) all properties need to be given at all pressure and temperature points in the file. <Number of components> 5 <Component labels> HC_G HC_L H2O PC1 <Mole weights (g/mol)> 20 300 500 600 <Property: critical P (atm)> 300 200 100 50 <Property: critical T (C)> 501 502 503 504 <Number of compositions> 2 <Composition label> FEED-1 <Component amount (mole percent)> 20 30 10 22 18 <Composition label> FEED-2 <Component amount (mole percent)> 5 10 30 30 25 PC2 700 30 505 Fluid properties file The file that contains the fluid data. Note that the fluid label cannot start with a number. 4. Subsequent pressure and temperature changes can result in a phase being present outside the region where it should be according to the TAB file. the numbers should be reasonable. but unreasonable values are often seen when extrapolation is performed far into the non-existing region. Step changes in property values will generally create numerical instabilities when a simulation is performed in that pressure and temperature region. and is not explained here. 3. Optional. Two or three phase table Equation of state used in generating the pvt table. Specifically. DENSITY1 r. Gas/oil ratio at standard conditions. SETPOINT). sym str.l.. The comment mark can be put anywhere on the line. it is ratio of gas volume MESHTYPE sym. FREETEMP: Pressure points are fixed first and the temperature points are specified for each of the individual pressure points. String protector: A string that contains spaces or commas should be protected with double quotes: " (double quote) List protector: Any list should be put inside a parenthesis: ( . Optional. repeated for each pressure/temperature point. ετχ ΠςΤΤΑΒΛΕ ΠΟΙΝΤ = ( ) For each of the pressure and temperature points End of pressure and temperature points End of tables ΠςΤΤΑΒΛΕ ΠΟΙΝΤ structure. For two-phase flow. Optional..).8. The values of all parameters except POINT must be written in a single line.. ) Table Structure A table is defined through the keyword: PVTTABLE The structure of the fluid property table is as follows: For each of the tables ΠςΤΤΑΒΛΕ ΛΑΒΕΛ = φλυιδ−1.l. Parameter set Default: [ ] [TWO] | THREE Description Name of the table. Line continuation: An input statement can be written on several lines by ending each line with the continuation character: \ (backslash) Comments: Comments are indicated with the comments mark: ! (exclamation mark) Any information on a line after a comment mark is ignored. (Pa) r. List of names of the components in the composition. r..5 ° C] r. i. STANDARD: Both temperature and pressure points are fixed independently FREEPRES: Temperature points are fixed first and the pressure points are specified for each of the individual temperature points. Optional Temperature at standard conditions (15.5 oC). Each keyword has a set of variables. Molecular weight for each of the components in the composition.. Separators: Items are separated by commas (.g. Optional.) indicate that the statement may contain more than one "KEY = Parameter list" combinations. Optional. Density for each of the components in the composition. Optional. . Set to –999 if not available. an input statement has the general form: KEYWORD KEY = Parameter list. . (kg/m3) MOLWEIGHT1 STDPRESSURE1 STDTEMPERATURE1 r. (° C) [ 1 ATM] [15. Mole fraction for each of the components in the composition. each identified by a KEY (e. Tabulation is treated as one single space.l. where the ellipses (. Fluid properties for each pressure/temperature point must subsequently be specified through the See also Keyword PVTTABLE Keyword PVTTABLE Key LABEL PHASE EOS[1] Type Unit: ( ) str. The KEYWORD identifies the input statement. (g/mol) r. [STANDARD] | FREEPRES | FREETEMP COMPONENTS1 MOLES1 str. Commas separate such combinations..e.l. GOR is interpreted as gas/liquid ratio. Easily export PVT data to spreadsheets See also The syntax of the keyword Table Structure Keyword PVTTABLE Examples The syntax of the keyword The syntax of OLGA input applies to the new table format. Pressure at standard conditions (1 atm) . (° C) NOPRES i. Only if MESHTYPE = FREEPRES Temperature points if MESHTYPE = FREEPRES or STANDARD Number of temperature points for each of pressure points given in subkey PRESSURE. Number of pressure points for each of temperature points given in subkey TEMPERATURE.r. TCHL (W/m° C) Oil thermal conductivity. Key . (-) DEWPRESSURES r. Pressure at the critical point Temperature at the critical point. set GOR = -999. (-) r. HWT (J/kg) Water enthalpy.t (s2/m2) pressure DROGDT Derivative of gas density w. PRESSURE COLUMNS r. The default unit is given in parenthesis TM (° C) PT (Pa) fraction to the liquid volume fraction at standard conditions.2 DROWTDP Derivative of water density w.t DROHLDP pressure (s2/m2) DROHLDT Derivative of oil density w. HHL (J/kg) Oil enthalpy. set GLR = 999.l. Oil density at standard conditions.l.2 VISG (Ns/m2) Gas viscosity.r.l.t (kg/m3° C) temperature ROWT (kg/m3) Water density. TEMPERATURE r. The subkeys DEWPRESSURES and DEWTEMPERATURES are optional.l.2 DROWTDT Derivative of water density w. Bubble point pressures Bubble point temperatures corresponding to the bubble point pressures given in keyword BUBBLEPRESSURES The subkeys BUBBLEPRESSURE and BUBBLETEMPERATURE are optional.2 STDGASDENSITY1 STDOILDENSITY1 STDWATDENSITY1. Gas/liquid ratio at standard conditions.r. For cases where there is no oil/liquid.r. Temperature Pressure Gas mass fraction in gas/oil RS (-) mixture Water vapour mass fraction in RSW (-) gas phase2 ROG (kg/m3) Gas density DROGDP Derivative of gas density w. (° C) NOTEMP i. (Sm3/Sm3) r. Leave out these two subkeys if no dew point curve is found Dewpoint temperatures corresponding to the dewpoint pressure given in keyword DEWPRESSURES. If the critical point is not found. C) CPG (J/kg° C) Gas thermal capacity. For cases where there is no liquid. VISHL (Ns/m2) Oil viscosity.r. either set the values of critical pressure and temperature to –999. (kg/m3) r.l.t (kg/m3° C) temperature.2 HG (J/kg) Gas enthalpy. (Pa) DEWTEMPERATURES BUBBLEPRESSURES r. CPWT (J/kg° C) Water thermal capacity. Water density at standard conditions. The subkeys CRITICALPRESSURE and CRITICALTEMPERATURE are optional. Dewpoint pressures. (° C) CRITICALPRESSURE r. (kg/m3) r.t (kg/m3° C) temperature ROHL (kg/m3) Oil density Type Unit: ( ) Parameter set Description Default: [ ] Derivative of oil density w. (Pa) CRITICALTEMPERATURE r.r. Mass fraction of water component in the composition. (Pa) BUBBLETEMPERATURES r. (pa) sym.[2] TOTWATERFRACTION2 r. Water cut standard conditions.(Sm3/Sm3) GOR1 GLR1 WC1. TCWT (W/m° Water thermal conductivity.l. (° C) r. CPHL (J/kg° C) Oil thermal capacity. or leave out these two subkeys.l.2 TCG (W/m° C) Gas thermal conductivity. Leave out these two subkeys if no bubble point curve is found.t (s2/m2) pressure.l.l. Only if MESHTYPE = FREETEMP Pressure points if MESHTYPE = FREETEMP or STANDARD Specify orders and units of parameters for a table point. Gas density at standard conditions. (kg/m3) r. for three-phase table only. 02.POINT r.81.\ 307.343.32.95. \ STDTEMPERATURE = 15.37. 9. Standard mesh type Example 2: Two-phase.7 KG/M3. 9.86) C.284E-02.12.66.TCHL.62.49.95.14.69.86. \ 4.1.34.513E-07. 0. 5.59) C. \ 28.5 C. 4.…) … PVTTABLE POINT = (1.330.0. \ CRITICALTEMPERATURE = 156.l.74. 14.90.74 .73. \ GLR = 768 SM3/SM3.79) BARA.884E+05.16.21.228.312. \ STDGASDENSITY = 1. 1.01.330.345.03.37.78.39.41.1.357.54.\ PRESSURE = (1.79. \ COMPONENTS =(N2.0.0.0.291.3.RS.-17.44. 70. HHL.41.0.81.331.358. 9.01.2.\ DEWTEMPERATURE = ( 281.557E-03. freepressure mesh type PVTTABLE LABEL = FLUID-1.SIGGHL. \ ! !both temperature points and pressure points are fixed ! TEMPERATURE =(1.1.22.57. \ 327. IC4.04. \ BUBBLEPRESSURE=( 352.338. \ 44.53.73. 55. 67.1. DROGDT.628E-01.35.67.) … ) PVTTABLE POINT = (5. Surface tension between gas and SIGGWT (N/m) water. 22.1.317. \ CRITICALPRESSURE (345. \ 328. 2. Note 3: The use of pressure and temperature dependant values in the complex fluid module is not yet implemented.1.278.\ 2. NC4.247.295.92.85.16.30.58..71.0.74.-32.312.88.0.0.324.CO2.289.\ 328.278.154.81.54.296.1.816E+02.28.160.194.331.0.331. \ -5.1.213. \ 332. C3.00.SEG.328.97.309.0.154.103.00.1.39. \ DROHLDT. 2 SIGHLWT Surface tension between oil and (N/m) water. C6.\ STDPRESSURE = 1 ATM.738E-02.\ MOLES = ( 4.85.617E-01.15.64.301.1.SEHL) PVTTABLE POINT = (1.86.58.\ 73. C6. -3. \ 261.56.39.931E-01.CPHL.56.65.194.335.3.5. Examples Example 1: Two-phase.\ 327.0.15. \ 247.58.35.96.1.302.\ 179.2.44.30.67.50. TM C. \ STDOILDENSITY = 787.70.72.5) C.0..85. \ COLUMNS =(PT BARA. IC4.96.0.46. 1. \ STDOILDENSITY = 787.666E-06.299E-03. -3. 11.TCG.15.01.379E-01. SEWT (J/kg° C) Water entropy.50. \ 179.156.85.321.67. PHASE = TWO.321.125.84.0. 8. 7. 26. 18.71.68) BARA.65.72.32.919E+02.\ MOLWEIGHT = (28. 1.C2. VISWT Water viscosity.99.\ MOLWEIGHT = (28.\ -13. \ 102.325. 18. 28.57.5. Temperature must be the same as specified in the keys TEMPERATURE for mesh type FREEPRES.0.44.39.65.27.44.44.13.78.298.325. 36.00. \ GLR = 768 SM3/SM3.56. 84.58.330. Note 2: The order and the units must be the same as specified in the key COLUMNS. \ -7.0.79.48..03) .85.152.0. IC5. Standard mesh type Example 1: Two-phase.04.41. PHASE = TWO.7 KG/M3 . DROGDP.72.37.5.VISG.00.312. 1.789) g/cm3 .4. 35.1.41.3.02.31.C1. \ . Pressure must be the same as specified in the keys PRESSURE for mesh type FREETEMP.\ DENSITY = (0.55. ROHL KG/M3.291.0. 6.302.NC5.298.NC5.321. ROG KG/M3.125.321.330.32.112.59) C.290.62.1.46.62.6.285.04.0. \ 18.0.0.76.65.254.87.C7) .2 Values of parameters.90.44.789) g/cm3 STDPRESSURE = 1 ATM.\ 261.27.1.CPG.72.69.11.66. freepressure mesh type Example 3: Two-phase.\ MOLES = ( 4.HG. SEHL (J/kg° C) Oil entropy.805E+03.0.65.91.5.00.356.3.00.15.) … ) PVTTABLE POINT = (5.0.99.39.65.32.72.1.52.317.74. 1. 10.7. \ STDGASDENSITY = 1.50. \ MESHTYPE = STANDARD.160.220.55.74. \ DEWPRESSURE = ( 5.50.68) BARA.36.2 Surface tension between gas and SIGGHL (N/m) oil. 7.44.0. \ COMPONENTS =(N2. \ 321.56.07. DROHLDP..22.44.170.…) Example 2: Two-phase.15.0 KG/M3.91. freetemperature mesh type Example 4: Three-phase.321.39.87.278. IC5. Note 1: The pressure and temperature values must be the same as specified in the keys PRESSURE and TEMPERATURE for mesh type STANDARD.5.64.054E-05.39.52.170.84.358.9.C7) .44.72.296. \ DEWTEMPERATURE = ( 281.320.28.96.84.2.228.300.15.65.0.39.01.85.3) .156.03).VISHL.13.5 C. \ 284.213.16. see note 1 and 2 below. \ 307. \ 354. \ 304.59 C.184.92.247.2.0.74.285. \ DEWPRESSURE = (5.55.331.3) DENSITY = (0.841E+02.2.03.97.11.-9.1.\ 14.85. NC4.4.40. C3.2.85.02.12.01.312.04. Standard mesh type PVTTABLE LABEL = FLUID-1.1.304.810E+02) PVTTABLE POINT = (1.CO2.346.09.0.55.0.2 (Ns/m2) SEG (J/kg° C) Gas entropy.48.81.963E+03.267. 2. 54. 3. \ BUBBLETEMPERATURE=( 139. \ STDTEMPERATURE = 15.85.66.68.72.62.13..6.317. -1.C1.1.C2.56.5) BARA.313.2.67.5.85.78.20.18.41.85.0 KG/M3. 48.284E-02.46.VISHL.11.15.312.102.7 KG/M3.5.213.44.\ -13.15.5.3.64.-17.40.DROHLDT.0.. \ 1.27. \ PRESSURE =(1.112. 8. \ 354.805E+03.15.0.41.13.617E-01.0.04.11.16.92.00.the pressure values are given in subkey POINT TEMPERATURE =(1.) PVTTABLE POINT = (7. \ CRITICALPRESSURE (345.330.96. 2.C2.296.15.\ MOLES = ( 4. \ COMPONENTS =(N2.-5.22. 9.55.52.0.328.72.304.0.46.59 C.345.513E-07. ! Number of temperature points and temperature values can change for ! (be dependent on) different pressure points.617E-01.35.) PVTTABLE POINT = (9.52.15.36.85.85.VISG.96.09.86) C.5.5.379E-01. \ CRITICALTEMPERATURE = 156.194.5.86) C.54.01. 1.49. TM C.0.313. DROGDP.44.810E+02) PVTTABLE POINT = (2.0. DROGDP.356.SEG.39. 36. \ 1.1.0. 1. 4.85.343.628E-01.SEG.931E-01. 1.0. ROHL KG/M3.2.295.357.302.299E-03. 7.963E+03.0) C.328.919E+02. 6.0.92.…) PVTTABLE POINT = (1.0.346.4.67.5.0.55.81.0.379E-01. 9.789) g/cm3.41.356.ROG KG/M3.0.335.44.295. ROG KG/M3..298.36.74.86.1.76..\ 179.841E+02.357. 10.55.72.184.0.C1.285.44.1.…) PVTTABLE POINT = (5. \ MESHTYPE = FREEPRES.0.35.84.\ MOLWEIGHT = (28.0.289. point contains five pressure points ranging from 1 to 10 bara PVTTABLE POINT = (1. 1..291. 6.59 C. 1.74.738E-02.220.12. \ BUBBLEPRESSURE=( 352.313. 4.0 KG/M3. 2.0.85.81. ! number of pressure points and pressure values can be different for ! (be dependent on) different temperature points.72.37.278.VISHL.919E+02.96.50.312.0.5. \ 1.299E-03.0. \ CRITICALPESSURE (345.1.…) ! ! more temperature points.90.-9. \ CRITICALTEMPERATURE = 156.14.53.0.963E+03.68) BARA.39. \ 247.85.97.01.358. \ BUBBLEPRESSURE=( 352. 8. ! number of pressure points for each of the temperature points are given here !.1.267. 26.…) PVTTABLE POINT = (1.\ 327.5.\ 307. NC4.RS. \ 84.228.1.\ -13.39.CPHL.99.2.56.254.13.65.15.0.79. \ 284.513E-07.12.6). \ 332.841E+02.62.0.78.58.331.67.18.3.325.TCHL.\ COLUMNS =(PT BARA.810E+02) PVTTABLE POINT = (1. ROHL KG/M3.\ 2.67. 26.-5. DROHLDP.54.66.HHL.71.666E-06.317.805E+03. \ 321.81.278. 7.\ 73.13.15.09.58.. \ ! ! Pressure points are specified here. 54.SIGGHL.160. PHASE = TWO.) PVTTABLE POINT = (6. \ ! ! temperature points are specified here.15.49.68. \ 332. 9.330.CPHL.79) BARA.TCG.52.C7) .76.0. freetemperature mesh type PVTTABLE LABEL = FLUID-1. \ DROHLDP.18.SIGGHL.358.301.321.125.85.74. 36.65.…) PVTTABLE POINT = (10.884E+05.0. Each has five pressure points. \ 304.VISG.\ 22.345...21.85.1. \ 247.46.289.00.\ DENSITY = (0.68) BARA.96.35.0) BARA.41.331. \ -3. \ -3..4. IC4.0.31.0. TM C.69.301.278.338.56. 9.65.0. \ 304.53.309.70.00.52.5.321. 1. \ 321.00.0.0.65.85.66.\ 328.358.320.5..152.85.125.125.324. \ STDOILDENSITY = 787. 2.2.152.5.267.) PVTTABLE POINT = (5.320.335.0.…) .37. \ BUBBLETEMPERATURE=(139.0.0.96.1. \ TCHL.44.3.0.931E-01.5.338. \ STDGASDENSITY = 1.72. \ DEWPRESSURE = (5.SEHL) ! First pressure point contains five temperature points ! Temperature ranging from 1 to 20 C PVTTABLE POINT = (1. \ 73. 3.15.57. 1.…) PVTTABLE POINT = (3.34.0.68) BARA.324.) PVTTABLE POINT = (8.184.317.92.247.46.2.07.22.0.39.317.0. 4.5.6.0.40.85.02.00.32.557E-03.0.290.\ 261.85..85.11.78.01.0. \ STDTEMPERATURE = 15. C3. \ HHL.30.07.73.557E-03.309.44. 18. \ BUBBLETEMPERATURE=( 139.65.91.68.5 C. \ 18.. C6.054E-05.220.1.00.59) C.156.0.01.81. \ 18.72.34..66.358.50.87.-32.85.41.CPG.0.884E+05.NC5.5.03).300.0.CPG.321.95.0.78.9. -1. 3. 14.\ 2.39.12.\ NOPRES =(5.0. \ STDPRESSURE = 1 ATM. ! … ! !last temperature point contains six pressure points ! PVTTABLE POINT = (1.85.31.816E+02.28.67.HG. 4.666E-06.300.284E-02.0.HG..103.81.-32. \ 354. \ DEWTEMPERATURE = ( 281.56.CO2. IC5. -7.96.44.62.4.7. \ 1.5.32.321. 10.0.DROGDT.-9.170.68) BARA.79) BARA.04.88.816E+02. -7.\ NOTEMP =(5.-3..290. 0.0.85.56.054E-05.39..-17.RS.304.154.628E-01.103.16.16.20.88.92.DROHLDT.12.6).02.346. 2.85.1.\ COLUMNS =(PT BARA.TCG.02. ! Number of temperature points for each of the pressure points are given here !.102.125.10.37.0.. \ 284.55.1. \ DROGDT.3).03. -3.44.112.28.) Example 3: Two-phase.0.The temperature values are given in subkey POINT MESHTYP = FREETEMP.21.5.0. 2.0.1.5.20.39.SEHL) ! first temp. -1.5.0.343. \ GLR = 768 SM3/SM3. 14.1.254.738E-02. 02. STDGASDENSITY.85.CO2.66.79.\ 261.CPHL.-.1..3.789) g/cm3 STDPRESSURE = 1 ATM.263150E-02.325.85. 35.01.148744E+00.39. \ GLR = 768 SM3/SM3.20.34.. 84..0..332632E+00.SEG.194. \ DEWPRESSURE = ( 5.85.96.69.86) C.248102E-01.41.85. ! … ! !last pressure point contains six temperature points ! PVTTABLE POINT = (5.152. \ .708593E+03.154.32..324.12. \ 102.67.00..99.13.86.88.TM..1.357.15.1.0.7 KG/M3.76.0.96.TCG.32.358.6.591224E-02.330..) PVTTABLE POINT = (5.01.979882E-05.PVTTABLE POINT = (1.196628E+07..345943E+06..66..52.112510E+01.DROHLDT.321. 7. while GOR.317. Each has five temperature points.-.-.2.118942E-01.0..2.112.358.30.5.44.62.-.) … ) PVTTABLE POINT = (5.72.72.HWT.56.. STDOILDENSITY is the density for HC only and thus does not contain the necessary information. \ -.182867E-02.184. A new key STDLIQDENSITY will be introduced in the next PVTsim version.97.37.346.0. \ CRITICALPRESSURE (345. \ ! !both temperature points and pressure points are fixed ! TOTWATERFRACTION = 0.44.\ 179.3. 10. \ 304.13.03. A more refined interpolation in the fluid property tables close to the two-phase envelope is performed only for the gas mass fraction utilising the bubble point pressure given in the file. If the keys are not present (removed manually since always written).09. \ BUBBLETEMPERATURE=( 139. 5.39.00. Standard format for fluid properties The fluid properties are given as functions of pressure and temperature.\ 307. 18. This will give more precise results in simulations where e. GORST in WELL is used and the table is coarse around the standard conditions (e.28.HG.278. These properties may be given as tables in the fluid properties file.DROGDP.20.0. KG/M3.65.39.296..0.55.) PVTTABLE POINT = (5.125.291.46. 1.68.C1.0.331. 70.0.338.289.71. If OLGA is used with the water option.313.328.92.16.731026E+02.285.TCWT. STDOILDENSITY.…) ! ! more pressure points. \ CRITICALTEMPERATURE = 156. water properties are also needed.15.1. 36.5.-17. \ 354. \ STDGASDENSITY = 1.78.321.00.56 ° C/60 F.58.g.07.156303E-06.74 ..\ 327.90.SIGGWT.301.37.85.113188E-04.1.2.31. 54.0.52.677649E+03. NC4.58.309.13.SIGHLWT.0.1.ROG. \ STDOILDENSITY = 787.278..312.4.0.SEWT) ! PVTTABLE POINT = (1.0.44.0.\ 14.RSW.156. 9.84. Standard mesh type PVTTABLE LABEL = FLUID-1. 67.0.02.87. 0. 55.15.39.22.. IC4..1.228.01. GLR.DROHLDP.220.15.302..CPG.50.-.2... 6.320... 26.) PVTTABLE POINT = (5.C7) .54. 22. \ COMPONENTS =(N2.15.372160E-01..489380E-02. \ 44. \ 18.95.50.. \ .DROWTDP.254.ROWT.72.5) C. 11. 28.65.) Example 4: Three-phase.330.1 and 10 bara) since the gas mass fraction is not linear with pressure for such low pressures.41.1.125.2. 18.73.356.0. PHASE = THREE.755188E-01.304.0 KG/M3..520848E-06.\ -13.74.59) C. \ DROWTDT.321.0.NC5.27.85.213..59 C. \ COLUMNS = (PT.85.11.0.202253E+04. \ STDWATDENSITY = 998.317. .\ MOLES = ( 4.570657E+00.85.67.449390E+04..418187E-02.176425E+04.0.300.C2.VISWT.49. \ TCHL.g.298.290. Figure A shows the above mentioned two-phase envelope as a function of pressure and temperature.79) BARA.3.) … ) PVTTABLE POINT = (5.0.12. 5.68) BARA. IC5.4. \ .0. Note that the given STDPRESSURE and STDTEMPERATURE will be used for both input and output instead of the default values of 1 atm and 15.44.53...03)..170. \ WC=.312.14.0.64.247. \ BUBBLEPRESSURE=( 352.96.72.544038E-01.HHL.) PVTTABLE POINT = (5.35.0.…) Standard conditions for keyword based PVT file STDPRESSURE and STDTEMPERATURE in the PVT table file (keyword format) are the standard pressure and temperature given in PVTsim when creating the file.ROHL.3) DENSITY = (0. 14.39. This table of properties can be equidistant or non-equidistant in pressure and temperature.36.1.40. \ MESHTYPE = STANDARD.56.RS.…) … PVTTABLE POINT = (1..65.345.535346E+00.\ TEMPERATURE =(1.435748E+03. C6.-32.04.335.0. \ 247. \ .) PVTTABLE POINT = (5.44.CPWT.20. \ DEWTEMPERATURE = ( 281.91.15.\ 2..55.0.DROGDT.57...81.04.16.0. \ 284.112.46.68) BARA.SIGGHL.74. or may be calculated by the code itself.78.5 C.. linear interpolation between the pressure and temperature points will be used as before.41. STDWATDENSITY and WC (the two latter only for 3 phase table files) are the properties at this standard condition.62.537537E+04) PVTTABLE POINT = (1. \ 332.\ 328.5. \ 321.85.103.\ MOLWEIGHT = (28.65.5) BARA. C3.\ PRESSURE = (1.331.92.56.5.295.-9.00. This gives the standard density of liquid water and hydrocarbons (HC) in the case where a two phase PVT file is generated from a composition with water.160. The dew point pressures are not used in the present OLGA version.0.81.1.SEHL. \ STDTEMPERATURE = 15.48.VISG.631419E+03. -1.\ 73.343.81.21.VISHL.0.267. if the two lowest pressure is 0. NTABT and I = 1.LAB_2. If the sub-string "NONEQ" is present. at the actual thermodynamic conditions.I) HGTB(J. NTABT For temperatures in the table which indicate single phase flow for the whole range of pressures (all points are outside the two-phase envelope for a specific temperature. Variables: Name Unit Definition File identification (60 characters) [FILEID] [NCOMP] Number of fluids in this file.I) (kg/m3) Gas densities ROOTB(J. Liquid properties must be for the mixture of oil and water. as follows: If the sub-string "WATER-OPTION" is present. REMARK: The gas may also contain water vapour.I) (s2/m2) pressure Partial derivatives of oil densities with respect to DROPTB(J. in the fluid identifier.NTABP Temperature values in the table. ( = 0 gives single phase liquid. FLUIDF.I) HOTB(J. gas or liquid. 2. however.I) (Ns/m2) (Ns/m2) (Ns/m2) (J/kgC) (J/kgC) (J/kgC) (J/kg) (J/kg) (J/kg) Dynamic viscosities for gas Dynamic viscosities for oil Dynamic viscosities for water Gas heat capacities at constant pressure Oil heat capacities at constant pressure Water heat capacities at constant pressure Gas enthalpies Oil enthalpies Water enthalpies . Partial derivatives of gas densities with respect to DRGTTB(J..I) (kg/m3C) temperature Partial derivatives of oil densities with respect to DROTTB(J. J = 1. NTABT Bubble point pressures. The content of the fluid identifier. J = 1. the gas mass divided by the gas and oil mass. NTABP ROGTB(J. NTABT Dew point pressures.. J = 1. only two-phase tables for fluid properties must be used.I) Oil densities (kg/m3) ROWTB(J. NCOMP and LC can be collectively omitted for single branch cases.I) (kg/m3C) temperature Partial derivatives of water densities with respect DRWTTB(J. Remarks: -The gas mass fraction may not be zero for pressures above the bubble point pressure due to linear interpolation in the tables. =1 gives single phase gas). J = 1. The input variables FILEID.I) (kg/m3C) to temperature. The following data are repeated for each fluid: Fluid identifier enclosed in apostrophes. the gas mass fraction calculated from the tables will. three phase tables are expected in the file.I) (s2/m2) pressure Partial derivatives of water densities with respect DRWPTB(J. Optionally. (LAB_1. default value = 0 (Only used together with three-phase tables) Pressure step in the table Temperature step in the table Pressure values in the table.I) CPOTB(J.I) HWTB(J. FLUIDF. NONEQ FLUIDF (-) [LC] NTABP NTABT RSWTOTB DP DT PP(I) TT(J) PBB(J) (-) (-) (kg/kg) (N/m2) (°C) (N/m2) (°C) (N/m2) or ENTROPY the tables will be read as explained above. The dew point pressures are not used in the present OLGA version PDEW(J) (N/m2) TABTEX(L) (-) Text string to identify the different properties.I) Water densities (kg/m3) Partial derivatives of gas densities with respect to DRGPTB(J. If the fluid contains water and it is decided to use the two phase option in OLGA.I) (kg/kg) VSGTB(J. . Whether there is more than one fluid. Gas mass fraction in gas and oil mixture. All values in this table must be set to a constant (between 0 and 1) (for all points) in case of no interphase RSGTB(J.I) CPGTB(J.LAB_NCOMP) Number of pressure points in the table Number of temperature points in the table Total water mass fraction for the feed. For pressures above the bubble point pressure.I) (s2/m2) to pressure. Fluid label The label must be unique and may be a number or a text string. If FLUIDF contains the sub-string WATEROPTION. the corresponding bubble point pressures must be greater than the largest pressure point in the tables. . The partial derivatives of gas and liquid densities with respect to pressure and temperature are required as separate tables. always be set to zero. These cannot be obtained from the densities by interpolation in the tables since the partial derivatives in that case would also include phase mass transfer/changes in phase compositions.I) CPWTB(J.I) VSOTB(J. non-equidistant spacing in the tables are expected. If the sub-string "ENTROPY" is present. I=1. Water vapour mass fraction in the gas phase RSWTB(J. NB! For all tables below. see Figure A). oil and eventually water are expected. given in the fluid properties file.I) (kg/kg) mass transfer.This is determined by the text. The reason is that the partial derivatives should be those of the isolated phase. Indicators for the fluid file content: The interpretation of tables in the fluid properties file is determined from: 1. entropy tables for gas.I) VSWTB(J. I) TKWTB(J. Note that RSWTOTB is set to zero by OLGA if omitted: FLUIDF [LC] NTABP NTABT RSWTOTB PP(1) . . . . . . then TABTEX(3) ROWTB(1. Note that RSWTOTB is set to zero by OLGA if omitted: FLUIDF [LC] NTABP NTABT DP DT PP(1) TT(1) RSWTOTB The file heading for non-equidistant tables. . Figure A Example of the use of the bubble and dew point pressures in relation to the two-phase envelope and the fluid property table points (NTABT=6 and NTABP=5). . . . . Data file structure: The data enclosed in brackets can collectively be omitted for single branch cases. . . . ROGTB(NTABT. . .I) TKOTB(J. . . DRGPTB(NTABT. . . . . .NTABP) . . .1) . .TKGTB(J. . PDEW(NTABT) TABTEX(1) ROGTB(1.1) . .I) (W/mC) () (W/mC) (N/m) (N/m) (N/m) (J/kgC) (J/kgC) (J/kgC) Gas thermal conductivities Oil thermal conductivities Water thermal conductivities Surface tension between gas and oil Surface tension between gas and water Surface tension between water and oil Gas specific entropy Oil specific entropy Water specific entropy. ROGTB(1. .I) SOTB(J. .1) . DRGPTB(1. . . . ROWTB(NTABT. . . . ROOTB(1. ROOTB(NTABT. .1) . . . ROWTB(NTABT. . . . . The figure does not correspond to the tables of fluid properties used in the sample case.NTABP) .I) SWTB(J.NTABP) . .1). DRGPTB(NTABT. PP(NTABP) TT(1) . PBB(NTABT) PDEW(1) .1) . . ROOTB(NTABT. . . The file heading for equidistant tables. .I) SIGWGT(J. ROWTB(1.I) SIGOGT(J. . . TT(NTABT) The fluid property tables: PBB(1) .NTABP) end WATER-OPTION TABTEX(4) DRGPTB(1.NTABP).NTABP) TABTEX(5) DROPTB(1.1). .1) . .NTABP) if FLUIDF contains substring WATER-OPTION. .1) .NTABP) TABTEX(2) ROOTB(1. . . . . . . . .I) SGTB(J. . DROPTB(NTABT. . . ROGTB(NTABT. . . . .I) SIGWOT(J. . . . . . . . . [FILEID] [NCOMP] The following data are repeated for each fluid composition.1) . . . . . . . . . .DROPTB(1.1) .NTABP) if FLUIDF contains substring WATER-OPTION.1) . . . .1) . . RSWTB(1. . . .NTABP). . . . then TABTEX(14) VSWTB(1. . CPWTB(NTABT. .1) . . .1) . . . .1).NTABP) if FLUIDF contains substring WATER-OPTION. . . HWTB(1. . VSOTB(NTABT. . .1) . .NTABP) end WATER-OPTION TABTEX(18) HGTB(1. RSGTB(NTABT. . . DROTTB(1. . DRGTTB(NTABT. .NTABP) end WATER-OPTION TABTEX(15) CPGTB(1. . . . . DRWPTB(1. . .1). . then TABTEX(6) DRWPTB(1. VSOTB(1. . . . . . . . DRWTTB(NTABT.1) .NTABP). . .NTABP) TABTEX(19) HOTB(1. DRWTTB(NTABT.1) .NTABP) end WATER-OPTION TABTEX(21) TKGTB(1. HGTB(NTABT.NTABP) . . . .1) .NTABP). . .1) . . .1) . RSGTB(1. . . TKGTB(NTABT. VSWTB(NTABT. . . . .1) . . . . CPGTB(NTABT. . . . . DRWTTB(1.1) .1) . . . .1) .NTABP) .NTABP) end WATER-OPTION TABTEX(7) DRGTTB(1. CPWTB(1. VSGTB(1. HGTB(NTABT. .1).NTABP).NTABP). .1). .1) . . . .1) . .NTABP) end WATER-OPTION TABTEX(10) RSGTB(1. . . . DROPTB(NTABT. . .NTABP) TABTEX(8) DROTTB(1. .NTABP) if FLUIDF contains substring WATER-OPTION. .NTABP) TABTEX(16) CPOTB(1. . CPOTB(NTABT. . . . . . DRWPTB(NTABT. . . . . . then TABTEX(17) CPWTB(1. .1) . .NTABP). .NTABP) .NTABP) . VSWTB(NTABT. .NTABP) if FLUIDF contains substring WATER-OPTION. CPWTB(NTABT. . . . . . CPGTB(1. .NTABP) . . . RSWTB(NTABT.1) .NTABP) end WATER-OPTION TABTEX(12) VSGTB(1.1) . DROTTB(NTABT. VSWTB(1. .NTABP). . . VSOTB(NTABT. . . . . then TABTEX(20) HWTB(1. . . . .1) . HOTB(NTABT. . . HOTB(1. HGTB(1. CPGTB(NTABT. . .1) . . . .NTABP) TABTEX(13) VSOTB(1.NTABP). . RSGTB(NTABT. then TABTEX(9) DRWTTB(1.1) . . HWTB(NTABT. . . .NTABP). . . . . . DRGTTB(1. . . . VSGTB(NTABT. . . . . . .1) . . . . . CPOTB(1.NTABP) . . . .1) .1). . . then TABTEX(11) RSWTB(1. HOTB(NTABT. . .NTABP) . DRWPTB(NTABT. . . CPOTB(NTABT.NTABP) if FLUIDF contains substring WATER-OPTION. . . . . . VSGTB(NTABT. . .NTABP) if FLUIDF contains substring WATER-OPTION. . . . . . . . DROTTB(NTABT. .1) . DRGTTB(NTABT. RSWTB(NTABT. . HWTB(NTABT. . .1) . . . . enthalpy and thermal conductivity are used only for temperature calculations. The fluid property file contains a table of yield stress for the water phase. The tables for heat capacity.1) .NTABP) .1) .NTABP) .NTABP) . . . . . . . .NTABP) . TKWTB(NTABT. . . . . .1) . SIGWGT(NTABT.1) . . .NTABP) TABTEX(28) SOTB(1. . . . then TABTEX(:) . SIGWOT(NTABT. . . . POWEXPL: POWEXPW: YIELDSTRL: YIELDSTRW: The fluid property file contains a table of the power law exponent for the oil phase. . then TABTEX(25) SIGWGT(1.NTABP) if FLUIDF contains substring WATER-OPTION. . . . TKOTB(1.1) . . . The Bingham fluid model (TYPE=COMPLEXFLUID and CFLUML=BINGHAM in the FLUID keyword) yields the coefficient of rigidity. . 3. .1) . SIGOGT(NTABT. . . .NTABP) . . SIGOGT(1. but related.NTABP) if FLUIDF also contains substring WATER-OPTION.1) . . The fluid identifier FLUIDF. SIGWGT(1. SGTB(NTABT.1) . . .1) . . In order to obtain the effective viscosity of the fluid at pipeline conditions. . TKGTB(1. . . . . . . see Standard format for fluid properties.NTABP) end WATER-OPTION if FLUIDF contains substring ENTROPY.NTABP). SWTB(1. VSWTB(NTABT. . SIGWOT(1. . TKOTB(NTABT.1) .NTABP) . VSWTB(NTABT. . K. TKOTB(NTABT. . . . . The strings required are explained below. . The water tables are used only if the water option is used. see Standard format for fluid properties. then TABTEX(27) SGTB(1.1) . . . . VSOTB(NTABT.1) . . then TABTEX(23) TKWTB(1. The text string that identifies the different properties TABTEX(). also have to include the same text strings as described above. VSOTB(NTABT. . . . .NTABP) . .1) . .NTABP) end WATER-OPTION if FLUIDF contains substring POWEXPL.NTABP) end WATER-OPTION end if The entropy data will be used if a Henry-Fauske type critical flow model is chosen for the flow through a valve. 1. . . . .NTABP) TABTEX(22) TKOTB(1. . SIGWOT(NTABT. .1) .NTABP). TKWTB(NTABT.. . Example: TABTEX(:) VSOTB(1. SWTB(NTABT. The fluid property file contains a table of the power law exponent for the water phase. . . . Complex fluid module The liquid viscosity table in the fluid properties file plays different.1) : : VSOTB(1.NTABP) end WATER-OPTION TABTEX(24) SIGOGT(1. have to include certain text strings in order to enable OLGA to interpret the fluid property file correctly.1) . . . . If the entropy is not given. . roles in the three different rheology models in the complex fluid module. . .NTABP) if FLUIDF contains substring WATER-OPTION. . The Newtonian option (TYPE=COMPLEXFLUID and CFLUML=NEWTONIAN in the FLUID keyword) yields the original interpretation. . TKWTB(1. the non-Newtonian parameters are used at the in situ shear stress to calculate the effective viscosity of the fluid at standard conditions. The power law model (TYPE=COMPLEXFLUID and CFLUML=POWERLAW in the FLUID keyword) yields the consistency factor. SOTB(1. SIGOGT(NTABT.NTABP) . . . . . . SOTB(NTABT.NTABP). . If simplified input is used (FULL=NO in the FLUID keyword).NTABP) TABTEX(26) SIGWOT(1. The fluid property file contains a table of yield stress for the oil phase. . SIGWGT(NTABT. . . SWTB(NTABT. SGTB(1. Examples of fluid property tables are given electronically with the OLGA software package.NTABP) if FLUIDF contains substring WATER-OPTION. . . . the entropy data will be computed by the code.1). . . .1) : : VSWTB(1. . SOTB(NTABT.1) . SGTB(NTABT. . then TABTEX(:) VSWTB(1. the effective viscosity at standard conditions have to be multiplied by the ratio of the viscosity (as given in the viscosity table in the fluid data file) at pipeline conditions and standard conditions. then TABTEX(29) SWTB(1. . .1) . . 2. TKGTB(NTABT. These curves are empirically developed by the pump manufacturer. then TABTEX(:) POWNWTB(1.1) : : CPGTB(1. but the sequence of the keywords must be as shown in the example. … . . For each table.NTABP) end if FLUIDF contains substring YIELDSTRW. xHS3) HEADS3 = (y1. YHS1) ! HS2 OMEGQ = (x1. y2. comprised of two dependent variables each as function of two independent variables. … .NTABP) . . The four quadrant curves must be converted to a dimensionless form by the development of homologous curves where the head and torque ratios (actual value to rated value) are functions of the pump speed and flow rate ratios. POWNTB(NTABT. The reading of the input is based on keywords. y2.NTABP) . y2.1) : : TAUITB(1. YHS2) ! HS3 OMEGQ = (x1. The structure of the table is as shown in the example below.NTABP) . xHS1) HEADS1 = (y1. … . the keyword QOMEG is used for q/ and the keyword OMEGQ is used for /q. !************************************************************************************************* ! Pump type and label !************************************************************************************************* TYPE = CENTRIFUGAL. . x2. A complete default set of homologous curves is tabulated in the code. x2. YHS3) ! HS4 QOMEG = (x1.1) : : TAUIWTB(1.NTABP) end if FLUIDF contains substring YIELDSTRL. . POWNWTB(NTABT. CPGTB(NTABT.flow ratio . .NTABP) Pump Data Files Pump Data Table for Centrifugal Pumps Pump Data Table for Displacement Pumps Pump Data Table for Centrifugal Pumps The pump characteristics for the centrifugal pump are presented in the form of four quadrant curves. YHS4) ! !************************************************************************************************* ! Table for two phase head HT !************************************************************************************************* ! HT1 QOMEG = (x1. x2. Single phase head HS Two phase head HT Single phase torque THS Two phase torque THT Each set of homologous curves consists of four curves. the users can change these data easily by specifying their own experimental or model-specific data through the pump data table. . … . then TABTEX(:) TAUITB(1. CPGTB(NTABT. For the independent variables.NTABP) end TABTEX(:) CPGTB(1. LABEL = Label of the table ! !************************************************************************************************* ! Table for single phase head HS !************************************************************************************************* ! HS1 QOMEG = (x1. the following variables are defined: . … .NTABP) .POWNTB(1. POWNWTB(NTABT. … . .1) . . .1) . TAUITB(NTABT. … . xHT1) .1) . 3. A more detailed description is given under Pumps . x2. . . TAUITB(NTABT. 4. TAUIWTB(NTABT. … .1) : : POWNTB(1.speed ratio .torque ratio where subscript R means rated value.1) .NTABP) . 2.NTABP) end if FLUIDF contains substring POWEXPW. xHS4) HEADS4 = (y1. Four sets of homologous curves are tabulated: 1. In order to interpret the homologous curves. the number of dependent and independent variable entries must be the same. . then TABTEX(:) TAUIWTB(1. .head ratio . . . POWNTB(NTABT. . . y2. . TAUIWTB(NTABT. However.1) .1) : : POWNWTB(1. . … . x2. . These are based on experimental data and are representative for centrifugal pumps. The transfer from single phase to fully degraded two phase conditions is described by the two phase head and two phase torque multipliers. xHS2) HEADS2 = (y1. … . xTHT3) TORQS3 = (y1. The reading of the input is based on keywords. x2. … . y2. y2. … . YHT1) ! HT2 OMEGQ = (x1. x2. xTHT1) TORQS1 = (y1. … .rpm. YTHT2) ! THT3 OMEGQ = (x1. … . … . xHV) HEADM = (y1. … . … . x2. YTHS3) ! THS4 QOMEG = (x1. y2. y2. … . x2. y2.Pa. nl . Liquid kinematic viscosity Gas volume fraction Pump speed The units can also be specified by users. … . xHT2) HEADT2 = (y1. . y2. … . y2. x2. y2. … . ΛΑΒΕΛ = Λαβελ οφ τηε ταβλε ! !∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗ ! Φιρστ πυµπ σπεεδ (1) !−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− ΠΥΜΠΣΠΕΕ∆ = Ν1 ! !∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗ ! Φιρστ συχτιον πρεσσυρε (2) . The default units of the variables in the table: PI. x2. xHT4) HEADT4 = (y1. … . YTHT3) ! THT4 QOMEG = (x1. Qb . xTV) TORQM = (y1. y2. y2. xHT3) HEADT3 = (y1. YTHT4) ! !************************************************************************************************* ! Table for two phase head multiplier !************************************************************************************************* VOID = (x1. xTHS2) TORQS2 = (y1. y2. xTHS1) TORQS1 = (y1. … . … . Linear interpolation is used to calculate the Qb-value and its partial derivatives at the operating point. aI. DP. x2. … .Pa. … . .m3 / s. x2. Pump Data Table for Displacement Pumps The back flow rate. x2. xTHS4) TORQS4 = (y1. y2. … . Volumetric back flow nl aI N . YTHS4) ! !************************************************************************************************* ! Table for two phase torque THT !************************************************************************************************* ! THT1 QOMEG = (x1. YTHS2) ! THS3 OMEGQ = (x1. YTHT1) ! THT2 OMEGQ = (x1. … . YHT2) ! HT3 OMEGQ = (x1. is a function of PI . Pump pressure increase Qb . x2. x2. The structure of the table is as shown in the example below.m2 / s. The structure of the table is: !∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗ ! Πυµπ τψπε ανδ λαβελ !∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗ ΤΨΠΕ = ∆ΙΣΠΛΑΧΕΜΕΝΤ. and N.HEADT1 = (y1. … . In order to define Qb a complete table with 5 independent variables and one dependent variable should be defined.(-). YTV) ! !************************************************************************************************* ! End of the table !************************************************************************************************* END ! NOTE ! The number of elements for each curve is limited to 10. x2. Pump inlet pressure DP . YHV) ! !************************************************************************************************* ! Table for two phase torque multiplier !************************************************************************************************* VOID = (x1. y2. YHT3) ! HT4 QOMEG = (x1. … . YTHS1) ! THS2 OMEGQ = (x1. … . … . xTHT4) TORQS4 = (y1. … . x2. … . … . . but the sequence of the keywords must be as shown in the example. xTHS3) TORQS3 = (y1. xTHT2) TORQS2 = (y1. … . y2. YHT4) ! !************************************************************************************************* ! Table for single phase torque THS !************************************************************************************************* ! THS1 QOMEG = (x1. the fluid composition in a pipe is generally different from the fluid compositions used in the PVT table (for example during the depressurisation of a pipeline).g. deltap and viscosity entries is limited to 10. where the compositional data is provided in a feed file and the code calculates the fluid properties internally. Condensate may accumulate in the lower parts of the pipe and result in large compositional differences between sections. δελταπ ! ανδ ϖισχοσιτψ χαν βε υσεδ φορ εαχη συχτιον πρεσσυρε. In particular. ! Restrictions and Limitations Memory consumption Flow Model Limitations Fluid properties Input/Output Limitations Standard Conditions in OLGA Important Numerical Recommendations Memory consumption OLGA will allocate memory for the simulation as needed. Limitations in the use of fluid properties All fluid properties are normally assumed to be unique functions of temperature and pressure.2. . That is. it is possible to perform a simulation using compositional tracking. . DΠ2. Thus. Thus. aI.1. . compositional tracking is more CPU demanding and may prolong the simulation time significantly. As an alternative to PVT tables.Κ.Κ.1 ! ΒΑΧΚΦΛΟΩ : : = (Θβ. The memory usage will be a function of the total number of pipe sections in the case. that one may use different fluid properties in different branches in a pipeline network. This means that the total composition may vary both in time and space. and have to be input to OLGA in a particular file. blowdown of pipelines. In transient simulations the fluids in the pipes have different compositions. Θ β.1. PROFILE).1 ! !∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗ ! Φιρστ ϖισχοσιτψ (4). double the number of sections for a given case.1.2. Θβ.ϑ) ΒΑΧΚΦΛΟΩ = (Θβ. changes in physical properties and equilibrium mass fractions due to changes in temperature and pressure will be different from the values in the PVT table. This difference will not affect the steady state results provided that the inlet flowing fluid has the same composition as in the PVT table. Due to the phase velocity differences. compositional tracking) and to some extent the number of plot variables (TREND. This limitation is important for mixtures with pronounced compositional dependent properties. Network simulations are special cases where total compositional changes in the pipeline may be important. Θ β. Θβ. If only gas is released from the pipe. Εαχη ΒΑΧΚΦΛΟΩ εντρψ ισ φορ ονε ! DΠ ανδ ρυνσ οϖερ αλλ ϖοιδφραχτιονσ.! !∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗ ! Λιστσ οφ ϖοιδφραχτιονσ ανδ δελταπ φορ φιρστ πυµπ σπεεδ ανδ ! συχτιον πρεσσυρε.Κ.1.J) ! ∆ΕΛΤΑΠ = (DΠ1. the total composition in the pipe will change.ϑ) ΒΑΧΚΦΛΟΩ ! !∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗ ! Σεχονδ ϖισχοσιτψ. aI. Θβ. ϖοιδφραχτιον. !−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− ΙΝΠΡΕΣΣΥΡΕ = Πλ. it is important to be aware that the amount of memory required during the simulation will roughly be proportional to the total number of sections in the network. . Θ β. and that no special consideration is needed for a pipeline network.2 ! !∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗ ! (2)+(3)+(4) ισ ρεπεατεδ φορ εαχη συχτιον πρεσσυρε ! ασσοχιατεδ ωιτη τηε φιρστ πυµπ σπεεδ. !−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− ΠΥΜΠΣΠΕΕ∆ = Ν2 : : !∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗ ! Ενδ οφ τηε ταβλε !−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− ΕΝ∆ΤΑΒΛΕ ! NOTE! The number of pump speeds and suction pressures is limited to 5.ϑ) ! !∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗∗ ! (1)+(2)+(3)+(4) ισ ρεπεατεδ φορ εαχη πυµπ σπεεδ. and you will double the memory usage. !−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− ςΙΣΧΟΣΙΤΨ = nl. ! ∆ιφφερεντ ϖαλυεσ φορ συχτιον πρεσσυρε.2.2 ! : : : : = (Θβ. the total composition (the mole fractions of the components) of the multiphase mixture is assumed to be constant both in time and space.1. (3) !−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− ςΟΙ∆ΦΡΑΧΤΙΟΝ = (aI. ! ∆ιφφερεντ ϖαλυεσ φορ ϖοιδφραχτιον. .1.2.2..2. Note however.2. . while the number of voidfraction.1. any special modules used (for instance: slug-tracking. e. δελταπ ανδ ϖισχοσιτψ χαν ! βε υσεδ φορ εαχη συχτιον πρεσσυρε. If the machine running the simulation is short on physical and virtual memory. DΠΚ) !−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− ΙΝΠΡΕΣΣΥΡΕ = Πλ. ! ! Φορ εαχη ϖισχοσιτψ βαχκ φλοω ισ λιστεδ ασ φυνχτιον οφ ϖοιδ− ! φραχτιον ανδ DΠ. This procedure is also more accurate in simulations where the fluid composition will change considerably with time. inhibitor tracking. These differences are usually small. this will ultimately lead to an unexpected program termination. However. !−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− ςΙΣΧΟΣΙΤΨ = nl. etc. but this phrase is often perceived to mean dry oil and gas. The file size limitation will be system dependent. if normal condensation takes place. For air/water. Due to the instantaneous mass transfer. OLGA uses the gas mass fractions and densities from the fluid property file to perform the conversion (requires that the tables contain standard conditions).7 psia and 15. This definition is the most commonly used in the petroleum industry. will normally not be influenced by the user input. OLGA also checks if all densities are zero. The pre-processor uses the OLGAS interface iteratively over all pipe sections to calculate pressure gradients and other parameters in the flow network until a consistent steady-state solution has been found. Finally OLGA also investigates if the enthalpies and temperature and pressure dependencies of the enthalpies seem reasonable. See limitations in the steady state pre-processor chapter for an explanation for this. (default OFF) uses the same principles as the CFL but is based on the speed of the pressure wave instead of the fluid velocity. the detailed slug flow parameters at one section do not explicitly influence those in the section following it. If they for some reason are smaller. The second time step control. Standard Conditions in OLGA ”Standard conditions” are often defined in SI units as 1 bara and 15 ° but the default value in OLGA it is defined as 1 atm/14. Printed output As this is a user specified quantity. the solution computed by the steady state pre-processor and the solution obtained when simulation with the dynamic solver until a steady-state is achieved may not be equal. the term ”standard conditions” is used in OLGA. another correlation should be applied and OLGA provides an alternative which may be activated by specifying the key SLUGVOID in the keyword OPTIONS. The flow history at a pipe location is to a small extent considered in the flow regime determination.. Oil can in turn however be both lighter or heavier than water. Other items. The user implicitly controls the size through the data specified in the keyword statements PLOT. OLGA will set these values to 10-5. Similarly if the gas density is larger than or equal to the water density. and thus flows at the top. Eventually. all slugs die at the entrance of the latter pipe. PRESSURE. Please note however that the numerical models in OLGA has only been verified and tuned for fluids where the density of oil is smaller than density of water. care must be taken to avoid a paper or file ”explosion”. slug flow may persist some distance downstream since a slug needs some time to disintegrate. The density of oil can both be smaller and larger than the water density. This is the maximum time step allowed if a mass transient is to be followed correctly. Thirdly OLGA checks if the surface tension between phases are smaller than 10-5. Unless stated otherwise these restrictions applies to table-based fluids and compositional tracking. and sets these viscosities to 10 -9 if they are. Important Numerical Recommendations Time step OLGA has time step control based on several criteria. A warning of this is then printed. First of all OLGA assumes that gas is the lightest phase. A warning is printed if something unexpected is found. hold-up. like the minimum and maximum variable values. This means that the time step is limited so that no mass is transported across a whole section in one time step. and terminates if they are.) differ. are computed based on the assumption of fully developed slug flow with an infinite number of identical slug cells. are interesting also for transient simulations. Output variables for volume rates at standard conditions assume that a single stage flash from in-situ to standard conditions has been performed. They can all be given at user specified sections through the keyword statement DTCONTROL. The selected correlation yields good agreement for all the above experiments. This is don in order to ensure the validity of the numerical models. The postprocessor will not give any information on any process equipment that is simulated. An exception is the correlation for the void fraction in liquid slugs. naphtha and stanco experiments at the SINTEF loop is applied by default. Also. A warning of this is then printed. compositional tracking and regular table based OLGA both has problems handling single component systems and systems with a very narrow phase envelope. the mixture will appear too compressible in OLGA and the pressure wave velocity will be smaller than if the mass transfer rate was finite. and to try to avoid numerical instabilities. Output postprocessor The output postprocessor summarizes the simulation results. Their possible consequences. The first time step control is based on the transport criterion of Courant-Friedrich-Levy (CFL): This criterion is by default switched on. but in OLGA this definition is not used. mass transfer between the phases from in-situ to standard conditions is taken into account. sections and output time intervals. Plot file sizes There are no formal program restrictions regarding the size of these files. the oil or water viscosity is set to a value slightly larger than the gas-viscosity at this point. but note that the numerical models in OLGA has only been verified and tuned for fluids where the density of oil is smaller than density of water. Although the most frequent input errors are found. That is. For Compositional tracking simulations a flash is performed for the in-situ fluid to standard conditions for each section and time the output variables are to be reported. the gas densities are modified to be slightly smaller than the oil density.56 ° C. In reality. This check is not performed in Compositional Tracking. Secondly OLGA checks if the viscosities are <10-9. Unless the slug tracking option is used. OLGA also imposes some restrictions on the physical properties of a fluid. and the pressure and temperature dependency of these. ”volume rates at standard conditions” are sometimes expressed as simply the in-situ mass rate divided by the density at standard conditions (for liquid). Initial value pre-processor OLGA contains a steady state pre-processor. slug fraction. An average correlation based on the diesel.g. one slug may proceed downstream and cause liquid blockage at a bend in a riser connection with possible build-up of a terrain slug. The amount of printed output is proportional to the number of output intervals and to the number of output variables and sections specified in the keyword statement OUTPUT. however. This special type of mechanism for the onset of terrain slugging is not represented in the standard OLGA model. there may be cases with faulty input that are not detected. etc. The latter has important implications for the pressure wave propagation (or speed of sound). due to water hammer). To simulate this phenomenon accurately the SLUGTRACKING model with HYDRODYNAMIC=ON should be used. However. This is because a small change in pressure and temperature might change the holdup and physical properties of the fluid dramatically Fluid property assumptions In addition to having some restrictions on the behaviour of fluids in pipes. such as slug bubble velocity and volume fraction. and such output variables should therefore be used with care for Compositional tracking simulations. the temperature and pressure are equal in both phases. Therefore. that computes values to be used as initial conditions in dynamic computations. The average description implies that if slug flow occurs in two adjacent sections. For 32-bit operating systems. if slug flow is predicted at a section boundary. For example. The gas is not dehydrated unless FLASHMODEL = HYDROCARBON is specified in the keyword OPTIONS. The third time step control. Another restriction on the Flow Model is that gas is assumed to be lighter than oil and water. larger than either of these. The default value can only be overridden when using keyword based PVT table. and any interface mass transfer occurs instantaneously. if slug flow is predicted in an upward sloping pipe and stratified flow in a following downward sloping pipe. TREND and PROFILE. the water density is modified to be slightly larger than the gas density. a rule-of-thumb says that files should not exceed 2GB. OLGA applies an average slug flow description. for some reason. If the gas viscosity is. That is. This can increase the simulation time as a flash is CPU demanding. Input/Output Limitations Input pre-processor The input pre-processor that checks the input data for inconsistencies is not foolproof. How OLGA deals with fluids where oil or water densities are equal to or smaller than gas densities is described in Limitations in the use of fluid properties. The size is determined by the number of variables. ”Stock tank conditions” are also used in the industry. A warning of this is then printed. C/60 F . Flow Model Limitations Generally. these limitations are difficult to assess. OLGA also checks if the gas-density is smaller than the oil and water viscosities. SOUND_CFL. The detailed flow parameters at another point along the pipeline will normally differ as the average flow parameters (pressure. the flow parameters at that boundary. . The actual correlation quite significantly influences the transition from stratified to slug flow.The gas and liquid phases are assumed to be in thermodynamic equilibrium. If the gas density for some reason is larger or equal to the oil density. (default OFF) is based on the second order time derivative of the pressure. Some of the information is dedicated to steady state cases. It has been introduced to better calculate shock waves (e. For table-based simulations. (default OFF) is based on the first order time derivative of the pressure. and it is always specified on case level: In the Properties window for the PLOT. Select the ‘OLGA Command prompt’ from the start menu (Start à All Programs àSPT Group à OLGA 7 à Tools à OLGA Command Prompt). A factor of 2 or less in length ratio between adjacent sections is recommended although factors of 5-10 might work in some cases.g. or the slug tracking option is activated. This has been introduced to be able to reduce the time step earlier for quick pressure changes. OLGA will choose the minimum time step from the activated time steps controls. inp-files. All Programs->SPT Group-> OLGA 7->Documentation OLGA Command Prompt Cases may be run without opening the GUI.opi The opi command may run opi-files. see the File menu/Tools –> External tools. Second. such as paint etc. Here are some examples of what can be done with the opi command: Run a single simulation from the current folder opi sample.> Tools within OLGA GUI File menu .0 a*. If the thermal conductivity of the thin layer is fairly close to the conductivity of one of the neighbours. GRADPRESSURE. only the thickness needs to be adjusted.opi Run all cases in the current folder opi *. The upper and lower limit for the time step is the usergiven MINDT and MAXDT in the keyword statement INTEGRATION. The accuracy of the solution increases with smaller sections but in a complex manner that is difficult to estimate quantitatively. All Programs->SPT Group-> OLGA 7->Documentation Click here Click here or F1 inside tool Start page. should be included in a neighbouring layer by adjusting the thickness and conductivity of that layer. Variable Mesh Length Past experience indicates that the section lengths should not differ too much along the pipeline. The numerical solution should. Tools available with OLGA Tool FEMThem Viewer Fluid definition tool Geometry editor Mud property table Multiphase toolkit OLGA viewer OLGA command shell Parametric study Rocx Started from File menu .> Tools within OLGA GUI File menu .The fourth time step control.e. . approach the analytical one as and approach zero. e. if either the inclination angle or the diameter of the pipes varies. the wall layer discretisation can be quite coarse. key-files. the time step decreases with decreasing section length if the CFL transport criterion is switched on.> Tools within OLGA GUI or from Well GUI File menu . Additional time step controls are activated when process equipment is simulated. both the plotting frequency DTPLOT and the variables must be specified. the number of arithmetic operations per time step increases proportionally to the number of sections. geninp-files and genkey-files. i.> Tools within OLGA GUI File menu . All variables are plotted for all flowpaths (branches) and all sections of the case. a pipeline with high pressure is opened into a small closed volume.> Tools within OLGA GUI From Tools on the case toolbar within OLGA GUI File menu . however. A command prompt is opened and allows for the use of the special ‘opi’ command. If all time step control criteria are switched on.opi Run all cases that starts with the letter ‘a’ with a specific version of the OLGA engine opi /recursive /version 7. Wall Layer Thickness The numerical solution of the wall temperatures in the wall layers is dependent on the wall layer discretisation. Type ‘opi /?’ to bring up help on all available options for this command. For steady state calculations. For transient calculations when the heat storage in the pipe walls can be important (cool down or heat up) a finer discretisation of the pipe walls may be necessary.> Tools within OLGA GUI File menu . First.. OLGA Viewer The OLGA Viewer is a stand-alone animation tool that is installed and defined as an external tool by default.> Tools within OLGA GUI File menu . The PLOT keyword is needed by the OLGA Viewer. one layer for each material layer. to reduce numerical 'smearing out' of these effects. Very thin layers.> Tools within OLGA GUI Location of documentation F1 inside tool F1 inside tool Click here or F1 inside tool F1 inside tool F1 inside tool Start page. each pipe should be divided into at least two sections to ensure meaningful results. Pipe-Section Discretisation In general. Section Lengths For a pipeline of fixed length the simulation time increases roughly quadratically with the number of sections in the pipeline. %N – will be replaced by case number %1 – will be replaced by name of parameter 1 Custom decorations can be created. The Parametric studies page is opened from the case toolbar. The figure below shows a snap-shot from the OLGA viewer. Parametric study A parametric study is a way to set up a series of OLGA cases based on a current case where each case has one or more parameters that change. Naming of cases The naming of the cases can be changed by selecting an alternative Decoration.plt file. This can be useful for machines with multiple processors or multithreading.plt file is generated during the OLGA simulation. A typical example is to define four cases where everything is the same except for the mass inflow through the source. When saving the case. The inflow increases incrementally in each case. the parametric study is saved in a separate folder together with the Project/Case. select the appropriate . Studies can only be performed on the local machine. The input screen for parametric studies is shown below. . After opening the OLGA viewer. A separate help document is available from the Help menu within the tool. The name applied as a result of the selected decoration is displayed in the list below.A *. the number of simultaneous simulation can be given (#Parallel simulations). however. The parametric study makes it easy to define and run these cases. where new studies can be added or previously performed studies reopened. in the list of selected keyword(s). In the matrix dialogue gives the option of entering a list of values for each parameter. Enter the number in the #Parameter field. Right-clicking the case column will bring up the option to insert more cases. Then select the parameters to change by right-clicking in the header of the table. end and step. run the study. Then. add values to the parameters. The functionality here is similar to the one described in general for plots. The check marks are removed after the simulations have completed if the Run Study option is used. The functionality here is similar to the one described in general for plots. click in the header where it says “Click to select parameter”. Clicking on the Matrix… button. start. decide how many parameters/properties that should be varied in the parametric study. This means that the parameter chosen for this keyword will be commonly changed for all pipes selected. In the dialogue that appears choose the flowpath. When all data are specified. several different plots can be used to view the results. This gives the option of giving a range of values. This parameter will be constant for each curve plotted. Select the variables that should be plotted. only the keys shown in black can be selected. click on the button Add Study. This option is only available if more than one parameter is given. it is possible to choose several pipes. meaning that there will be a curve for each value of this parameter. While the Run Study button will start the simulations more integrated with GUI. Right-click on one of the parameter headings and choose Set Value(s)… . Press Plot and the plot will be created. A list all parameters for the selected keyword will show. Note that only the cases with a check mark will be run. The case table will then automatically be filled in for the selected parameter. . Secondly. press OK and the plot will appear. The variable for the y-axis then needs to be selected. which then again will update the case table with all combinations of parameters specified. Note that for pipe. where it says <Right-click to select parameter>. press OK and the plot will appear. First. Then. controller. Select one parameter and press OK.Creating a study First. choose one of the listed items in the left part of the dialogue. meaning that the status will be shown in the case table. separator. Next choose the keyword from the list shown on the right by double clicking on the keyword or by using the arrows between the lists. Select the variables that should be plotted. Below is a short description for each of the options Trend Plot Click on the Trend Plot button and the Select variables… dialogue appear. Profile Plot Click on the Profile Plot button and the Select variables… dialogue appear. XY Plot Click on the XY Plot button and a dialogue will appear. select variable type. case or library to where the parameter to change belongs. trend or profile. Then select the 2nd parameter. then Select Parameter… . There are several ways of entering data: Typing values directly into the table. The Run Study Batch button will start a command shell which will run independently of the OLGA GUI and only report status while running in the command shell window. Viewing results After the parametric study has been run. When all parameters to change have been selected. node. select the parameter for the x-axis. This will be obtained if the Matrix… option is used to add data to the case table. two views are available. renamed or deleted. The tool can be open in several ways: · · · · File menu page/Tools/Geometry Editor (opens with only default data) or Select the Property page for the active geometry or flowpath (opens with data for the selected geometry/flowpath) Double click on the flowpath in the diagram view Right click on flowpath in model view and select properties Edit Geometries When opening the Geometry Editor. the plot tab and drag it towards the bottom of the window (as has been done below). the graph of the profile and a table of pipes. Changing Length-Elevation affects X-Y and vice-versa.Within the XY plot. . X and Y in the table give the data for the end point of the pipe.g. Several tables can be added. The option Tabulate will show the value of the variable as function of parameter 1 and parameter 2 at selected time/pipeline length in a table. Note that this option only makes sense if one or more parameters are kept constant while other parameters are varying. “Diameter [m]”) and selecting a unit. Geometry Editor The geometry editor is used for editing the flowpath profiles. Edit the table New pipes are added. the time for trend plot variables and the time and pipeline length for profile variables can be changed by the dropdowns shown at the bottom of the plot. The two windows can be viewed simultaneously by selecting for example. by right-clicking in the Pipe column and selecting the relevant action. Units are changed by right clicking in the title cell (e. The values in the tables can easy be copied out by clicking on the Copy tables button. When filtering has been completed it is a good idea to compare the angle distributions of the original geometry and the filtered ones. Define sectioning The pipe sectioning can be performed in two ways: 1. Y can be changed) X Bound (Point X-value cannot be moved upstream or downstream neighbours) Y Fixed (Y remains fixed. select “Exchange Geometry” and pick the desired geometry. Manually enter number of sections in the “# Sections” column. open section lengths mean that the value above is repeated. Geometries can also be exchanged between flowpaths in the same case. set the # of sections to 0. These values define a moving rectangle (a box) within which all data points will be filtered out. Menus The Geometry Editor features the following menus: . The color of the bars and the % values in the output window indicate the difference between the average angle of the pipes within a group and the mean value of the angle group. Use the new geometry A new geometry may be imported to a case as follows: Open the geometry files to use (it can be opened from the Geometry editor or in explorer). By double clicking in the Length of Section list. Then all pipes are given the same selected number of sections. The same Geometry file can be used for several branches however. To start over again. Green (and a low % deviation) means a good relevance of the angle group. Right click on FLOWPATH or Piping in the Model View. 2. The "remaining of total" is the total pipe length minus length accumulated over the section lengths specified (including the open ones). Moreover. 3. Use the discretization tool (Tools/Discretize). There are two options: a Box filter or a preservation of angle distribution /total flowpath length. The main rule is that the tool ensures that the sum of sections is equal to the pipe length. The filter with the best reproduction of the original geometry should be used – keeping in mind that the angle groups should be representative. a tool to distribute sections of various lengths over the pipe-length is provided. These angel groups can also be changed. The % value is a numerically calculated standard deviation divided by half of the angle group span. The filtered data appear as a new geometry which may be further filtered/ edited. This provides equally long sections for a given pipe. Enter the horizontal sample distance and the vertical sample height. Filter the data Select Tools/Filter. the Geometries must be re-labelled to secure that the labels are genuine. Angel distribution: Enter the maximum pipe length that shall be used to filter the profile while maintaining the angle distribution and the total pipe length. Box filter: This filter is more relevant for removing relatively small disturbances from a pipeline survey. Select the flow path and its Property Page of the Geometry to be distributed to other flowpaths.Edit the graph The Geometry can also be edited by the following actions under the Actions menu: Normal (no change) A: Add a point M: Move a point D: Delete a point Restrictions on the graphic editor can be imposed (Actions -> Restrictions): X Fixed (X remains fixed. The angle groups that are used can also be seen by right clicking when in the output window of the angle distribution calculation. X can be changed) Y Bound (Point Y-value cannot be moved above or below neighbours) Recursive (all points downstream will follow the point that is being moved) Check angle distribution The angle distribution of a Geometry can be checked by selecting Tools -> Check angle distribution. diameters. Open the Excel-file with the profile-data to input. The new Geometry must be given relevant sections. select the X-Y columns and copy the data. New window with active data (works on same data set) Select graph or table representation Enter a new profile Working with an existing profile in the . A dialogue will be presented asking about the size of data being pasted into the Geometry Editor. roughness and walls.File New Import Open Close Save Save As Print Print Preview Print Setup <Recent File> Send Exit Edit Undo Cut Copy Paste Configure View Global Overview Standard Restrictions Graph Status Bar Labels Walls Actions Graphical Restrictions Tools Angle groups Check Angle Distribution Check section lengths Discretize Filter Reset Pipe Labels Reverse geometry Window New window New window New Horizontal Tab Group New Vertical Tab Group More Windows Help Help Topics About Geometry Not implemented Version Information New geometry Imports xy-data Opens geometry file (*. Automatic pipe sectioning (all equal) Filter data Use default pipe labelling Creates a geometry that is the mirror image of the original geometry (in x-direction). This can also be copied directly from an Excel –worksheet: Open the Geometry Editor and select File New. The geometry is now presented in a tabular format and allows for toggling between this and the graphic format by clicking on the relevant tab.geo) Closes geometry Saves geometry Saves geometry as new file Prints active window Configures graph window Toggle the visualization of pipe labels Toggle the visualization of walls Normal/Add/Move/Delete X Fixed/X Bound/Y Fixed/Y Bound/Recursive Calculates the length ratio of adjoining sections. as given below. 0 in the Geometry Editor with the default geometry open and then Paste. A new Geometry with one pipe and default values will be generated. Answering yes will allow for the data to be passed directly over the existing open geometry. .xy-format can be done by selecting File/Import and opening the relevant xy-file with the browser. Select the Start Point 0. A source is defined in the first section of the pipeline.ready for simulation. The case consists of a single flowpath with a closed inlet node and a pressure outlet node. Basic Case This template generates a complete basic case . There are no sources. Compressor Manual Controls Compressor Manual Controls is a simple model to demonstrate compressors with a manual speed controller and a manual controller attached to the compressor recycle valve. A manual controller C-MAN-SPEED adjusts the speed of the compressor. Case description The model consists of a single branch with a compressor CMPR-1. The terminal signal adjusts the compressor recycle valve. Basic Network Case This template generates a simple network case consisting of two flowpaths leading into an internal node which again is connected to a third flowpath. The manual controller CMAN-RECYCLE adjusts the opening of the compressor recycle valve. Anti –surge signal in range 0 to 1. OLGA Compressor Control OLGA Compressor Control is a template case for a compressor with anti-surge and pressure performance controllers. The terminal signal adjusts the compressor speed: CompressorSpeed = MinRPM + (MaxRPM .Limitations The following important limitation applies: 1. CMPR-1 SPEEDSIG – terminal for compressor speed controller. . dot (“. instead the inlet nodes are massflow nodes. All information must be given from scratch.”) must be selected as decimal separator for Excel Template descriptions Empty Case The OLGA Empty case template is used to create new case with no predefined content.1 at time 500 seconds. Speed signal range 0 to 1. The controller C-SCALE-SPEED normalizes (scales the speed from rang MinRPM–MaxRPM to range 0-1) the speed input to the compressor. Signal connections CMPR-1 ACSSIG – terminal for compressor anti-surge controller.MinRPM) * Speed Signal Dynamic simulation To test the performance of the compressor the speed is changed (set-point change in controller C-MAN-SPPED) at time 100 and 200 seconds and the recycle valve opening is changed for closed to 0. For export to Excel. To test the anti-surge controller. changes to the pressure controller C-PT are introduced at times 200 and 400 seconds. The source flow rate is lowered from 100 to 50 MMscf/d in the time interval 800 to 900 seconds and from 50 to 30 MMscf/d in the time interval 1200 to 1300 seconds. C-ASC SETPOINT (controller input) is connected to transmitter TM-5 with variable QGSURGE in unit m3/s. Signal connections CMPR-1 ACSSIG (compressor input) is connected to C-ASC CONTR (controller output).Case description Model consists of a single branch with compressor CMPR-1. the set point to the anti-surge controller is the surge limit for the compressor at the current operation conditions. The terminal signal adjusts the compressor speed: CompressorSpeed = MinRPM + (MaxRPM . control set-point changes to the pressure controller C-PT-SEP are introduced at times 300. The set point terminal of C-ASC SETPOINT (controller input) is connected to transmitter TM-3 with variable QGSURGE in unit m3/s.MinRPM) * Speed Signal C-PT MEASRD (controller input) is connected to transmitter PT-1 with variable PT in unit bar. Speed signal range 0 to 1. from 20 to 18 bar at time 1800 seconds and 18 to 16 bar at time 3600 seconds. SOUR-1). OLGA Single Separator 3-Phase Compressor OLGA Single Separator 3-Phase Compressor is a template case for a three phase separator with a compressor at the gas outlet. C-ASC MEASRD (controller input) is connected to transmitter QG with variable QG in unit m3/s. C-ASC MEASRD (controller input) is connected to transmitter QG with variable QG in unit m3/s. The controller setpoint is changed from 25 bar to 20 bar at time 300 seconds. PID controller C-PT-SEP controls separator pressure by adjusting compressor speed. Speed signal range 0 to 1. PID controllers C-LC-OIL and C-LC-WAT controls separator levels by adjusting valves at separator liquid outlets. Transmitter QG is placed on the same section boundary as compressor.MinRPM) * Speed Signal C-PT-SEP MEASRD (controller input) is connected to transmitter TM-3 with variable PTSEP in unit bar. C-LC-WAT MEASRD (controller input) is connected to transmitter TM-2 with variable WATLV in unit mm. 1800 and 3600 seconds. Dynamic simulation To test the performance of the compressor control set point. Note the speed signal is normalized in range 0 – 1 corresponding to range MinRPM MaxRPM. C-LC-OIL MEASRD (controller input) is connected to transmitter TM-1 with variable OILLV in unit mm. . This is the set point to the anti-surge controller and is the surge point for the compressor at the current operating conditions. The controller set point is changed from 33 bar to 30 bar at time 200 seconds and from 30 to 25 bar at time 400 seconds. the flow through the compressor is lowered (changed in the source.MaxRPM. PID controller C-PT controls compressor suction pressure by adjusting compressor speed. Transmitter QG is placed at the same section boundary as the compressor. The anti-surge controller keeps the recycle valve slightly open to achieve sufficient constant margin to the surge line. Case description Single three phase separator model with compressor CMPR-1 at gas outlet. CMPR-1 SPEEDSIG (compressor input) is connected to pressure controller C-PT-SEP CONTR (controller output). Anti-surge controller C-ASC to adjust the opening of the recycle valve to avoid that the compressor surges. Anti-surge controller C-ASC adjusts the opening of the recycle valve to avoid the compressor surges. V-LV-OIL INPSIG (valve input signal) is connected to C-LV-OIL CONTR V-LV-WAT INPSIG (valve input signal) is connected to C-LV-WAT CONTR Dynamic simulation To test the performance of the compressor. Signal connections CMPR-1 ACSSIG (compressor input) is connected to C-ASC CONTR (controller output). CMPR-1 SPEEDSIG (compressor input) is connected to pressure controller C-PT CONTR (controller output). Note the speed signal is normalized in range 0 – 1 corresponding to range MinRPM . The terminal signal adjusts the compressor speed: CompressorSpeed = MinRPM + (MaxRPM . Within the water. The pipeline is 100 m long with a 50 m gain in elevation. Initially. These are located on the folder: C:\Users\Public\Public Documents\SPT Group\OLGA 7.opi illustrates the improved accuracy that can be achieved by applying a 2nd-order scheme when solving the mass equations. While numerical diffusion rapidly smears out the MEG using the 1st-order scheme. see Figure 2. see Figure 1. All sample projects can also be started from the start menu (All Programs > SPT Group > OLGA 7 > OLGA Samples). Sample cases The OLGA installation includes a set of sample cases. As the simulation starts. pushing the water out of the pipeline. Well GUI templates Please refer to the Well GUI documentation for a description of the Well GUI templates.Well templates The purpose of the well templates is to give a starting point for each of the well inflow models. Leak and Choke Well and Pressure Boost Slugging project: Start-up slug (with and w/o compositional tracking) Hydrodynamic slugging (with and w/o compositional tracking) Valve project: Plug-in project: Plug-in hydrate formation Plug-in_sand in water Sample case: 2nd-order scheme The case Second-order-MEGsteps. oil is injected at the inlet. the first 100 m of the pipe is filled with oil whereas the rest of the pipe is filled with water. pronounced peaks are preserved throughout the simulation using the 2nd-order scheme. . They can be accessed from the Help page in the GUI. Figure 1 Initial MEG fractions. The sample cases are organized in projects as follows: Advanced Thermal project: Fluid bundle Solid bundle Compositional project: Blackoil Compositional Tracking MEG Tracking CO2 Tracking (Single component) H2O Tracking (Single component) H2O Tracking (Steam/Water–HC) Tracer Tracking FA-Models project: 2nd-order scheme Advanced Well Corrosion Drilling Fluid Hydrate Kinetics Network Wateroptions Waxdeposition OPC Server project: Server demo with opc Pigging project: Pigging (with and w/o tracking of slug and with and w/o compositional tracking) Process project: Process Equipment PID Controller Simplified Pump Centrifugal Pump Displacement Pump Pump Battery Separator Source. What should be noted are the differences in results when running the case using a 2nd-order scheme for the mass equations as compared to a 1st-order scheme. there are three regions with various amounts of MEG. The name of the templates reflect the inflow model used. 1 seconds.Figure 2 MEG fractions 85 s into the simulation. The boundary conditions are constant through the simulation. A wellhead choke is placed at the last section boundary of the branch. The mechanical skin is 3. three regions containing different amounts of MEG are set up. OUTPUT: OLGA variables are printed to the output file every 10000 seconds. Output: ANIMATE: 3D plot of holdup for liquid along the pipeline is plotted every 10 seconds. The C. The outlet boundary condition is set to a constant pressure of 4. The black curve is using a 1st-order scheme for the mass equations whereas the red curve illustrates the use of a 2nd-order scheme. and is interpolated vertically in between. 300 bar at the outlet. 1 km long with an elevation of 50 m. INTEGRATION: The case is simulated form 0 to 5 hours with a maximum time step of 2 seconds. FLOWPATH — Boundary&InitialConditions — SOURCE: The mass source is ramped up to a steady mass flow of 53. NODE: The inlet node is closed and the inlet flow is specified with a productivity correlation based on physical reservoir properties (see WELL). A 3500 m vertical well is producing from a gas reservoir through a 5. TREND: Trend variables are plotted every 0.5" ID tubing. Case Comments: CaseDefinition: OPTIONS: The steady state pre-processor is deactivated.01 1/mmscf/d is used. . ΦLOWPATH — Output —ΣΕΡςΕΡ∆ΑΤΑ: Server variables are available for plotting in interactive simulations. FLOWPATH — Piping: The 3500 m long vertical well is described by 9 pipes. An overall heat transfer coefficient of 10 W/m2K has been used. OUTPUT: OLGA variables are printed to the output file every 100 seconds. and a turbulent non-Darcy skin of 0.34 kg/s over the first 8. FlowComponent: FLOWPATH — Boundary&InitialConditions — INITIALCONDITIONS: The first 100 m of the pipe is filled with oil whereas the rest of the pipe contains only water. The well C production is calculated using the Forchheimer model and the linear model is used for injection. Output: ANIMATE: 3D plot of holdup for liquid along the pipeline is plotted every 10 seconds.5 MPa and a temperature of 30° C. The formation has a permeability of 500 mD and the Forchheimer inflow correlation is applied. FLOWPATH — Piping: The branch is a single pipe. NODE: The inlet node is closed. pressure is set to 400 bar at the inlet. This is a typical inflow correlation for a gas reservoir where the non-linear behavior between the produced gas rate and flowing bottom hole pressure is important. PROFILE: Profile variables are plotted every 5 seconds. The heat transfer number outside the wall have to be given. The source temperature is 30° C. FlowComponent: FLOWPATH — Boundary&InitialConditions — HEATTRANSFER: A linear ambient temperature profile is used for the well. FLOWPATH — Boundary&InitialConditions — INITIALCONDITIONS: The pipeline is initialized with gas at 30° The mass flow is set to zero throughout the pipeline. ΦLOWPATH — Output —ΣΕΡςΕΡ∆ΑΤΑ: Server variables are available for plotting in interactive simulations. FLOWPATH — Boundary&InitialConditions — WELL: A gas well with reservoir pressure of 412 bara and reservoir temperature of 43. The minimum time step is set to 0. FLOWPATH — ProcessEquipment — VALVE: A wellhead choke with 10% opening is placed at the outlet. Within the water. Sample case: Advanced well The case AdvancedWell.5 seconds of the simulation.opi demonstrates some of the features in the advanced well functionality. The outlet node is of type pressure. FLOWPATH — Output — PROFILEDATA: Variables of interest are hold-ups and inhibitor fractions.001 seconds. Case Comments: CaseDefinition: OPTIONS: The discretization scheme applied when solving the mass equations is determined by the key MASSEQSCHEME. The reservoir permeability is 500 mD and the net pay from the zone is 14 m.5° is placed at the b ranch inlet. Case Comments: CaseDefinition: OPTIONS: To activate the blackoil module. volumetric holdup. PROFILE: Profile variables are plotted every 6000 seconds.02. Following this is a 100 m long pipe leading up to a 200 m tall riser to the topside. and overall content of water are plotted. temperature. The pipeline is divided into 10 sections.TREND: Trend variables are plotted every 100 seconds. FLOWPATH — Output — TRENDDATA: Pressure. FLOWPATH — Output — OUTPUTDATA: Pressure.01 s. The pipeline is 400 meters long and has an elevation of 10 meters. Output: ANIMATE: 3D plot of holdup for liquid along the pipeline is plotted every 10 seconds. C FLOWPATH — Boundary&InitialConditions — SOURCE: The source has a constant flow rate throughout the simulation. In the second hour.5 W/m2K is used. a pump outlet valve. a centrifugal pump. The content is given as cubic meters for the entire pipeline. The system consists of a 100 m long horizontal wellhead pipe followed by a 300 m m long pipe containing a pump inlet valve. and an N2 mole fraction of 0. Sample case: Blackoil The case Blackoil. the system's inlet pressure is 8 bar higher than its outlet pressure.7. A sketch of the model is shown in Figure 1. This line has a bypass valve on the inlet and a check valve on the outlet. volumetric oil holdup and volumetric water holdup are plotted at the first and last section of the pipe.opi demonstrates how OLGA can be used to model a centrifugal multiphase pump with recycle function and bypass lines. The outlet node uses the BLACKOILFEED (set in the FEEDNAME keyword). The two components are combined to give a GOR of 200 Sm3/Sm3 at standard conditions. NODE: There is a mass source at the inlet. There is a constant pressure condition at the outlet. liquid holdup. The flow rate is set to 1000 STB/d (in the FEEDSTDFLOW keyword). overall mass flow and gas mass flow are plotted. ΦLOWPATH — Output —ΣΕΡςΕΡ∆ΑΤΑ: Server variables are available for plotting in interactive simulations. The gas component is given a CO2 mole fraction of 0. and a check valve at the outlet of that pipe. PROFILE: Profile variables are plotted every 5 minutes. temperature. the inlet pressure is reduced to be the same as the outlet pressure so that no production is expected without a pump. FlowComponent: FLOWPATH — Boundary&InitialConditions — HEATTRANSFER: A constant ambient temperature of 6° and an ambie nt heat transfer coefficient of 6. PROFILEDATA: Pressure. BLACKOILFEED: The BLACKOILFEED combines the two BLACKOILCOMPONENTs. The maximum and minimum time steps are 5 s and 0. The case comprises of a single branch with one ascending pipe. OUTPUT: OLGA variables are printed to the output file every hour. gas mass flow and overall mass flow are written to the output file. Then. and the centrifugal pump starts to increase the pump speed in order to yield the flow rate 50 kg/s. The name of the fluid (feed) is given by the key FEEDNAME. The production is to go through the bypass line and the total flow rate is about 45 kg/s. The overall content of oil. Operation scenario: In the first hour. the key COMPOSITIONAL has to be set to BLACKOIL. . the inlet node is therefore closed. Compositional: BLACKOILCOMPONENT: One gas component and one oil component is defined.1. the bypass line closed.opi demonstrates the blackoil module. Sample case: Centrifugal Pump The case Pump-Centrifugal. The oil component is defined by a specific gravity of 0. A bypass pipeline is connected to the pump pipeline. respectively. TREND: Trend variables are plotted every 15 seconds. the pump line is opened. Figure 1 Sketch of the model. INTEGRATION: The simulation end time is set to 100 seconds.8 whereas the gas component is defined by a specific gravity of 0. 15 m3/s. Fluid: 100% CO2 The transient starts in the gas region. which means that the built-in bypass line is closed. the pump recycle flow is controlled by the pump inlet pressure.tab. this controller is defined as TYPE=MANUAL and SETPOINT=1. FLOWPATH — ProcessEquipment — PUMP: The centrifugal pump is defined by following parameters: DENSITYR=900 kg/m3. 0.0. The controller is used to control the built-in valve in the centrifugal pump module to stop the flow if the pump is deeded. the outlet pressure is increased to 80 bar.Case Comments: CaseDefinition: OPTIONS: The full heat transfer calculation option with heat transfer through the pipe walls is used. The pump inlet pressure is measured by Transmitter TRAN-B-PL-PT. PIDCONTROLLER: C-PUMP-C-RE: This controller is required by the pump module. OUTPUT: OLGA variables are printed to the output file every 10 hours. reduction in outlet temperature (release of heat due to condensation). Time constants are set: TCONDENSATION=1. T=5° and P =30 bar. zero means no bypass flow through the built-in bypass).g. The C. PROFILE: Profile variables are plotted every 30 minutes. This leads to condensation of gas which slows down the C. TEMPERATURE=ADIABATIC (no heat exchange with walls) Compositional: SINGLEOPTIONS: CO2 is activated by setting COMPONENT=CO2. as the rest of the pipe.12 m. The inlet pressure is 47 bara over the first hour and is then reduced to 39 bara. BYDIAMETER=0 (bypass diameter. MANUALCONTROLLER: C-PUMPV-1: This controller is optional. the inlet temperature is reduced to 5° thereby moving into the liquid side of the dense phase region. C. Temperature and pressure varies with time. FILES: The characteristic data of the pump is found in the file ol-pumpc-2. FLOWPATH — Piping: 100 m horizontal pipe. The inlet temperature is held constant at 30° The outlet pressure is held constant at 39 ba ra and the temperature is 20° Two internal nodes are used to connect the bypass around the pump. RECDIAMETER=0. After 10 minutes. In this case.1 m (diameter of the built-in recycle pipe). The bypass line. After 60 seconds. diameter=0. and if the pump inlet pressure is lower than 38. EFFIMECH=0. the initial conditions have to be given. thereby crossing the saturation line from the liquid side to the gas side. After half an hour. can be set to zero.2 m diameter which leads up to a 200 m tall riser. Output: ANIMATE: 3D plot of holdup for liquid along the pipeline is plotted every 10 seconds. Sample case: CO2 Tracking (Single component) Case: Single-CO2. A temporary drop in outlet temperature down to about saturation temperature occurs due to the evaporation of water. FlowComponent: FLOWPATH — Boundary&InitialConditions — SOURCE: Liquid source delivering 2 kg/s.2 m. the built-in bypass function of the pump module is obsolete since any bypass line can be modeled using an additional flow-path. the pump speed is controlled by the total mass flow rate (PUMPGT) through the pump. Case Comments: CaseDefinition: OPTIONS: The single component module is activated by setting COMPOSITIONAL=SINGLE. NODE: A closed node is placed at the pipe inlet. is 300 m long and has the same diameter. minimum heat transfer coefficient on inner walls is set to 10 W/m2K. RECDIAMETER. At topside a 100 m pipe leads to the outlet. TBOILING=1. The total mass flow rate is measured by and defined in the Transmitter TM-2. In this sample case. the outlet pressure is reduced to 30 bar. A co rresponding increase in C C outlet temperature follows. NODE: Both the inlet and outlet nodes are pressure nodes. the inlet temperature is increased and reaches 50° after 120 seconds. A temporary small increase in outlet flow rate occurs due to the lower density of gas at the increased temperature. A temporary increase in outlet temperature occurs due to compression of the gas and a temporary reduction in outlet flow rate can also be seen. the bypass controller is a manual controller withSETPOINT=0. TREND: Trend variables are plotted every second. Controller-models: PIDCONTROLLER: C-PUMP-C-SP: This controller is required by the pump module. the recycle flow will be started.. After 20 minutes. If no recycle flow is required. The steady state pre-processor is turned off. FLOWPATH — Piping: The pipeline consists of a 500 m long pipe horizontal pipe with a 0. 20 sections ΦLOWPATH — Output —ΣΕΡςΕΡ∆ΑΤΑ: Server variables are available for plotting in interactive simulations. which means that the valve is fully opened. In this sample case. FLOWPATH — Boundary&InitialConditions — HEATTRANSFER: The ambient temperature is set to 15° The heat t ransfer coefficient on outer walls is set to 500 W/m2K. The lower gas density leads to an increase in volumetric flow rate. SPEEDR=1500 rpm. FlowComponent: FLOWPATH — Boundary&InitialConditions — INITIALCONDITIONS: Since the steady state pre-processor is not used. Output: . The outlet flow rate of gas shows an oscillatory behavior and finally goes to zero when all the vapor is either condensed or has left the pipe. C. HEADRATED=150 m. FLOWRATED=0. thereby moving into the dense phase region on the gas side. constituted by six sections.0. MANUALCONTROLLER: C-PUMP-C-BY: This controller is required by the pump module. However. a manual controller with SETPOINT=0 can be used for the recycle controller or the recycle diameter. MAXSPEED=8000 rpm. There is also an overshoot in gas flow rate due to the volume increase.12 bara. In this sample case.7. e.opi Purpose: "Walk around" the critical point. if the pump is shut down and no back flow is allowed. FLOWPATH — Output — TRENDDATA: Pump variables are plotted. The outlet is a pressure boundary. ΦLOWPATH — Output —ΣΕΡςΕΡ∆ΑΤΑ: Server variables are available for plotting in interactive simulations. FA-models: WATEROPTIONS: Water flash and water slip are turned on. Output: ANIMATE: 3D plot of holdup for liquid along the pipeline is plotted every 10 seconds. The fluid composition is of a gas condensate type. liquid phase and overall are plotted. After 50 hours. Sample case: Corrosion The case Corrosion. FILES: A feed file generated with PVTSim has be specified using the key FEEDFILE. Case Comments: Library: WALL: The pipe walls consist of steel (two layers) covered by one layer of insulation. The gas is dissolved in the under-saturated oil. gas pockets are generated at the highest points of the pipeline. After 51 hours all the gas has disappeared and the system returns to the original steady state. the key COMPOSITIONAL has to be set to ON. but the source flow rate and temperature changes. The overall mole fraction is also plotted at these positions.3 km long horizontal pipe ending in a 90 m riser followed by a short horizontal pipe.41 m. The maximum and minimum time steps are 20 s and 0.1 s. The water cut is about 80%. The initial time step is set equal to the minimum one. the production is shut-in and the pipeline is closed. ΦLOWPATH — Output —ΣΕΡςΕΡ∆ΑΤΑ: Server variables are available for plotting in interactive simulations.ANIMATE: 3D plot of holdup for liquid along the pipeline is plotted every 10 seconds. FLOWPATH — Output — PROFILEDATA: Standard variables are plotted. INTEGRATION: The simulation end time is set to 70 hours. TREND: Trend variables are plotted every second. Then. The name of the fluid (feed) is given by the key FEEDNAME. At the outlet. OUTPUT: OLGA variables are printed to the output file every 600 seconds. overall mass flow and gas mass flow are plotted. CaseDefinition: OPTIONS: The full heat transfer calculation option with heat transfer through pipe walls is used. Heat transfer through pipe walls is calculated. Case Comments: CaseDefinition: OPTIONS: To activate compositional tracking. INTEGRATION: The simulation runs for five hours using a minimum time step of 0. oil is injected at the inlet. respectively. Figure 1 Schematic view of the pipeline geometry. The flow rate is specified in FEEDMASSFLOW. Sample case: Compositional tracking The case CompTrack. After 50 hours the source is restarted.opi is an example illustrating the use of the corrosion model. the system is shut-in and cooled down due to a low ambient temperature. Mole fractions in the gas phase. This fluid is the same as the one the pipeline was filled with initially. FlowComponent: FLOWPATH — Boundary&InitialConditions — SOURCE: The source produces the same fluid throughout the simulation. OUTPUT: OLGA variables are printed to the output file every hour. FlowComponent: . a constant pressure condition is applied. NODE: The inlet node is closed since there is a mass source at the inlet producing at varying flow rate. The same fluid is used at both nodes (given by the key FEEDNAME). Initially the pipeline is filled with live crude and the fluid is under-saturated throughout the pipeline.opi comprises one branch with ascending and descending pipes. The inner diameter of the pipe is 0. PROFILE: Profile variables are plotted every hour. After 30 hours. liquid holdup. The feed file contains information about the fluids and the components used in the simulation. The main pipeline starts with a 3. PROFILE: Profile variables are plotted every 5 minutes. temperature. PROFILEDATA: Pressure. After 30 hours. TREND: Trend variables are plotted every three minutes. FLOWPATH — Output — TRENDDATA: Mass fractions in the gas and liquid phases are plotted at the inlet and outlet.01 s and a maximum one of 10 s. is set to 5%. the ratio of CO2 partial pressure to total pressure in the gas. the system's inlet pressure is 4 bar higher than its outlet pressure. Controller-models: PIDCONTROLLER: C-PUMP-D-SP: This controller is required by the pump module. both factors are multiplied with the corrosion rate. Since water flash is active. the pump recycle flow is controlled by the pump inlet pressure. The presence of glycol yields a reduction factor of the corrosion rate. In this case.2 bara. The fraction of glycol in the glycol/water mixture is set to 50% and the inhibitor efficiency is set to 90%. the pump line is opened. MANUALCONTROLLER: C-PUMP-C-BY: This controller is required by the pump module. the recycle flow will be started. and a check valve at the outlet of that pipe. Case Comments: CaseDefinition: OPTIONS: The full heat transfer calculation option with heat transfer through the pipe walls is used.opi demonstrates how OLGA can be used to model a displacement multiphase pump with recycle function and bypass lines. the initial conditions have to be given. The pipes are divided into 58 sections. The system consists of a 100 m long horizontal wellhead pipe followed by a 300 m m long pipe containing a pump inlet valve. minimum heat transfer coefficient on inner walls is set to 10 W/m2K. FLOWPATH — Piping: The pipeline is 3. The total number of pipes. The steady state pre-processor is turned off. In this sample case. ΦLOWPATH — Output —ΣΕΡςΕΡ∆ΑΤΑ: Server variables are available for plotting in interactive simulations.3. A sketch of the model is shown in Figure 1. Figure 1 Sketch of the model. a manual controller with SETPOINT=0 can be used for the recycle controller or the recycle diameter. Following this is a 100 m long pipe leading up to a 200 m tall riser to the topside. the equilibrium is used to determine the gas source at the inlet. By default. The production is to go through the bypass line and the total flow rate is about 22. Sample case: Displacement Pump The case Pump-Displacement. mass fraction of free water is set to 0. FILES: The characteristic data of the pump is found in the file ol-pump1-2. overall mass flow. The CO2 fraction. there is additional water in the vapor phase given by the water vapor mass fraction in the PVT table. including topside. The outlet boundary condition is to a constant pressure of 24 bara and a temperature of 26° C.181 kg/s and temperature of 60° The C. . only the largest of these two factors is multiplied with the corrosion rate while for the de Waard 95 model. see WATEROPTIONS keyword.3 km long. The total mass flow rate is measured by and defined in the Transmitter TM-2. A bypass pipeline is connected to the pump pipeline. can be set to zero. OUTPUT: OLGA variables are printed to the output file at the start and end of the simulation. the inlet pressure is reduced to be the same as the outlet pressure so that no production is expected without a pump. i.. Output: ANIMATE: 3D plot of holdup for liquid along the pipeline is plotted every 10 seconds. is 9. This line has a bypass valve on the inlet and a check valve on the outlet. If no recycle flow is required. The pump inlet pressure is measured by Transmitter TRAN-PUMP-IN-PT. Then. Operation scenario: In the first hour. The effect of a second inhibitor is given directly though the key INHIBITOREFFICIENCY. FLOWPATH — Output — PROFILEDATA: Pressure. the pump speed is controlled by the total mass flow rate (PUMPGT) through the pump. a displacement pump. For the NORSOK model. and the displacement pump starts to increase the pump speed in order to yield the flow rate 30 kg/s.e. and if the pump inlet pressure is lower than 38. In the second hour.2 kg/s. PROFILE: Profile variables are plotted every 50 seconds. FlowComponent: FLOWPATH — Boundary&InitialConditions — INITIALCONDITIONS: Since the steady state pre-processor is not used. temperature. The pipe walls consist of steel (two layers) covered with a layer of insulation. In this sample case. The C. FLOWPATH — FA-models — CORROSION: Both Model1 (NORSOK) and Model3 (de Waard 95) are activated on flow path B-INLET. which means that the built-in bypass line is closed. and oil and water hold-up and velocities are profile plotted for all pipelines. gas velocity. PIDCONTROLLER: C-PUMP-D-RE: This controller is required by the pump module. the bypass line closed. the built-in bypass function of the pump module is obsolete since any bypass line can be modeled using an additional flow-path. a pump outlet valve. RECDIAMETER. NODE: The inlet node is closed. the bypass controller is a manual controller with set-point 0. TREND: Trend variables are plotted every 10 seconds.tab.FLOWPATH — Boundary&InitialConditions — SOURCE: The inlet boundary condition is a constant mass source with mass flow of 34. However. FLOWPATH — Boundary&InitialConditions — HEATTRANSFER: The ambient temperature is set to 15° The heat t ransfer coefficient on outer walls is set to 500 W/m2K. The inlet pressure is 43 bara over the first hour and is then reduced to 39 bara. NODE: The outlet pressure held constant at 30 bara and the temperature is 4° C. ΦLOWPATH — Output —ΣΕΡςΕΡ∆ΑΤΑ: Server variables are available for plotting in interactive simulations. FlowComponent: FLOWPATH — Boundary&InitialConditions — HEATTRANSFER: The ambient temperature is vertically interpolated from 80° at the bottom of the borehole to 20° at the C C wellhead. FLOWPATH — Output — TRENDDATA: Pump variables are plotted. A sketch of the model is shown in Figure 1. Over the next half an hour. BYDIAMETER=0 (bypass diameter.2 m. Output: ANIMATE: 3D plot of holdup for liquid along the pipeline is plotted every 10 seconds. is 300 m long and has the same diameter. RECDIAMETER=0. as the rest of the pipe.FLOWPATH — ProcessEquipment — PUMP: The centrifugal pump is defined by following parameters: SPECAPACITY=0. TREND: Trend variables are plotted every second. FLOWPATH — Boundary&InitialConditions — SOURCE: The mass source injects water based mud at the well bottom hole at a rate of 60 kg/s over the first hours. MAXSPEED=8000 rpm. The heat transfer coefficient on outer walls is set to 500 W/m2K. Trend plots of the total mass flow rate at topside (GT). FLOWPATH — Output — TRENDDATA: The mass fraction of mud is plotted. The steady state pre-processor is used to generate initial conditions.2 m diameter which leads up to a 200 m tall riser. C. . ΦLOWPATH — Output —ΣΕΡςΕΡ∆ΑΤΑ: Server variables are available for plotting in interactive simulations. The inlet temperature is held constant at 30° The outlet pressure is held constant at 39 ba ra and the temperature is 20° Two internal nodes are used to connect the bypass around the pump. The well production will push the drilling mud out of the tubing and start normal production. and mud source mass flow rate (GTSOUR) show the flow rate changing. MAXDENSITY=2400 kg/m3. Sample case: Drilling Fluid The case DrillingFluid. The mud is then reduced to zero over half an hour. At topside a 100 m pipe leads to the outlet. the rate is reduced to zero.opi demonstrates how OLGA models drilling fluid in a well clean-up case. The minimum heat transfer coefficient on inner walls is set to 10 W/m2K. BINJ=10-8 kg/s/Pa and BPROD=3. is defined with TYPE=WATER. constituted by six sections. Output: ANIMATE: 3D plot of holdup for liquid along the pipeline is plotted every 10 seconds. C. PREFSPEED=3000 rpm. MINDENSITY=600 kg/m3. liquid density (ROL) and hold-up show changes in the amount of mud and liquid in the pipeline. NODE: Both the inlet and outlet nodes are pressure nodes. C. Operation scenario: Water based drilling mud is injected from the well bottom hole during the first hour in order to fill-in the well tubing. Case Comments: Library: DRILLINGFLUID: The drilling fluid. A source injects water based drilling mud from the well bottom hole to fill-in the well tubing. zero means no bypass flow through the built-in bypass). PROFILE: Profile variables are plotted every 30 minutes. 0.5·10-6 kg/s/Pa. AINJ=APROD=0.1 m (diameter of the built-in recycle pipe).01 m3/R. FLOWPATH — Boundary&InitialConditions — WELL: The reservoir pressure is 200 bara and reservoir temperature 80° Production and injection type is L INEAR. MINVISCOSITY=10-4 Ns/m2 and MAXVISCOSITY=1 Ns/m2 CaseDefinition: OPTIONS: The full heat transfer calculation option with heat transfer through the pipe walls is used. the total well flow rate (GTWELL). Profile plots of the mass fraction of mud (MFAMUD). FLOWPATH — Piping: The pipeline consists of a 500 m long pipe horizontal pipe with a 0. DRFL_LIQ_1. The well production will push the drilling mud out of the tubing and start normal production. OUTPUT: OLGA variables are printed to the output file every 10 hours. The system consists of a well tubing pipeline with 1875 m TVD and 2725 m MD and a 150 m long wellhead pipe. The bypass line. Figure 1 Sketch of the model. FLOWPATH — Output — OUTPUTDATA: In addition to standard OLGA variables. The bundle also contains a methanol line. FLOWPATH — Boundary&InitialConditions — SOURCE: During the initial heating up of the system. T=360° and P=150 bar. FLOWPATH — Output — PROFILEDATA: In addition to standard OLGA variables. FlowComponent: FLOWPATH — Boundary&InitialConditions — INITIALCONDITIONS: The flow line is initially filled with gas and the pressure is set equal to the outlet pressure. Sample case: Fluid bundle The case FluidBundle. ThermalComponent: FLUIDBUNDLE: The bundle consists of four pipelines (BundleComponents). when importing similar cases from OLGA 5. The part of the pipeline which is on the seabed is contained within a bundle where the carrier line contains heated water injected on the platform end. TBUN is profiled for all bundle lines. An internal node is used for the crossover from the carrier line to the return line. For the part of the pipeline contained in the bundle. CaseDefinition: OPTIONS: The full heat transfer calculation option with heat transfer through the pipe wall has been used as this is required by the bundle module.OUTPUT: OLGA variables are printed to the output file every 10 hours. The steady state initialization has been turned off. TREND: Trend variables are plotted every 10^#160. A temporary increase in outlet temperature occurs due to compression of the gas and a minor reduction in outlet flow rate can also be seen. The flow in the carrier line is counter current to the flow in the other lines and in the flowpath. The water is going in a loop consisting of the carrier and return lines where constant pressure and temperature is set on the platform side. This leads to condensation of gas which slows down the C. N. The pipe has a hydraulic diameter of 30. ΦLOWPATH — Output —ΣΕΡςΕΡ∆ΑΤΑ: Server variables are available for plotting in interactive simulations. Sample case: H2O Tracking (Single component) Case: Single-H2O. TBUN is trended for the bundle lines at selected positions. a certain amount of manual labor is required. the ambient conditions are exterior to the flow line. A temporary small increase in outlet flow rate occurs due to the lower density of gas at the increased temperature. Ramping up to a steady production flow rate is commenced after 10 hours. The pipe defined as FLOWPATH defines that the bundle starts at the beginning of the second pipe and ends at the riser base. One is defined as a FLOWPATH and the other three as LINEs. WALL: The flow line pipe wall is 2. After 60 seconds the inlet temperature is increased and reaches 450° after 120 seconds. PROFILE: Profile variables are plotted every 6 minutes. OUTPUT: OLGA variables are printed to the output file.seconds. A sketch of the cross-section of the bundle is shown in Figure 1. Both these lines have pressure boundaries specified at the outlet. Please refer to the conversion documentation for a detailed description.opi Purpose: "Walk around" the critical point. the inlet temperature is reduced to 360° thereby moving into the liquid side of th e dense phase region.54 cm thick and has been divided into 4 layers. Output: ANIMATE: 3D plot of holdup for liquid along the pipeline is plotted every 10 seconds.. C FLOWPATH — Boundary&InitialConditions — HEATTRANSFER: The ambient conditions are constant along the whole system. thereby moving into the dense phase region on the gas side. every 10th hour.48 cm. Case Comments: Library: MATERIAL: Carbon steel is the only material used in the pipe walls. the source is turned off. The pipeline consists of a 5480 m long pipe along the seabed followed by a 162 m vertical riser and a 100 m horizontal topside pipe. FLOWPATH — Output — TRENDDATA: In addition to standard OLGA variables.B. The initial temperature is 4° both in the pipeline and bundle lines.opi demonstrates how OLGA can be used to simulate how a bundled pipeline initially filled with gas is heated up before production is started. The carrier line water returns to the platform through the return line before it is heated up again and reinjected into the carrier line. FLOWPATH — Piping: The pipeline along the seabed (5480 m) is described by seven pipes whereas the riser and topside are single pipes. Fluid: 100% H2O The transient starts in the gas region. Figure 1 Cross-section of the bundle. A corresponding increase C C in outlet temperature follows. TBUN is printed to the output file. PROFILE: Profile variables are plotted every hour. After 10 minutes. the outlet pressure is increased to 227 bar. NODE: The flow line has a closed inlet node whereas the methanol line has a mass flow node on the inlet. After 20 minutes. TREND: Trend variables are plotted every minute. The data of both fluid and line pipe walls are given so that OLGA calculates a u-value for each of the lines. . Inlet temperatures are specified for the bundle lines. ΦLOWPATH — Output —ΣΕΡςΕΡ∆ΑΤΑ: Server variables are available for plotting in interactive simulations. A temporary drop in outlet temperature down to about saturation temperature occurs due to the evaporation of water. 20 sections. The outlet is a pressure boundary. During the oscillations in outlet flow of vapor negative values can be seen. A temporary small increase in outlet flow rate occurs due to the lower density of gas at the increased temperature. regions where the conditions might cause hydrate plugs to form can be detected. There is also an overshoot in gas flow rate due to the volume increase. NODE: A closed node is placed at the pipe inlet. After half an hour.reduction in outlet temperature. TBOILING=1. Fluid: 100% H2O The transient starts in the gas region. This leads to condensation of gas which slows down the C. a 150 m long wellhead pipe. Case Comments: CaseDefinition: OPTIONS: The steam\water–HC module is activated by setting COMPOSITIONAL=STEAMWATER-HC.opi Purpose: "Walk around" the critical point. which is due to the oscillations being of numerical nature. A sketch of the model is shown in Figure 1. After 20 minutes. After 10 minutes.12 m. The system consists of a well tubing pipeline with a 1875 m true vertical depth (TVD) and a 2725 m measured depth (MD). which is due to the oscillations being of numerical nature. OUTPUT: OLGA variables are printed to the output file every 600 seconds. After 60 seconds the inlet temperature is increased and reaches 450° after 120 seconds.0. diameter=0. After half an hour. The conditions are quite close to the critical point where the behavior of the fluid properties is highly nonlinear. diameter=0. TEMPERATURE=ADIABATIC (no heat exchange with walls) Compositional: COMPOPTIONS: Time constants are set: TCONDENSATION=1. thereby crossing the saturation line from the liquid side to the gas side. PROFILE: Profile variables are plotted every 5 minutes. Temperature and pressure varies with time. the outlet pressure is reduced to 150 bar. In order to avoid hydrate plugs. thereby crossing the saturation line from the liquid side to the gas side. The outlet is a pressure boundary. A temporary drop in outlet temperature down to about saturation temperature occurs due to the evaporation of water. TVAPORIZATION=1. Output: ANIMATE: 3D plot of holdup for liquid along the pipeline is plotted every 10 seconds. the outlet pressure is reduced to 150 bar. TREND: Trend variables are plotted every seconds. the inlet temperature is reduced to 360° thereby moving into the liquid side of th e dense phase region.12 m. Sample case: Hydrate Kinetics The case HydrateKinetics. The outlet flow rate of gas shows an oscillatory behavior and finally goes to zero when all the vapor is either condensed or has left the pipe. Case Comments: CaseDefinition: OPTIONS: The single component module is activated by setting COMPOSITIONAL=SINGLE.0 FlowComponent: FLOWPATH — Boundary&InitialConditions — SOURCE: Water source delivering 2 kg/s. A temporary increase in outlet temperature occurs due to compression of the gas and a minor reduction in outlet flow rate can also be seen.0. Operation scenario: The well is a gas well.0.0 FlowComponent: FLOWPATH — Boundary&InitialConditions — SOURCE: Liquid source delivering 2 kg/s. reduction in outlet temperature. The hydrate kinetics model enables approximate predictions of where hydrate plugs might form in oil and gas pipelines. The outlet flow rate of gas shows an oscillatory behavior and finally goes to zero when all the vapor is either condensed or has left the pipe. Time constants are set: TCONDENSATION=1.2 m vertical riser and a 100 m long horizontal topside pipe. a 3150 m pipeline leading up to a 391. A corresponding increase C C in outlet temperature follows. The fluid temperature may be below the hydrate temperature in the flow line. The conditions are quite close to the critical point where the behavior of the fluid properties is highly nonlinear. TBOILING=1. During the oscillations in outlet flow of vapor negative values can be seen.0. 20 sections. thereby moving into the dense phase region on the gas side. TEMPERATURE=ADIABATIC (no heat exchange with walls) Compositional: SINGLEOPTIONS: H2O is activated by setting COMPONENT=H20. FLOWPATH — Piping: 100 m horizontal pipe. Temperature and pressure varies with time. NODE: A closed node is placed at the pipe inlet. The total production is controlled by the wellhead choke. Sample case: H2O Tracking (Steam/Water–HC) Case: SteamWater-HC. ΦLOWPATH — Output —ΣΕΡςΕΡ∆ΑΤΑ: Server variables are available for plotting in interactive simulations.opi demonstrates how the hydrate kinetics model can be used in an OLGA simulation. TVAPORIZATION=1. T=360° and P=150 bar. . There is also an overshoot in gas flow rate due to the volume increase. the outlet pressure is increased to 227 bar. FLOWPATH — Piping: 100 m horizontal pipe. Figure 1 Schematic illustration of the pipeline geometry. In the flow line and riser. adiabatic flow is assumed.Figure 1 Sketch of the model. respectively. 140 m high.5·10-6 kg/s/Pa. Temperature exchange with the walls are not accounted for. A sketch of the pipeline geometry is shown in Figure 1. FLOWPATH — Output — TRENDDATA: Hydrate variables are plotted. FILES: The fluid is described by either a pvt-file or an equivalent feed-file depending on the type of simulation. FLOWPATH — FA-models — HYDRATEKINETICS: The hydrate kinetics model is applied for all flowpaths. OUTPUT: OLGA variables are printed to the output file every 10 hours. FLOWPATH — FA-models — HYDRATECHECK: Hydrate checking is activated in all flowpaths. Case Comments: Library: HYDRATECURVE: Definition of hydrate curve used by HYDRATECHECK. C. 2K. Sample case: Hydrodynamic slugging The cases HydrSlug-pvt. FLOWPATH — Output — PROFILEDATA: Hydrate variables are plotted. ΦLOWPATH — Output —ΣΕΡςΕΡ∆ΑΤΑ: Server variables are available for plotting in interactive simulations. TREND: Trend variables are plotted every 10 seconds. W/m FLOWPATH — Boundary&InitialConditions — WELL: The reservoir pressure is 200 bara and reservoir temperature 50° Production and injection type is L INEAR.5 km pipeline through slight uphill terrain leads up to the second. Output: ANIMATE: 3D plot of holdup for liquid along the pipeline is plotted every 10 seconds. but no heat storage is accounted for. The initial conditions are generated by the steady state pre-processor.opi illustrate slug-tracking using hydrodynamic slug initiation with and without and with compositional tracking. NODE: The outlet pressure held constant at 50 bara and the temperature is 20° C. respectively. Case Comments: CaseDefinition: OPTIONS: The two cases run with COMPOSITIONAL=OFF/ON. vertical interpolation on ambient temperature along the tubing. the ambient temperature is 4° The heat transfer coefficient on outer wall is set to 500 C. A platform to platform transportation is simulated where the fluid enters into a short horizontal pipe before descending down a 173 m long riser. riser and a short horizontal topside pipe. BINJ=10-7 kg/s/Pa and BPROD=2. The minimum heat transfer coefficient on inner wall is set to 10 W/m2K. CaseDefinition: OPTIONS: Temperature calculations use heat transfer on the inside and outside of pipe walls as well as heat conduction. AINJ=APROD=0. FlowComponent: FLOWPATH — Boundary&InitialConditions — HEATTRANSFER: The inlet ambient temperature of the well is 50° and outlet ambient temperature is 4° The code will do a C .opi and HydrSlug-comp. A 7. . PROFILE: Profile variables are plotted every hour. The boundary conditions vary between given pressure. and well productivity index.3 bara and a temperature of 20° C. The fluid temperature is 72. NODE: A closed node is placed at the pipe inlet. CaseDefinition: OPTIONS: To activate MEG tracking. no slugs can be initiated or propagate through these sections. The MEG concentration in the aqueous phase changes from 60% to 30% after 1. E. . the key COMPOSITIONAL has to be set to MEG. Sample case: MEG Tracking The case Meg-Tracking. FLOWPATH — Output — TRENDDATA: In addition to standard plotting variables such as liquid content.g. ΦLOWPATH — Output —ΣΕΡςΕΡ∆ΑΤΑ: Server variables are available for plotting in interactive simulations.FA-models: SLUGTRACKING: Hydrodynamic slug initiation is enabled (HYDRODYNAMIC=ON) is enabled through the entire simulation. OUTPUT: OLGA variables are printed to the output file every 2 hours. FLOWPATH — Output — PROFILEDATA: The mole fraction of MEG in the water phase is plotted. to a processing platform. TRENDDATA: In addition to standard plotting variables. TREND: Trend variables are plotted every 6 minutes. one from each wellhead.. OUTPUT: OLGA variables are printed to the output file every hour. i. given mass flow. FlowComponent: FLOWPATH — Boundary&InitialConditions — SOURCE: The source introduces fluid into the pipeline at a constant rate of 130200 kg/h. Two wells merge at the first wellhead and the other three wells at the second one. FLOWPATH — ProcessEquipment — VALVE: A valve with constant valve opening is put in the middle of the top-side pipe at the outlet. Here. various slug related properties are plotted. A horizontal pipeline with a source at the inlet is used to show that the concentration of MEG can be changed during the simulation and how this can be tracked through the pipeline. PROFILE: Profile variables are plotted every 15 minutes. Five wells merge into two different wellheads. Sample case: Network The case Network.. the number of slugs in the pipeline (NSLUG) and the accumulated number of slugs initiated (SLUPRO) are plotted.. ΦLOWPATH — Output —ΣΕΡςΕΡ∆ΑΤΑ: Server variables are available for plotting in interactive simulations. A constant pressure is applied at the outlet. FLOWPATH — FA-models — SLUGILLEGAL: The sections in the pipe TO-SEP are declared as illegal sections.5 hours. FLOWPATH — Output — TRENDDATA: The mole fractions of all three components in the gas and water phases are plotted.opi demonstrates the features of the inhibitor tracking module. NODE: The inlet node is closed. Output: ANIMATE: 3D plot of holdup for liquid along the pipeline is plotted every 10 seconds. Two slightly different geometries are used for the wells. Output: ANIMATE: 3D plot of holdup for liquid along the pipeline is plotted every 10 seconds. FLOWPATH — Piping: The branch consists of 11 pipes. pressure. the flow merge into a common header and then flows through some horizontal piping before reaching the outlet. hold-ups. The fluid is transported through two pipelines. FlowComponent: FLOWPATH — Boundary&InitialConditions — SOURCE: A mass source with constant mass flow is placed at the inlet.opi is a network case.2° C. PROFILE: Profile variables are plotted every 10 minutes. Case Comments: FA-models: WATEROPTIONS: Water flash and water slip are turned on.e. etc. variables like HOLEXP show the instantaneous holdup at the position specified. The two pipelines have identical geometries. TREND: Trend variables are plotted every second. The outlet boundary condition is set to a constant pressure of 68. Branches 4 and 7 are connected to internal nodes and have no terminal nodes. Output: SERVERDATA: SIMTIME. This causes a snap-file (a.5. FLOWPATH — Piping: The number of pipes and their coordinates are defined for each branch. The maximum and minimum time steps are 10 seconds and 0. Defining this keyword is all that is needed to start the built in OPC server in OLGA. Manipulation of server commands: Saving a snap file: Specify a filename in the OPC item Toolkit. an ESD controller and a valve. which gives the possibility to change the requested simulationspeed using a connected OPC client. the mass flow is specified in terms of volumetric flow rate of liquid at standard conditions. FlowComponent: FLOWPATH — Boundary&InitialConditions — SOURCE: Branches 1 and 5 use constant mass sources. . OPC Interactivity: Manipulation of input items: Using a standard OPC client. Controller: ESDCONTROLLER: An emergency shutdown controller is used to close the valve whenever the holdup upstream goes above the controller setpoint.ServerDemo. ΦLOWPATH — Output —ΣΕΡςΕΡ∆ΑΤΑ: Server variables are available for plotting in interactive simulations. the section lengths are gradually reduced to the values in the riser. INTEGRATION: SIMULATIONSPEED is set to 100.8. These will be visible on the OPC server. The ESD controller is set to close the valve whenever the upstream holdup goes above 0.SaveSnap to ‘true’.k. x and z represent horizontal coordinates whereas y is the vertical axis. The setpoint of the controller is selected in the EXPOSE key. FlowComponent: FLOWPATH –ProcessEquipment-VALVE: The valve is initially fully open and is regulated by the ESD controller. Sample case: server-demo-with-opc Server-demo-with-opc.8. Branch 8 has a constant pressure node at the outlet. Case Comments: CaseDefinition: SERVEROPTIONS : A modelname “ServerDemo” is specified. restart file) to be saved to disk. FLOWPATH — ProcessEquipment — VALVE: The wellhead choke in Branch 3 is fully open during the entire simulation. NODE: Branches 1. No heat transfer through the pipe walls is assumed.B. Further. meaning that it is possible to dynamically change the setpoint using an OPC client connected to the OLGA OPC server. SPEED is set.File. Without user interaction the holdup stays around 0. the setpoint for the controller is changed to 0. the user may note the length and inclination of each pipe section as printed to the output file at the end of the initialization. indicating the model is requested to simulate at 100 times real-time speed. TREND: Trend variables are plotted every 30 seconds. TIME. As a verification of the input.65. for instance “snap. OUTPUT: OLGA variables are printed to the output file at the end of the simulation. FLOWPATH — Boundary&InitialConditions — WELL: The reservoir pressure and temperature are given together with a linear productivity index for gas and liquid flow at the midpoint of the first section in branch 3.Figure 1 Schematic view of the network. Case Comments: CaseDefinition: OPTION: Temperature option "ADIABATIC" has been chosen.01 seconds.opi is a simple case with one horizontal flowpath.. for Branch 1. INTEGRATION: The simulation end time is set to 3 hours. 3 and 5 have closed nodes at the inlets.ServerDemo. SIMULATIONSPEED is selected in the EXPOSE key.SaveSnap. Branches 2 and 6 have constant pressure nodes at the inlets. leaving the valve completely open. which is set to 0. Toward the end of the flow lines. N. Output: ANIMATE: 3D plot of holdup for liquid along the pipeline is plotted every 10 seconds. respectively.rsw”. HT. PROFILE: Profile variables are plotted every 15 minutes. This causes the valve to close. There is a 50 bara pressure difference between the boundary nodes driving the fluid towards the outlet. Then toggle the command item Toolkit.a. Stop to ‘true’ causes the simulation to shut down.ServerDemo.LoadSnap. .Loading a snap file into the running server: Specify the same filename as in the save-snap command argument.rsw” and toggle Toolkit.ServerDemo.LoadSnap to ‘true’.File to “snap.ServerDemo. e. The snap-file is then loaded and the simulator state from the snap file is restored. set Toolkit. Toggeling Toolkit.g. Further.5 PTSIG: Measures the pressure upstream CHOKE-1-1. Controller: PIDCONTROLLER C-1: Controller C-1 is used to control the pressure at riser base (upstream the valve CHOKE-1-1) by adjusting the opening. FLOWPATH – Output – SERVERDATA: VALVOP is selected for the valve. Then launch MatrikonOPC Explorer. MINSIGNAL. NODE: NODE-2: The node PRESSURE is exposed. MEASVAR. The controller C-1 is a scheduling controller. At the bottom of the riser a valve labeled CHOKE-1-1 is included. SPEED and SIMTIME are defined to be updated on the OPC server with DTPLOT set to 10 seconds. Note the use of controller sub-key NORMRANGE which is set to 1e5. SETPOINT. The purpose with this sample case is to demonstrate the possibilities to interact with a PID controller through the OLGA OPC Server and exemplify how vectors can be addressed through the OLGA OPC Server. FLOWPATH : BRAN-5-Boundary&InitialConditions-SOURCE: SOUR-2-1: MASSFLOW is exposed. Then one will obtain a display similar to the one below. HT.Sample case: Network-server The case Network-server. GT trend is selected for position TOPSIDE-OUT in BRAN-8. TIME. DERIVATIVECONST. BIAS. INTEGRATION: SIMULATIONSPEED is set to 15. integral constants and derivative constants rather than one value for each. ERRVAR are defined to be updated on the OPC server with DTPLOT set to 10 seconds.opi is an OPC server version of the demo case Network.opi sample. MANUALOUTPUT. OPENINGTIME. TIME.opi. Further. OLGA will automatically filter out any keys that cannot be exposed and issue a harmless warning when the case starts. lowering Toolkit. the running case can be manipulated. SPEED. add a group and add all items to the provided by the OLGA OPC server to the group. ERROR.PRESSURE from 243 to 40 will cause the holdup in BRAN-8 to drop. The EXPOSE key of controller C-1 is set to ALL. indicating the model is requested to simulate at 15 times real-time speed. indicating the model is requested to simulate at 10 times real-time speed. The signal is pressure in unit Pa. For other comments see the Network. Output: Global SERVERDATA keyword: Variables VOLGBL. FlowComponent: FLOWPATH P1: One horizontal pipe followed by two downwards inclined pipes and a vertical riser.opi is a simple case with one flowpath modeling a pipeline riser system.OLGAOPCServer. Case Comments: CaseDefinition: SERVEROPTIONS : The model name sub-key is set to “TEST” and the server name is set to OLGAOPCServer INTEGRATION: SIMULATIONSPEED is set to 10. LAGIND is set. which gives the possibility to change these input values using a connected OPC client. LAGFACT. Case Comments: Only server specific items are commented here. SERVERDATA keyword defined on controller C-1: Variables CONTR. In this case the following keys are exposed as input items on the OPC Server: MAXSIGNAL. The set-point to the controller is 75e5. The controller measures the pressure in unit Pa.NetworkDemo. . Defining this keyword is all that is needed to start the built-in OPC server in OLGA. In this case the keys STDFLOWRATE. NORMRANGE.1. HT. INTEGRALCONST and DERIVATIVE CONST are vectors of size four in the definition of controller C-1. FlowComponent: FLOWPATH : BRAN-3-ProcessEquipment-VALVE: The valve OPENING is selected in the EXPOSE key. Output: SERVERDATA: SIMTIME. For instance. These will be visible on the OPC server. Upstream the valve a pressure transmitter is included. Note that the keys: AMPLIFICATION. A controller C-1 acts on the valve CHOKE-1-1 to control the pressure upstream the valve. SETPVAR. PTSIG is connected to the MEASRD terminal of controller C-1. The OPC Server will then expose all input keys that are explicitly set in the controller. which gives the possibility to change the requested simulation speed through the OPC server. HOL and PT profile is selected for BRAN-8. OPC Interactivity: Manipulation of input items: Start simulating the OLGA case by pressing one of the run buttons in the OLGA GUI. SIMULATIONSPEED and MINDT are selected in the EXPOSE key. It uses a table of amplification factors. the valve opening can be set from a connected OPC client. see figure below. MODE. SIMULATIONSPEED is set in the EXPOSE key. ERROR. connect to SPT. For further description of PID controller with scheduling functionality refer to the OLGA PID controller documentation. INTEGRALCONST. setting the pressure back to 243 causes the same holdup to rise again. CHOKE-1-1: controller C-1 manipulates the CHOKE-1-1 and the initial output of the controller is 0. FLOWPATH : BRAN-1-Boundary&InitialiConditions-SOURCE: SOUR-1-1: All possible keys are selected as exposed. CaseDefinition: SERVEROPTIONS : A modelname “NetworkDemo” is specified. TEMPERATURE and WATERCUT are ultimately exposed on the OPC server.NODE-2. Sample case: PID-net-gainsched-normrange-server PID-net-gainsched-normrange-server. Thus. OPC Interactivity: Fiddling with the exposed input parameters. CLOSINGTIME For further information of these keys see the description of PID controller. AMPLIFICATION. Case Comments: CaseDefinition: OPTIONS: Temperature option ADIABATIC has been chosen.Note that the values on the exposed keys automatically comes up with the values set in the model. Pig-TrackSlug-comp. At the inlet. the pressure is 117 bara and the temperature is 10° The temperature at the outlet is the same. The section pressure is transmitted with unit bara. By default. and ends at time t=1. FLOWPATH — ProcessEquipment — VALVE: A valve is placed before the riser but downstream the transmitter. The pig is launched 1500ɢm into the pipeline and it is trapped at 75 m into the topside pipe.opi demonstrates pressure control at a riser base. liquid mass flow and gas mass flow are plotted.opi Pigging of a pipeline using standard OLGA tracking the liquid slug in front of the pig. For instance decreasing the set-point of controller C-1 to 74e5 causes the controller to open the valve from 5. FlowComponent: FLOWPATH — Boundary&InitialConditions — SOURCE: The inlet boundary condition is a constant mass source with mass flow 10. The transmitter is used to collect the pressure from the pipeline. By increasing the NORMRANGE the controller is thus detuned for all ERROR ranges. A range of 50 bara is set for the controller (NORMRANGE key).opi Pigging of a pipeline using compositional tracking.8).1 initially (see the BIAS key). ΦLOWPATH — Output —ΣΕΡςΕΡ∆ΑΤΑ: Server variables are available for plotting in interactive simulations. The engineer can detune the controller either by reducing the amplification factors or increasing the integral constants. The valve opening is regulated by the pressure controller. The pipeline consists of 5 pipes. The geometry is shown in Figure 1. The valve has the same maximum cross section as the pipeline.opi Pigging of a pipeline using compositional tracking without tracking the liquid slug in front of the pig. First a horizontal pipe and two weakly descending pipes before a vertical pipe and a short horizontal pipe. The pipeline is simulated without heat transfer through the pipe walls. A valve is used to control the pressure at the riser base. but the C. If the engineer wants to detune the controller for a specific error range one need to adjust the corresponding element in the array of amplification factors or integral constants. OUTPUT: OLGA variables are printed to the output file at the start and end of the simulation. Pig-TrackSlug-pvt. which is 0. FLOWPATH — FA-models — DTCONTROL: The CFL criterion is used to limit the simulation time step. liquid holdup. A PID controller is used to regulate the valve opening. A safety margin of 20% is added to the CFL criterion to get a stable simulation (CFLFACTOR = 0. Manipulation of server inputs: The engineer has the possibility to change the values of all the exposed keys. NODE: The inlet node is closed. etc. The pressure setpoint is 75 bara. INTEGRATION: The simulation starts at t=0 s. Through the OPC Server the maximum. also tracking the liquid slug in front of the pig. The amplification factor is scaled by dividing by the NORMRANGE.0 kg/s and a temperature of 62° The mass C. FLOWPATH — Output — PROFILEDATA: Profiles of pressure. The measured value is taken from the transmitter. The rate of change constraints on the output can be changed through OPENINGTIME and CLOSINGTIME. temperature. Sample case: PID Controller The case PID-Controller.5 h. FLOWPATH — Output — TRENDDATA: The valve opening is plotted. Output: ANIMATE: 3D plot of holdup for liquid along the pipeline is plotted every 10 seconds. Pig-noSlug-comp. By changing the elements in the array exposed as ERROR the engineer can change the error ranges. TREND: Trend variables are plotted every second. By further reduction in the set-point to 73e5 causes the controller to open the valve to 8. The outlet boundary condition is a constant pressure of 55 bara.01 s and is limited to a maximum value of 25 s. The time step starts at the minimum value of 0. pressure is 100 bara. which is transmitted to the controller. PROFILE: Profile variables are plotted every 6 minutes. minimum constraint on the controller output can be changed through the MAXSIGNAL and MINSIGNAL keys.opi Pigging of a pipeline using standard OLGA without tracking the liquid slug in front of the pig.1%. . Sample case: Pigging The following cases illustrate the following pigging scenarios: Pig-noSlug-pvt. Controller: PIDCONTROLLER: A pressure control valve is used to control the pressure at the riser base. The pipeline has pressure nodes both on the inlet and outlet.6%. fraction of free water is set to 0.8% to 6. the equilibrium is used to determine the gas source at the inlet. FLOWPATH — ProcessEquipment — TRANSMITTER: A transmitter is positioned at the riser base. 2 Formation of hydrate if the temperature drops below the hydrate equilibrium temperature 4 1. Therefore we don’t need to give values for heat capacity in the UDPHASE field. NODE: Both the inlet and outlet nodes are pressure nodes. The case consists of a single 500 m horizontal pipe. its length is plotted. At topside. Whether the liquid slug in front of the pig is tracked or not is determined by the key TRACKSLUG. adiabatic flow is assumed. See section 1. enthalpy. 1. The dll name “OlgaPlugInHydrateTutorial.2. and no hydrates.Figure 1 Illustration of the pipe geometry. PROFILE: Profile variables are plotted every 30 seconds. 1 .1 Case description.4 Hydrate PVT properties. need to set a dummy value for the hydrate particle density to bypass the input error check. 3 . providing the PID controller with its input signal.1 Hydrate equilibrium curve. 4. in which the trap position is located. The value is overridden by the density model in the plug-in DLL. under CaseDefinition. Initially the pipe is filled with gas. The hydrate phase which is recognized by the DLL has been defined as follows: The case uses internal models from the plug-in for hydrate heat capacity. The case name is HydrateTutorial. Hydrate model TESTCASE. Controller-models: PIDCONTROLLER: A PID controller regulates the opening of the outlet valve based on the gas mass flow. thermal conductivity. A hydrate phase has been added to calculate the following effects: · Tracking the hydrate particles forming and following the flow · Calculating the effects of hydrates on the viscosity of the water film 1. 1.11 m.2. it is not necessary to specify any initial conditions for hydrates in this case. LABEL has been set to “HYDRATE”. there is a 100 m horizontal pipe. FLOWPATH — Output — TRENDDATA: In cases where the slug in front of the pig is tracked. however. and viscosity.4 for further info about the plug-in DLL PVT-property models. 3. 3 . 1. 1. PARTDIAMETER = 0. FLOWPATH — ProcessEquipment — VALVE: An outlet valve controlled by the PID controller is situated at the end of the topside pipe. Both nodes have a temperature of 10° C. The launch and trap positions are indicated. ΦLOWPATH — Output —ΣΕΡςΕΡ∆ΑΤΑ: Server variables are available for plotting in interactive simulations. 1. 2. The pipe diameter is 0. The “dummy” hydrate density is set to 940 kg/m3. FLOWPATH — Piping: The branch is split into three pipes. Temperature exchange with the walls are not accounted for. 5 . oil and water. Case Comments: CaseDefinition: OPTIONS: The two cases run with COMPOSITIONAL=OFF/ON. 5 .. FLOWPATH — ProcessEquipment — TRANSMITTER: A transmitter is located in the second last boundary on topside.2. TYPE=PARTICLE.3 Increased oil viscosity. The inlet pressure is 117 bara and the outlet pressure is 100 bara. OLGA Plug-In hydrate formation Test Case Contents 1.2. The DLL to use in this case is specified as follows: In the GUI. TRENDDATA: The velocity of the pig and its are plotted. The hydrate particle diameter is 0. respectively. 1 .dll” which is included in the executable folder for the OLGA 7 installation package. 1. OUTPUT: OLGA variables are printed to the output file every 2 hours. Hydrate model TESTCASE This is an example case for a pre-defined plug-in dll with a hydrate formation model.1 Case description The physical models needed to handle the tasks listed above are included in the plug-in DLL “OlgaPlugInHydrateTutorial. FlowComponent: FLOWPATH — FA-models — PIG: A pig is launched after 300 s.. density. 1. FILES: The fluid is described by either a pvt-file or an equivalent feed-file depending on the type of simulation. A 10 km long horizontal pipe leads up to a 500 m riser. Thus. TREND: Trend variables are plotted every 3 seconds.dll” has been entered in the PLUGINDLL field.001 m and PARTDENSITY = 940 kg/m3. UDOPTIONS has been added. . UDPHASE has been added. The dll is located in the same folder as the OLGA 7 engine executable. We do.2. and it is thus not necessary to include path in this case.001 m. The case is set up to use INITIALCONDITIONS. Output: ANIMATE: 3D plot of holdup for liquid along the pipeline is plotted every 10 seconds.opi.2 Physical effects modeled. Under Library. 1) The value chosen for a is 6. the model has explicitly been set to start with zero hydrates at time = 0. the UD dispersion phase name (Hydrate) and the layer where it is located (InOil). PROFILEDATA. The HydrateTutorial. P-US have been specified for FLOWPATH: BRAN-1/Output.0 Under FLOWPATH:BRAN-1/Boundary&InitialConditions/INITIALCONDITIONS[1]/User Defined. LAYER = WATER has been chosen.2. At case level. For PHASE. “HydrateTutorial. It is thus not necessary to specify hydrate inflow for the source. 6. MASSFRACTION = 0. . HYDRATE has been chosen. 1.tab. The following format is chosen: <Hydrate curve (C.2) ) drops below the hydrate equilibrium temperature ( ).4) (1. The format of the table file is dictated by the plug-in DLL. 1. HYDRATE has been chosen. The effect of hydrate particles on oil viscosity can be seen by plotting the following profile variables in the same plot: VISHLEFF and VISHL. Bar)> 31 -10. PHASE = HYDRATE. it is necessary to refer to the table file used by the plug-in DLL which is applied for the specific branch. TIME = 0. Mass limitation for hydrate formation rate: (1.opi.tab” has been chosen through the UDPVTFILE file browser. UserDefined/UDGROUP has been added. UDFRACTION[2 ] has been added. P-HOL. Source entry: At FLOWPATH: BRAN-1/Boundary&InitialConditions/SOURCE:SOURCE-1-1. FLOWLAYER = OIL has been specified in this case. MASSFRACTION = 0.87. Under FlowComponent/FLOWPATH:BRAN-1/Piping/BRANCH. the hydrate inflow has explicitly been defined to zero for the source in the first pipe section.However. is the gas mass reacted per time and section volume.2 Formation of hydrate if the temperature drops below the hydrate equilibrium temperature When the fluid temperature ( Reaction rate: (1. UDGROUP label =” HYDRATE -INIT” Under UDPhasesAndDispersions. PHASE=HYDRATE. 8. Here. 1.tab has been chosen.g. LAYER = GAS has been chosen. LAYER = OIL has been chosen. An example of a hydrate curve is given in the HydrateTutorial. UDFRACTION has been added: LAYER=WALL. hydrate particles will form according to the hydrate reaction. UDFRACTION[3 ] has been added. However. The hydrate curve information is provided through a table file which is read by the plug-in DLL. 5.3) (1. Plotting of results: The variables P-G.2.00 3. The variable name is a composite name based on the generic P-HOL (holdup for UD dispersed phase). 7. For PHASE. TIME = 0. P-M. Here “<Hydrate curve (C.5) . “31” is the number of data points given. The other “P-“ variables have the same composite structure. P-Q. UDGROUP= HYDRATE-INIT has been chosen. in order to illustrate the use of initial conditions. Under UDPhasesAndDispersions.1 Hydrate equilibrium curve The hydrate equilibrium is given as a tabulation of temperature and pressure. The hydrate formation and propagation through the pipeline can be inspected by plotting e. In order to refer to the hydrate curve for the fluid in a given branch. Under CaseDefinition/FILES. Under UDPhasesAndDispersions. MASSFRACTION=0. the following profile variable: P-HOL_HydrateInOil.59 ………. Bar)>” is a tag telling how the temperature and pressure data is given. The hydrate curve is given through the OLGA input in the FILES UDPVTFILE field. by using a zero hydrate fraction for all layers. TIME = 0.tab is used in the HydrateTutorial. UserDefined/UDGROUP has been added. UDPVTFILE= HydrateTutorial. As we are going to inspect the oil layer.2 Physical effects modeled The hydrate reaction: (1.29 -8. BRANCH and NODE both have a key named UDPVTFILE where the user can select which file is used. The hydrate curve must be user given. In order to illustrate how to enter hydrates from a source. UDGROUP label =” HYDRATE-SOURCE” Under UDPhasesAndDispersions/UDFRACTION[1]. PHASE = HYDRATE. so it is possible to give multiple input files in a simulation. P-U. UDGROUP= HYDRATE -SOURCE has been chosen. There is no inflow of hydrates in this case. Only hydrate formation within the pipeline. MASSFRACTION = 0 has been set.00 3. It is therefore possible to use different hydrate curves in different branches of a network simulation. At case level. FILES UDPVTFILE is a string vector. partial enthalpy with respect to temperature and entropy is derived from the enthalpy equation.2.65. Hydrate heat capacity: (1.4 Hydrate PVT properties Hydrate enthalpy: (1. 1.opi. To distribute the phase values. The tasks in this case are as follows: · Tracking the sand particles following the flow in the water layer · Tracking the sand forming a bed. · Calculating the effects of sand on the viscosity of the water film · Calculating the slip velocity between suspended sand particles and the water in the water layer . These phase values must be distributed to fields. SAND model TESTCASE. 1.10) Hydrate viscosity: (1. 1. Krieger-Dougherty correlation: (1. Water and sand is injected in the first pipe section.11) OLGA Plug-In sand model test case Contents 1. SAND model TESTCASE The case consists of a single 2000 m pipe with an elevation of 150 m.2 Physical effects modeled.1 Sand offset velocity due to density differences. the mass is distributed equally on all fields. we use the following logic: · The hydrate particles is only present in the oil layer.2 m.. The pipe diameter is 0.3 Bed formation.088e6 J/kg. 1 .2.9) Hydrate thermal conductivity: (1. 3 . and the dispersion viscosity will give a higher pressure drop over the pipeline. 1. The effective viscosity is used in the friction calculations in OLGA. partial enthalpy with respect to pressure..8) Hydrate density: (1. 1.2.7) Where is the enthalpy and is the constant heat of reaction assumed to be 4. 4 . · If the gas or water phase mass is missing.2 Increased friction due to sand particles in the water 3 1.3 Increased oil viscosity The effective viscosity of the hydrate-oil dispersion is higher than the pure oil viscosity. · Gas and water field masses are distributed based on field mass fractions (field mass / phase mass).1 Case description 1 1. is the time step and is the phase mass per section volume. 3 . 1.2. Initially the pipe is filled with water only.6) Where is the oil viscosity without particles. Distribution of phase mass on fields: The reacted mass rates are given as overall phase values.Here is the stoichiometric constant in the hydrate reaction. The case name is SandInWater. The heat capacity. is the particle volumetric concentration in water and is the maximum concentration set to 0. The effective oil viscosity will be modeled with the Krieger-Dougherty correlation. The case is set up to use INITIALCONDITIONS.2. g is the gravity constant and rp is the particle radius. The DLL is specified as follows: In the GUI. Sand is injected together with water in the first pipe section. PROFILEDATA.1 Sand offset velocity due to density differences The density of the sand particles are larger than the water density. and the specified layer: (InWater).2.2 Physical effects modeled The three following physical effects has been modeled: · Sand offset velocity due to density differences · Increased friction due to sand particles in the water · Bed formation 1. P-U for FLOWLAYER = WATER.2 Increased friction due to sand particles in the water The effective viscosity of the water-sand dispersion is higher than the pure water viscosity. P-U_SandInWater. P-HOL_SandAtBed. Other sand properties are not required. LAYER = WATER has been chosen. The deposition rate can therefore be expressed as: . and the velocity of the sand particles in the water film is different from the water velocity.3 Bed formation A dummy bed formation model is used to demonstrate how to set mass transfer rates.03 m. The dll is located in the same folder as the OLGA 7 engine executable.001 m. The case is set up to use INITIALCONDITIONS. is the particle volumetric concentration in water and is the maximum concentration set to 0. due to the pipe inclination.4) Where is the water viscosity without particles. MASSFRACTION = 0. ρf is the fluid density. The UD phase specific input is described below: 1. 3. µf is the fluid viscosity. At FLOWPATH: BRAN-1/Output. Krieger-Dougherty correlation: (1. under CaseDefinition.1. the following profile plot variables: P-HOL_SandInWater. Source entry: At FLOWPATH: BRAN-1/Boundary&InitialConditions/SOURCE:SOURCE-1-1. UDGROUP=SAND-SOURCE has been chosen. the dll name “OlgaPlugInSandWaterTutorial.2) Where uOffset is the offset velocity which will be used by OLGA. 1. The sand particle diameter is 0. sand mass will deposit on the bed. The offset velocity will be calculated by Stokes’ law. the variables P-HOL. BED and PHASE = SAND have been specified to get the output variables described above. At case level. TIME = 0.65. PARTDIAMETER = 0. TYPE=PARTICLE.dll” has been entered in the PLUGINDLL field. 1. Under Library.001 m and PARTDENSITY = 2000 kg/m3. SAND has been chosen. The PHASE is referring to a UD phase. The sand velocity (uSand) will then be: (1. (Sand). get a negative offset velocity. ρp is the particle density. This can be seen by inspecting e.1 has been set.2. and the dispersion viscosity will give a higher pressure drop over the pipeline. and therefore we don’t need to model the sand heat capacity and enthalpy. The effective water viscosity will be modeled with the Krieger-Dougherty correlation. A fixed deposition rate to the bed is used. The effective viscosity is used in the friction calculations in OLGA. UDGROUP label =” SAND-SOURCE” Under UDPhasesAndDispersions/UDFRACTION[1].dll”. 4. Stokes’ law: (1. P-U.g. ULWT.1 Case description The physical models needed to handle the tasks listed above are included in the plug-in DLL “OlgaPlugInSandWaterTutorial. If the bed height is lower than 15% of the pipeline diameter. 2.opi case. The phase which is recognized by the DLL is defined as follows. The offset velocity then becomes: (1. in the SandAndWater. which is included in the executable folder for the OLGA 7 installation package. LABEL has been set to “SAND”. The other UD phase output variables have the same composite structure. with a constant mass fraction of sand = 0. and pure water viscosity from tables. 1. The case uses OPTIONS TEMPERATURE=OFF. UDOPTIONS. as the sand should enter in the water layer. Thus. The variable name P-U_SandInWater is a composite name based on a generic name.3) Where uWater is the water film velocity. 5. UDPHASE has been added. The effect of sand on water viscosity can be seen by plotting the effective viscosity of the water layer. the bed should build up from zero to 0. and the particles will. and it is thus not necessary to include path in this case. UserDefined/UDGROUP has been added.1) Where ufall is the terminal settling velocity. VISWTEFF.1. Initially the pipe is filled with water only. the defined UD phase. and θ is the pipe angle with the gravity vector. Plotting of results: Sand propagates through the pipeline and forms an expanding bed. The sand density is 2000 kg/m3. VISWT in the same plot. As a result.2. it is not necessary to specify any initial conditions for sand in this case. the deposition rate is set to zero. At steady state. The bed height. is the mass [kg m-3] of sand particles. it has two amplification factors.5) Where is the deposition rate [kg s-1 m-3].opi is an example of a simulation with process equipment.01 s. The time step starts at the minimum value of 0. Downstream the compressor. Figure 1 shows the process flow sheet. i. Case Comments: CaseDefinition: OPTION: Temperature option UGIVEN has been chosen. One pressure controller (PC) is used to control the pressure in the separator.25 m is controlled by the ASC controller..12 m.6) Where rp is the pipe diameter. The separator has a gas and liquid outlet. there is no sand that can deposit and make a bed. a heat exchanger is included to cool the gas. The bed height is calculated from the “Wetted angle”. For the tutorial case remember that the pipeline initially is filled with only water. After 10 hours the separator feed is dropped from 70 to 50 kg/s. i. The heat exchanger is connected to a temperature controller. Controller: 5 controllers are used to stabilize the process. e. The valve is used to control the overall flow into the separator. The steady state pre-processor is deactivated. When the bed height is 15% of the pipeline diameter or higher. β.. h.(1. The gas outlet is 400 m long. The pipeline has a valve close to the outlet. The compressor speed is used to control the separator pressure. valves. but the deposition rate is limited. The simulation time is 20 hours. FlowComponent: FLOWPATH — ProcessEquipment — COMPRESSOR: The compressor is used to lift the gas from the separator. and is divided into 7 sections. A maximum of 50 mass percent of the particle mass can be deposited over the next time step. A total of 5 PID controllers are used to stabilize the process. Figure 1: “Wetted angle”. The liquid outlet is 100 m long and has a diameter of 0. and thus are in units of [kg m-3]. A temperature controller is used to control the temperature at the outlet of the gas pipeline.5 meters. An anti-surge controller (ASC) is used to stabilize the operation of the compressor. The gas line contain a compressor with recycle and anti-surge control. is calculated as (See Figure 15): (1.1”. Note that in OLGA the masses are divided with the section The deposition rate is fixed to “0. A level controller (LC) is used to stabilize the liquid level of the separator. compressor. that are given as input to the entrainment/deposition and flash interface. has a diameter of 1.e. The liquid line contains a valve that is used for level control of the separator. The pipelines are simulated with a constant outer heat transfer coefficient. and height. separator.0 m. Sample case: Process Equipment The case Process-Equipment. FLOWPATH — ProcessEquipment — HEATEXCHANGER: A controlled heat exchanger is used to manipulate the pressure out of the gas pipeline. Figure 1 Process flow sheet. INTEGRATION: The simulation start at t=0 s and ends at time t=20 h. volume. and a diameter of 0. The ASC is an asymmetric PID controller. One pipeline feeds the separator with a mixture of gas and liquid. of water bed interface. h. and is limited to a maximum value of 10 s. β. The heat exchanger is given a .g. A recycle valve with diameter 0. the compressor lift from approximately 71 to 110 bara.e. This pipeline is 15100 meters long divided into 12 sections. One controller (FC) is used to manipulate the feed flow rate of the separator. and heat exchanger. The pipe has only two sections. The case shows examples of several types of process equipment. All controllers are of type PID. and is the current time step [s]. FLOWPATH — Boundary&InitialConditions — HEATTRANSFER: The ambient temperature is vertically interpolated from 80° at the bottom of the borehole to 20° at the C C wellhead. It separates gas and liquid. respectively. MINCAPACITY=0 m3/s. the pump speed is controlled by the total mass flow rate at the wellhead as measured by Transmitter TRAN-WH-TT. MINSPEED=0 rpm. The pump battery speed is controlled by the flow rate at the wellhead. The valve has the same maximum cross section as the pipeline. FLOWPATH — Output — TRENDDATA: Gas volume flow at the compressor boundary and the compressor surge flow setpoint for the ASC controller (QGSURGE) are trended. ΦLOWPATH — Output —ΣΕΡςΕΡ∆ΑΤΑ: Server variables are available for plotting in interactive simulations. A sketch of the model is shown in Figure 1. The steady state pre-processor is turned off. TREND: Trend variables are plotted every 20 seconds. The outlet boundary conditions for the gas and liquid outlets are constant pressures of 110 bara and 65 bara. AINJ=APROD=0. NODE: The case has three nodes. FLOWPATH — Output — TRENDDATA: Pump variables are plotted. The heat transfer coefficient on outer walls is set to 500 W/m2K.06 m3/s. Sample case: Pump Battery The case Pump-Battery. ProcessEquipment: SEPARATOR — Output — TRENDDATA: SEPARATOR: The separator is horizontal with length 15 m and diameter 2 m. Operation scenario: Due to the reservoir conditions. The inlet boundary condition is a constant pressure of 108 bara and temperature 40° The mass fraction of free water is set C. In this sample case. FLOWPATH — Boundary&InitialConditions — WELL: The reservoir pressure is 200 bara and reservoir temperature 80° Production and injection type is L INEAR. to 0 and the gas faction to 0. this well can only produce a flow of 6 kg/s. A pump battery is installed downstream of the well bottom hole in order to increase the production.opi demonstrates how how OLGA can be used to model a pump battery.capacity of -3 MW. FLOWPATH — ProcessEquipment — VALVE: One valve is placed before the riser. and liquid level are trended. Figure 1 Sketch of the model. After the pump battery is installed near the well bottom hole. FlowComponent: FLOWPATH — Boundary&InitialConditions — INITIALCONDITIONS: Since the steady state pre-processor is not used. OUTPUT: OLGA variables are printed to the output file at the start and end of the simulation. The system consists of a 2 km long well tubing followed by a 150 m long wellhead pipe. Case Comments: CaseDefinition: OPTIONS: The full heat transfer calculation option with heat transfer through the pipe walls is used. The minimum heat transfer coefficient on inner walls is set to 10 W/m2K. BINJ=10-7 kg/s/Pa and BPROD=10-6 kg/s/Pa. temperature. . PROFILE: Profile variables are plotted every 30 minutes. Controller-models: PIDCONTROLLER: C-PUMP-SP: This controller is required by the pump module. but downstream the transmitter. FLOWPATH — ProcessEquipment — TRANSMITTER: Transmitters are used to transmit the temperature and overall flow from the pipeline to the controllers. MAXSPEED=8000 rpm. A pressure controller is connected to the valve to manipulate the valve opening. all of type pressure.7. C. MAXPRESSURE=230 bara. Output: Pressure. FLOWPATH — ProcessEquipment — PUMP: The pump battery is defined by following parameters: MAXCAPACITY=0. ANIMATE: 3D plot of holdup for liquid along the pipeline is plotted every 10 seconds. the initial conditions have to be given. the production can be increased to 10 kg/s or higher. a gas outlet. . NODE: The outlet pressure held constant at 60 bara and the temperature is 20° C. Within the water. an oil outlet. FLOWPATH — Boundary&InitialConditions — SOURCE: The mass source is ramped up to a steady mass flow of 53. Case Comments: CaseDefinition: OPTIONS: Full temperature calculations are enabled. The initial conditions are determined by the steady state pre-processor.ΦLOWPATH — Output —ΣΕΡςΕΡ∆ΑΤΑ: Server variables are available for plotting in interactive simulations. PROFILE: Profile variables are plotted every 5 seconds. OUTPUT: OLGA variables are printed to the output file every 10 hours. The source temperature is 30° C. TREND: Trend variables are plotted every second. TREND: Trend variables are plotted every 0.5 MPa and a temperature of 30° C. Output: ANIMATE: 3D plot of holdup for liquid along the pipeline is plotted every 10 seconds.opi illustrates the use of a separator.1 seconds. and an emergency drain.5 seconds of the simulation. FLOWPATH — Piping: The branch is a single pipe. A sketch of the model is shown in Figure 1. NODE: The inlet node is closed. On topside a 120 m pipe leads into a separator. Output: ANIMATE: 3D plot of holdup for liquid along the pipeline is plotted every 10 seconds.5 m. A 4100 m long pipe leads up to a 300 tall riser. Sample case: Separator The case Separator. PROFILE: Profile variables are plotted every 30 minutes. Sample case: Simplified Pump The case Pump-Simplified. The outlet boundary condition is set to a constant pressure of 4. valves controlled by controllers are applied. Figure 1 Sketch of the model. The inlet pressure is only 5 bara and the outlet pressure is 50 bara. FlowComponent: FLOWPATH — Boundary&InitialConditions — INITIALCONDITIONS: The first 100 m of the pipe is filled with oil whereas the rest of the pipe contains only water. Case Comments: CaseDefinition: OPTIONS: The full heat transfer calculation option with heat transfer through the pipe walls is used. The separator has three outlets. FLOWPATH — Output — PROFILEDATA: Variables of interest are hold-ups and inhibitor fractions. On the separator outlets. No speed controller is required for a simplified pump. The separator is 4 m long and has a diameter of 2.opi demonstrates how to model a simplified pump in OLGA. The system consists of a 500 m long horizontal pipe followed by a 250 m tall vertical riser. The pressure is 50 bara at the gas outlet and 20 bara. A valve and check vale are placed at the topside pipe. ΦLOWPATH — Output —ΣΕΡςΕΡ∆ΑΤΑ: Server variables are available for plotting in interactive simulations.34 kg/s over the first 8. at the oil outlet and emergency drain outlet. 1 km long with an elevation of 50 m. OUTPUT: OLGA variables are printed to the output file every 100 seconds. three regions containing different amounts of MEG are set up. A pump is installed in order to deliver the water to a higher pressure tower. and a 100 m long horizontal topside pipe. when importing similar cases from OLGA 5. NODE: Both the inlet and outlet nodes are pressure nodes. The fluid bundle contained within the solid bundle is marked in gray shading. The steady state initialization is turned on. FLOWPATH — Piping: Three pipes are defined for the geometry. on the other hand. CaseDefinition: OPTIONS: The full heat transfer calculation option with heat transfer through the pipe wall has been used as this is required by both the bundle and FEMTherm modules. An internal node is used for the crossover from the carrier line to the return line.FlowComponent: FLOWPATH — Boundary&InitialConditions — HEATTRANSFER: The ambient temperature is 20° The heat transfer coefficient on outer wall is set to 500 W/m2K. The first pipe is a 500 m long horizontal pipe and the pump is placed at the second section boundary. heat transfer coefficient on inner wall is set to 10 W/m2K.001 m FLOWPATH — Output — TRENDDATA: Mass flow rates and pump variables are plotted. a 100 m horizontal topside pipe The riser of branch 1 is contained within the inner fluid bundle where the carrier line contains heated water. The minimum C. TREND: Trend variables are plotted every second. ΦLOWPATH — Output —ΣΕΡςΕΡ∆ΑΤΑ: Server variables are available for plotting in interactive simulations.e.opi demonstrates how OLGA can be used to simulate the transient and spatial distribution of temperatures in the solid interior of a complex bundle by means of finite element calculations. FLOWPATH — ProcessEquipment. The inlet pressure is 5 bara and the outlet pressure is 50 bara. It is assumed that the pump pressure only depends on the pump flow rate. The topside branch consists of a single pipe. and back up to the platform through the return line. HEATING and METHANOLFLUID are fluids used by the bundle module. WALL: Five different walls are used in the flowpaths and lines specified. more specifically from its first section entering into the solid bundle. They are both fully open throughout the simulation. the border of the solid bundle. The water is going in a loop consisting of the carrier and return lines where constant pressure and temperature is set on the platform side. is given by the shape specified under Library. At the top of riser is a 100 m long horizontal topside pipe. PROFILE: Profile variables are plotted every 30 minutes. before being ramped up to a higher rate during 10 minutes. a 300 m vertical riser.. The water is heated at the platform end. These two branches lead up to an internal node where they merge into the topside branch which has a pressure boundary at the outlet. They consist of a 4300 m long pipeline on the seabed. The branches 1 and 2 are identical with a 12. Sample case: Solid bundle The case SolidBundle. Case Comments: Library: MATERIAL: Carbon steel (MATER-1) and insulation (MATER-2) are the materials used for the pipe walls. Inlet temperatures are specified for the bundle lines. N. Output: ANIMATE: 3D plot of holdup for liquid along the pipeline is plotted every 10 seconds.0 cm inner diameter. A sketch of the cross-section of the bundle is shown in Figure 1. Pipe diameter is 12" and roughness 0. FLOWPATH — Piping: The pipeline along the seabed (4300 m) is described using three pipes whereas the riser and topside as single pipes. FLOWPATH — ProcessEquipment — PUMP: The simplified pump is defined with following parameters: DENSITYR=1000 kg/m3. FlowComponent: FLOWPATH — Boundary&InitialConditions — HEATTRANSFER: The ambient conditions are defined for all branches. FLOWPATH — Boundary&InitialConditions — SOURCE: The sources at the inlet of each seabed pipeline is kept at a constant low rate for the first three hours. Output: ANIMATE: 3D plot of holdup for liquid along the pipeline is plotted every 10 seconds. This fluid bundle is contained within a solid bundle together with branch 2 and a methanol line. OUTPUT: OLGA variables are printed to the output file every 10 hours. SPEEDR=2000 rpm. Both nodes have a temperature of 20° C. NODE: The two inlet nodes for the seabed branches are closed. Please refer to the conversion documentation for a detailed description. SHAPE: The shape defining the solid bundle.B. FLOWRATED=600 m3/h. a certain amount of manual labor is required. The outer border. Figure 1 Cross-section of the bundle. sent down into the carrier line. in this case a circle with radius 80 cm made of insulation. Downstream of the horizontal pipeline is a 250 m high vertical riser. VALVE: One valve is installed at the outlet of each of the parallel pipelines just upstream of the internal node. may vary along the length of the solid bundle and the values are taken from its first constituent branch. They merge into branch 3.. DPRATED=70 bara. ΦLOWPATH — Output —ΣΕΡςΕΡ∆ΑΤΑ: Server variables are available for plotting in interactive simulations. Its value is taken from the first component in the solid bundle definition. The ambient temperature. . The ambient heat transfer coefficient for the solid bundle is assumed constant along the length of it. and a 100 m horizontal topside pipe. i. The outside pressure of the leak is also constant.1 second. The dip is filled with liquid and the pipe leading from the dip to the outlet is half filled.1 s). FLOWPATH — ProcessEquipment — LEAK: The controller reference number for the leak is C-503. FA-models: SLUGTRACKING: Level slug initiation is enabled (LEVEL=ON). The time that the devices need to adjust to a new set point (the actuator time) is 33. Output: ANIMATE: 3D plot of holdup for liquid along the pipeline is plotted every 10 seconds. Figure 1 Illustration of the pipe geometry and initial condition. PROFILE: Profile variables are plotted every 20 minutes. the leak will use 2. adiabatic flow is assumed. The geometry and initial condition is shown in Figure 1. computed from the equilibrium gas mass fraction values in the fluid properties tables. Case Comments: CaseDefinition: OPTION: The steady state pre-processor is not used since the initial state of the closed pipe is a fluid at rest. A time series for the flow area is given. Case Comments: CaseDefinition: OPTIONS: The two cases run with COMPOSITIONAL=OFF/ON. A horizontal pipe is initially at high pressure and closed at both ends. NODE: The pipe is closed at both ends. The simulation starts with a rapid blow down of the pipe with critical flow in the leak.1 after 35 seconds. The pipe leading up to the dip is filled with gas and the inlet is a gas source. Figure 1 Schematic illustration of the simulated pipeline. void fraction and temperature. The temperature calculation is performed without heat transfer through the wall. and time step for saving thermal data (DTPLOT) define the FEMTherm calculations. a controlled sources and a leak.opi illustrate tracking of a start-up slug without and with compositional tracking.opi and StartupSlug-comp.opi is a simple demonstration of a the simulation using a choke. the leak at the end and the source at the inlet. The outside pressure is held constant at 2 bar. FLOWPATH — Boundary&InitialConditions — SOURCE: The controller reference number for the source is C-502. Sample case: Source. but very low. The pipe is 80 m long and parallel to the x-axis. All three devices are given a constant flow area. The meshfineness (recommended value is between 128 and 640). The initiation of slugs is limited to initiate a single start-up slug (MAXNOSLUGS=1) at the start of the simulation (STARTTIME=0 s and ENDTIME=0. The pipe is divided into four sections. The pipeline is symmetric with two 200 meter long horizontal pipes leading up to a 50 meter long and 2 meter deep dip. Due to the actuator time. FLOWPATH — Piping: Only four sections are specified in the horizontal pipe. TREND: Trend variables are plotted every 0. Inlet mass flow starts when the pipe pressure decreases and a steady state is obtained when the mass flows of the source and the leak are equal. a LINE. The maximum flow area in the source equals the pipe area. The other components are a FLOWPATH. ΦLOWPATH — Output —ΣΕΡςΕΡ∆ΑΤΑ: Server variables are available for plotting in interactive simulations. The choke with a constant diameter is positioned at the middle of the pipe. The outside pressure is held constant at 168 bar and the temperature is held constant at 73° The negativ e value of the gas mass fraction indicates that the phase mass fractions are C. respectively. and a FLUIDBUNDLE. ThermalComponent: SOLIDBUNDLE: The shape of the solid bundle containing all the pipes is defined through the Library keyword SHAPE. Sample case: Start-up slug The cases StartupSlug-pvt.03 to 0.33 seconds. TREND: Trend variables are plotted every 10 seconds. PROFILE: Profile variables are plotted every 6 seconds. Controller: MANUALCONTROLLER: The controllers for the source (C-502) and the leak (C503) are specified as manual ones.33 seconds before it reaches a relative opening area of 0. calculation time step (DELTAT). . FLOWPATH — ProcessEquipment — VALVE: The choke is positioned at boundary number 3. OUTPUT: OLGA variables are printed to the output file every 10 seconds. Leak and Choke The case Src-Leak-Choke. FILES: The fluid is described by either a pvt-file or an equivalent feed-file depending on the type of simulation.1. The relative leakage area is increased from 0. respectively. The flow area specified is 3% of the maximum. The temperature in the pipe decreases during the blow down and increases slowly as warm fluid enters through the inlet. The controller signals determine the flow area and are specified using time series. FlowComponent: FLOWPATH — Boundary&InitialConditions — INITIALCONDITIONS: The fluid is initially at rest with constant pressure.OUTPUT: OLGA variables are printed to the output file every 5 hours. The shape is one out of four BundleComponents in this case. The maximum flow area in the choke equals the pipe area. The outside pressure of the source is set constant and equal to the initial pipe pressure. The maximum flow area in the leak equals the pipe area. Temperature exchange with the walls are not accounted for. 5 MPa and a temperature of 30° C. The KHI flow rate and mass fraction in the water phase can be checked for different KHI age groups along the pipeline. FLOWPATH — Piping: The branch is split into five pipes. vertical interpolation on ambient temperature along the tubing. Therefore. FlowComponent: FLOWPATH — Boundary&InitialConditions — INITIALCONDITIONS: Since the steady state pre-processor is not used. Furthermore. Sample case: Tracer Tracking The case KHI-TracerTracking. lead from the dip to the outlet. A sketch of the model is shown in Figure 1. Two horizontal pipes. OUTPUT: OLGA variables are printed to the output file every minute. a 150 m long wellhead pipe. each 100 m and split into 20 sections. The total production is controlled by the wellhead choke. In the flow line and riser.2 m vertical riser and a 100 m long horizontal topside pipe. the initial conditions have to be given. PROFILEDATA: Integrated additional pressure drops are plotted. The KHI inhibitor is injected into the first section of the wellhead pipe. Operation scenario: The well is a gas well. and the pipe leading from the dip to the outlet is half filled. FLOWPATH — Boundary&InitialConditions — SOURCE: The gas source is ramped up to a steady mass flow of 5. The fluid temperature may be below the hydrate temperature in the flow line.opi demonstrates how OLGA can be used to model an inhibitor tracer tracking case.5 seconds. TREND: Trend variables are plotted every 0.17 m below the horizontal pipes. the instantaneous values of the droplet volume fraction and droplet velocity are plotted at boundaries ΦLOWPATH — Output —ΣΕΡςΕΡ∆ΑΤΑ: Server variables are available for plotting in interactive simulations. The pipe leading up to the dip is filled with gas. the dip is filled with liquid. The dip is constituted by two 25 meter long pipes split into 5 m sections and the lowest point 2. NODE: The inlet node is closed. . but no heat storage is accounted for. Case Comments: Library: HYDRATECURVE: Definition of hydrate curve used by HYDRATECHECK. The outlet boundary condition is set to a constant pressure of 4. the ambient temperature is 4° The heat transfer coefficient on outer wall is set to 500 C. A 200 m long horizontal pipe split into 20 sections lead up to the dip. The source temperature is 30° C.FlowComponent: FLOWPATH — Boundary&InitialConditions — INITIALCONDITIONS: The pressure and temperature in the branch is set constant and equal to the conditions at the output node. a KHI tracer is injected at the wellhead to prevent hydrate formation. A wellhead choke and a check vale are placed at the wellhead pipeline downstream of the KHI injection position. FLOWPATH — Output — TRENDDATA: Various properties for the slug are plotted. TRENDDATA: The number of slugs in the pipe is plotted. The system consists of a well tubing pipeline with a 1875 m true vertical depth (TVD) and a 2725 m measured depth (MD). TRACERFEED: Definition of the tracer feed TR-KHI. Figure 1 Sketch of the model.5 seconds. Output: ANIMATE: 3D plot of holdup for liquid along the pipeline is plotted every 10 seconds. FLOWPATH — Boundary&InitialConditions — HEATTRANSFER: The inlet ambient temperature of the well is 50° and outlet ambient temperature is 4° The code will do a C .5 seconds of the simulation.325 kg/s over the first 8. CaseDefinition: OPTIONS: Temperature calculations use heat transfer on the inside and outside of pipe walls as well as heat conduction. The steady state preprocessor is turned off. PROFILE: Profile variables are plotted every 2. a 3150 m pipeline leading up to a 391. AINJ=APROD=0. INTEGRATION: The simulation time is 3 minutes with a maximum time step of 5 seconds.Sub critical none flashing liquid valve flow. and have an overall elevation of 10 m. The outlet node is a PRESSURE node. There are no heat transfer to the surroundings. ΦLOWPATH — Output —ΣΕΡςΕΡ∆ΑΤΑ: Server variables are available for plotting in interactive simulations. HENRYFAUSKE and EQUILIBRIUM will give a large difference in pressure drop. Valve_Termal_Equilibrium. FLOWPATH — Boundary&InitialConditions — WELL: The reservoir pressure is 200 bara and reservoir temperature 50° Production and injection type is L INEAR. Sample cases: Valve Model To demonstrate some of the model options for the valve. phase fractions and temperature outlet pressure valve opening fluid table Figure 1 GUI snapshot from the Sub_Critical_Valve_Flashing_Liquid. TVALVE Sample cases: Critical two phase valve flow This case is created to demonstrate the possible effect of the valve model option EQUILIBRIUMMODEL. THROATSLIP. OUTPUT: OLGA variables are printed to the output file every 10 hours. Case Comments: CaseDefinition: OPTION: The steady state pre-processor is enabled.opi .opi . Gas at 25° is used as boundary fluid.Two phase sub critical valve flow.5·10-6 kg/s/Pa. NODE: The outlet pressure held constant at 30 bara and the temperature is 20° C.opi .The HYDROVALVE model is used. The siumlation is adiabatic. NODE: The pipe is closed at the inlet. FLOWPATH — Output — TRENDDATA: Tracer variables are plotted.opi .opi . The HENRYFAUSKE option lies between the FROZEN and EQUILIBRIUM option. Valve TREND variables included: ICRIT. The diameter is 0. five simple valve cases have been created: Sub_Critical_Valve_Flashing_Liquid. The cases differ in: source mass flow. TREND: Trend variables are plotted every 10 seconds. All these cases have the same geometry and configuration. The geometry is described with one pipe divided in 10 equal sections. The pipeline is 400 m long.Three phase sub critical valve flow. The left boundary condition is a closed node and a mass flow source in the first section. FlowComponent: FLOWPATH — Boundary&InitialConditions — Source: A constant mass source is positioned at the first section of the pipeline.opi case. Profile variables are plottet at the start and end of the simulation. C Output: OUTPUT: OLGA trend variables are printed to the output file every 15 seconds. C. Valve_Recovery.Sub critical valve flow of a flashing liquid Critical_Valve_Two_Phase. The EQUILIBRIUM option gives the largest pressure drop over the valve. . FLOWPATH — FA-models — HYDRATECHECK: Hydrate checking is activated in all flowpaths. The pipeline diamater is 0. Output: ANIMATE: 3D plot of holdup for liquid along the pipeline is plotted every 10 seconds. TVALVEOUT. The right boundary condition is a gas pressure node. The minimum heat transfer coefficient on inner wall is set to 10 W/m2K. VALVDP. FLOWPATH — Boundary&InitialConditions — SOURCE: The tracer source injects tracer at a rate of 1 kg/s. FLOWPATH — ProcessEquipment — Valve: The valve is positioned at the middle of the pipeline. and the FROZEN option gives the lowest pressure drop.12 m. The valve diamater is identical to the pipeline diameter. Running the case with EQUILIBRIUMMODEL FROZEN.Critical two phase valve flow.W/m2K. FLOWPATH — Piping: One pipe is used to describe the pipeline. BINJ=10-7 kg/s/Pa and BPROD=2. The pipeline is split in 10 sections. FLOWPATH — Output — PROFILEDATA: Tracer variables are plotted. The pipeline is 400 m long and have an elevation of 10 m. PVALVE.12 m. Valve_Slip. PROFILE: Profile variables are plotted every hour. The sub critical model for the FROZEN and HENRYFAUSKE option are identical and will give the same pressure drop. No water is included in the source. Sample cases: Sub critical valve flow of a flashing liquid This case is constructed to demonstrate the possible effect of the valve model option EQUILIBRIUMMODEL. Running the case with EQUILIBRIUMMODEL FROZEN/HENRYFAUSKE and EQUILIBRIUMMODEL EQUILIBRIUM will give a large difference in pressure drop.1. NODE: The outlet node pressure is set to 95 bar. The reason for the difference in pressure drop. In a non flashing case the models will give very similar results. Figure 1 Pressure profile for EQUILIBRIUMMODEL FROZEN and EQUILIBRIUM. and the gas fraction is 0. is due to the flashing of the liquid.03. The EQUILIBRIUM option includes flashing while the FROZEN option don't. FLOWPATH — ProcessEquipment — Valve: The valve opening is set to 0.6 bars larger than with the FROZEN option.Figure 1 Pressure profile for EQUILIBRIUMMODEL FROZEN/HENRYFAUSKE/EQUILIBRIUM at critical valve flow. CaseDefinition: FILES: 2phase. The temperature is set to 90ºC. NODE: The outlet node pressure is set to 50 bar. No water is included in the source.tab FlowComponent: FLOWPATH — Boundary&InitialConditions — Source: Mass flow is set to 18 kg/s. and the gas fraction is 0.05. The temperature is set to 90ºC. Case Comments: See Valve Model for a more detailed description of the case. FLOWPATH — ProcessEquipment — Valve: The valve opening is set to 0. Sample cases: Thermal equilibrium in valve flow . CaseDefinition: FILES: 2phase. Case Comments: See Valve Model for a more detailed description of the case.tab FlowComponent: FLOWPATH — Boundary&InitialConditions — Source: Mass flow is set to 22 kg/s. The pressure drop with the EQUILIBRIUM option is 9. For this case the valve pressure drop (VALVDP) change when applying thermal equilibrium is approximaly 0. and the gas fraction is 0. Sample cases: Valve Recovery This case is constructed to demonstrate the effect of the valve model option RECOVERY. The change in the lowest gas themperature in the valve (TVALVE) is almost 16ºC.1. The pressure drop over the valve will witout recovery always be greater with recovery.This case is constructed to demonstrate the possible effect of the valve model option THERMALPHASEEQ. FLOWPATH — ProcessEquipment — Valve: The valve opening is set to 0. . Figure 1 Trend plot of VALVDP for THERMALPHASEEQ YES and NO.5 bar. Figure 2 Trend plot of TVALVE for THERMALPHASEEQ YES and NO.2. The temperature is set to 25ºC. The total water fraction is stet to 0. Running the case with THERMALPHASEEQ YES and NO will give a difference in pressure drop due to the change in gas density for the valve model.05. NODE: The outlet node pressure is set to 120 bar.tab FlowComponent: FLOWPATH — Boundary&InitialConditions — Source: Mass flow is set to 22 kg/s. Running the case with RECOVERY YES/NO will give a difference in pressure drop over the valve. This model option will affect the throat gas temperature (TVALVE) . CaseDefinition: FILES: 3phase. Case Comments: See Valve Model for a more detailed description of the case. No water is included in the source. NODE: The outlet node pressure is set to 160 bar. FLOWPATH — ProcessEquipment — Valve: The valve opening is set to 0. Figure 1 Pressure profile for SLIPMODEL NOSLIP and CHISHOLM.25. Heat transfer through pipe walls is calculated. Sample case: Wateroptions The case WaterOptions.tab FlowComponent: FLOWPATH — Boundary&InitialConditions — Source: Mass flow is set to 22 kg/s. CaseDefinition: FILES: 3phase. and the gas fraction is 0. The CHISHOLM model will apply a slip between gas and liquid in the valve.tab FlowComponent: FLOWPATH — Boundary&InitialConditions — Source: Mass flow is set to 20 kg/s. The inner diameter of the pipe is 0. No water is included in the source. Case Comments: See Valve Model for a more detailed description of the case. NODE: The outlet node pressure is set to 50 bar. The main pipeline starts with a 3. FLOWPATH — ProcessEquipment — Valve: The valve opening is set to 0. Figure 2 Trend plot of THROATSLIP (The slip ratio in the throat) for SLIPMODEL NOSLIP and CHISHOLM. and the gas fraction is 0. Running the case with SLIPMODEL NOSLIP and CHISHOLM will give a large difference in pressure drop.05.3 km long horizontal pipe ending in a 90 m riser followed by a short horizontal pipe.41 m. CaseDefinition: FILES: 2phase. Case Comments: See Valve Model for a more detailed description of the case. The temperature is set to 50ºC.opi is an example of a three phase simulation using WATEROPTIONS.Figure 1 Trend plot of VALVDP with and witout pressure recovery.1. The temperature is set to 30ºC. Sample cases: Valve slip This case is constructed to demonstrate the possible effect of the valve model option SLIPMODEL. Case Comments: Library: . NODE: The inlet node is closed.wax. A controller is used to achieve a desired flow rate. FlowComponent: FLOWPATH — Boundary&InitialConditions — SOURCE: The inlet boundary condition is a constant mass source with mass flow of 34. the fluid is cooled and wax precipitation C. The PressureBoost pump is used to increase the production. Since water flash is active. The pipe walls consist of steel (two layers) covered with a layer of insulation. The wax porosity is set to 0. The pipeline consists of an 8 km long horizontal pipe. CaseDefinition: OPTIONS: The full heat transfer calculation option with heat transfer through pipe walls is used. Furthermore.WALL: The pipe walls consist of steel (two layers) covered by one layer of insulation. such as wax layer thickness (DXWX). mass of wax dispersed and dissolved in oil (MWXDIP and MWXDIS. A constant outlet pressure of 20 bara is applied. the simulation time is set to 10 days. The inner diameter is 0. and deposition starts once the temperature is low enough. sections of length 250 m are used. The fluid enters the pipeline with a temperature of 70° which is above the wax appearance temperatur e. FA-models: WATEROPTIONS: Water flash and water slip are turned on. Wax properties are taken from the table WAXTAB in the file wax_tab-1.6 and the built in routine for calculating the viscosity of oil with precipitated wax is used. INTEGRATION: Since wax deposition is a slow process. respectively) and the wax appearance temperature (WAXAP). Sample case: Well-PressureBoost The case Well-PressureBoost. This is sufficient for a wax layer to start appearing. FLOWPATH — Piping: For the horizontal part of the pipeline. PROFILE: Profile variables are plotted every 50 seconds. CaseDefinition: FILES: The wax properties are defined in the file wax_tab-1. PROFILE: Profile variables are plotted every day. Output: ANIMATE: 3D plot of holdup for liquid along the pipeline is plotted every 10 seconds. FLOWPATH — Piping: The pipeline is 3. OPTION: The steady state pre-processor is activated to generate the initial conditions. FlowComponent: FLOWPATH — Boundary&InitialConditions — SOURCE: The flow rate at the inlet is set to 17.B. FLOWPATH — FA-models — WAXDEPOSITION: Deposition of wax is allowed in the entire pipeline. ΦLOWPATH — Output —ΣΕΡςΕΡ∆ΑΤΑ: Server variables are available for plotting in interactive simulations. OUTPUT: OLGA variables are printed to the output file at the start and end of the simulation. Case Comments: Library: WALL: The pipe wall consists of steel. The outlet boundary condition is to a constant pressure of 24 bara and a temperature of 26° C. the fluid temperature increases in the parts of the pipeline where wax is deposited. If higher accuracy of the position where the wax starts depositing is needed.. Output: ANIMATE: 3D plot of holdup for liquid along the pipeline is plotted every 10 seconds. and 60 m long horizontal topside pipe.01 s and a maximum one of 10 s. mass fraction of free water is set to 0. concrete. Four columns of results are printed on each page. the wax layer makes the effective area of the pipe decreases.3 km long.opi is a simple demonstration of a controlled PressureBoost pump.wax. This happens about 2 km from the inlet.opi demonstrates a simulation of wax deposition.51 kg/s with a temperature of 70° C. there is additional water in the vapor phase given by the water vapor mass fraction in the PVT table. NODE: The inlet node is closed. Sample case: Wax deposition The case WaxDeposition. Contribution to the wall roughness from deposited wax is not considered (WAXROUGHNESS=0 by default). TREND: Trend variables are plotted every hour. On its way through the pipeline. resulting in an increasing inlet pressure in order to maintain a constant flow rate. and an insulating polypropylene layer. INTEGRATION: The simulation runs for five hours using a minimum time step of 0. A typical geometry from well to platform is used. shorter sections should be used. . wax is not accounted for in the pre-processor.3. including topside. The initial time step is set equal to the minimum one. Full temperature calculation (TEMPERATURE=WALL) is required when simulating wax deposition. By default. Due to the thermal insulation effect of the wax layer. the equilibrium is used to determine the gas source at the inlet.17 m throughout the pipeline. TREND: Trend variables are plotted every 10 seconds. ΦLOWPATH — Output —ΣΕΡςΕΡ∆ΑΤΑ: Server variables are available for plotting in interactive simulations. FLOWPATH — Output — PROFILEDATA: Variables of interest are pressure and temperature in addition to wax related variables.181 kg/s and temperature of 60° The C. The pipes are divided into 58 sections. OUTPUT: Pressure and temperature in all sections are written every 10 days. a 110 m vertical riser. N. is 9. The total number of pipes. which is pressure dependent. see WATEROPTIONS keyword. opi case.0e-6. FT. FlowComponent: C FLOWPATH — Boundary&InitialConditions — HEATTRANSFER: A constant ambient temperature of 6° and a const ant ambient heat transfer of 6. is connected to the MEASRD terminal. suppying the measured flow rate in the pipeline. is positioned close to the PressureBoost pump. and the reservoir temperature is set to 68° The producti on and injection model C. C Output: OUTPUT OLGA variables are printed to the output file every 10 seconds. The isentropic efficiency is set to 0. NODE: The pipe is closed the inlet. The AMPLIFICATION and INTEGRALTIME is tuned to get a stable simulation. Gas at 22° is used as boundary fluid. The controller output CONTR and the pressure increase PUMPDP is included among the TREND variables. FLOWPATH — ProcessEquipment — TRANSMITTER: The flow transmitter. The controller output is connected to the PressureBoost pump. and the pressure increase of the Pressureboost pump is therefore zero at time 0.The controller bias is set to zero. is used to achieve the desired flow rate of 10 kg/s. C. ANIMATE: 3D plot of holdup for liquid along the pipeline is plotted every 10 seconds.5 W/m2/° is used. The pipeline is 6500 m long. The temperature calculation is performed using a constant overall heat transfer coefficient (UGIVEN). The temperature calculation is performed with a heat transfer through the wall and heat accumulation in the wall. A flow transmitter. FLOWPATH — Boundary&InitialConditions — WELL: The reservoir pressure is set to 150 bara. FLOWPATH — Output —SERVERDATA: Server variables are available for plotting in interactive simulations. Case Comments: CaseDefinition: OPTION: The steady state pre-processor is enabled. The outlet node is a PRESSURE node.Figure 1 GUI snapshot from the Well-PressureBoost. setting a pressure of 50 bara. INTEGRATION: The steady state pre-processor is enabled.9. FLOWPATH — Piping: 9 pipes is used to describe the pipeline from the well to the platform. FT. FC. FT measures the overall mass flow (GT) in the pipe.. and have an overall elevation of 1800 m. is linear with AINJ = APROD = 0 and BINJ = BPROD = 6. . FLOWPATH — ProcessEquipment — PRESSUREBOOST: The pump is given a maximum pressure increase of 60 bar. Controller: PIDCONTROLLER: The flow controller.