SapGS09

Ecrin v4.30 - Doc v4.30.01 - © KAPPA 1988-2013 Saphir Guided Session #9 • SapGS09 - 1/21 Saphir Guided Session #9 A01 • Introduction When horizontal wells were introduced some 30 years ago the well test analyst suddenly had a problem; there was no analytical model available. This was quickly remedied and a simple horizontal analytical well model was introduced, however it was strictly horizontal and was not able to cut through different horizons. This meant that the actual layers were also strictly horizontal. The reservoir was homogeneous, double porosity, or composite and could be bounded by a circle, rectangle or any shape using the 2D Map (analytical or numerical). The well could not extend from one zone to another, and subsequently the first equivalent numerical wells followed the stratigraphy of the zone where the well started. An analytical multilayered slanted well was later introduced, however the layers were still strictly horizontal. This model is described in the DDA book chapter 6 (6.I.5). It was evident that a model which could realistically represent a true horizontal well cutting through different facies and zones would be necessary to develop. B01 • How to build a wiggly well model in Saphir In order to follow the guided session with ease it is expected that all the other guided sessions in the repertoire have been completed. The guided sessions are found under the menu ‘Help Tutorial’ in the applications Saphir, Topaze and Rubis. There are two main approaches when building the wiggly, or in this instance a slanted or an undulating horizontal well. The wells can be placed in strictly horizontal multi or single layers in Saphir and Topaze. They can be slanted or placed horizontal in one layer. If the linear numerical model is used, then the application will only generate the single phase solution using the declared main phase, and there will be no cross flow between layers. In order to impose cross flow it is necessary to use the non-linear option. In Rubis a horizontal or undulating well can cut through any horizon layer, horizontal or not, and can even cut through the same horizon several times. Cross flow between layers can be imposed even if a single phase has been declared. The wiggly well can only be generated with the nonlinear and linear numerical model; however it is interesting to compare the final results with the analytical models which would represent the numerical configuration closest. There is no difference in building a wiggly well model in Topaze and Saphir and the main difference in building the model in Rubis is the characteristics of the geometry of the reservoir. Ecrin v4.30 - Doc v4.30.01 - © KAPPA 1988-2013 Saphir Guided Session #9 • SapGS09 - 2/21 C01 • Slanted well in Saphir Start a new Saphir oil project and leave all well and PVT parameters as default except for the payzone h=100 ft. Double click on the ‘tested well’ in the ‘2D Map’, set the well to ‘slanted’ and define a 65 ° angle. Fig. C01.1 • Well initalization In order to view the cross section, change the well configuration to ‘Wiggly’ (the geometry will be retained) and an button will appear in the dialog. Fig. C01.2 • Created well info Click on the button and two tabs will appear; the first showing the cross section of the slanted well and the second the perforations. Click on the ‘Tested well-perforations’ tab. Ecrin v4.30 - Doc v4.30.01 - © KAPPA 1988-2013 Fig. C01.3 • Geometry cross section Saphir Guided Session #9 • SapGS09 - 3/21 Fig. C01.4 • Perforation cross section Click on the well and the perforations will be selected. The perforations can be adjusted by dragging the black dots, or by double clicking on the well and entering the data manually. Double click on the well and enter a perforated interval running from MD=88.3 ft to MD=148.3 ft as displayed below. Fig. C01.5 • Perforation description table Press 1000 hours. and proceed to enter the rates under the production tab; 1000 STB/D for Fig. C01.6 • Production input table Ecrin v4.30 - Doc v4.30.01 - © KAPPA 1988-2013 Press Saphir Guided Session #9 • SapGS09 - 4/21 and go back to ‘Analysis 1’. Click on ‘Test Design’ in the ‘More tools’ page. Fig. C01.7 • More Tool control panel for pressure simulation Select the ‘Numerical’ tab and change the kz/kr to 0.1. Press . Fig. C01.8 • Numerical Model definition dialog Click on ‘Extract dP’ in the ‘Interpretation’ page and press to accept the defaults. in the next two dialogues The interpretation page should now display the log-log plot, semi-log plot and the history plot. Ecrin v4.30 - Doc v4.30.01 - © KAPPA 1988-2013 Saphir Guided Session #9 • SapGS09 - 5/21 Fig. C01.9 • Simulation results main window Now, we will validate the numerical model against the standard analytical model in Saphir. Click on ‘Model’ in the ‘Interpretation’ page, and select Analytical and then ‘Slanted’ for the well model and ‘Rectangle’ for the boundary model. Change the value for ‘hw’ to 60 ft and the well deviation to 65°. Leave all the other parameters. Fig. C01.10 • Analytical slanted well definition Click on . Ecrin v4.30 - Doc v4.30.01 - © KAPPA 1988-2013 Saphir Guided Session #9 • SapGS09 - 6/21 Fig. C01.11 • Analytical validation Log log plot A perfect match is obtained which validates the numerical model to the analytical model. Now we will try and validate a numerical model for a complex well trajectory with 2 perforated segments using the ‘wiggly well’ option. Now start a new analysis by clicking on and initialize from nothing. Fig. C01.12 • New Analysis creation dialog Select the ‘2D Map’ and double click on the ‘Tested well’. Select ‘Wiggly’ in geometry and click on ‘Edit’. A cross section of the well should now be displayed on the screen. Ecrin v4.30 - Doc v4.30.01 - © KAPPA 1988-2013 Saphir Guided Session #9 • SapGS09 - 7/21 Fig. C01.13 • Wiggly well cross section Double click on the well, add 3 lines and enter the following coordinates: Fig. C01.14 • Wiggly well geometry input table Press and click on the perforations tab. Click on the well and the perforation should now be selected. Double click on the perforation, add a line and enter the following: Fig. C01.15 • Perforation input table Ecrin v4.30 - Doc v4.30.01 - © KAPPA 1988-2013 Saphir Guided Session #9 • SapGS09 - 8/21 The cross section of the well should now look like this: Fig. C01.16 • Wiggly well perforation cross section Press and check the rate values under the production tab: Fig. C01.17 • Production input table Now press and return to the 2D Map. In order to make the reservoir seem infinitely acting over the test period, we will increase the reservoir area. Double click on the reservoir boundary and tick the box ‘set as rectangle’. Tick the box ‘define by area’ and enter 100000 acres. Ecrin v4.30 - Doc v4.30.01 - © KAPPA 1988-2013 Saphir Guided Session #9 • SapGS09 - 9/21 Fig. C01.18 • Contour definition dialog Press . Due to the complexity of the well trajectory, it is necessary to refine the gridding near the wellbore in order to achieve an accurate simulation. Click on located at the top of the screen in the toolbar and uncheck ‘Automatic’. Now change the ‘progression ratio’ to 1.2. Fig. C01.19 • Progression ratio setting in the grid dialog Press Click on . and zoom into the well to view the gridding and the well trajectory from the top. Ecrin v4.30 - Doc v4.30.01 - © KAPPA 1988-2013 Saphir Guided Session #9 • SapGS09 - 10/21 Fig. C01.20 • Grid aspect around the wiggly well Return to the ‘Analysis 2’ screen, and run a ‘Test design’ on the numerical model. Ensure the kz/kr ratio is set to 0.1, generate the simulation, it may last few seconds. Fig. C01.21 • Numerical wiggly well model dialog Click on ‘Extract dP’; the log-log, semi-log and history plots will be displayed. Ecrin v4.30 - Doc v4.30.01 - © KAPPA 1988-2013 Saphir Guided Session #9 • SapGS09 - 11/21 Fig. C01.22 • Wiggly well simulation main window We will now compare this numerical simulation with a similar geometry computed analytically. It occurs that this later model is not included in the standard models catalog, but in the external models package. We need first to install or update the external models – to achieve this, go to the KAPPA Ecrin download page, and download the external models v4.20.07 (or above). Note: To access the software download page you need to be a registered user with a username and password. If you are not registered yet, click here. Your account will be validated within 24 hours. Fig. C01.23 • Ecrin download page Once you have downloaded the External Models installation package from our web site, unzip the file and run the setup.exe file. Ecrin v4.30 - Doc v4.30.01 - © KAPPA 1988-2013 Saphir Guided Session #9 • SapGS09 - 12/21 An 'External Models' folder will automatically be created under C:\Program Files\KAPPA\ExternalModels4.20. Direct Ecrin to the external models by visiting the ‘External Models’ tab in the ‘Interpretation’ option of the ‘Settings’ page. In the ‘external models’ tab, click on the folder icon and browse to the external models folder. The model names should appear as indicated below. Fig. C01.24 • ‘External Models’ tab Now that the external models have been imported, click on ‘model’ in the ‘interpretation’ page and select the ‘multi-segmented well’ from the selection of ‘external models’. Change kz/kr to 0.1, click on and enter the following coordinates: segment 1 segment 2 x1 0 x2 450 y1 0 y2 0 zw1 0.5 zw2 0.5 x1 700 x2 1200 y1 250 y2 250 zw1 0.25 zw2 0.25 Fig. C01.25 • Multi segmented well coordinates Generate the model. A good match is obtained suggesting consistency between the numerical model and the analytical model. The small discrepancy is due to the gridding in the numerical model. Ecrin v4.30 - Doc v4.30.01 - © KAPPA 1988-2013 Saphir Guided Session #9 • SapGS09 - 13/21 Fig. C01.26 • Multi segmented vs wiggly well loglog plot D01 • Geometry plot In order to view the geometry plot we are going to generate the numerical model through the ‘Model’ dialogue. Click on and start a new analysis from ‘analysis 2’ by clicking in the ‘New analysis’ dialogue. Now click on ‘Model’ and select the ‘Numerical tab’. Check the ‘store pressure fields’ box and click on . Fig. D01.1 • Numerical wiggly well model parameter table Ecrin v4.30 - Doc v4.30.01 - © KAPPA 1988-2013 Saphir Guided Session #9 • SapGS09 - 14/21 Once the model has been generated an additional plot is available for analysis. Maximize the 2D geometry plot and zoom in on the well. Create a cross section through the well by clicking on in the toolbar and joining the dots where the well coordinates were defined. When the dot turns green, the mouse should be released and the cross section dragged towards the next dot. The end of the cross section is defined by double clicking on the mouse. Fig. D01.2 • Cross section creation in 2D geometry plot Open the plot settings dialogue by clicking on Check the box ‘values’ and press in the toolbar or by right clicking the mouse. . Click on to skip to the last time step. Now click on in order to view the pressure profile at different depths by scrolling up and down. Recall that the 2 perforated segments were 50 ft and 75 ft below the top of the reservoir. Scroll to view the reservoir at relative depths 0.5 and 0.75 to view the pressure profiles near the wellbore for both segments. Ecrin v4.30 - Doc v4.30.01 - © KAPPA 1988-2013 Saphir Guided Session #9 • SapGS09 - 15/21 Fig. D01.3 • Pressure maps at different stratigrafic depth Click on to view the 3D plot. Open the plot settings dialogue by clicking on in the toolbar or by right clicking the mouse. Go to the cross section tab and check the boxes ‘enabled’ and ‘erase after’ and uncheck the box ‘erase before’. Fig. D01.4 • 3D cross section view settings tab Zoom in on the well and increase the vertical gain by repeatedly clicking on until the cross section of the well can be visualised. Play back the simulation by clicking on pressure profile along the entire well. and observe the Fig. D01.5 • 3D cross section pressure map at final time Ecrin v4.30 - Doc v4.30.01 - © KAPPA 1988-2013 Saphir Guided Session #9 • SapGS09 - 16/21 The complex 3D grid around the well can be visualized by setting the 3D plot settings display to ‘lines’: Fig. D01.6 • 3D cross section grid view in lines E01 • Creating a Wiggly in Rubis  Building the reservoir The objective is to build a wiggly well using Rubis that cut through three different reservoir horizons. In this case we have the survey of the trajectory and will use this survey to build the well and the perforations. Start a new Rubis project use all the default parameters and settings. Build a three layer reservoir by using the option ‘1 Top + n-thickness’ the type of the top is ‘Data Set’ and the data set is illustrated in the following table: Top layer depth: 6000 ft Add two more layers; Layer 1: 500 ft, layer 2: 100 ft and layer 3: 250 ft: Fig E01.1 • Reservoir geometry description  Setting the PVT Set the fluid type to Saturated Oil, add Water and keep all the default values. Ecrin v4.30 - Doc v4.30.01 - © KAPPA 1988-2013  Saphir Guided Session #9 • SapGS09 - 17/21 Setting the reservoir parameters properties Click on the button in the Simulation panel. Choose the option layered reservoir . The three layers created in the ‘geometry’ set up previously will appear as layer 1, 2 and 3. Chose layer 1 marked the ‘Default’ region. Change the default parameters as per the next figure: Fig E01.2 • Default region properties To set the parameters for the next two layers click on the button ‘New property set’ is PS0 as illustrated in the automatic dialog: the default name of the Fig E01.3 • New Parameter set This name can be changed as per the user’s choice. Create two parameter sets, PS0 and PS1, that are automatically assigned to Layer 2 and 3; click on the PS0 and PS1 and set the values as illustrated below. Fig E01.4 • PS0 properties Fig E01.5 • PS1 properties Ecrin v4.30 - Doc v4.30.01 - © KAPPA 1988-2013 Saphir Guided Session #9 • SapGS09 - 18/21 Press the button to set the initial state of the reservoir: - Reference depth 6000 ft - Reference Depth initial pressure 5000 psia - GOC 6200 ft - WOC 6700 ft Keep the relative permeability curves and capillary pressure at the default values.  Building the well and trajectory Create a new wiggly well by using the button display the well properties dialog, click on Geometry in the toolbar. Double click on the well to : Fig E01.6 • Well geometry information Click on the ‘Cross-section view’ tab. The well is just a slanted well until we input is exact trajectory. Fig E01.7 • Well geometry cross section Ecrin v4.30 - Doc v4.30.01 - © KAPPA 1988-2013 Saphir Guided Session #9 • SapGS09 - 19/21 There are two ways to construct the well trajectory:  Interactively: Simply by using the mouse and moving the existing black nodes or creating new nodes by a single click on the well to modify the trajectory in the vertical plan. The same interactive procedure can be used in the 2Dmap to modify it in a view from the top.  Trajectory table input: A double click on the well and the dialog to load from a file, enter manually or paste the trajectory of the well will appear. The trajectory is stored in our example in the file ‘wiggly_well_trajectory.txt’ supplied. You can also copy/paste it from the below table: Well trajectory: x y z -16.3711 -9.55708 12.3479 34.2530 81.1923 146.907 223.995 272.343 343.963 441.061 497.680 583.005 670.753 723.376 792.517 855.130 917.547 114.598 114.598 114.598 114.598 114.598 114.598 121.661 126.092 132.655 141.552 151.483 191.205 249.370 286.255 341.583 389.817 462.169 6000.00 6153.55 6282.95 6361.37 6467.23 6522.13 6526.24 6528.82 6532.63 6537.81 6537.81 6561.34 6608.39 6631.92 6655.44 6655.44 6667.21 Fig E01.8 • Well geometry table By clicking on the button you will have access to the depth and azimuth trajectory which can be simplified at the user’s discretion. Ecrin v4.30 - Doc v4.30.01 - © KAPPA 1988-2013 Saphir Guided Session #9 • SapGS09 - 20/21 Fig E01.9 • Well geometry simplification dialog Pressing OK displays the detailed trajectory in the vertical plan, with possibility of the WOC and GOC: Fig E01.10 • Well geometry in vertical plan Fig E01.11 • Well geometry vs contacts In the 2D Map zoom in on the well and activate the ‘red’ well nodes by clicking on the green well trace, you can add and delete nodes as you wish by clicking on the well where there is no red node or hover the mouse over any red node and click to delete it. Fig E01.12 • Well geometry in a view from the top in 2Dmap Ecrin v4.30 - Doc v4.30.01 - © KAPPA 1988-2013 Saphir Guided Session #9 • SapGS09 - 21/21 To create a cross section that shows the well use the button and trace through the well and the nodes in the 2D Map. The nodes will turn green as the automatic ‘glue’ to the node is activated, a click will snap the cross section to the node. When defined, go to the Simulation tab, press grid, accept the defaults. Maximize the 3D geometry plot. Zoom on the well. Click on , select the cross-section tab and enable the cross section and in the Display tab, select the ‘lines’ display. Zoom and orient the 3Dmap in necessary, to display the complex 3D grid: Fig E01.13 • The complex 3D grid for the wiggly well