Development of Akkas Gas Field in IraqPrepared By Wisam Al-Shalchi Petroleum Expert Amman – 2008 Contents Summary 2 Section One Akkas Gas Field 1-1 1-2 1-3 1-4 1-5 1-6 1-7 1-8 Introduction Geological Information of Akkas Field Reservoir Data of Akkas Field Gas Specifications of Akkas Field Condensates Specifications of Akkas Field Wells Drilling, Completion and Connection Environmental Conditions of Akkas Field Infrastructures Close to Akkas Field 3 4 5 7 9 10 11 12 Section Two Development of Akkas Field 2-1 2-1 2-3 2-4 Development of Akkas Field to Produce 50 MMscf/d of Natural Gas Development of Akkas Field to Produce 100 MMscf/d of Natural Gas Development of Akkas field to Produce 300 or 500 MMscf/d of Natural Gas The Possibility of Building a GTL Project in Akkas Gas Field 16 17 25 27 31 32 References The Author 1 Summary Iraq is one of the Arab countries that owns huge natural gas resources. The Iraqi natural gas reserves consist of 110 Tcf of proven natural gas, and 350 Tcf of potential natural gas. About 70% of Iraq's gas reserves are associated gas (gas produced in conjunction with oil), with the rest up of non-associated gas (20%), and dome gas (10%). Iraq's primary sources of associated gas in the north are the Kirkuk, Ain-Zalah, Butma, and Bai-Hassan. The oil fields in the south which produce associated natural gas are the North & South Rumaila, as well as Zubair fields. About 70% of Iraq's associated gas production capacity is located in the southern part of the country. The Iraqi non-associated (free) natural gas fields occur mainly in the north region, with an estimated total content of about 9.5 Tcf (300 Bcm). The fields of this region comprise AlAnfal (1.8 Tcf), Chemchemal (2.1 Tcf), Jeria Pika (0.9 Tcf), Khashim Al-Ahmar (1.4 Tcf), and Mansuriyah (3.3 Tcf). The only free natural gas field that occurs in the south territories is Siba (60 Bcm) gas field, which is located in Shat al-Arab coasts near the Iraqi-Iranian border. In November 2001, a large non-associated natural gas field reportedly was discovered in the North West region of Iraq (Akkas region), near the border with Syria. The field which is named Akkas (Saladin) gas field is considered as one of the giant gas fields in Iraq. It contains around 4.5 Tcf proved reserve of natural gas. It is also thought that most of the Iraqi undiscovered reserves are located in the western territories of Iraq. Although, many new studies have pointed out that this region has many geological structures which may have high hydrocarbon contents, it still has not been explored enough, except Akkas natural gas field. Iraq is keen for exploiting its huge natural gas reserves, to fulfill the domestic demands, and to export considerable amounts to the international markets to provide new source of income for the country. One of the available options to invest in this sector is the development of Akkas gas field. The Iraqi Ministry of Oil has prepared many studies proposing possible scenarios to develop this field in the conventional ways. Any development plan will depend of course on the production capacity of the field. In addition to the conventional development plans for this field, there is also an opportunity to develop the field by building a Gas to Liquids (GTL) project which is also considered briefly as an option in this study. The Author* *Wisam Al-Shalchi – Petroleum Expert, Email:
[email protected] 2 Section One Akkas Gas Field 1-1 Introduction: Akkas (Saladin) gas field is located in the North West region of Iraq near the Iraqi – Syrian borders. It is located at a distance of 52 km far away from (T1) pumping station, and 285 km from (K3) pump station. The distance between this field and Baji town, where the entire Iraqi gas grid passes, is around 300 km. The nearest industrial complex to this field is the Al-Qaim Industrial complexes which consists of a fertilizer plant & cement plant and located at a distance of less than 40 km from it. Akkas gas field is one of the giant fields in Iraq. It contains around 5.68 Tcf (160 Bcm) of potential reserve of natural gas and 4.55 Tcf (130 Bcm) of proved reserve. The first vertical exploratory well (SA-1) was drilled in this field in 25th August, 1992. The drilling was supposed to reach a depth of 5000 m, but this was not achieved due to technical difficulties. The drilling operations in this reached a depth of 4238 m well and it confirmed the presence of natural gas with a flow out of around 6-8 MMscf/d. In 2001 the development of Saladin gas field was referred to the Syrian Petroleum Company (SPI), according to the "Combined Cooperation Deal" signed between Iraq and Syria. The company started its operations in the western region of Iraq in 15th August 2001. The operations consist of horizontal drilling of 5 new wells, as well as the workover of the previously drilled well (SA-1) by drilling it again horizontally. Figure (1-1): The location of Akkas (Saladin) gas field. 3 The explorations made by the company were ended in mid 2002 after completing the drilling of the following wells: (a) (b) (c) (d) (e) (f) Work over of (SA-1) well which was completed in April 2002. Drilling of (SA-2) well which was completed in April 2002. Drilling of (SA-3) well which was completed in March 2002. Drilling of (SA-4) well which was completed in March 2002. Drilling of (SA-5) well which was completed in June 2002. Drilling of (SA-6) well which was completed in June 2002. Figure (1-2): The drilled wells in Akkas Field. 1-2 Geological Information of Akkas Field: Akkas gas field consists of three geological formations, these are: (a) Ora Kaista Pirispiki Formation: This formation is composed of successive layers of Sand Stone, compact Shale layer of low and medium porosity followed by Dolomite and Lime Stone layers. The laboratory tests of the layers of this formation made during the drilling of (SA-1) well proved that it contains reservoir water of no oil traces in the region (1365 – 1424 m). The pressure development test of the investigated sections proved that this formation in general is characterized with high porosity. 4 (b) Akkas Formation: It consists of successive layers of Sand Stone and compact Shale layer of low porosity. The results of the laboratory tests of this formation made during the drilling of the well (SA-1) proved that light oil of a density 0.8326 gm/cm3 exists in the region (1993-2002m). On the other hand the layer tests made in the well (SA-4) showed that natural gas of Weak Bubble Flow exists in this region. (c) Khabour Formation: This formation is also composed of Sand Stone and compact Shale layer of low porosity. The results of the layer tests in this formation proved that many natural gas accumulations exist in regions between (2332 – 2360 m) deep for SA-1 well, (2365 – 2375.5 m) deep for SA-2 and (2341 -2355 m) deep for SA-3. The specific gravity of the tested gas were (0.726 – 0.6953), and for the condensates was 0.7792. Figure (1-3): Geological formations of Akkas gas field. 1-3 Reservoir Data of Akkas Field: The field explorations data of Akkas field obtained from the drilling of six exploratory wells gave the following information: (a) Gas content of the field: 1) Estimated natural gas content: 5.680 Tcf 2) Proved natural gas content: 4.550 Tcf 5 (b) Capacities of production from Akkas field: 1) 2) 3) 4) 50 MMscf/d from the already existing six drilled wells. 100 MMscf/d from 10 wells. 300 MMscf/d from 30 wells. 500 MMscf/d from 50 wells. (c) Production test results of Khabour formation: The following results are the summarized characters of Khabour formation obtained from the tests made in (SA-1) well: 1) Reservoir pressure: 3720 lb/in2 2) Standard depth: 2295 m from the rotating drill string (13412.6 LSDf) 3) Reservoir temperature: 210o F 4) Porosity Average: 3% 5) Width of the investigated layer: 60 m (197 ft) 6) Liquids percentage: 28 bbl/MMscf 7) Density of condensates: 50 API degree 8) Gas specific gravity: 0.726 9) Closing pressure at the well head: 3000 lb/in2 10) Viscosity of the reservoir gas: 0.023527 centipoises 11) Gas/fluid proportion: 93556.8 scf/bbl 12) Thermal measurements made during the drilling of SA-1 well showed that the value of the Thermal Factor varies among (1.099– 2.85 oF/100 ft) and its value depends on the layer depth. Other separated thermal tests were found to be as shown below: Depth, m 4040 3750 3632 3557 3360 2661.5 2395.5 2349.5 2025 Region 2362-2397 2328-2351 2026-1998 1735-1752 1365-1424 1068- and above Average Temperature, oF 327.5 297.5 288.7 285.3 275.2 240 225 205 165 165 160 140 Thermal Factors 2.27 2.85 2.25 2.25 1.49 1.10 Table (1-1): Hierarchy of the thermal factor with the drilling depth in SA-1 well. 6 Excluding the results obtained from the well SA-1, the results obtained from the layers tests made on the other drilled wells showed that it is difficult to obtain an exact reservoir information which enable to evaluate the reservoir. The reservoir pressure evaluation obtained by acidizing the formation in both the vertically and horizontally drilled well SA-1 showed high average production levels. On the other hand, the results of similar tests made on SA-2 well showed declining of the reservoir pressure as well as the production levels with the period of the testing due to the method of the well completion. The results obtained from the tests of the vertical section of SA-3 well were similar to those of SA-1 well, but when the drilling became horizontal it gave higher production levels, but the reservoir pressure couldn’t be measured due to technical problems. The results of SA-4 well showed low production levels compared with the wells SA-1 and SA-3. The well SA-5 tests showed only the flowing of reservoir water. Therefore, the surface production of the wells were estimated in general according to the test results obtained from the well SA-1 which means that it is necessary to make more future hydraulic calculations to determine the wells production behavior and the surface pressure values at the separation station. 1-4 Gas Specifications of Akkas Field: a- Free Gas Specifications: No enough information available about the quality and specifications of the gas produced from the Khabour formation. Several gas samples were taken from the wells SA-1, SA-2 and SA-3 and sent for analysis. The main results considered were those obtained from analyzing the gas samples of the well SA-1 taken from the region (2332-2360 m) of the rotating drill string because it contains the highest proportions of heavy hydrocarbons. Surface samples of the wells SA-2 and SA-3 were also taken and analyzed in Syria but the results were short of very important information like the sampling temperature, sampling pressure and amount of liquids produced. This shortage necessitated making a recombination with the results obtained from the analysis of the gas and condensates produced from the separator, as shown in the following table: 1 2 3 4 5 6 Liquid Gas (5/Sum) Comp. Liq* 2.265 Gas* 83.6 3-4 % mole % mole *100 N2 0 0 0 0 0 0 C1 0 82.973 0 6937.89 6947.89 80.5299 C2 1.18 9.18 2.6728 767.597 770.27 8.9407 CO2 0.04 2.13 0.0906 178.103 178.193 2.0683 7 C3 3.9 3.36 8.8338 250.951 i-C4 1.12 0.36 2.5369 30.1015 n-C4 5.53 0.87 12.5259 72.7461 i-C5 3.74 0.2 8.4714 16.7232 n-C5 5.84 0.23 13.2280 19.2317 n-C6 14.73 0.3 33.3646 25.0849 n-C7 19.64 0.28 44.4861 33.4125 n-C8 14.59 0.25 33.0475 20.9041 n-C9 12.48 0.2 28.2651 16.7232 n-C10 5.36 0 12.1408 0 n-C11 11.55 0 26.1616 0 Total 99.7 100.353 230.3581 8389.4685 * 2.265= Mole of liquid / bbl for separation liquid * 83.6= Mole of gas. 289.784 3.3636 32.6387 0.3788 85.272 0.9898 25.1946 0.2924 32.4598 0.3768 58.4494 0.6784 67.8956 0.7881 53.9515 0.6262 44.9914 0.5222 12.1408 0.1409 26.1615 0.3037 8615.3 99.9998 Table (1-2): Results obtained from analyzing samples taken from Akkas drilled wells. The compositions and specifications of the free gas for SA-1 & SA-2 wells are as shown in the following table: Component N2 C1 C2 CO2 H2S C3 I-C4 n-C4 i-C5 n-C5 C6 C7 C8 Specific Gravity Density 15.5, 1AT-G/L Molecular Weight Heating Value Kcal/m3 - Gross: Net: SA-1 (2332-2360m) 1.54 80.49 8.92 2.2 3.54 0.4 1.0 0.35 0.41 0.54 0.39 0.22 0.726 0.89 21.02 10702 9700 SA-2 0 80.5299 8.9407 2.0683 3.3636 0.3788 0.9898 0.2924 0.3768 0.6784 0.7881 1.593 0.787 22.811 - Table (1-3): Specifications of the free gas from the wells SA-1 & SA-2. 8 Notes: • One of the samples of the well SA-1 taken after the second acidizing process of the above region showed a presence of H2S gas in a proportion of 1.09 ppm, the thing which was not obtained similarly with the samples taken from the wells SA-2 and SA-3. This matter necessitates making more precise tests on the well head gas to confirm this result and to be assured of the H2S content of free gas. • The highest accepted molar proportion of CO2 content in the gas is 3%. b- Reservoir Gas Specifications: The following table shows the specifications of the reservoir gas: Pressure PSI 400 800 1200 1600 2000 2400 2800 3200 3600 4000 Z-Factor 0.960 0.925 0.895 0.873 0.859 0.855 0.850 0.871 0.890 0.914 Viscosity CP 0.014 0.014 0.015 0.016 0.017 0.019 0.020 0.021 0.023 0.024 Table (1-4): Specifications of the reservoir gas. 1-5 Condensates Specifications of Akkas Field: The condensates analysis of the samples taken from the wells SA-1, SA-2 and SA-3 gave the following results: Specifications Specific Gravity Water Content (% by volume) Sulphur Content (% by weight) Asphalt Content Pour Point (oF) Kinematics Viscosity (Cst) at: 80 oF 100 oF 120 oF SA-1 0.779 0.2 0.06 Nil - 30 1.52 1.27 1.08 SA-2 0.7538 Nil 0.0163 Trace - 45 0.98 0.82 0.75 SA-3 0.7448 Nil 0.0131 Nil - 45 1.016 0.941 0.876 Table (1-5): Specifications of the condensates. 9 1-6 Wells Drilling, Completion and Connection: a- Drilling & completion of new wells: The horizontal drilling of new wells in Akkas field can be implemented by using: 1) 2) 3) 4) 20" casing (steel tubing) till 400 m deep. 13 3/8" casing till 1100 m deep. 9 5/8" casing till 2000 m deep. The horizontal drilling starts at 2100 m deep using 8 1/2" casing till 3000 m with a total vertical depth of 2380 m. 5) Using 7" gimleted casing in the horizontal section 6) The production pipe will be 3 1/2" to a depth of 2150 m. The vertical drillings can be completed by using 7" casing and 4.5" production pipes. b- Wells connection: The hydraulic calculations of Akkas wells showed that the flow pressure is lost through the surface pipelines assuming that: 1) The flow pressure at the well heads are 2015, 1515, 1015 lb/in2. 2) The diameter of the surface flow pipes are 8" and 6". 3) The length of the flow pipe is 15- 20 km of 8" diameter and 5-8 km of 6" diameter. 4) The diameters of the flow controller openings are 1/2", 1"and 2/3". 5) Average flow: 1-30 MMscf/d/well. c- Wells tests: The available well tests of the already drilled wells in Akkas field are as following: 1) SA-1 well (Vertical): The average production of the well is 7.37 MMscf/d with a flow pressure at the well head equal to 500-600 lb/in2 with a controller opening of 1". The well is turned now into a horizontal well with a production capacity of 34.6 MMscf/d and flow pressure at the well head of 2870 lb/in2 when the controller opening is 3.4". The production capacity became 17.3 MMscf/d when the flow pressure is 3045 lb/in2 and the controller opening is 1/2". 2) SA-2 well (Horizontal): The results obtained from this well are not reliable. 3) SA-3 well (Vertical): The average production of this well is 4 MMscf/d with a flow pressure at the well head of 800 lb/in2 with a controller opening of 1/2". 10 4) SA-4 well (Horizontal): The production capacity is 15.8 MMscf/d with a flow pressure of 1530 lb/in2 for a controller opening of 1/2". The production became 29.8 with a flow pressure of 925 lb/in2 for a controller opening of 1". 5) SA-5 well (Horizontal): It produced only water. 6) SA-6 well (Horizontal): The production capacity is 2.4 MMscf/d with a flow pressure of 1530 lb/in2 and a controller opening of 1/4". The production became 2.9 MMscf/d when the flow pressure becomes 925 lb/in2 with a controller opening of 64/24". d) Conclusions: From the above results the following conclusions can be reached: 1) The results of the vertical wells are consistent with each others. 2) For the horizontal wells only the results of the wells SA-1, SA-3 and SA-4 are available, and they are too optimistic about the capacity of productions except the results of the well SA-4. 3) It is difficult to rely on these results which mean that more reservoir tests must be made on the wells for studying and comparison. Therefore, it is proposed for the time being that the average production capacity of the existing wells is 10 MMscf/d/well with a flow pressure of 2800 lb/in2 when the controller opening diameter is 1/2", and an average production of 25 MMscf/d/well for a flow pressure of 2000 lb/in2 and controller opening of 1" diameter. To maintain the temperature of the produced gas it is necessary to bury the flow pipes at a depth of 1 m under the surface after protecting it by coating and cathodic protection. The pressure of the gas at the treatment plant must be reduced to reach 1100 lb/in2 and temperature of 85 oF for a production capacity 10 – 25 MMscf/d. 1-7 Environmental Conditions of Akkas Field: a- Ambient Temperature (in Dark): 55 oC in summer, -10 oC in winter. b- Design Temperature of equipments: 82 oC (under sun). c- Dominate winds direction: North-West / South-East. d- Winds velocity: 165 km/hr. e- Relative humidity: 10% (min.), 100% (max.). f- Average rain falling: 258 mm/year. g- Soil Temperature in 1 m deep: 26.7 oC in summer, 12 oC in winter. h- Earth quake: rare i- Average heat conductivity: 12 Kcal/hr.m2.oC (for buried pipes). 11 1-8 Infrastructures Close to Akkas Field: Akkas gas field is located in the western desert of Iraq. In order to put suitable plans to develop the field it is very important to have an idea about the infrastructure available close to the field. There are many industrial complexes and residential aggregations in the region which are located not very far from the field and contain very important infrastructure establishments. a- Al-Qaim City: Al-Qaim is a town located nearly 400 km north-west of Baghdad and few kilometers from the Iraqi-Syrian border and situated along the east bank of the river Euphrates. It is the center of Al-Qaim district which belongs to Anbar governorate and has a population of about 170,000 persons. As a relatively big city, Al-Qaim has its own normal infrastructure like water treatment station, electricity transforming station, hospital and railways station …etc. The main road which connect Haddithah city with the Syrian Albu-Kamal city passes also through Al-Qaim and Qusaybah cities. Not very far away from Al-Qaim city there is an industrial complex which contains a cement factory, fertilizers factory, destroyed uranium extraction factory, electricity transforming station and railways station. This industrial complex is located at a distance of about 40 km from the center of Akkas gas field. b- (T1) Pumping Station: (T1) is a crude oil pumping station of the old Iraq-Syria oil pipeline which transports oil from the north Iraqi oil fields (from Kirkuk governorate) to the Syrian exporting port Baniyas. (T1) is located at about 320 km (200 mile) north-east of the Jordanian border. According to the old Jordan-Iraq protocols, oil was delivered by pipeline to the (T1) pumping station, where it was then loaded onto trucks for transportation by road to Jordan. Akkas field is located at a distance of 52 km south west of (T1) pumping station. (T1) pumping station consists of three huge oil pumps, storing tanks, electricity transforming station and a residential complex. 12 Figure (1-4): Picture of Akkas Field and Ti Pumping Station. c- National Electricity Grid: There is a main hydroelectricity generation station located at Haddithah city. From this station there is an electric high voltage line of 400 kV to Al-Qaim city passing through the industrial complex near Al-Qaim. This high voltage line branches at Al-Qaim city into three subsidiary lines one goes to Rawah city north east of Al-Qaim, one goes to Qusaybah city near the border while the third one goes to Akashat mining complex. The later line passes at about 40 km distance from Akkas field. The main transforming station which transforms the high voltage (400 kV) to the normal voltage (220 kV) is located at Al-Qaim industrial complex at about 40 km from Akkas field. 13 Figure (1-5): The electricity grid in the middle and north parts of Iraq. d- Roads and Railways: (1) The main road which connect Haddithah city with Albu-Kamal Syrian city and passes through Al Qaim and Qusaybah cities passes also at about 50 km distance north Akkas gas field. A subsidiary road branches from this main road to the industrial complex reaches a distance of about 40 km from Akkas field. On the other hand, the main road between Al Qaim city and Akashat mining complex passes also at about 40 km west of Akkas gas field. (2) There is a main railways line between Baghdad and Al-Qaim city of about 516 km long which also passes through Al-Ramadi city (Capital of Anbar Governorate). This line also passes in its way through AlQaim industrial complex at about 40 km from Akkas field. This line branches at the industrial complex into two lines one goes to Al-Qaim and then to Qusaybah cities while the other goes to Akashat mining complex and passes at about 30 km west of Akkas gas field. 14 Figure (1-6) Roads and railways which pass near Akkas gas field. 15 Section Two Development of Akkas Field There are many possible scenarios to develop Akkas gas field. Any development plan depends on the gas production capacity of the field. It is also necessary to construct road networks to connect the field and its new establishments with the main roads in the region. The following development plans were put according to the expected production capacities of the field: 2-1 Development of Akkas Field to Produce 50 MMscf/d of Natural Gas: This production capacity means that only the existing five drilled & gas producing wells will be considered. The best plan to develop Akkas gas field with this production capacity is by building a power generation plant. Such a plant and its supplements (the switchyard, transmission interconnection …etc) can be built in the field site, and then be connected with the country grid by a 40 km long high voltage line to the transforming station in Al-Qaim industrial complex and then to (T1) pumping station. The potential power generation of this power plant could be around 225 MW. Figure (2-1): Development of Akkas gas field by building 225 MW power generation plant in the field site 16 The development of Akkas field by this plan will require the following equipments: a- Slug catcher. b- Small treatment plant to separate the water, acidic gases if existing and the condensates from the gas. The condensates can be transported by trucks from the field to (T1) pumping station where it can be pumped to other places for local uses. 2-1 Development of Akkas Field to Produce 100 MMscf/d of Natural Gas: This production capacity necessitates the drilling of 4 additional vertical wells and working over the already existing 6 horizontal wells so that the total number of gas producing well will be (8-10). At this production capacity, it is possible to develop Akkas gas field by one of the following two plans: a- Building big treatment plant in the field site: In this plan the produced natural gas is mainly treated in the field site and then the produced dry natural gas is transported by a new (52 km x 20") pipeline to (T1) pumping station and from there to Haddithah (K3), where the country gas pipelines network passes. The LPG can be transported from the plant to the local markets either by trucks, or by building a 285 km pipeline from the treatment unit in the field to the country LPG network in (K2) pumping station. The NGL products (condensates) can be exported to other countries by transported it from the treatment unit by a (40 km x 6") pipeline to a connection point with the old Iraq-Syria oil pipeline, or by building a new pipeline for this purpose. The treatment plant in the field site must consist of two assemblages one for production and the other for testing with all connection requirements such as pipes, valves and other accessories. These two assemblages should contain number of connection points which enable the connection of the production wells (not less than 8 wells) together, as well as 15% more connection points for the future. These two assemblages must be designed according to the head wells pressure at the time of closing (which is about 3000 llb/in2), and must be capable for future extension to contain any increasing in the field production in the following stages of development. 17 Figure (2-2): Development of Akkas field by building a treatment plant in the field site (1) Production and Test Lines: It is necessary to install a production line of 100 MMscf/d and a test line of 50 MMscf/d. These two lines should consist of the following equipments: High pressure heater for production. High pressure heater for testing. Special equipments to reduce the pressure to 1050 llb/in2. Three phases production separator. Three phases testing separator. Gathering system to collect the natural gas from the production & testing separators. • Internal connection pipeline network for gases and condensates as well as pipeline to transport the separated water to the evaporation pit. • • • • • • (2) Treatment Line: In order to achieve 100 MMscf/d production of dry natural gas from the field and transport it to the national gas network it is necessary to treat this gas before transportation. This task can be reached by building a gas treatment plant consisting of the following units: • Gas Drying Unit (T.E.G. Unit) of 120 MMscf/d capacity, with a special system to supply & circulate the Glycole used for drying. • Two filters (Pre/Post filters), one must be installed before the drying tower while the other is installed after it. 18 • Cooling system to recover the natural gas liquids (NGL) in order to produce standard dry natural gas. The following two options can be used: o Turbo-Expander cooling unit: Consists of the following parts: Turbine to reduce the inlet gas pressure to 350 lb/in2 Low temperature separator to separate and collect the natural gas liquids (NGL). Compressor to increase the outlet gas pressure to 900 lb/in2. The gas must be cooled after the compressor from 135 oF to 100 oF by using Air Cooler. Small compressor of small capacity to increase the produced dry gas to 1100 l lb/in2 so that it can be injected in the country gas grid under the pressure 1050 lb/in2. o Throattling gas cooler: In this unit propane is used for cooling which can be obtained from the produced natural gas by a small distillation & extraction unit. • De-ethanizer Unit: This unit is used to extract the dry gas from the natural gas liquids (NGL). The extracted gas from this unit is mixed with the dry natural gas produced from the above cooling system. • 52 x 20" pipeline of a capacity of 100 MMscf/d to transfer the dry natural gas to the country gas grid. • LPG & C5+ Recovery unit. • Two spherical type tanks (Horton Spheres): of a volume of 100 m3 and pressure of 200 lb/in2 each to store the produced gas. • Two cylindrical tanks to store the natural gas liquids (NGL). • 285 km x 6" pipeline to transport the LPG to a connection point with the country 14" LPG pipeline in (K2) pumping station. • Two pumps (one working and one standby) to pump the LPG through the 285 km x 6" pipeline to (K2) pumping station. • Dry natural gas flow measuring instrument. • Dew point measuring instrument. (3) Condensates Recovering System: This system consists of the following parts: • System for collecting the (NGL) from the production and testing separators. • Pressure reducer. • Low pressure heater. • Three phases condensates separator. • Two spherical type tank of 500 m3 capacity to collect 950 bbl/d of condensates from the separator and 900 bbl/d from the LPG unit. The vapor pressure of the condensates in the tank is assumed to be not 19 more than (RVP= 12 Psia) which make it allowable to be mixed with the exported oil in the Iraqi-Syrian oil pipeline. The condensates can be disposed by the following two options: o Using an 18 km x 6" pipeline to transport the condensates to a connection point in the Iraqi-Syrian oil exporting pipeline. This option needs also two main pumps (one working & one standby), and two auxiliary pumps (one working & one standby). : o Using a 52 km x 6" pipeline to transport the condensates to the tanks in (T1) pumping station. • The gas produced from the separator (not more than 0.6 MMscf/d) is either flared or re-compressed with gas entering the dryer. (4) The test system: This system consists of the following parts: Testing system to collect the condensates from the testing separator. Low pressure heater. Pressure reducing equipments. Three phases separator of the following specifications: One spherical type tank of 80 m3 capacity to store the condensates. Two pumps (one working & one standby) to inject the condensates from the testing tank to the spherical condensates tank of the following specifications: • The gas produced from the system condensates recovering unit (which is not more than 1 MMscf/d) is either sent to the flaring system or can be used by the different units of the plant. • • • • • • (5) Gas Transporting System: The gas is transported from the treatment plant by a (52 km x 20") pipeline to a connection pint at the gas pipeline arriving at (T1) pumping station of flow pressure equal to 1050 lb/in2 at the point of connection. The new constructed pipeline is designed to transport 200 MMscf/d to be capable to transport any extra gas produced from future extension. The gas is pumped by using a Turbo-Expander compressor after the cooling system, or by using a Throaltling Unit. The pipeline must be furnished with (Pigging Traps Launcher & Receiver) at the beginning and end of the pipe. 20 Figure (2-3): The gas treatment plant at Akkas field site. b- Treating the produced gas in T1 pumping station: In this option the natural gas is collected from the producing wells in the field, and sent it to a high pressure heater to separate the water and the natural gas liquids (NGL). The collected natural gas can then be transported by a new (52 km x 20") pipeline to (T1) site, where a big treatment unit will be built to treat the gas. 21 Figure (2-4): Development of Akkas field by building gas treatment plant at T1 Pumping station site. (1) The partial treatment plant at the field site: This unit must consist of two assemblages one for production and the other for testing with all connection requirements such as valves and other accessories. These two assemblages should contain number of connection points which enable the connection of the production wells (not less than 8 wells) as well as more 15% connection point for future. These two assemblages must be designed according to the head wells pressure at closing which is not less than 3000 llb/in2. • The Production line: This line must be of 100 MMscf/d capacity and consists of the following parts: o High pressure heater. o Anti corrosion inhibitor injector. o (52 km x 20") Pipeline to transfer the natural gas to (T1) Site. • Testing Skid: This line must be of 50 MMscf/d capacity and consists of the following equipments: o o o o o o High pressure heater. Three phases test separator. Low pressure heater. Pressure measuring instruments. Three phases condensates separator. Spherical type tank of 50 m3 capacity. 22 o The condensates are disposed to the evaporating pit while the gases are connected with a flaring system or can be used for the unit consumption. (2) The complete treatment plant at (T1) Site: This complete treatment unit must consist of the following parts: • The production line: It should be of 50 MMscf/d capacity and consists of the following equipments: o High pressure heater. o Pressure reducing equipments. o Three phases gas production separator. o Internal connection pipeline networks. • The treatment line: This should be of 100 MMscf/d capacity and consists of the following parts: o Gas drying unit (T.E.G. Unit) with Glycole supplying & circulating system. o Pre & Post filters. o Cooling tower to separate C3+ compounds which could be of the Turbo-Expander Unit type or the Throalttling Unit type. o De-ethanizer Unit. o LPG recovery unit. o (233 km x 6") to transport the LPG to a connection point with country LPG pipeline at (K2) pumping station. o Two pumps (one working & one standby) to pump the LPG to (K2) site. o Dry gas metering unit. o Dew point analyzer. (3) Condensates recovering & gathering system: This system consists of the following parts: • Equipment to gather the condensates from the production separator and the test separator. • Pressure reducing equipment. • Low pressure heater. • Three phases condensates separator. • 950 bbl/d of condensates produced form the separator and 900 bbl/d of condensates produced from the LPG unit are mixed with the crude oil exported by the Iraqi-Syrian oil pipeline. • The gas produced from the separator which will be around 0.6 MMscf/d is sent to the flaring system or can be used for the unit consumption. 23 (4) Gas transporting system: The dry gas produced from the treatment plant which will be of 100 MMscf/d capacity is compressed in the dry gas pipeline reaching (T1) pumping station. Figure (2-5): The gas treatment plant at T1 pumping Station site. c- Supporting Facilities: The following supporting facilities must be built in the field site if a gas treatment plant is decided to be built there: 24 (1) Electrical System: Two electricity generating station (one working and one standby) of 8 MW and 11000 V must be built in the field site to feed the treatment unit with its needs of electricity. (2) Cathodic protection system: (3) Communication system: of the following parts: • Transmission system. • Switching distribution system. (6) Control system: of the following parts: • Digital distribution control system. • Simplified scada system. • Mimic Panel. (6) Compressed air system. (7) Drainage system. (8) Fire fighting system. (9) Portable drinking water system. (10) Industrial water supply system. (11) Flare system. (12) Sewage system. (13) Civil works: of the following parts: • Industrial buildings. • Services buildings. • Roads. If the gas treatment plant is decided to be built at (T1) pumping station then the same above facilities will be also needed with following differences: (1) Electricity generation station: Two electricity generating stations (one working and one standby) of 250 kW and 400 V will be needed to feed the constructed plant at (T1) pumping station. (2) Fuel system: An independent fuel tank must be installed to feed the plant and of enough capacity to operate the plant for 48 hr. 2-3 Development of Akkas field to Produce 300 or 500 MMscf/d of Natural Gas: To produce 300 MMscf/d of natural gas it is necessary to have about 30 gas producing wells in the field which means that it is necessary to drill 25 wells as well as the existing five producing wells. For such a big amount of natural gas, field-site-treatment option is the best choice followed by transporting the produced gas by new pipelines to different directions. A 100 MMscf/day of dry natural gas can be sent to (T1) site by a new 52 km 25 x 20" pipeline to support the local gas network. The rest which will be around 200 MMscf/d of dry natural gas can be exported to Al Malih site in Syria where the Syrian gas network ends by a new 99 km x 22" pipeline (43 km in the Iraqi territories and 56 km in the Syrian territories). Figure (2-3): Exporting natural gas from Akkas field to Syria The natural gas can then be transported through the Syrian gas network to a connection point in the Arab Gas Pipeline to export it to Europe. Figure (6-8): The Arab Gas Pipeline. 26 The condensates (C5+) can also be exported either by mixing it with the exported natural gas, or separately by injecting it in the old Iraq-Syria oil pipeline. The treatment plant in Akkas field site will not be different than the unit described above except that the capacities of equipments will be higher. For a higher development plans such as producing 500 MMscf/d of natural gas from Akkas field it is necessary to have about 50 gas producing wells. The methods of treatment and ways of dealing with the products will not be different than the methods described above. 2-4 The Possibility of Building a GTL Project in Akkas Gas Field: Presently, Iraq is suffering from shortages of the treated natural gas. The reason of this shortage is due to low production of natural gas on one hand, and low production capacities of the north and south treatment projects on the other. Iraq is also suffering at the present time from very big shortages in the electrical power generation and delivery. This shortage is referred to several reasons, political and technical. A considerable percentage of electrical power currently generated in Iraq is produced by burning various liquid fuels including diesel oils, heavy and residual oil. This reliance on liquid fuels results in loss of oil sales revenue in addition to shortages and delivery problems throughout the country. The rising electrical demand in Iraq will create pressure on the electric production, transmission capacity, and fuel production and delivery infrastructure. For this reason natural gas is being considered for use in new electric power generation. Therefore, the electricity generation sector is expected to absorb any rising in the production of natural gas in the future. This situation will continue until the mid of the coming decade, but things may change after 2020, especially if serious developments of the free natural gas fields take place. Iraq also suffers from huge shortages in the production of petroleum products, especially the light and middle distillates. These shortages are due to the low production capacity of the old fashioned Iraqi petroleum refiners. These shortages are expected to continue until 2025. For example, in 2020 Iraq will need at least 110,000 m3/day (695,000 bbl/day) of light and middle distillates, while the local refiners are not expected to produce at that time more than a 60,000 m3/day (380,000 bbl/day). The difference (50,000 m3/day or 315,000 bbl/day) could be covered in several ways like importing, building at least two new big oil refiners, or investing some of the natural gas by building a Gas to liquid (GTL) project. 27 The building of a Gas to Liquids (GTL) project in Iraq is practicably possible, but this is not expected to take place in the near future due to the shortage in the natural gas production. The quantity of the produced associated and free natural gas at the present time and in the seen future will be used mainly to feedstock the existing power plants, and to produce the LPG which the country also needs most. By the end of the coming decade, things will be changed, and an excess in the availability of natural gas is expected to take place. Nevertheless, the expected extra quantity of the natural gas will be also used to feed new power stations which will be built in the future. Even if an unused quantity of natural gas will be available then, no intension to invest this quantity of gas in a GTL project is anticipated. The thought of investing in the Gas to Liquids technology needs lots of thinking and studying, because such an investment is not beneficial with all of the Iraqi natural gas fields. Iraq is now burning huge quantities of associated natural gas due to the lack of the treatment facilities, and this behavior is expected to continue for the next ten years. Despite that this action is a wasting of a fortune; it also damages the environment very badly. But, after the invention of small and mobile GTL plants, installed in any place easily, it becomes possible to buy or even hire such plants and industrialize the flared gas by the GTL technology. This development will save a big fortune to Iraq, as well as protecting the local and the global environment from the harms which the flaring of the gas causes. It will also provide the country during the coming years with millions of barrels of high quality light and middle petroleum products. To build a GTL project in any place, there are some requirements and conditions which must be available. One of the most important conditions in this direction is that the natural gas field must be remote or stranded. Most of the Iraqi natural gas fields, whether they produce associated or non-associated natural gas, are not remote fields because they are located not far from the treatment factories, or the country gas pipeline network. This situation makes things more likely to invest the natural gas in the traditional ways rather than building a GTL projects. The only exception from this is the Akkas natural gas field because it is located in a remote area and very far from the consuming markets. This condition makes the field very suitable to be invested by a GTL technology. In addition to the conventional development plans described above, it is possible also to develop the field by building a GTL project. To build a reasonable GTL plant in Akkas field, then its production capacity must be at least 350 MMscf/day, i.e. some 35 gas producing wells must be drilled in the field. This production capacity will be suitable to build a 35,000 bbl/day GTL 28 plant similar to Oryx project which is built recently in Qatar by Sasol Company. The project will also need a complete gas treatment unit to produce dry natural gas, which is then feedstocked to the GTL plant. Figure (6-9): Flow diagram of a proposed GTL plant for the development of Akkas field. The place of the treatment unit must be near the place of which the GTL plant will be built on. It was mentioned above that for such a production capacity of the field it is better to build the treatment plant in the field site. This fact is true if the produced gas is going to be exported, but in case of investing the gas by a GTL project it is better to build an industrial complex combining both the treatment and the GTL plants in (T1) site for the following reasons: a- The old Iraq-Syria oil pipeline passes through the same place which can be used after rehabilitation to export the synthetic crude oil. b- The high voltage electrical line (400 kv) which feeds Al-Qaim industrial complex with power passes through the same place. c- The two plants as well as the other facilities of the station can share many of the infrastructures which they all need. d- The same new industrial complex can be used for the same purposes, if other natural gas fields are discovered in the future in the west region of Iraq. The investing of Akkas gas field by a GTL project is profitable to Iraq for the following reasons: • The GTL project will produce petroleum products, which the country needs most for the coming twenty years. • The high quality petroleum products produced by this project will help in protecting Iraq's environment which is extremely suffering from pollution. 29 • It will be possible to export some of the produced petroleum products either by using the old Iraqi-Syrian oil pipeline after rehabilitating it, or by building a new pipeline. This action will provide Iraq with much-needed extra income to fund the reconstruction projects. • In case of applying the federal governing system in Iraq, a GTL project could be the base of establishing a petroleum and natural gas industry in the north-western region, which might form a federation government. It will provide the local governorates of this federation with their needs of petroleum products, as well as employing the workers of the region. Such a policy will bring, from the political & economic points of view, some stability for this kind of governing system. 30 References (1) General Development of Akkas Gas Field by: Ban Hamza-Expert, Hamid Habib-Expert, Yasmine Abdul-Aziz-Chief Engineer, Insaf Faydhi-Chief Engineer, Adnan Sadam-Engineer. (2) Gas To Liquids (GTL) Technology by Wisam Al-Shalchi. – 2006 (3) Overview of the Oil Downstream Industry in Iraq / Nabiel N. Lammoza / Ministry of Oil – Iraq (4) The Real Image of the Gas Industry in Iraq/Ministry of Oil – Iraq (5) The Economic Prospects of Using the Natural Gas in the Arab Countries/ Thamer Abas Ghdhban, Ghazi Mahdi Hayder, Sabah Hadi Al- Jawhar 31 The Author Name: Wisam Al-Shalchi Date and Place of Birth: Baghdad / Iraq - 1956 Nationality: Iraqi Place of Residence: Amman – Jordan Telephone No.: 00962-6-5621049, Mobile: 00962-785200764 E-mail:
[email protected] Level of Education: 1) M.Sc. in Petroleum Chemistry - University of Essex / UK 2) B.Sc. in Chemistry- University of Baghdad Experience: 1) Working as Planning Manager in Al-Qabas Oil Services Co. - Jordan 2) Working as Petroleum Expert in the Directorate of Studies & Planning & Follow-up – Ministry of Oil / Iraq. 3) Working as Senior Technical Observer in the United Nations Development Programme (UNDP)- Iraq. 4) Working as Head of Oil & Gas Technologies in the Iraqi Oil Institute. 5) Working as Technical Lecturer in the Iraqi Oil Institute - Iraq. 6) Working as Process Engineer at Dora Oil Refinery/ Baghdad – Iraq 7) Working as Process Engineer at Shwaikhat Oil Refinery which belongs to OMV Petroleum Company/ Vienna – Austria. Publications: 1) Petroleum Environment Directory – Iraq, 2007 2) Industrial Safety – Iraq, 2007 3) Environment Protection – Iraq, 2006. 4) Instrumental Chemical Analysis – Iraq, 1994. 5) Oil and Gas Technology – Iraq, 1992 Published Researches and Studies: 1) Carbon Capture & Storage - 2008 2) Gas To Liquids Technology (GTL) – 2006 / Won the international annual prize of the Oapec Organization for the year 2006. 3) Traces analysis in Natural Gas. – 2005 4) Using Natural Gas Derivatives as Fuels for Vehicles – 2005 / Won appreciation prize from UNEP. 5) Compressed Natural Gas (CNG). – 2004 6) Comprehensive Petroleum Education and Training in Iraq - 1996 7) Development of the Phenolic Plastics prepared in acidic medium – 1990 8) Mechanism of the acid catalysed hydrolysis of esters. - 1988 32