Reservoir Simulation Modeling of the Yubari CO2-ECBM/Sequestration Pilot, Ishikari Basin, Japan

Transcription

1 Reservoir Simulation Modeling of the CO2ECBM/Sequestration Pilot, Ishikari Basin, Japan Prepared by: Scott R Reeves Advanced Resources International, Inc Houston, TX February 2, 27 Tokyo, Japan

2 Presentation Outline Pilot Description Model Development HistoryMatching Conclusions/Recommendations 2

3 Location/Geology Faults YUBARI Test Site

4 Summary of Reservoir Data Provided Parameter Value Remarks Depth: 89 IW Thickness: 566 m Formation Dip: 25 degrees Initial Average Reservoir Pressure 2 MPa Reservoir Temperature: 295 C Cleat Interval 75 mm Initial Water Saturation: % Initial Absolute Permeability: md Relative Permability Linear Gas Content (insitu) Dry, AshFree Langmuir Volume CH4 222 cm /g 28 ml/gr Dry, AshFree Langmuir Volume CO2 44 ml/gr Dry, AshFree Langmuir Volume N2 9 ml/gr Ash& Moisture Content 84% InSitu Coal Density Langmuir Pressure CH4 4 g/cc 785 MPa Langmuir Pressure CO2 972 MPa Langmuir Pressure Ｎ MPa Sorption Time Constant CH4 5 days Sorption Time Constant CO2 25 days 974% CH4; 2% CO2; 6% N2 Initial Free Gas IW o oversaturated 4

5 Illustration of Isotherms 45 4 Gas Content, m/tonne Methane Carbon Dioxide 5 Nitrogen 5 2, 4, 6, 8,, 2, 4, 6, Pressure, kpa 5

6 Simulation Model Description 2 x 27 x (,62 gridblocks) 25 dip N 67m 6

7 Injection/Production/Pressure History Injection Well Production Well INJECTION BHP BHP kpa BHP (Kpa) Bottomhole Pressure PRODUCTION BHP Time (days) Time (Days) GAS AND WATER PRODUCTION RATES Injecting Well Production/Injection History Water Production (converted injector) CO2 Injection Rate Gas Production rate 5 N2 Injection Rate Rate, m/d 6 5 Water production rate (m/d) Gas production Rate (m/d) Production/Injection Time (Days) 2 4 Time (Days)

8 Well Control and Match Parameters PW Well Control Match Parameters (weight factors) IW Gas Production Rate Gas Production/Injection Rate Gas Production Rate () Gas Production Rate () Gas Injection Rate () Water Production Rate () Water Production Rate () Bottomhole Pressure () Bottomhole Pressure () 8

9 Genetically Optimized History Matching (GenOHM) Procedure Workflow Case Definition Reservoir characterization Model construction Ranges selected for uncertain parameters Error Function Calculation COMET2 input file created # interations/batch ClearVu variable selections generated COMET run Error functions computed No Acceptable Match? Yes Finish 9 NuTech Solutions 2 Advanced Resources International

10 Fixed Model Inputs Parameter Formation Properties Depth Thickness Dip Initial Pressure Reservoir Temperature Sorption Properties Dry, AshFree Langmuir Volume CH4 Value Units Source m m Degrees MPa C 28 ml/g Dry, AshFree Langmuir Volume CO2 44 ml/g Dry, AshFree Langmuir Volume N2 925 ml/g Langmuir Pressure CH4 785 MPa Langmuir Pressure CO2 972 MPa Langmuir Pressure Ｎ MPa Sorption Time Constant CH4 5 Days Sorption Time Constant CO2 25 Days Sorption Time Constant N2 Ash& Moisture Content Density Permeability Relationships Permeability Exponent Relative Permeability Relationships Krw max Sgr Days % g/cc assumed assumed assumed assumed

11 History Match Variables Parameter Formation Properties Porosity Initial Water Saturation Absolute Permeability Permeability Anisotropy Permeability Zfactor Pore Compressibility Matrix Compressibility Differential Swelling Factor, CO2 Differential Swelling Factor, N2 Relative Permeability Relationships Swir Krg max Expw Expg Well Parameters Skin Producer/Injector Value Units Source Min Max % md /kpa /kpa 5 9 E5 E7 5 E E * 4 variables

12 Permeability Models Permeability Model 2 = 8 i + Cp (PPi) ( ) Cm dpi [ C CH4 + CkCO2 CCO2 + CkN2 CN2 Ci ] dci 6 k = ki i n CH CO2 4 N2 6 Relative Permeability Model Pressure, kpa 9 Relative Permeability, fraction Permeability, md 4 8 Krw = Krwmax Krg = Krgmax Sw Swr Krwexp Krwmax SwrSgr SwSgr Krgexp SwrSgr Krgmax Krwexp Krgexp Krw Krg Sgr Swr Water Saturation, fraction 7 8 9

13 Variable Convergence* Irreducible Water Saturation Convergence Permeability Anisotropy Convergence Permeability Anisotropy Value Irreducible Water Saturation value Number of Runs Number of Runs Differential Swelling Factor, CO2 Differential Swelling Factor, N Differential Swelling Factor Value Differential Swelling Factor Value Number of Runs * Not from final historymatch case Number of Runs

14 Error Function Reduction* PRODUCER: BOTTOMHOLE PRESSURE ERROR FUNCTION PRODUCER: WATER PRODUCTION RATE ERROR FUNCTION Error Function Value Error Function Value Number of Runs Number of Runs INJECTOR: BOTTOMHOLE PRESSURE ERROR FUNCTION TOTAL ERROR FUNCTION Error Function Value Error FUnction Value Number of Runs * Not from final historymatch case Number of Runs 5 4

15 Final Match: PW GAS PRODUCTION RATE WATER PRODUCTION RATE 9 8 Actual Simulated 7 Actual Simulated Rate, m/d Simulation Days 2 4 Simulation Days BOTTOMHOLE PRESSURE 2 Actual Simulated Pressure, kpa Rate, m/d Simulation Days

16 Final Match: IW N2 INJECTION RATE Gas and Water Production Rates 4 4 Actual Data Simulated Data N2 injection rate, m/d Water Rate, m/d Gas Rate, m/d Time (Days) Gas Production Rate Actual Water Production Rate CO2 INJECTION RATE 4 4 Simulated Days BOTTOMHOLE PRESSURE 8 Actual Actual Data Simulated Data Simulated 5 7 BottomHole Pressure (KPa) Gas Injection Rate, m/d 2 Simulated Water Production Rate Simulated Days Simulated Days

17 Illustration of GasMovement Detailed Gas Production N2 and CO2 Production Rate, m/d CH4 Gas Production Rate, m/d Time (Days) ch4 n2 co2 7 CH4 N2 CO Rate, m/d Simulation Days Note: N2 observed at producer well (in field) one day after injection ceased, or days after injection began 7

18 Final History Match Variables Parameter Formation Properties Porosity Initial Water Saturation Absolute Permeability Permeability Anisotropy Permeability Zfactor Pore Compressibility Matrix Compressibility Differential Swelling Factor, CO2 Differential Swelling Factor, N2 Relative Permeability Relationships Swir Krg max Expw Expg Well Parameters Skin Producer/Injector Value Units Source Min Max Optimized % md /kpa /kpa 5 9 E5 E7 5 E E E4 69E

19 HistoryMatch Permeability Models Absolute Permeability Relative Permeability 6 CH4 CO2 Krw N2 9 Krg Relative Permeability, fraction Permeability, md Pressure, kpa Water Saturation, fraction 9

20 Effect of N2 Injection on Permeability 2 Permeability distribution on last day of N2 injection

21 Conclusions Representative model of reservoir conditions constructed; successful historymatch of ECBM performance achieved Results indicate: ~2 md permeability ~2% porosity ~95 initial water saturation ~9: permeability anisotropy ~+9 skin damage N2 injection appears to improve permeability and injectivity 2

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