17:15 〜 18:45
[HSC07-P08] Numerical Simulation of Geophysical Changes based upon CO2 Injection and Leakage into the Saline Aquifer and Gas Field
キーワード：CO2地中貯留、CO2漏洩、数値シミュレーション、地球物理学的モニタリング
For the monitoring of CO2 geological storage, a variety of geophysical data will be useful to perceive the behavior of injected CO2 and to detect a leakage if occurs (Huang, 2022). In the case of that the reservoir is a saline aquifer, the geophysical properties of the injected CO2 are largely different from those of the natural fluid in the formations, that is saline water, while are relatively close to those of the methane gas in a gas field. These differences may affect the effectiveness of some geophysical monitoring.
In this presentation, we will report the results of numerical calculations of change of geophysical data based upon hypothetical CO2 geological storage and leakage simulations with a saline aquifer and a gas field as the reservoir. Calculated geophysical data includes seismic reflection, microgravity and self-potential. The results indicate in which method and location observable changes will occur and a leakage will be detected in the early stage, and applicability of those monitoring methods in different reservoir conditions.
A 3D model with the simple combination of a reservoir, a thick seal, and a top Quaternary sediment was built for the analyses. Two vertical wells were modelled; one is the injection well and the other is the observation well which is located 1,000 m away from the injection well. The center depth of the reservoir is 1,000 m, and its thickness is 100 m. CO2 is injected into the reservoir at a rate of 1 Mt/year for 50 years. Numerical simulations of the injection period and following shut-in period were carried out for a no leakage case and a few cases where a leakage takes place along the well, which is one of the most likely leakage paths. Fluid flow simulations were carried out using the "STAR" reservoir simulation code (Pritchett, 1995; Pritchett, 2002) with the equations of state "SQSCO2" package (three pore components: H2O, CO2 and NaCl) and/or "SQSGAS" package (four pore components: H2O, CO2, CH4 and NaCl) (Pritchett, 2008), and then geophysical data was calculated using STAR’s "Geophysical Postprocessor" (Pritchett, 2003; Ishido et al., 2011; Ishido et al., 2015).
References
Huang, L. (Edt.) (2022): Geophysical Monitoring for Geologic Carbon Storage. John Wiley & Sons, Inc.
Ishido, T., Tosha, T., Akasaka, C., Nishi, Y., Sugihara, M., Kano, Y. and Nakanishi, S. (2011): Changes in geophysical observables caused by CO2 injection into saline aquifers. Energy Procedia 4, 3276-3283.
Ishido, T., Pritchett, J.W., Nishi, Y., Sugihara, M., Garg, S.K., Stevens, J.L., Tosha, T., Nakanishi, S., Nakao, S. (2015): Application of Various Geophysical Techniques to Reservoir Monitoring and Modeling. Proc. World Geothermal Congress, Melbourne, Australia, 19-25 April 2015.
Pritchett, J.W. (1995): STAR-a geothermal reservoir simulation system. Proc. World Geothermal Congress, Florence, 853-858.
Pritchett, J.W. (2002): STAR User’s Manual Version 9.0, SAIC Report Number 02/1055
Pritchett, J.W. (2003): Verification and Validation Calculations Using the STAR Geophysical Postprocessor Suite. SAIC Report Number 03/1040; 2003.
Pritchett, J.W. (2008): New "SQSCO2" equation of state for the "STAR" code, SAIC.
In this presentation, we will report the results of numerical calculations of change of geophysical data based upon hypothetical CO2 geological storage and leakage simulations with a saline aquifer and a gas field as the reservoir. Calculated geophysical data includes seismic reflection, microgravity and self-potential. The results indicate in which method and location observable changes will occur and a leakage will be detected in the early stage, and applicability of those monitoring methods in different reservoir conditions.
A 3D model with the simple combination of a reservoir, a thick seal, and a top Quaternary sediment was built for the analyses. Two vertical wells were modelled; one is the injection well and the other is the observation well which is located 1,000 m away from the injection well. The center depth of the reservoir is 1,000 m, and its thickness is 100 m. CO2 is injected into the reservoir at a rate of 1 Mt/year for 50 years. Numerical simulations of the injection period and following shut-in period were carried out for a no leakage case and a few cases where a leakage takes place along the well, which is one of the most likely leakage paths. Fluid flow simulations were carried out using the "STAR" reservoir simulation code (Pritchett, 1995; Pritchett, 2002) with the equations of state "SQSCO2" package (three pore components: H2O, CO2 and NaCl) and/or "SQSGAS" package (four pore components: H2O, CO2, CH4 and NaCl) (Pritchett, 2008), and then geophysical data was calculated using STAR’s "Geophysical Postprocessor" (Pritchett, 2003; Ishido et al., 2011; Ishido et al., 2015).
References
Huang, L. (Edt.) (2022): Geophysical Monitoring for Geologic Carbon Storage. John Wiley & Sons, Inc.
Ishido, T., Tosha, T., Akasaka, C., Nishi, Y., Sugihara, M., Kano, Y. and Nakanishi, S. (2011): Changes in geophysical observables caused by CO2 injection into saline aquifers. Energy Procedia 4, 3276-3283.
Ishido, T., Pritchett, J.W., Nishi, Y., Sugihara, M., Garg, S.K., Stevens, J.L., Tosha, T., Nakanishi, S., Nakao, S. (2015): Application of Various Geophysical Techniques to Reservoir Monitoring and Modeling. Proc. World Geothermal Congress, Melbourne, Australia, 19-25 April 2015.
Pritchett, J.W. (1995): STAR-a geothermal reservoir simulation system. Proc. World Geothermal Congress, Florence, 853-858.
Pritchett, J.W. (2002): STAR User’s Manual Version 9.0, SAIC Report Number 02/1055
Pritchett, J.W. (2003): Verification and Validation Calculations Using the STAR Geophysical Postprocessor Suite. SAIC Report Number 03/1040; 2003.
Pritchett, J.W. (2008): New "SQSCO2" equation of state for the "STAR" code, SAIC.