Modeling Hydrogeological and Geomenchanical Processes Related toCO2 Injection in a Faulted Multilayer System
This paper presents a numerical study of coupled hydrological and geomechanical processes during a deep underground injection of supercritical CO{sub 2} in a hypothetical brine aquifer. We consider a multilayer system in which the injection zone is situated below a sequence of caprock and aquifer layers that are intersected by a vertical fault zone. The fault zone consists of highly fractured shale across the first caprock layers that are located just above the injection zone. Initially, the fractured shale zones are considered sealed with minerals, but we allow fractures (and the fractured zones) to open as a result of injection induced reductions in effective stresses. Our results indicate that even when assuming a very sensitive relationship between effective stress and fractured-zone permeability, the injection-induced changes in permeability across are only moderate with largest changes occurring in the first caprock layer, just above the injection zone. As a result, the upward leakage rate remains relatively small and therefore changes in fluid pressure and hydromechanical effects in overlying zones are also relatively small for the case studied in this paper.
- Research Organization:
- Ernest Orlando Lawrence Berkeley NationalLaboratory, Berkeley, CA (US)
- Sponsoring Organization:
- USDOE. Office of the Chief Financial OfficerAssistantSecretary Range: 400000000 - 40ZZZZZZZ. Cost of Reimbursable Work andCooperative Work -Other Federal Entities, Cost of Reimbursable Work andCooperative Work -Other Federal Entities
- DOE Contract Number:
- AC02-05CH11231
- OSTI ID:
- 920327
- Report Number(s):
- LBNL--58998; BnR: 400408000
- Country of Publication:
- United States
- Language:
- English
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