Coupled Hydro-Mechanical Fault Reactivation Analysis

Oil reservoir seals are natural traps that prevent the upward migration of hydrocarbons. Geological discontinuities, such as faults, are inherent in most petroleum formations. A fault plane (or fault zone) is a discontinuity in the rock mass, quite common in most sedimentary basins. These fractures are naturally sealed and they act as a barrier for the migration of fluids. In fact, the sealant condition of the fault is an essential requirement for the existence of the oil reservoir. However, natural events (e.g. earthquake) or human actions (e.g. CO2 injection at high pressure) may induce seal rupture with the possibility of connecting the reservoir with other rock blocks and finally with the surface. This process may lead to oil release and the associated environmental accident. Injection of fluids at high pressure represents a central activity around oil production strategies. Perhaps one of the biggest challenges of engineers and geologists involved in H2O/CO2 injection projects is to estimate the maximum allowable injection pressure that will not hampered the seal condition of the fault. A number of recent modeling efforts have been made to better understand the mechanical and flow behavior in the damage zones. For example Goodarzi et al. (2012) performed