Understanding CO 2 migration and distribution in fault systems is essential to evaluate long-term secure CO 2 storage and prevent hazardous effects caused by CO 2 leakage. To elucidate the role of the fault system on subsurface CO 2 migration and leakage processes, a two-dimensional multi-phase transport model was constructed to represent Little Grand Wash (LGW) and Salt Wash (SW) faults, where naturally originating CO 2 is being leaked to the surface. According to simulation results, buoyant CO 2 leaked through various pathways including the faults themselves, fault offsets, and damaged caprock. Because of both fault systems and caprocks serving as barriers, multiple trapped CO 2 plumes were developed in this region. Presence of trapped CO 2 plumes in the subsurface is supported by multiple field-observations (e.g., elevated soil CO 2 fluxes, travertines, and CO 2 -driven cold-water geysers/CO 2 springs) adjacent to both LGW and SW faults. Sensitivity studies were conducted with different permeabilities for faults and caprock, various CO 2 source locations, and differing fault parameters (e.g., fault throw and cutoff angle), which affected subsurface CO 2 distribution including size, shape, and location of trapped CO 2 plumes. Finally, such trapped CO 2 plumes have played a key role in the development of CO 2 -driven cold-water geysers in these regions.
All Science Journal Classification (ASJC) codes
- Water Science and Technology