Expansion of Geological CO 2 Storage Capacity in a Closed Aquifer by Simultaneous Brine Production with CO 2 Injection

Structural trapping is the primary mechanism for intensive CO 2 sequestration in saline aquifers. This is the foundation for increasing global CO 2 storage; gradual switch to preferable trapping mechanisms, such as residual saturation, dissolution, and mineral trapping, will require a long-time scale. The major constraints limiting the storage capacity of structural trapping are formation pressure and structure size. Over-pressure owing to CO 2 injection causes a disruption of seal integrity indicating a failure in geological sequestration. The other constraint on storage capacity is a spill point determining geological storage volume. Overflowing CO 2 , after filling the storage volume, migrates upward along the aquifer geometry with buoyancy. This study proposes a methodology to maximize CO 2 storage capacity of a geological site with a substructure created by an interbedded calcareous layer below spill point. This study provides various conceptual schemes, i.e., no brine production, simultaneous brine production and pre-injection brine production, for geological CO 2 storage. By the comparative analysis, location of brine producer, production rate, and distance between injector and producer are optimized. Therefore, the proposed scheme can enhance CO 2 storage capacity by 68% beyond the pressure and migration limits by steering CO 2 plume and managing formation pressure.