| Abstract |
Carbon capture and storage (CCS) is a critical technology in reducing CO2 emissions into the atmosphere, operating by permanently storing captured CO2 in geologic formations. This geologically stored CO2 can be utilized in a geothermal power system, known as CO2-Plume Geothermal (CPG), which utilizes CO2 as the heat extraction fluid in an open-loop power cycle as part of a carbon capture, utilization, and storage (CCUS) process. However, the injection of CO2 into sedimentary basins can increase the reservoir pressure due to the displacement and compression of the native brine, particularly during the CO2 plume development phase for a CPG system. This can increase the risk of CO2 leakage and the formation of fractures in the reservoir and require additional pumping, and thus power consumption, to inject the CO2. Active CO2 Reservoir Management (ARM) can reduce the pressure buildup during CO2 injection by producing brine to the surface through the CPG production wells. Brine production during plume development can reduce the CO2 injection pressure and shorten the plume development period, while simultaneously producing hot brine at the surface that can be used to produce electricity (or heat) and/or fresh water by employing enhanced water recovery (EWR) methods. Here, we present how a CPG system, can be combined with ARM to manage reservoir pressures during CO2 plume development, to produce electricity using the hot brine and reduce the reservoir development time for a CPG system. Our investigated system is comprised of a single reservoir, with a vertical injection well and a horizontal production well, vertical wells connecting them to the surface, and a surface power plant. We found ARM reduced the breakthrough time by 4% to 7%, reduced the overpressure by 20% to 30%, and provided electricity from the extracted brine. Unfortunately, ARM decreased the CO2 mass fraction produced once breakthrough occurred. |