Sensitivity of Reservoir and Operational Parameters on the Energy Extraction Performance of Combined CO2-EGR–CPG Systems

There is a potential for synergy effects in utilizing CO2 both enhanced gas recovery (EGR) and geothermal energy extraction (CO2-plume geothermal, CPG) from natural reservoirs. In this study, we carried out reservoir simulations using TOUGH2 to evaluate the sensitivity of recovery, pressure buildup, power generation performance combined CO2-EGR–CPG system key operational parameters. The parameters included horizontal permeability, permeability anisotropy, temperature, pore-size-distribution index; while wellbore diameter ambient surface temperature. Using an example model, also investigated different strategies transitioning CO2-EGR stage CPG on energy-recovery metrics two-phase fluid-flow regime production well. simulation results showed that overlapping stages, having relatively brief period injection, but no (which called CO2-plume establishment stage) achieved best overall (natural geothermal) performance. Permeability anisotropy temperature were was most sensitive to. diameter. study pave way future CPG-based power-generation optimization studies. For project, can be guide terms required accuracy during exploration data acquisition.