Coupled Carbon Dioxide Sequestration and Energy Production From Geopressured/Geothermal Aquifers

The current approach to carbon capture and sequestration (CCS) from pulverized-coal-fired power plants is not economically viable without either large subsidies or a very high price on carbon. Current schemes require roughly one-third of a power-plant's energy for carbon dioxide (CO2) capture and pressurization. The production of energy from geopressured aquifers has evolved as a separate, independent technology from the sequestration of CO2 in deep, saline aquifers. A game-changing new idea is described here that combines the two technologies and adds another-the dissolution of CO2 into extracted brine that is then reinjected. A systematic investigation covering a range of conditions was performed to explore the best strategy for the coupled process of CO2 sequestration and energy production. Geological models of geopressured/geothermal aquifers were developed with available data from studies of Gulf Coast aquifers. These geological models were used to perform compositional reservoir simulations of realistic processes with coupled aquifer and wellbore models.