Analytical Approaches for Porous Media Geothermal Power Calculations

Geothermal electricity generation may play a role in reducing greenhouse gas emissions and addressing climate change in a cost-effective manner. Reservoir equations for pressure and temperature must be coupled to a power cycle model to calculate electricity generation from a geothermal power plant. This work focuses on sedimentary basin geothermal power production, which relies on flow through porous and permeable aquifers in sedimentary basins. Previous work has used numerical reservoir simulators, but we introduce analytical reservoir solutions for reservoir impedance, wellbore heat loss, and reservoir heat depletion in this work. The reservoir impedance and wellbore heat loss solutions are combined with a power cycle model to calculate electricity generation. The reservoir heat depletion solution provides insight into the reservoir lifetime because electricity generation decreases with reservoir temperature. We compare the analytical and numerical approaches and discuss their implications for geothermal electricity generation from sedimentary basins. Both approaches have merits, and the comparison herein can guide those who want to understand geothermal electricity production.