Stanford Geothermal WorkshopFebruary 9-11, 2026

Geochemical interactions play a pivotal role in the long-term productivity, injectivity, and sustainability of Enhanced Geothermal Systems (EGS). This study investigates how fluid–rock reactions, mineral dissolution–precipitation dynamics, and scaling mechanisms influence permeability evolution and reservoir behavior under EGS operating conditions. Using coupled reactive transport modeling and geochemical simulations, we evaluate the effects of temperature, pressure, and fluid composition on mineral equilibria within fractured crystalline formations using CMG’s thermal simulator . Results indicate that dissolution of primary silicates enhances early-stage permeability, while secondary mineral precipitation (e.g., calcite, quartz, and clay minerals) progressively reduces flow pathways over time. Sensitivity analysis shows that even minor variations in injected fluid chemistry or CO₂ content can significantly alter reaction kinetics and porosity trends. The findings emphasize the importance of integrating geochemical monitoring and predictive modeling into EGS reservoir management to mitigate scaling, preserve injectivity, and optimize thermal recovery. These insights contribute to a more comprehensive understanding of coupled thermo-hydro-chemical-mechanical (THCM) processes critical for sustainable geothermal energy development.

Topic: Geochemistry