Reactive Transport Simulations of CO2 Sequestration and Mineralization in Deccan Basalt

Summary The Deccan Basalt formation in the Deccan Volcanic Province offers significant potential for geologic carbon sequestration (GCS) due to its extensive coverage and unique mineral composition. Previous studies estimate that the region could store between 94 and 305 gigatonnes of CO2, making it a key candidate for carbon mitigation in India. However, understanding the factors influencing CO2 migration, trapping mechanisms, and mineral carbonation in these basalt formations remains an area of ongoing research. This study builds on prior work by investigating how temperature, pressure, pH, petrophysical properties, and CO2 injection strategies affect the efficiency of mineral carbonation in the Deccan Basalt over 250 years. Using multiphase and multicomponent reactive transport modeling, the study examines the role of various minerals (including albite, anorthite, and diopside) in CO2 sequestration under different reservoir conditions. Results indicate that CO2 trapping is most effective under moderate temperature and pressure, with anorthite being the most reactive. Cyclic CO2 injection outperforms continuous injection, enhancing mineral precipitation and clay formation. The study concludes that CO2 sequestration in Deccan basalt is viable with proper management and monitoring, though site-specific studies are needed for practical implementation. Further research on mineral variations and microbial effects on carbonation is recommended.