Recent Advances in Geochemical and Mineralogical Studies on CO2–Brine–Rock Interaction for CO2 Sequestration: Laboratory and Simulation Studies

The urgent need to find mitigating pathways for limiting world CO₂ emissions to net zero by 2050 has led to intense research on CO₂ sequestration in deep saline reservoirs. This paper reviews key advancements in lab- and simulation-scale research on petrophysical, geochemical, and mineralogical changes during CO₂–brine–rock interactions performed in the last 25 years. It delves into CO₂ MPD (mineralization, precipitation, and dissolution) and explores alterations in petrophysical properties during core flooding and in static batch reactors. These properties include changes in wettability, CO₂ and brine interfacial tension, diffusion, dispersion, CO₂ storage capacity, and CO₂ leakage in caprock and sedimentary rocks under reservoir conditions. The injection of supercritical CO₂ into deep saline aquifers can lead to unforeseen geochemical and mineralogical changes, possibly jeopardizing the CCS (carbon capture and storage) process. There is a general lack of understanding of the reservoir’s interaction with the CO₂ phase at the pore/grain scale. This research addresses the gap in predicting the long-term changes of the CO₂–brine–rock interaction using various geochemical reactive transport simulators. Péclet and Damköhler numbers can contribute to a better understanding of geochemical interactions and reactive transport processes. Additionally, the dielectric constant requires further investigation, particularly for pre- and post-CO₂–brine–rock interactions. For comprehensive modeling of CO₂ storage over various timescales, the geochemical modeling software called the Geochemist’s Workbench was found to outperform others. Wettability alteration is another crucial aspect affecting CO₂–brine–rock interactions under varying temperature, pressure, and salinity conditions, which is essential for ensuring long-term CO₂ storage security and monitoring. Moreover, dual-energy CT scanning can provide deeper insights into geochemical interactions and their complexities.