Interfacial interactions of CO2-brine-rock system in saline aquifers for CO2 geological storage: A critical review

CO2 geological storage (CGS) is a promising technology to reduce anthropogenic greenhouse gas emissions. In CGS, the CO2 is injected into underground reservoirs to offset CO2 emissions. In underground reservoirs, the capillary force traps the injected CO2. This process is important to sealing integrity and influences the fate of underground CO2. Given that the capillary force is a function of CO2-brine-rock interactions, we comprehensively reviewed the current advancements and outline the knowledge gaps of interfacial interactions between CO2brine-rock. We summarized the experimental results of CO2-brine-rock interfacial interactions from surface scale to core scale. We comprehensively reviewed the modelling methods for CO2-brine-rock interfacial interactions from molecular scale to core scale. To be specific, we compared the main modelling methods for interfacial interactions, including molecular dynamics modelling, geochemical modelling, and Deryaguin-Landau-Verwey-Overbeek (DLVO) modelling. We evaluated the strength of each modelling method, concluded the limitations, and provided suggestions for future improvements. This review packed both experimental and theoretical investigations to understand the critical role of interfacial interactions in storage integrity of CGS.