The reduction of CO₂ emissions is one of the critical enablers for humanity to continue to rely (partially) on hydrocarbons as source of energy. CO₂ storage in saline aquifers or depleted oil and gas fields could potentially contribute for diminishing CO₂ emission into the atmosphere and mitigate its adverse effects on the climate. Our research focused on the physical-chemical numerical modeling of CO₂ injection into geological formations. The goal is to provide the basis for the development of new models and numerical tools capturing more realistically a spectrum of important physical effects (thermodynamics of water-hydrocarbon-CO₂ systems, dissolution and precipitation of minerals, interfacial phenomenal, etc.). Ongoing projects, were conducted mostly as part of the CATO program. They are aimed at a better description of wettability changes in rocks, natural convection and dry-out and sal-precipitation induced by CO₂ injection.