Simulations of the Impact of Co-injected Gases on CO2 Storage, the SIGARRR Project: First Results on Water-gas Interactions Modeling

When capturing CO2, the collected gas mixture can vary considerably both qualitatively and quantitatively, based on the CO2 origin, the capture process and the industrial sector. Co-injected with CO2, these impurities might be an issue in case of leakage but may also impact the subsurface storage. Operators of the whole CCS chain are therefore waiting for recommendations in terms of admissible concentrations while regulators are waiting for tools allowing them to formulate these recommendations. The SIGARRR project aims at proposing accurate reactive-transport simulations to model the long-term behavior of CO2 and its co- injected gases within storage sites focusing on the reactivity with reservoirs and the possible inferences on the environment. The paper presents first numerical results on water-gas equilibriums in agreement with experiments.