Modelling and Effects of Evaporation Kinetics on Mass Transfer and Salt Precipitation During CO2 Sequestration

Geological CO2 storage is a key method to reduce industrial emissions, using oil and gas reservoirs or saline aquifers as subsurface containers. Injecting dry or under-saturated supercritical CO2 into water-bearing formations can create a dry-out zone, affecting rock porosity and permeability due to mineral precipitation. This may impair injectivity, posing both operational and financial challenges. However, limited attention has been dedicated to study the size of the affected zone and the impact of capillarity on fluid transport within it.

We addressed limitations in current reservoir simulation tools by developing a DuMux-based module focusing on evaporation and reaction kinetics, and dry-out phenomena during supercritical CO2 injection. We approach this question with numerical simulations to determine the size of the zone affected by the undersaturated CO2. We investigate the major parameters governing this zone and the fluid transport therein. We also conduct meter-scale core flood experiments using CT imaging to monitor fluid and solid saturation. Besides that, monitoring differential pressure helps assess changes in permeability and injectivity. The gathered experimental data allows us to calibrate our numerical model and to upscale the results to the field scale. Anyhow, the experimental work is currently in progress.