Physicochemical interactions between Carbonates/Brine/CO2 and their impact on Residual Trapping: Application for CO2 geo-storage

The degree of success of CO2 storage depends on many factors that control the safety and efficiency of such projects. Wettability is considered one of the main physicochemical properties affecting this promising technique (Krevor et al., 2015). Specifically, it controls the degree of CO2 trapped by residual trapping and structural trapping, two main trapping mechanisms (Iglauer et al., 2017). Therefore, the need to provide deeper insights on how the latter can affect residual trapping is highly recommended. The scope of this study is to explore experimentally the effect of wettability on CO2 residual trapping in carbonate/brine/CO2 geo-systems, hence CO2 storage calculations. After detecting a great discrepancy in literature regarding the effect of wettability in carbonate/CO2/brine system, and due to the scarcity in experiments and data sets generated in this research area, further experiments are needed to contribute in the establishment of well-defined trends of residual CO2 saturation behavior. This study represents for the first time full core samples treatment with stearic acid for wettability alteration purposes, as well as an extensive investigation on residual trapping efficiency affected by wettability in limestone reservoirs.