A Numerical Evaluation of the Impact of Wettability on CO2 Trapping Capacity: Implications for Carbon Geo-Sequestration

Abstract

Abstract Subsurface reservoir wettability is of vital importance in the prediction of CO2 trapping capacity and containment security. However, quantifying the effect of reservoir wetting behavior on CO2 sequestration potential in heterogeneous reservoirs remains to be challenging. This study conducts field-scale numerical simulations to understand the role of wetting characteristics and injection duration on the migration trend of CO2 plume and trapping capacity. These simulations were conducted on a heterogeneous sandstone reservoir with realistic relative permeability curves. The results indicate that CO2 plume migration and storage efficiency are influenced by wettability and injection duration. A water-wet system leads to higher residual gas trapping with less mobile CO2 and less dissolution. Moreover, an increase in injection duration would result in a decrease in residual trapping but the solubility trapping and plume migration distance would both increase.