Numerical analysis of CO2 injection into deformable saline reservoirs: benchmarking and initial observations

Abstract

A numerical scheme is presented for the solution of coupled multiphase hydromechanical problems in deformable porous media. Model verification is conducted against analytical solutions for multiphase flow with capillarity and coupled multiphase hydromechanical consolidation. A hybrid monolithic(flow)-staggered(mechanical) numerical solution scheme is verified to be stable for real materials, provided proper error control is placed on the hydraulic to mechanical iteration and the time-stepping scheme. Initial results of CO2 injection into an aquifer-caprock system do not show significant differences in CO2 migration rate between flow-only and hydro-mechanical simulations for conservative injection scenarios. However, the results highlight important regions in the reservoir with regard to potential mechanical failure and caprock integrity and suggest the need for further analysis.