Geomechanical Behavior of Caprock and Cement: Plasticity in Hydrodynamic Seals

AbstractThe geomechanical behavior of caprock and wellbore systems determines the robustness of the CO2 storage system to disturbances from stress, pressure and temperature. In this study, we conduct triaxial coreflood and x-ray tomography experiments to directly measure permeability of water and supercritical CO2 in caprock (shale and anhydrite), cement and synthetic wellbores. The observed plastic behavior and large deformation that occurred prior to distinct sample failure demonstrates substantial stress accommodation in these systems. Fracture development resulted in total sample permeability ranging from 10-1000 mD depending on sample properties and the applied stress configuration