Geological sequestration of CO2 involves high pressure injection of liquid CO2 (deeper supercritical) into deep underground porous reservoirs covered by a layer of impermeable cap rock. Fluids injections may induce stress and chemical perturbations and even cause irreversible deformation in and around injection formations leading to reservoir clogging, borehole instability, damage in caprock, and the creation of new fractures or the reactivation of existing faults in rock reservoirs (Rutqvist et al., 2007). Here, via laboratory pilot studies, mimicking injection into a reservoir on a miniature scale, we will characterize the effect of pressurized water and weak acid such as CO2, on yield and ultimate strengths of porous reservoir rocks and how does these high-pressure fluids influence the failure mechanisms.
