Flow path development in different CO2 storage reservoir scenarios: A critical state approach

This study deals with the pressure-dependence of porous rock deformation, the permeability changes associated with this deformation, and the consequent effects of fluid flow during the CO2 injection phase in different configurations of deep saline aquifers. The study is approached from the standpoint of critical state soil mechanics, analyzing the effect exerted by different aspects that influence the geomechanical behaviour of porous rocks during CO2 storage. Through the study of the hydromechanical response of the environment, this paper shows how to assess the advisability of the use of CO2 storage, also identifying those cases and environments that would be less likely to lead to the creation or reopening of potential leakage paths.

► A model for the analysis of saline aquifers during CO2 injection is proposed. ► Different scenarios for the geological storage of CO2 are studied. ► Flow conditions influence the effective stress paths in the storage systems. ► Flow paths can develop as a consequence of strain localization.