Rock fracturing due to CO2 injection

One of the challenges posed by the growing consumption of energy is to limit CO2 emissions. To that end, CO2 geological storage has been proposed as a potential solution. In particular, deep saline aquifers can potentially store many decades worth of CO2 emissions. However, before an underground formation can be considered for geological storage, its ability to trap the injected fluid over thousands of years must be proven. When injecting into deep saline aquifers, a potential problem is fracturing of the caprock that may result from excessive overpressures. In this context, this work proposes an investigation of caprock tensile failure behavior. Using a model built in CMG GEM, 23 parameters have been selected and varied in order to determine their influence on caprock failure. The work concludes by summarizing all investigated parameters in a tornado plot. Within the range of considered values, parameters such as reservoir matrix permeability, caprock Young modulus, and the number of injection wells have been found to have the strongest impact on the CO2 mass that can be injected before the caprock undergoes tensile failure.