Impact of material properties on caprock stability in CO2 geological storage

In this study, thermo-hydro-mechanical coupled simulations are performed to investigate caprock stability under cooling and pressurization during the injection of carbon dioxide. It is shown that failure potential of caprock increases with a higher value of the material parameter R which is defined as a ratio of material properties (the thermal expansion coefficient and the elastic properties) of caprock and aquifer. The study also underlines that the consideration of the Biot coefficient of the aquifer is essential for properly estimating aquifer examination. The analysis shows that the cooling of caprock is mainly transferred by conduction, and the temperature drops with time t at a rate of erfc12Dt, where the rate increases if caprock has a higher thermal diffusivity D.