A review of chemical and mineralogical concerns of CO₂ sequestration in deep saline aquifers

The aim of this paper is to provide a comprehensive review of potential changes in the chemical and mineralogical environments of saline aquifers due to CO₂ injection under in situ conditions, and the influence of these changes on the hydromechanical behavior of reservoir rock. The effect of aquifer characteristics, such as pH and ionic composition, on the hydromechanical properties of reservoir rock are also considered. However, the CO₂ injection-induced hydromechanical properties of saline aquifers vary significantly with the properties of the aquifer and the injecting gas, which causes this to be complex, and to date, insufficient studies have been undertaken. Furthermore, this study identifies the chemically corrosive nature of different host fluids, which leads to decreased rock strength and increased crack propagation velocity during CO₂ sequestration.