Stress from NaCl crystallisation by carbon dioxide injection in aquifers

The goal of this paper is to identify the mechanical impact of water evaporation and salt crystallisation during supercritical carbon dioxide injection (drying-out process) in aquifer rocks. The precipitation of salt and the resulting crystallisation pressure are inferred from the chemical equilibrium of the carbon dioxide-rich gas phase, the in-pore brine and the crystal. The induced rock strain and equivalent tensile stress are then estimated within the framework of isotropic linear poroelasticity. A one-dimensional numerical simulation is conducted to illustrate the ability of the model to estimate the poromechanical behaviour of a structure submitted to a constant flow of nearly dry supercritical carbon dioxide.