CO2 storage in porous media unsteady thermosolutal natural convection -Application in deep saline aquifer reservoirs

Abstract

In this paper, the storage of CO2 is investigated numerically under supercritical conditions in deep saline aquifer reservoirs. The simulations were performed on a non-deformable, saturated porous material inside a vertical enclosure that was assumed to be impermeable and insulated on three sides. The porous medium is homogeneous and isotropic with constant thermo-physical properties except for the fluid density, which varies according to Boussinesq approximations. A dynamic model assumes that flow is two-dimensional and obeys Darcy's motion law. The thermal equilibrium assumption (LTE) is also considered. The set of conservation equations and the appropriate initial and boundary conditions have been resolved numerically by the classical finite volume method. Spatio-temporal variations of different state variables such as pressure, velocity, temperature, and concentration were numerically simulated and plotted versus controlling parameters, particularly the thermal and solutal Rayleigh numbers, RaT and RaS; the Lewis number, Le; and the reservoir's aspect ratio, A. According to regulating factors, and physical and geological qualities, we could predict the behavior of CO2 that would be stored in a geologic reservoir that is thought to be porous media. We could also estimate the time and direction of CO2 mass transfer based on the abovementioned factors. Great attention was paid to examining the sensitivity of fluid flow, heat, and mass transfer rates according to the reservoir form and the operating conditions.