Determination of Diffusion Coefficient of Supercritical CO2 in Low Permeability Formation Core

CO2 diffusion in oil phase in the presence of porous media is of great importance to forecast the performance of enhanced oil recovery (EOR) and carbon dioxide capture and storage (CCS). When CO2 is brought into contact with oil phase, the diffusion occurred. The indirect pressure decay methodology has been applied successfully to determine the mutual diffusion coefficients of supercritical CO2 and crude oil at temperature of 65℃. Theoretically, a one-dimension double-way mass transfer model incorporating the capillary and adsorption effects of porous media has been constructed to quantify the mutual dynamic diffusion coefficients. The crude oil has been characterized into five pseudo-components for the accurate description of the phase behavior of CO2 gas and oil phases. An optimization method along with the PR Equation of State (EOS) is employed to determine each component’s diffusion coefficients in the gas and oil phases for the purpose of minimization of the difference between the experimental data a...