Study on CO2 diffusion process in heavy oil saturated porous media using experiment and simulation

To explore the CO2 diffusion in heavy oil saturated porous media, a mathematical model was developed to simulate the diffusion process by coupling the gas state equation. Then the experiment of CO2 diffusion in heavy oil saturated porous media was carried out and CO2 diffusion coefficient was determined by fitting the experimental data with the established model. Using the measured diffusion coefficient as an input parameter, the CO2 diffusion process in porous media was simulated and the factors that affected the diffusion process were analysed in this paper. The simulation results show that diffusion direction on the rock surface is in the tangential direction of the rock and points to where the CO2 concentration potential decreases. Furthermore, the contact area of the heavy oil and CO2 has a vital impact on the CO2 diffusion amount and CO2 concentration distribution. [Received: November 24, 2019; Accepted: August 7, 2020]