Investigation of water and CO2 flooding using pore-scale reconstructed model based on micro-CT images of Berea sandstone core

To better understand the complex interplay of displacing and displaced fluid in porous reservoir, an investigation of water and CO2 flooding adopting pore-scale reconstructed model is conducted in this paper. Since accurate prediction and understanding of the disorder microstructures in the porous media contribute to acquiring the macroscopic physical properties, high resolution micro-computed tomography (micro-CT) is employed to obtain the origin pore geometry for establishing the pore-scale rock core models for both experimental and numerical study. Then visualised water flooding experiment is conducted to acquire benchmark data. Following that, numerical study on the water and carbon dioxide (CO2) flooding at the pore-scale model is carried out. Through this process, not only the location of the residual oil after the flooding process is investigated, but also the displacement of the interface between two immiscible fluids is obtained when oil is displaced by water and CO2, respectively. Results show that numerical simulations are in good agreement with experimental results. Consequently, the effects of micro pore characteristics on oil displacement efficiency by water and CO2 and two-phase flow seepage mechanism in it are revealed.