Numerical pore-scale simulation of propane injection for heavy oil displacement processes

Solvent injection processes offer a promising alternative to steam-based techniques for heavy oil recovery. Multiple mass transfer mechanisms, including interphase mass transfer, diffusion, and convection, would affect the process efficiency and recovery performance. Understanding the mass transfer processes in solvent-based heavy oil recovery processes is fundamental to accurately model the solvent/heavy oil interfacial dynamics and design efficient solvent recovery methods. A robust simulation framework based on the level-set method is proposed in this study to simulate the in-jection of a vaporized solvent (i.e., propane) into a bitumen-oil system. A pore-scale two-phase multi-component flow simulation is constructed. The solution of the Navier-Stokes equation is coupled with the level-set formu-lation to track the fluid/fluid interface; a concentration jump is applied to simulate the mass transfer across the gas-liquid interface. The model is validated against several bulk fluid systems where analytical solutions can be derived. Next, the model is tested using a more complex pore-scale system; a macro-scale mass transfer coeffi-cient is estimated based on the linear mass transfer model. The values are compared to those described in the literature. The level-set simulation framework is useful for simulating multiphase multi-component interphase mass transfer in porous media. It serves as a tool to examine these different mechanisms' interactions and relative importance under various conditions. The proposed simulation framework can be readily applied to studying other subsurface processes, including carbon dioxide storage and groundwater flow.