Pore-scale characterization of CO2 front progress through a porous medium using a free energy model based on Phase-Field Lattice Boltzmann Method

Abstract

Pore-scale simulation of CO2 front progression through a porous medium has been investigated by a free energy model based on phase-field lattice Boltzmann method. Visualization of the fluids distribution in the breakthrough time reveals a strong dependence of front pattern on viscous and capillary forces interaction. Therefore, the dominance of each force imposes a different front pattern on the system. According to the percolation theory, increasing the capillary number reduces the invading fluid saturation and, consequently, the sweep efficiency, because the viscous fingering regime will intensify. However, a uniform pattern is observed when the mobility ratio is high, whereas the front evolution is facilitated in the opposite case. Impressive results have also been obtained regarding the wetting conditions. Since an upward trend in the displacement efficiency from strong drainage to strong imbibition processes is expected, this trend has changed due to the capillary suction effects in the strong imbibition process. According to experimental studies, the viscous fingering phenomenon will be proportional to the capillary suction. Furthermore, new areas have also been introduced to predict the displacement regimes.