Simulation of the influence of surface wettability on viscous fingering phenomenon in porous media

Fingering phenomena are common occurrence in the natural world. It generally takes place when a less viscous fluid displaces a more viscous fluid typically in porous media. Nowadays, such phenomena have extensively been studied due to its importance in many industrial fields. In this paper, the effects of surface wettability on finger pattern are studied and simulated numerically by the Lattice Boltzmann method (LBM). The displacement efficiency is investigated by using two parameters, namely, the breakthrough time and the areal sweep efficiency. The simulation has demonstrated that surface wettability will influence the finger pattern no matter the gravity is considered or not, but in the presence of gravity, the finger pattern is much more complicated and irregular due to the coexistence and competition of capillary force, viscous force and gravity.