Application of Adaptive Artificial Viscosity Method to Reduce Grid Orientation Effect in Numerical Simulations for Steam Thermal Recovery

In the context of numerical simulators for multi-phase flow in porous media, there exists a long-standing issue known as the grid orientation effect (GOE), wherein different numerical solutions can be obtained when considering grids with different orientations under certain unfavorable conditions. It usually occurs during steam thermal recovery process where the viscosity of displacing fluid (typically steam and water of high temperature) is smaller than the viscosity of the displaced fluid (typically heavy oil). The occurrence of GOE seriously reduce the reliability of the simulation results. To address this issue, an adaptive artificial viscosity term is introduced into the discrete saturation equation within the framework of the sequential solution algorithm (SEQ). Numerical simulation results demonstrate that the proposed numerical strategy of augmenting adaptive artificial viscosity can effectively reduce the GOE and can provide more reliable numerical simulation results for steam thermal recovery.