Stability Evaluation of Lattice Boltzmann Method for High Viscosity Fluid Model Applied in Pore Scale Porous Media

Abstract

This study examines the applicability of the Lattice Boltzmann Method (LBM) in the term of numerical simulation stability. One of the issues in LBM application is the numerical simulation stability when modeling fluid flow with high viscosity fluid in pore-scale porous media domain. The problem that encountered in the LBM is the range of the time relaxation that represents the fluid viscosity that can be related to the macro scale viscosity in Navier-Stokes equation with the multi-scale method of the Chapman - Enskog. The intention to simulate the high viscosity fluid is to simulate the fluid flow of heavy oil model in porous media. However, during the first attempt, numerical instability occurred when using the lowest relaxation parameter that represents the highest fluid viscosity. Therefore, several evaluations were conducted by manually fine-tuning the relaxation parameter to verify the simulation stability in the pore scale of the deduced porous media domain. The results show, there is a certain boundary limit of the relaxation parameter could be applied to model high viscosity fluid to represent the heavy oil in acceptable stability during the simulation, especially in the complex geometry such as porous media. By doing this verification prior to conducting fluid flow simulation of high viscosity in porous media with LBM, will ensure the simulation will run smoothly and modeling the heavy oil fluid flow in pore-scale porous media could be conducted.