An improved pore-network model including viscous coupling effects using direct simulation by the lattice Boltzmann method

•A new multiscale strategy is proposed for multiphase flow in porous media.•Lattice Boltzmann method is used to simulate two-phase flow at pore scale for empirical terms of viscous coupling.•Empirical coupling terms are used in pore-network model for relative permeability at core scale.•Including viscous coupling leads to better predictions of relative permeability. Viscous coupling during simultaneous flow of different fluid phases has a significant impact on their flow through porous media. In this work, a new multiscale strategy is proposed for multiphase flow in porous media. We use the lattice Boltzmann method (LBM) to simulate two-phase flow at pore scale and obtain empirical terms for the viscous coupling inside individual pores. The empirical coupling terms are then used in a pore-network model to efficiently simulate two-phase flow through porous media at core scale. It is shown that including viscous coupling leads to better predictions of relative permeability.