Modelling capillary trapping using finite-volume simulation of two-phase flow directly on micro-CT images

•Predicting capillary trapping using finite-volume simulation of two-phase flow directly on micro-CT images•Studying effects of capillary number, flow direction and initial saturation on the residual non-wetting phase saturation•Comparison with experimental measurements and network modelling We study capillary trapping in porous media using direct pore-scale simulation of two-phase flow on micro-CT images of a Berea sandstone and a sandpack. The trapped non-wetting phase saturations are predicted by solving the full Navier–Stokes equations using a volume-of-fluid based finite-volume framework to simulate primary drainage followed by water injection. Using these simulations, we analyse the effects of initial non-wetting-phase saturation, capillary number and flow direction on the residual saturation. The predictions from our numerical method are in agreement with published experimental measurements of capillary trapping curves. This shows that our direct simulation method can be used to elucidate the effect of pore structure and flow pattern of capillary trapping and provides a platform to study the physics of multiphase flow at the pore scale.