Steady-state three-phase flow in a mixed-wet porous medium: A pore-scale X-ray microtomography study

We use three-dimensional X-ray imaging to investigate steady-state three-phase flow in a mixed-wet reservoir rock, while measuring both relative permeability and capillary pressure. Oil occupied the smallest pores, gas biggest, water medium-sized pores. report distinct pattern, where flows form of disconnected ganglia by periodically opening critical pathways. Despite having capillary-controlled displacements, significant fraction pore space was intermittently gas-oil oil-water phases. Both types intermittency occurred intermediate-sized Gas mainly displaces oil, oil as rate is increased, gas, decreased. At resolution images, no detectable trapped rock due its mixed-wettability which prevents either or completely surrounding suppressing snap-off trapping, has implications for design storage systems.