From pore-scale physics to macroscopic flow dynamics in porous media micromodels with different wettability

Abstract

Multiphase flow through porous media involves complex pore-scale phenomena. In this work, we investigated water-oil flow in a PDMS-based porous media micromodel under different wettability conditions (water-wet, hybrid-wet, and oil-wet). Using fluorescence microscopy combined with in-situ pressure drop measurements, we analyzed fluid distributions in the pore space and flow intermittency dynamics as a function of capillary number and fractional flow rate. The effect of wettability conditions on the flow dynamics was correlated with the phase distribution in the pore space. Oil-wet media favors the continuity of the oleic phase. In contrast, water-wet media preferentially favors the flow of the aqueous phase through the porous medium, leaving behind a larger amount of oil. These findings provide a detailed perspective on two-phase flow behavior in micromodels of porous media, significantly improving our understanding of the underlying mechanisms that govern the impact of wettability on phase distribution, macroscopic flow pattern and intermittency dynamics.