Dynamical instabilities of two-fluid interfaces in a porous medium: A three-dimensional video imaging study

TL;DR

This study uses 3D imaging to analyze how two-fluid interfaces in porous media become unstable and form complex patterns like fingers and droplets as flow rate increases, influenced by pore geometry and wettability.

Contribution

It provides detailed real-time 3D visualization of pore-scale processes governing fluid interface instabilities in porous media, highlighting effects of physical and chemical heterogeneities.

Findings

Interface transitions from flat to fingers and droplets with increased flow rate

Physical and chemical heterogeneities influence instability dynamics

Identifies pore-scale mechanisms driving pattern formation

Abstract

Two-fluid interfaces in porous media, an example of driven disordered systems, were studied by a real time three-dimensional imaging technique with pore scale resolution for a less viscous fluid displacing a more viscous one. With increasing flow rate the interface transforms from flat to fingers and thence to droplets for both drainage and imbibition. The results compare and contrast the effects of randomness, both physical (geometry of the pore space) and chemical (wettability of the fluids), on the dynamical instability and identify the origin of the pore-scale processes that govern them.