# Forced imbibition in porous media: a fourfold scenario

## TL;DR

This paper provides a detailed analysis of four distinct pattern formation scenarios during forced imbibition in porous media, linking pore-scale instabilities to large-scale morphologies through experiments and microscopy.

## Contribution

It introduces a comprehensive framework connecting pore-scale instabilities to large-scale patterns in forced imbibition, based on experimental observations and microscopy.

## Key findings

- Identification of four distinct imbibition scenarios
- Linking pore-scale transitions to large-scale patterns
- Observation of long-time pattern coarsening

## Abstract

We establish a comprehensive description of the patterns formed when a wetting liquid displaces a viscous fluid confined in a porous medium. Building on model microfluidic experiments, we evidence four imbibition scenarios all yielding different large-scale morphologies. Combining high-resolution imaging and confocal microscopy, we show that they originate from two liquid-entrainment transitions and a Rayleigh-Plateau instability at the pore scale. Finally, we demonstrate and explain the long-time coarsening of the resulting patterns.