Prediction of the capillary pressure of fluid surrounding a cylinder representing an idealized rock structure in porous media

TL;DR

This paper models and predicts the shape and capillary pressure of liquids surrounding a cylinder in porous media, validated through simulations, aiding understanding of fluid movement in complex rock structures.

Contribution

It introduces a new predictive approach for capillary pressure around cylindrical structures in porous media, validated by Surface Evolver simulations.

Findings

Predicted liquid shapes match simulation results across various contact angles.

Capillary pressure depends systematically on cylinder radius and contact angle.

Model improves understanding of fluid behavior in complex porous geometries.

Abstract

Liquids in oil-bearing porous media assume complex shapes that depend on the reservoir characteristics and the wetting properties of the liquid. The wide variation in the geometry of rock formations makes it difficult to accurately predict the capillary pressure of small volumes of liquid and hence the likelihood of being able to move it. Here we consider the situation in which a small volume of liquid surrounds an upright cylinder on a flat substrate and predict the shape that the liquid takes and its capillary pressure. We validate our predictions by comparing with Surface Evolver simulations for a range of contact angles and cylinder radii.