Simulation of Two-Phase Flow in Porous Media using a Network Model.

Abstract

A network simulator has been used to study two-phase flow in porous media. The medium has been modeled as a bundle of tubes and the capillary forces inside these tubes have been investigated. This has been done by applying well known theory of immiscible flow to tubes of different shapes. How the wettabillity of the media affect the meniscus curvatures have been studied and how this relates to the cross-section geometry and width of a single tube. The tube radius was modeled by a function being narrow in the middle of the tube and wider towards the end. How the menisci was affected by this curvature due to varying radius have been investigated. Different degrees of complexity have been used to see if simple approximations are able to capture the relevant physics or if a higher order of complexity is needed. It was found that the cross-sectional shape does not have a big impact on the flow, however thin film flow is neglected. When looking at how the radius affected the results it was found that approximations used in previous work was sufficient for small wetting angles, however at large wetting angles this expression became inaccurate. Finally different radius functions was tested to see if the shape of the radius had impact. Some differences was observed but it is hard to conclude which case was the most physically correct due to lack of experimental data.