Prediction of three-phase relative permeabilities of Berea sandstone using lattice Boltzmann method

TL;DR

This study uses lattice Boltzmann simulations to analyze three-phase flow in Berea sandstone, revealing how relative permeabilities and interfacial lengths vary with saturation, wettability, and viscosity ratios under critical interfacial tension conditions.

Contribution

It introduces a numerical approach using lattice Boltzmann method to predict three-phase relative permeabilities in Berea sandstone, considering wettability and viscosity effects.

Findings

Relative permeability increases with saturation for each fluid.

Interfacial lengths show monotonic or non-monotonous variations with saturation.

Viscosity ratio influences phase stability and interfacial length.

Abstract

Three-phase flows through a pore network of Berea sandstone are studied numerically under critical interfacial tension condition. Results show that the relative permeability of each fluid increases as its own saturation increases. The specific interfacial length between wetting and non-wetting fluids monotonously decreases with increasing the saturation of intermediate-wetting fluid, while the other two specific interfacial lengths exhibit a non-monotonous variation. As the wetting (non-wetting) fluid becomes less wetting (non-wetting), the relative permeability of wetting fluid monotonously increases, while the other two relative permeabilities show a non-monotonous trend. Due to the presence of spreading layer, the specific interfacial length between wetting and non-wetting fluids always stabilizes at a low level. As the viscosity ratio of wetting (non-wetting) to intermediate-wetting fluids increases, the relative permeability of wetting (non-wetting) fluid increases. With the viscosity ratio deviating from unity, the phase interfaces become increasingly unstable, leading to an increased specific interfacial length.