An improved multicomponent pseudopotential lattice Boltzmann method for immiscible fluid displacement in porous media

TL;DR

This paper introduces an improved multicomponent pseudopotential lattice Boltzmann method for simulating immiscible fluid displacement in porous media, accurately capturing physical phenomena and allowing independent control of surface tension and viscosity.

Contribution

The authors develop a new numerical model with advanced boundary conditions that suppress non-physical behaviors and enable realistic simulation of oil-water flows in heterogeneous porous media.

Findings

The model accurately simulates realistic viscosity ratios.

It correctly captures residual saturations and wettability effects.

Simulations agree well with experimental data.

Abstract

Immiscible fluid displacement in porous media occurs in several natural and industrial processes. For example, during petroleum extraction from porous rock reservoirs, water is used to displace oil. In this paper, we investigate primary drainage and imbibition in a heterogeneous porous medium using an improved numerical model based on the multicomponent pseudopotential lattice Boltzmann method. We apply recent developments from the literature and develop new pressure boundary conditions. We show that the proposed model is able to simulate realistic viscosity ratios, and it allows independent tuning of surface tension from viscosity. Moreover, the model suppresses a non-physical behavior of previous schemes, in which trapped fluid volumes significantly change with time. Furthermore, we show that the developed model correctly captures the underlying physical phenomena of fluid displacements. We simulate oil-water flows and verify that the measured values of irreducible water and residual oil saturations are realistic. Finally, we vary the wetting conditions of the porous medium to represent different wettability states. For the different scenarios, we show that the simulations are in good agreement with experimental results.