Numerical Simulation of Two-Phase (Oil-Water) Flow in a Porous Media Using COMSOL Multiphysics for Predicting Oil Recovery Efficiency

Abstract

Abstract Efficient waterflooding design requires an accurate understanding of the complex interaction between oil and water flow within porous media. In this study, a two-dimensional numerical model of two-phase (oil-water) flow was developed using COMSOL Multiphysics® software to predict waterflood performance and assess oil recovery efficiency. The model was built on the Two-Phase Darcy Flow interface, incorporating capillary pressure, relative permeability, and viscosity effects. Boundary conditions were defined for one injector and one producer well, and simulations were conducted under varying injection rates, porosity, and permeability conditions. Results showed that increasing injection rate from 5 to 10 m³/day improved oil displacement efficiency by approximately 14%, but also reduced breakthrough time by 22%, indicating a trade-off between recovery and water production. Higher permeability zones exhibited faster saturation fronts and lower pressure gradients, while low-permeability regions retained more residual oil. Comparison with Buckley-Leverett analytical predictions revealed good agreement, with less than 6% deviation in predicted water saturation profiles. The developed COMSOL model effectively captures the dynamic behaviour of two-phase flow and provides a practical tool for optimizing injection strategies and predicting reservoir performance prior to field-scale implementation.