CFD Simulation of the Oil Displacement in Micromodel for Enhanced Oil Recovery Application

Abstract

Diminishing hydrocarbon reserves in oil reservoirs and the need to sustain continuous oil production have prompted researchers to further investigate Enhanced Oil Recovery (EOR) techniques. Researchers also test run these processes before EOR fluid injection into the reservoir to maximise oil production whilst minimising reservoir damage and fluid loss. This study aims to simulate oil displacement during the injection of two different types of EOR injection fluid, namely of water and polymer, using a commercial CFD software known as ANSYS Fluent. A heterogeneous 2D micromodel that has randomised pore network was selected as the basis of the flow system. By doing so, it is hoped to replicate a reservoir prototype using an innovative approach in a 2D geometry that appropriately simplifies complex reservoir properties represented. Initially, micromodel is fully saturated with crude oil. Then, water and polymer are injected separately on a case-to-case basis at flowrate of 0.8 mL/min. Visual inspection of the phase fraction contour results found that polymer flooded micromodel had smaller regions of oil volume fraction as compared to that of water flooded micromodel. Polymer flooded micromodel also had smaller and more branched fingering front as compared to water flooded micromodel. The analysis found that polymer flooding had better oil displacement efficiency as compared to traditional water flooding due to higher mobility ratio, reduced viscous fingering and lower residual oil saturation.