Investigation of oil-based CO2 foam EOR and carbon mitigation in a 2D visualization physical model: Effects of different injection strategies

Abstract

CO₂ flooding in low-permeability and tight oil reservoirs often encounters gas channeling, which affects oil recovery. To address this, oil-based CO₂ foam development is explored using a two-dimensional visual physical model. The study includes three experimental setups: CO₂ flooding followed by oil-based CO₂ foam flooding, CO₂ Huff-n-Puff (HnP) followed by oil-based CO₂ foam HnP, and oil-based CO₂ foam HnP followed by oil-based CO₂ foam flooding. Findings reveal that using oil-based CO₂ foam after CO₂ development increases recovery factors by 15.62 % and 35.86 % for HnP and flooding, respectively, and significantly boosts CO₂ storage. The CO₂ storage is 1.96 times and 6.03 times higher than the initial one. After oil-based CO₂ foam is used, the red area near the outlet of the visualization model becomes shallower, indicating a further decrease in residual oil saturation. The oil-based CO₂ foam method reduces residual oil saturation and extends production duration while decreasing gas production rates. This approach effectively plugs gas channels, enhancing CO₂ sweep efficiency, crude oil mobility, and recovery. The results provide innovative strategies for oilfield development, supporting carbon sequestration and offering substantial economic and environmental benefits.