Effect of Oil Presence on CO₂ Foam Based Mobility Control in High Temperature High Salinity Carbonate Reservoirs

Foam is one of the most cost-effective means of solving the drawbacks associated with the process of gas injection. The presented work is focused on probing the impact of oil saturation on CO₂ foam generation and its stability in the presence of high temperature and high salinity conditions. In this work, initially a texture-implicit local equilibrium model is used for parametric matching of a core flooding experiment conducted in the absence of oil. Once the foam parameters are calculated and tuned, the designed model is later up-scaled and studied with the inclusion of oil. The key objective is to study the effect of miscibility on the foam displacement front and the degenerating effect instilled by the residual oil saturation on the stability of foam. Different field scale models are designed and compared to validate the observed effect and hypothesis. The results of this work suggests that during CO₂ foam flooding the oil saturation has a profound effect on oil recovery especially when CO₂ is in an immiscible state with oil when compared with the miscible state.