Laboratory Investigation of Enhanced Heavy Oil Recovery by Foam Flooding with Low Gas-Liquid Ratio

This article presents the results of a laboratory study of foam flooding with low gas-liquid ratio for heavy oil in Shengli oilfield. Foam flooding tests were performed in cores, sandpacks, and using a 3D physical model to study the factors affecting displacement efficiency such as gas-liquid ratio, injection slug size, and the viscosity of crude oil. The results showed that the tertiary oil recovery of polymer-enhanced foam flooding with a gas-liquid ratio of 0.2:1 could reach 39% for heavy oil with a viscosity of 325 mPa center dot s at 55 degrees C, which was 11% higher than alkali/surfactant/polymer flooding by injecting 0.3 pore volume of the same chemical slug. However, the tertiary oil recovery decreased with increasing viscosity of the crude oil.