Low gas-liquid ratio foam flooding for conventional heavy oil

Abstract

The recovery of heavy oil by water flooding is 10% lower than that of conventional crude oil, so enhanced oil recovery (EOR) is of great significance for heavy oil. In this paper, foam flooding with a gas-liquid ratio (GLR) of 0.2:1 for the Zhuangxi heavy oil (325 mPa·s at 55 °C) was performed on cores, sand packs and plate model. In sand pack tests, polymer enhanced foam flooding increased oil recovery by 39.8%, which was 11.4% higher than that for alkali/surfactant/polymer (ASP) flooding under the same conditions. Polymer enhanced foam flooding in plate models shows that the low GLR foam flooding increased oil recovery by about 30%, even when the extended water flooding was finished at 90% water cut. Moreover, it was discovered by microscopy that foam was more stable in heavy oil than in light oil. These results confirm that low GLR foam flooding is a promising technology for displacing conventional heavy oil. © 2011 China University of Petroleum (Beijing) and Springer-Verlag Berlin Heidelberg.