This paper reports a laboratory study of a novel alkaline-surfactant-foam (ASF) process. The goal of the study was to investigate whether foaming a specially designed AS formulation could meet the two key requirements for a good enhanced oil recovery (EOR), i.e. lowering the interfacial tension (IFT) considerably and ensuring a good mobility control. The study included phase behavior tests, foam column tests and CT scan-aided core-floods. It was found that the IFT of the designed alkali-surfactant (AS) and a selected crude oil drops by four orders of magnitude at the optimum salinity. The AS proved to be a good foaming agent in the column tests and core-floods in absence of oil. The mobility reduction due to the AS foam was hardly sensitive to salinity and increased with decreasing foam quality. CT scanned core-floods demonstrated that AS foam following a small AS pre-flush recovered almost all the oil left after water-flooding. The oil recovery mechanism by ASF combines the formation of an oil bank and the transport of emulsified oil by flowing lamellae. Further optimization of the ASF is needed to ensure that the oil is produced exclusively by the oil bank.

You can access this article if you purchase or spend a download.