The role of biodegradable surfactant in microbial enhanced oil recovery

Many aerobic microorganisms can produce bio-surfactants which are capable of effectively reducing interfacial tensions between oil, water and rock. However, there are few publications on the production of bio-surfactants from anaerobic organisms. The combined effect of bio-surfactant, green surfactant and alcohol in the MEOR process, are not well understood yet and require further investigation. This experimental study was conducted to examine the effectiveness of combination of two microbial by-products, bio-surfactant and bio-alcohol, in recovering residual oil within the pores of rock. It also considered whether bio-surfactant capability could be improved by blending it with non-ionic green surfactant. Two formulations of surfactant and co-surfactant mixtures were selected for core-flood experiments based on phase behaviour study and IFT reduction to examine their potential for enhanced oil recovery. In the first formulation, JF-2 bio-surfactant was mixed with butanol; it was found that this formulation did not produce a significant quantity of incremental oil after water flooding. Lastly, a bio-surfactant (anionic) was blended with non-ionic green surfactant alkyl polyglucoside and butanol; this produced about 25% tertiary oil and 64% OIIP.