Study of phase behaviour and ionic effect of green surfactants in MEOR

Abstract

The phase behaviour of surfactant systems is an important characteristic for microbial enhanced oil recovery (MEOR) and is a key method for understanding and predicting the performance of surfactant systems. In addition, ions play a vital role in surfactant chemistry and the ionic effects of green surfactants are not yet well characterised. Green surfactants are biodegradable and environmental friendly and perceived to have great potential for MEOR. This study characterises some green anionic and non-ionic surfactants through phase behaviour study, interfacial tension (IFT) and core flooding experiments. At the same time, the combined effect of the surfactants with alcohols on IFT through laboratory experiments are looked into. Our laboratory experiments have confirmed that the non-ionic surfactant is more active in the reduction of IFT than anionic surfactant. Bio-surfactant is unable to form stable middle phase. Temperature and pressure appear to have little effect on the IFT of non-ionic surfactant. There is no significant reduction in IFT values when the non-ionic surfactant is combined with pentanol in varying concentrations. The role of alkyl group carbon number in non-ionic surfactant was also investigated in this study. It was found that the IFT value decreased by increasing the lower limit alkyl group carbon number.