EOR study based on combination of microbe with ASP flooding

The application of alkane/surfactant/polymer (ASP) flooding is not satisfying, because of the low acid value of crude oil in the oilfield. To further enhance oil recovery, the method combining microbe with ASP flooding is presented. Study is conducted on the change of crude oil quality after microbes take effect, the effect of crude oil on the interfacial tension of the ASP system, the scale of microbe injection with air, the microcosmic flooding model and physical simulation flooding experiments. Results show that the quality and flowability are improved after microbes take effect. The acid value of crude oil is increased by 20 times higher than before, and the interfacial tension with the ASP system drops further. Indoor physical simulation oil displacement experiment shows that the oil recovery may be enhanced by 8.66% by injecting 0.05PV functional microbe firstly and then using ASP formulation (main flooding agent is made in Daqing ) to displace oil, compared to the method of using ASP flooding only. So the approach of using functional microbe to displace oil combined with ASP flooding may further enhance oil recovery, reduce ASP flooding costs, offering an economic and effective method for exploitation of reservoirs with low acid value.