After primary and secondary oil recovery in some blocks of Changqing oilfield,nearly half of the remaining oil has not been produced.Surfactant flooding is currently an important technical means to improve the oil recovery rate.In this paper,combined with the high salinity of produced water in low permeability reservoirs,the surfactant RYQ and RZ-1 were selected as the compound system,and the oil-water interfacial tension,compatibility,compound ratio,optimum salt concentration and oil washing efficiency of the system were determined.The experimental results show that the ultra-low interfacial tension of the salt-tolerant surfactant system RYQ/RZ-1 can be achieved at the mass fraction 0.9%of 10-3mN/m.The concentration of the system was 0.9%,the compound ratio was 2∶1,and the optimum salt concentration was 0.5%.The oil washing efficiency is about 25%,and the system has good performance.
维普
万方数据