Low salinity (LS) water injection can enhance oil recovery,and the addition of surfactant to the injected water can improve recovery by increasing the number of capillary tubes.In this paper,alcohol propoxyl sulfate mixed with endolefin sulfonate was used to compare the recovery rate of low-salinity surfactant (LSS) oil drive process under medium-low interfacial tension with that of optimal salinity surfactant (OSS) injection process under ultra-low interfacial tension.The effect of different injection schemes on crude oil recovery was studied using sandstone cores from the Liaohe oilfield.The results showed that the recovery of LSS drive was two orders of magnitude lower than that of surfactant drive at ultra-low interfacial tension.In addition,the recovery rate of LSS drive was about 60% higher than that of LS.On this basis,the LSS process was more cost-effective than the OSS injection process under ultra-low IFT.
维普
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