ASP flooding is proven a great success in China due to its large number of field tests and incredible oil production. Latest progress of ASP flooding field tests and application in China is summarized. Incremental oil recovery of ASP flooding can be as high as 30%, much higher than all the other chemical enhanced oil recovery (CEOR) techniques. Although one recent surfactant-polymer flooding (SP) field test is reported 18% incremental oil recovery, other SP flooding field tests are not so successful. More incremental oil recovery does not always ensure more economic benefits. With progress of surfactant production technology in Daqing, alkali NaOH was finally proven better than Na2CO3. Too high polymer concentration may block low permeability strata. The allowable maximum polymer parameter (molecular weight and concentration) is key to success, especially when emulsification is taken into consideration. There is no one-fit-all ASP formulation and the dynamic adjustment is necessary in ASP flooding. Why pre-slug is used is still worth investigation. The average cost of ASP flooding can be lower than SP flooding due to more oil produced.

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