A Study On The Combination Flooding System Of Bio-enzyme And Surfactant

The combination flooding system of bio-enzyme and surfactant flooding is a EOR technology which is used by the combination system of bio-enzyme and surfactant for flooding. Bio-enzyme and suitable surfactant are prepared into the flooding agent according to the proportion, and then inject the flooding reservoir to enhanced oil recovery. Bio-enzyme has high efficiency, specificity and the synergistic effect with surfactant. Therefore, the combination flooding system of bio-enzyme and surfactant not only possesses the characteristics of bio-enzyme,but also has the characteristics of surfactant, and enhances the adaptability of the reservoir environment.In this paper, the bio-enzyme which provided by Daqing Oil Field Industrial Co.Ltd and fluoride heavy alkylbenzene sulfonates, petroleum sulfonate and lignosulfonate were optimized combination, optimized the combination flooding system of fluoride heavy alkylbenzene sulfonates and bio-enzyme to study. The auxiliary agent ethanol was added into the bio-enzyme and surfactant combination flooding system which is in order to make the interfacial tension of combination flooding system and crude oil drop to7.5×10-3mN·m-1.Through the flooding mechanism study experiments on the combination flooding system,it is found that the flooding mechanism of bio-enzyme and surfactant combination flooding system is mainly to change rock wettability, emulsify crude oil and have ability of washing oil etc. Through the flooding fulfilled factors study on the bio-enzyme and surfactant combination flooding system, it is found that the most suitable environmental temperature is60 ℃ for the combination flooding system, the most suitable reservoir water salinity is3500mg/L, the suitable environment pH is 7 and crude oil viscosity of the most suitable used reservoir is 13mPa·s. Through the optimization of flooding scheme, confirmed that the application concentration of bio-enzyme and surfactant flooding system was 0.6%, the injection dosage is 0.3PV, the advance speed in the reservoir is 2.95m/d.