The emulsifying characteristics research of the produced liquid in weak base alkaline-surfactant-polymer lay the theoretical foundation for the process ofoil-water separation and the choice of operating parameters, this paper mainly researchs the degree of emulsification of produced fluid, the properties of electrostatic double layer and interfacial tension. Studies have shown that the emulsified state of produced fluid is complex, it shows the coexistence of multiple emulsion, the average

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... l diametre of internal phase in emulsion fluid is 4.48-7um, and the thickness of boundary mask increases until the maximum thickness reachs to 2.5um ~ 3.75um; the Zeta potential in diffuse electric double layer of charged ions is between -30mV ~ -50mV; the boundary mask of produced liquidis always between 0.01 ~ 1 mN / m, less than the oil/water interfacial tension of the produced liquid in strong base alkaline-surfactant-polymer.The stability of emulsion is good, and not conducive to oil-water separation. Strong base three compound combination flooding is mostly used in Daqing oil field [1-5]. The existence of NaOH causes scaling and blocking of oil layer [6-11] and the scaling and corrosion of oil well holddown, ground gathering pipeline and process equipment in production. Moreover, the produced liquid is difficult to be processed and the cost is high [12,13] . In order to avoid these adverse effect, substitution of NaOH, namely weak base ASP flooding, with Na2CO3 or NaHCO3 has been applied in Daqing oil field at present [14][15][16][17]. However, there is no quantitative study on interfacial characteristic and emulsification of produced liquid of ASP flooding pilot block. The paper makes emulsification characteristic research on produced liquid based on some weak base ASP flooding pilot block. It can provide lay theoretical basis for the selection of oil-water separation technology of weak base ASP flooding produced liquid, the optimization of equipment structure, processing temperature and dosing concentration and facilitate the application of weak base ASP flooding in the oil field.