模拟二元复合驱采出液稳定性影响因素研究

Simulation Study on Influencing Factors of Produced Fluid Stability in SP Flooding

二元复合驱是中高渗透油藏提高采收率的主要技术之一。为了研究聚表二元驱对乳状液稳定性的影响,选取含聚表水与模拟油组成油水界面体系,测试了油水界面张力、界面剪切黏度等参数,并结合乳状液静置脱水效果,分析聚表二元驱对油水采出液稳定性的作用机理。采用含聚合物和表面活性剂的水相与模拟油配制成模拟油采出液,用于测试不同聚合物及表面活性剂浓度对界面张力的影响。界面张力结果表明:聚表二元驱成分能够显著增大油水乳状液的稳定性,但聚合物与表面活性剂在界面活性上存在明显差异;界面剪切黏度的影响因素主要为聚合物;静置脱水实验表明,影响油水乳状液稳定性的主要因素为表面活性剂。这与过去的观点存在矛盾,即认为界面剪切黏度是影响乳状液稳定性的关键。因此本研究认为存在其他因素影响乳状液稳定性。

Polymer/surfactant binary flooding is one of the main technologies for improving oil recovery in medium and high permeability reservoirs.In order to study the effect of polymer/surfactant binary flooding on emulsion stability,an oil-water interface system consisting of polymer/surfactant water and simulated oil is selected.The interfacial tension,interfacial shear viscosity and other parameters are tested,combined with the static dehydration effect of the emulsion,the acting mechanism of the polymer/surfactant binary flooding on the stability of the oil-water production fluid is analyzed.The water phase containing polymer and surfactant and simulated oil is used to formulate a simulated oil production fluid to test the effects of different polymer and surfactant concentrations on the interfacial tension.The interfacial tension results show that the polymer/surfactant binary flooding components can significantly increase the stability of oil-water emulsions,but there is a great difference in the interfacial activity between the polymer and the surfactant.The main factors affecting the interfacial shear viscosity are polymers.The static dehydration experiment shows that the main factor affecting the stability of oil-water emulsion is the surfactant.This contradicts the previous view that the interfacial shear viscosity is the key to affecting the stability of the emulsion.Therefore,this study reveals that there are other factors that affect the stability of the emulsion.