三元复合驱碱/表面活性剂/聚合物模拟原油乳状液稳定动力学特性

Stability Dynamic Characteristics of Alkali/surfactant/polymer Flooding Crude Oil Emulsion

基于两相分离的乳状液稳定模型,研究了三元复合驱模拟原油乳状液稳定动力学特性;通过液膜强度和油水界面张力探讨了碱/表面活性剂/聚合物对模拟原油乳状液稳定动力学特性的影响机理。结果表明,乳状液稳定模型可以很好的评价乳状液的稳定性,并得到乳状液的稳定动力学特性;碱浓度小于900 mg/L有利于乳状液的稳定,碱浓度大于900 mg/L不利于乳状液的稳定;表面活性剂和聚合物浓度的增加使得形成的模拟原油乳状液更加稳定;模拟原油乳状液的稳定作用主要是通过碱、表面活性剂降低油水界面张力并增加油水界面膜强度,聚合物通过提高界面膜强度实现的,三者存在协同效应。

Stability dynamic characteristics of alkali/surfactant/polymer（ASP） flooding crude oil emulsion was studied using emulsion stability model based on two-phase separation.Effect of alkali/surfactant/polymer on dynamic characteristics of ASP flooding crude oil emulsion was also studied by analyzing oil film strength qualitatively and measuring oil-water interfacial tension.The results showed that Civan model was suitable to evaluate the stability of ASP flooding crude oil emulsion and thus the stability dynamic characteristics were obtained.The crude oil emulsions became more stable with the increase of alkali concentration firstly at low alkali concentration（900 mg/L） and then less stable with the increasing alkali concentration at high alkali concentration（900 mg/L）.The stabilities of crude oil emulsions were improved with the increase of the concentrations of surfactant and polymer.The stability mechanism of ASP flooding W/O emulsion could be ascribed to the decrease of oil-water interfacial tensions when alkali and surfactant were used and increase of the oil-water interfacial strength when the polymer was added to the system.Therefore alkali,surfactant and polymer have synergistic effect.