复合驱油体系油水界面张力测试条件优化

Optimization of the Test Conditions of Interfacial Tention for the Complex Flooding System

为了规范行业标准SY/T 5370—2018《表面及界面张力方法》中非牛顿流体油水界面张力的测定,对影响复合驱油体系油水界面张力影响因素如:温度、转速、非牛顿流体浓度及相对分子质量、测试时间以及表面活性剂浓度进行了规范:温度选用目标油藏温度;转速选用使仪器成像清晰的转速,建议使用(5000数6000)r/min;聚合物用量为0.1%,根据目标油藏储层物性选用适当相对分子质量的聚合物,但仲裁或抽检时建议使用1000万数1500万聚合物。界面张力取值选用不同时间下的平衡界面张力,回缩或拉断体系选取重复测试3次拉断前界面张力数据取值。二元体系中表面表面活性剂评价时选用体系为0.2%表面活性剂+0.1%聚合物,三元体系中表面活性剂评价是选用体系为1.2%碱+0.1%表面活性剂+0.15%聚合物和0.6%碱+0.3%表面活性剂+0.15%聚合物。

In order to regulate the test method of interfacial tention for the non-Newtonian fluid in industry standard of the SY/T 5370—2018“Test method for surface tension and interfacial tention”,the influence factors of oil and water interfacial tension in compound flooding such as temperature,rotation speed,concentration of the non-Newtonian fluid and polymer molecular mass,testing time and surfactant concentration were regulated.It was suggested that the interfacial tension between the complex flooding and the crude oil should be measured under the optimal conditions that measurement temperature was the target reservoir temperature,the rotation speed was 5000-6000 r/min,at which the instrument could produce clearly image,and the polymer concentration was 0.1%,the molecular mass of the polymer should be chosen according to the property of the target reservoir,however,it was recommended to apply the polymer with the molecular mass of 10 million to 15 million during arbitration or sampling.The interfacial tension value was determined according to equilibrium interfacial tension at different time,and when retraction or fracture happened during the measurement process,the interfacial tension before retraction or fracture should be measured three times and calculated mean value.When the surfactant was evaluated,the SP flooding system of 0.2%surfactant+0.1%polymer was recommended,meanwhile,the ASP flooding system of 1.2%alkali+0.1%surfactant+0.15%polymer and 0.6%alkali+0.3%surfactant+0.15%polymer were recommended.