聚合物表面活性剂溶液微观驱油特征*

为从微观研究聚合物表面活性剂(简称聚表剂)的驱油机理和驱油效果,采用微观刻蚀仿真模型进行微观可视化驱油实验,并与岩心驱替实验驱油效果对比。结果表明,在微观驱油实验中,水驱后微观模型中产生6种类型残余油,而聚表剂驱后对盲端残余油的驱替效果不明显;聚表剂的驱油机理主要是通过其增黏作用、黏弹性作用和乳化作用来扩大波及体积,降低渗流阻力",拉""、拽"残余油,将大油滴乳化分散成小油滴,从而将残余油有效驱出;不同浓度的聚表剂在微观模型和岩心驱替实验中的驱油效果基本相符,聚表剂浓度越大,残余油启动能力越高,驱油效果越好。聚表剂质量浓度为2000 mg/L时的驱油效果最好,采收率增幅为19.69%。图27表1参15。

Microscopic Oil Displacement Characteristics of Polymeric Surfactant Solution

In order to microscopic study mechanism and oil recovery efficiency of oil displacement of polymeric surfactant,the micro-etching simulation model was used to carry out the oil displacement experiment,and the result was compared with that of core flooding experiment.The results showed that in the microscopic oil displacement experiment,six types of residual oil were produced in the model after water flooding.Flooding effect was not obvious that polymeric surfactant displaced residual oil at blind end.The mechanism of oil displacement of polymeric surfactant was viscosity-increasing effect,viscoelastic effect and emulsification,which could expand swept volume,reduce percolating resistance,and pull and squeeze residual oil to emulsify large oil droplets into small oil droplets,respectively.Therefore,the residual oil was effectively displaced.Comparing the microscopic model with the core flooding experiment,the oil recovery efficiency was basically consistent.When the concentration of polymeric surfactant was higher,the ability of displacing residual oil was stronger and the oil recovery was better.When the concentration of polymeric surfactant was 2000 mg/L,the oil recovery efficiency was the best and the enhanced oil recovery was 19.69%.