钠蒙脱土颗粒对聚驱采油污水乳化稳定性的影响

通过室内实验方法研究了钠蒙脱土颗粒对聚驱采油污水油水分离性能和油水界面性质的影响。采用界面张力仪和Zeta电位仪研究了钠蒙脱土颗粒对聚驱采油污水中油滴Zeta电位、油水界面张力和界面扩张黏弹模量的影响。在光学显微镜下,观察钠蒙脱土颗粒在油滴表面的吸附状态。结果表明,当钠蒙脱土颗粒质量浓度低于200mg／L时,随其质量浓度增大、Zeta电位下降,、界面张力降低、黏弹模量提高,采油污水中出现稳定液滴型(oil-mineral aggregate,OMA)结构,此时钠蒙脱土颗粒对聚驱采油污水稳定性影响比较显著, 采油污水处于比较稳定的阶段。当其质量浓度大于250mg／L后,Zeta电位基本不再下降,而界面张力略有提高,黏弹模量也有增大,颗粒油滴形成大的聚集体结构,油滴更容易发生聚并,聚驱采油污水稳定性变差,从而更易于处理。

Effects of Na-montmorillonite particles on emulsification stability of polymer flooding produced water

The effects of Na montmorillonite(Na-Mt)particles on the oil-water interfacial properties and oil-water separation of polymer flooding produced water were experimentally investigated. By using an interfacial rheometer and Zeta potentiometer to analyze the influences of Na-Mt particles on Zeta potential, interfacial tension and dilational viscoelasticity of polymer flooding produced water, and the adsorption of the Na-Mt particles on oil droplets was observed under optical microscopy. The result showed that with the Na-Mt particles concentration increasing, and when the Na-Mt particle concentration was less than 200mg／L, the Na-Mt particles could cause the Zeta potential of oil droplets to rapidly decrease, interfacial tension to decline and dilational viscoelasticity to be enhanced. The results also showed that a stable oil-mineral aggregate(OMA) structure appeared in polymer flooding produced water, which had noticeable effects on emulsification stability of polymer flooding produced water. The polymer flooding produced water was stable in this stage. When Na-Mt particle concentration was higher than 250mg／L, the Zeta potential of oil droplets keeps stable, while interfacial tension and dilational viscoelasticity showed a slight increase. The system formed a large oil-mineral aggregate structure, which was apt to aggregate, and could enhance the treatment of polymer flooding produced water.