弱碱替代强碱的三元复合驱研究

Research of weak-alkali alkali-surfactant-polymer flooding

通过实验对比了不同碳链长度表面活性剂和混合碳链表面活性剂(NS)的界面张力,优选出NS表面活性剂。研究了NS表面活性剂在弱碱条件下的界面张力,从而确定了弱碱三元复合体系中,弱碱和表面活性剂的浓度。参照强碱三元复合驱室内驱油模拟实验,进行了弱碱三元体系驱油模拟实验。讨论了弱碱(NaHCO3)条件下,不同浓度NS表面活性剂对驱油效果的影响。最后,得出一种弱碱三元复合驱油体系配方。

The interfacial tension of different carbon chain length of non-ionic surfactant was compared with that of mixed carbon chain of non-ionic surfactant（NS） by experiment, and the NS surfactant was to be chosen. The interfacial tension of the NS surfactant under the condition of weak alkali had been studied. Thus the concentration of alkali and surfactant in weak-alkali alkali-surfactnat-polymer （ASP） flooding has been determined. Referring to the parameters of the ASP flooding in the laboratory, relative molecular weight of polymer solution, chemistry plugs and injection rate have been determined in the oil displacement experiments. The influence of different concentration NS surfactant on displacement efficiency have been discussed under the condition of weak alkali （NaHCO3）. Finally the formulation of weak-alkali ASP flooding have been determined.