乙醇胺提高延长稠油油藏聚/表二元驱采收率研究

针对延长稠油油藏的水驱后含水率上升的问题,通过室内实验方法,在原有聚表二元驱的基础上,研究一种适用于延长油田的有机碱,优选三元复合体系的配方;并通过物理流动驱油实验对三种化学驱油体系的驱油性能进行了分析和评价。结果表明:油藏的原油酸值为1.95 mg/g,适合进行三元复合驱的研究;筛选出的有机碱是乙醇胺,其能有效减低油水界面张力并对复合体系的黏度几乎没有影响,试验优化的三元复合体系的配方是:1 500 mg/L聚合物2 000 mg/L表面活性剂+3 500 mg/L乙醇胺。驱油实验表明:在均质岩心和三层非均质岩心模型中,与聚合物驱和聚表二元驱相比,三元复合驱都能提高原油的采收率,其中模拟油藏条件的三层非均质岩心条件下,采收率增值达13.38%,达到了控水增油的目的。

The study of organic alkali enhancing polymer / surfactant flooding oil recovery in Heavy oil recovery

For the problem of treating high water-cut of yanchang heavy oil reservoir after water flooding, a suited organic alkalis was selected on the basic of polymer- surfactant flooding. The recipe of ASP system was optimized by the tests of reducing oil water interfacial tension. By physical flow oil-displacement experiments, the oil displacing capacity of three chemical flooding was analyzed and evaluated. The result shows that the acid-value of yanchang was 1.95mg/g and the reservoir was fit to ASP flooding. The selected organic alkalis was ethanol amine which could decrease the oil water interfacial tension and had little effect to the viscosity of compound. The tested recipe was 3500mg/L ethanol amine +1500mg/L polymer 2000mg/L surfactant. The results of oil displacement experiment shows that the ASP flooding could enhance oil recovery efficiency more than P and SP flooding in the homogeneous and three layer heterogeneity models. The value of EOR was13.38% in the three layer heterogeneity model to aim to control water and improve production.