聚合物/两性表面活性剂二元体系提高水驱后残余油采收率研究

STUDY ON ENHANCING RECOVERY RATIO OF RESIDUAL OIL BY USING POLYMER/AMPHOTERIC SURFACTANT COMPOUND SYSTEM AFTER WATER FLOODING

针对三元复合驱中的碱大幅度降低聚合物溶液的黏弹性,降低波及效率和驱油效率,含碱驱油体系引起地层黏土分散和运移、形成碱垢、导致地层渗透率下降等问题,利用不加碱可形成超低界面张力的聚丙烯酰胺/两性表面活性剂二元复合体系,通过人造岩心驱油实验,研究了聚表二元复合体系提高水驱后残余油采收率的可能性。研究表明,聚表二元复合体系在驱替水驱后残余油中,可以同时发挥活性剂的超低界面张力特性和聚合物溶液的粘弹特性,使得该二元体系的采收率高于单一的表面活性剂体系和聚合物驱油体系,并且二元体系的聚合物浓度越高,采收率越高。

The questions that clay is dispersed and migrated, alkali incrustation is formed, permeability is reduced can be resulted from the displacement liquid with alkali in ASP compound flooding. At the same time, alkali can reduce viscoelasticity of polymer solution to make sweep efficiency reduction. So the binary compound displacement liquid with no alkali is considered and used for enhancing recovery. Using no alkali polymer/amphoteric surfactant compound liquid which can form an ultralow interfacial tension, the displacement effect of polymer/amphoteric surfactant compound system on residual oil after water flooding are studied through the oil displacement experiment of artificial core. The investigation results indicate that visco elastic behavior of polymer and ultra-low interfacial tension characteristic of surfactant can be utilized fully in polymer/amphoteric surfactant flooding, the recovery ratio of polymer/surfactant compound system flooding is higher than that of any one of surfactant or polymer flooding,and if the concentration of polymer solution is higher in binary compound system, the recovery rate is higher.