聚合物驱前后储层含油性与渗透性变化特征试验研究

注入聚合物溶液后,储层的含油性和渗透性将发生相应的变化。通过聚合物驱岩心试验,对比分析了注聚合物前后岩心的束缚水饱和度、残余油饱和度、绝对渗透率和相对渗透率的变化特征。试验结果表明,和注聚合物前相比,注聚合物后岩心的束缚水饱和度增大,残余油饱和度明显减小,而岩心的绝对渗透率变化不大,聚合物/油体系的相对渗透率曲线除具有水湿岩心相渗曲线的典型特征外,其水相的相渗曲线及其端点值明显低于常规油/水体系的相渗曲线,而且降低幅度随束缚水饱和度增大而增大,但其油相相渗曲线与常规油/水体系的油相相渗曲线的差距很小。

Experimental Study on the Characteristics of Reservoir Oil Saturation and Permeability Changes Both before and after Polymer Flooding

After polymer flooding, corresponding changes will be taken place in reservoir saturation and permeability. Through core test of polymer displacement, the irreducible water saturation, remaining oil saturation and the characteristics of changes of absolute permeability, and relative permeability of cores are contrasted and analyzed both before and after the polymer flooding. Test results indicate that compared with the situation before polymer flooding, after polymer flooding, the irreducible water saturation of cores increases, remaining oil saturation decreases obviously, while the absolute core permeability remains unchanged. Relative permeability curve of oil/polymer solution system has the characteristics of water phase relative permeability and end point is noticeably lower than that of conventional oil/water relative permeability besides having all the typical features of water wetted relative permeability curve, and its decrease degree increases with irreducible water saturation, whereas oil phase relative permeability curve has slight change compared with oil-phase relative permeability curve in conventional oil/water system relative permeability curve.