The distribution characteristics of additional extracted oil displaced by surfactant-polymer flooding and its genetic mechanisms

Some characterization parameters were defined, including area of the sub-region, degree of the circularity and position of the centroid. Some sensitivity studies were conducted to find out the influence of surfactant and polymer concentration on the distribution characteristics of AEO and IFP. The results showed that the increased extent of PS region area reduced and the cross flow phenomenon caused by low interfacial tension of surfactant became serious when surfactant concentration was higher than 0.45%. Within a certain range, the areas of three sub-regions all increased as the polymer concentration increased. However, when the polymer concentration increased from 2000 mg/L to 2500 mg/L, the effect of increasing IFP and improving sweep efficiency was significantly decreased. Moreover, the increased extent of PS region area also reduced.