Research Article
Study on Distribution Characteristics and Displacement Mechanism of Microscopic Residual Oil in Heterogeneous Low Permeability Reservoirs
Figure 4
Distribution of residual oil under polymer surfactant flooding with a permeability ratio of 1 (① cluster, ② oil drop, ③ oil film, and ④ columnar; the red part represents oil; the injection direction of the displacement agents is from right to left).