Abstract:Through the microscopic simulation of etching model, combined with the pore structure of Henan oilfield,surfactant flooding, polymer flooding and polymer / surfactant flooding,were made basing on water flooding. The remaining oil after the water flooding are classified into five major categories, which are called the blind end, membranous, adsorption, cluster (column), shaped island.Analyze the starting mechanism of five patterns of remaining oil each displacement solution. At the same time, quantize the displacement efficiency of three kinds of chemical systems on different types of remaining oil in the model. The experimental results show that, the blind end of remaining oil is suitable for high viscosity polymer system, and different interfacial tension systems have a different effect on different shapes of blind end;isolated remaining oil is suitable for high viscosity,interfacial tension had little effect on this type of remaining oil; adsorption type is suitable for the polymer system, which of viscosity is between 10mPa.s to 20mPa.s, and reducing the interfacial tension is favorable toward starting this type of residual oil, but in the process of starting other types of remaining oil,this type will mostly be formed;residual oil film can be very fine started by low viscosity polymer system, suitable for the interfacial tension between 10-1~10-2; since the chemical flooding has started the residual oil,in the process of migration of the following oil, clusters of oil is easy to be formed in some small pores,and its content in the remaining oil accounts for the high degree of saturation.