Parameter Optimization Of Polymer Flooding In The Sabei Transitional Zone

At present,polymer flooding is a mature method to improve oil recovery.It has entered the stage of large-scale industrial application.With the development of polymer injection field,the injection of polymer in transition zone is gradually expanding.In the transitional zone of Daqing oil field,the reserves of crude oil are considerable,and the reserves of the Sabei Transitional Zone of the oil field are about 24.6 % of the total reserves.At present,the average rate of water content of oil wells in this area has exceeded 94%,but its recovery is only about 32.17%.Recoverable reserves are still largely unused.Because of the difference between the development of the transitional zone and the nature of the crude oil,it is different from that of the pure oil area.The formation condition of the transition zone block is complex and the heterogeneity is strong.In the transition zone of high viscosity,high wax content and poor reservoir property,it is necessary to optimize and adjust the research and test to improve the efficiency of polymer flooding in the Sabei transitional zone and improve the development effect.Through the determination and component analysis of fluid properties with crude oil and pure oil in Sabei transitional zone,compared with the differences in the nature of the oil of transitional zone and the pure oil of single oil area,the results of the study show that the oil in the transitional belt belongs to the conventional reservoirl crude oil,can be applied to conventional reservoir mining technology.To carry out a series of constant pressure injection flow experiment,qualitative analysis the flow characteristics of polymer injection,microstructure changes of pore,evaluation of different molecular weight and concentration of polymer solution in the cores of different permeability can be injected into the ability to optimize the injection parameters of polymer flooding.This paper analyzes the quantitative relationship of various parameters,and gives the criteria for judging the quality of polymer injection transitional zone.On the basis of the optimization of the parameters,the simulation experiment is carried out to simulate the displacement of oil in a one-dimensional heterogeneous model.The experiments were carried out in the pure oil zone and the transitional zone crude oil respectively,and the effects of different viscosity polymer solution on the enhanced oil recovery of the pure oil zone and transitional zone were studied.It is of great significance for the future development of the polymer flooding technology and the development potential of the transitional zone in order to guide the production practice and maximize oil recovery.