Research on enhanced oil recovery effect standard of polymer flooding classified well group based on EnKF

Due to the different sedimentary environment, development and oil generation conditions of thetarget reservoirs of polymer flooding, the reservoir physical parameters of polymer flooding blocks are quitedifferent, there is a large difference in the extent of enhanced oil recovery between different polymerflooding well groups, and it is difficult to track development and adjust evaluation. In order to formulateadjustment standards for polymer flooding phases, it is necessary to formulate phase recovery rate standardcurves for different types of polymer flooding well groups. This paper analyzes the dynamic and static dataof the polymer flooding block to determine the sensitivity of each factor that affects the well groupclassification, and establishes the well group classification method using the gray correlation method andmathematical statistical analysis method; on this basis, the EnKF method is used to invert different wellgroups. Through the combination of EnKF method and polymer flooding numerical simulation technology,the physical parameters of flooding and the relative permeability curve are used to predict the developmenteffect of different types of polymer flooding well groups, and the development effect standards of differenttypes of polymer flooding well groups are given.