In order to solve the problems of serious heterogeneity

breakthrough of injected water along high permeability zone

low recovery percent of reserves and limited EOR capability of water flooding in the middle and low permeability fault-block reservoir of Wang-17 Block in Wangji Oilfield

the EOR technology of chemical flooding has been studied

and polymer and preformed particle gel（PPG） have been evaluated and screened. The slug structure

oil displacement efficiency and diversion rate of heterogeneous oil displacement system formed by compounding have been evaluated by physical simulation technology. And the slug volume and structure have been optimized by numerical simulation technology. It is confirmed that multi-stage heterogeneous profile control and slug polymer flooding can improve the recovery rate in Wang-17 Block by 8.25 percentage points. The field application has achieved initial results. This technology has been used for reference and popularized in the polymer flooding project of B238 Block in Xiaermen Oilfield.