With the increasing of drilling depth in China and the increasing of low producing zones in wells,it is more difficult to extract oil in wells.Although the existing deep well jet pump can use high pressure fluid (manually pressurized into the well from the surface) to lift the oil,the production cost of this method is high,and when the lifted oil is mixed with fine sand particles,the sand particles in the oil can make a certain impact on the jet pump.In order to reduce the degree of erosion and wear of jet pump,improve the efficiency of oil production and reduce the cost of production,a jet pump was designed according to the characteristics of oilfield layers (high and low pressure oil layers).The jet pump can realize the exploitation of low pressure oil layers by transforming the existing contradictions between layers and using high pressure oil as the power fluid.Through the analysis of the overall structure of the jet pump,it is found that there is a 90° curved flow channel in the jet pump.The inner wall of the flow channel is the opposite to the incoming flow wall at the inlet of the suction liquid,and the erosion and wear from the sand particles are larger.In order to obtain the erosion wear degree and influencing factors of sand on the wall surface,CFD and DPM models were used to accurately simulate the erosion process.After verifying the mesh independence of the simulation model and the convergence of simulation results by changing the mesh size,control variable method and numerical simulation were used to analyze the influence of fluid velocity and sand diameter on the erosion of the passage.Finally,it is found that the maximum erosion rate and the maximum erosion thickness increase more obviously when the flow rate is greater than 4 m/s or the sand diameter is greater than 0.7 mm.As far as the erosion area is concerned,the erosion wear area formed on the flow passage is elliptic,and the erosion wear in the center of the erosion area is relatively less,and the size of the area does not change greatly with the change of fluid velocity and other influencing factors.