Research On Erosion In The Electric Submersible Pump Impeller

Single well injection-production technology contributes to the development of low permeability small block oilfield,could reduce production costs greatly and shorten the construction period. At the same of single well injection-production technology being widely used,low concentration of fine sand usually leads to electric submersible pump impeller erosion,reduces its working performance,influences the normal production of oil field.Based on the flow characteristic of solid-liquid two-phase flow with water in impeller,the calculation of the water in the Euler coordinates,the calculation of sand in the Lagrangian coordinate system,considering the coupling effect of turbulence sand and grit on the water,the paper builds mathematical models of solid-liquid two-phase flow with water in ESP impeller.The paper has studied the erosion rule of the ESP impellers' materials D-3 nickel-iron.Experimental study erosion at different impact velocities,the paper got the erosion rate of the material under different conditions. According to the experimental data of some empirical constants of the original classical theory was modified,this paper established a erosion model suitable for submersible electric pump flow components.Using the established model of solid-liquid two-phase flow and erosion model,the paper studied the rule of erosion and flow in the ESP impeller by numerical simulation.Erosion analyses has been conducted by the conreast of the erosion rate in different particle sizes,different flow,different particulate mass flow rate.Research report analyzed the main parts of the erosion patterns and erosion occurred,investigated the causes of erosion generated.It could provide a theoretical basis for the improvement of the impeller.Correctness of numerical simulation methods have been verified by CMM and test methods.CMM is used to measure the actual erosion surface morphology.Its results are used to compare with the numerical simulation's.Acquired erosion area in numerical simulation substantially coincides with sctual working conditions. In order to simulate the erosion of high erosion rate point in impeller,the erosion test has been accomplished in different conditions.Also,the comparison between test data and numerical simulation data has been completed. Finally,it verificates the numerical simulation method has a correct and feasible.According to the numerical simulation results,the paper improved the geometric parameters of impeller,analysized its erosion resistance and hydraulic performance in the same method. The results show that the improvement make erosion reduce significantly and hydraulic performance reduce inconspicuous.In response to the erosion area obtained in numerical simulation,we use surface treatments for protection on the erosion area.According to the characteristics of particles,we selected the appropriate water treatment equipment.The structure of single well injection-production process pipe column was improved.The research provided effective methods to predict the flow and erosion and solid-liquid two-phase flow character of ESP impeller,was able to provide enough theoretical basis to improve the ESP impeller.According to erosion rules and characteristics,the protection scheme was proposed,can provide guidance for prolonging the service life of equipment, lowering production cost. The thechnical guarantee could be supplied for the development of scattered block oilfield.