Structure Optimization And Performance Simulation Of Screw Pump Well Centralizer

In the later period of development of extra-high water cut in oil field,various new production problems emerge constantly,among which partial wear of rod pipe in rod pump well is particularly prominent.Sucker rod centralizer,as a means of preventing eccentric wear,has played a positive role in solving the problem of eccentric wear of rod and tube.However,in the actual application of centralizer,due to the influence of oil well type,well condition,structure and material of centralizer and other factors,the partial wear phenomenon in some Wells is serious,and there are still pipe break,pipe crack,pipe release and rod break,etc.,which cannot achieve the expected effect.Therefore,a new universal centralizer for pumping well and screw pump well was developed on the basis of the shortage of rod centralizer found in the previous investigation.The research content mainly includes the following aspects:The hydraulic and mechanical characteristics of the new type centralizer were simulated based on ANSYS Workbench platform.The changing law of flow velocity and pressure in the centralizer basin is defined.The order of influence of resistance and environmental factors is determined,and the distribution law of stress and displacement in the centralizer basin is revealed.The sensitivity of the structural Parameters of the centralizer to its hydraulic and mechanical characteristics is studied.Based on ANSYS Workbench platform,the hydraulic and mechanical characteristics of rod diameter respectively ?22 mm,?25 mm,?28 mm three kinds of centralizers in screw pump well are optimized.Based on the above analysis,the optimal structural parameters are obtained,which provides a theoretical basis for improving the structure of the centralizer.At the same time,the orthogonal experiment method was used to optimize the centralizer material,and the optimal formula of different proportions of carbon fiber and glass fiber was studied.The mechanical properties,hydraulic properties,alkali resistance,acid resistance,oil invasion resistance and other properties of the new material were verified.The mechanical model and mathematical model of the motion law of the buttress inscrew pump well were established,and the motion law of the buttress in the oil well was simulated.The reasonable value range of rectifying guiding Angle is determined,and the formulae for calculating the driving torque and resistance torque of centralizing body in screw pump well are determined.Based on the theory of energy wear,a mathematical model of the wear law of screw pump well centralizer and bushing is established to predict the wear life of centralizer,which provides technical support for further improving the structure of centralizer.