Load-carrying Method Of Bearing String To Axial Force And Its Simulation Analysis

Electrical submersible motor driven progressing cavity pumping system is a new technology for rodless oil recovery.It has high mechanical efficiency,small floor space and no rod tube eccentric wear.It is suitable for oil production in inclined shafts,horizontal wells and offshore platforms,playing a unique role in the mining of high waxy,high viscosity heavy oil and high sand and high hydrocarbon chain crude oil.It is called “green” oil exploration equipment and is currently favored in the petroleum engineering field.The submersible screw pump production system has two key performance indicators: service life and downhole depth of the downhole unit.Bearing life is the main constraint factor.The purpose of this paper is to innovate and optimize the original single bearing structure in the submersible screw pump.The series thrust ball bearing group structure is used to replace the original bearing structure to break the limitation of the radial size of the submersible screw pump and achieve the purpose of improving the overall axial bearing capacity of the bearing system.In this paper,the structural and engineering principles,technical and working conditions of the submersible screw pump oil production system are systematically analyzed and the axial force generation factor and the axial force analysis and calculation method of the screw pump rotor feedback to the coupling device(or the reduction gear)during the system operation are determined.Innovative in the bearing structure of the submersible screw pump,using the series bearing group instead of the original single bearing structure.Through the parallel connection of the series structure,each bearing in the bearing string group evenly shares the axial load fed back by the screw pump rotor,In order to improve the total bearing capacity of the bearing and break the limitation of the radial size of the oil well.The modern numerical analysis method is used to simulate the bearing capacity of different cascade thrust ball bearings.The aim is to obtain the equivalent stress,equivalent elastic strain,total displacement and maximum bearing capacity data of thrust ball bearings and to verify the uniform load effect of the series thrust ball bearing group structure on the axial force.Since the thickness of the inner sleeve and the radial dimension of the thrust ball bearing have a reverse constraint relationship under the same radial dimension,the optimal combination of the inner sleevethickness and the thrust ball bearing radial dimension is sought by modern calculation means.The results obtained in the thesis have been put into practical use in the series of submersible screw pump production systems produced by Fuxin Chiyu Petroleum Machinery Co.Ltd.,and achieved very good results.