Fracture Analysis And Optimization Design Of Sucker Rod Coupling In Tahe Oilfield

Rod pump is the main form of mechanical oil production in oil field.The main factors which restricts oil field production is the broken coupling of rod.Especially in Tahe oilfield the problems of the broken coupling of rod are highlighted for the strong corrosiveness and high viscosity and fracture of sucker rod coupling.There are limitations of the application of the existing sucker rod fracture prevention technology in Tahe oilfield.So it is necessary to put forward new technology and equipment to prevent the rod from breaking in order to meet the needs of efficient production in Tahe oilfield.The paper determines the main influence factors which cause he coupling failure of the sucker rod by using of the macroscopic appearance,metallographic analysis,microscopic analysis and mechanical test analysis of the coupling.Based on it,the paper establishes the model of the finite element model of sucker rod and coupling.And also,the paper carries out the numerical simulation analysis of sucker rod coupling with different eccentric wear under different tension and compression loads basing on the experimental test analysis and the feasibility of the research method.The paper conclude that the stress and deformation characteristics of sucker rod coupling under corresponding stress conditions and the failure limits of sucker rod coupling under different eccentric wear are obtained.On the basis of the above research,the paper puts forward a kind of anti stripping and anti eccentric wear device of Tahe oilfield which has the characteristics of anti tripping and anti eccentric wear.Combined with the stress analysis and application Layout of the sucker rod string in the up and down stroke of Tahe oilfield the paper carries out the numerical simulation analysis and experimental test analysis of the designed sucker rod anti stripping and anti eccentric wear device.Combined with the strength test and fatigue test of the structure,the paper determines the reliability of the device.The paper realizes the targets of the partial eccentric wear prevention and torque release,and the feasibility of its function is verified by using of the partial eccentric wear test and torsion test of the device.The paper provides the theoretical basis and scientific basis of the fracture prevention of the sucker rod coupling,and provides assistance for the efficient production of oil wells.