Drill pipe joints on stress distribution analysis, is used to improve the performance of key drill

Drill pipe is used for power transmission, conveying the main tool for drilling, oilfield drill pipe failure accidents often to bring huge economic losses. Statistical analysis showed that 65% of the drill string failure drill pipe joints in the accident. Drill pipe joints in use will determine the stress distribution pipe  High pressure needle valve  and sealing performance. Therefore, the tool joint distribution of stress analysis is used to improve the performance of key drill. Tool joint drill by the elastic-plastic finite element model of the threaded joints  Instrument valve manifolds  with female buckle buckle male contact surface is a space helical surface and drill pipe joint force is more complex, in addition to passing the turntable torque, but also by tension (mainly caused by the weight drill pipe), the pressure (mainly caused by the drilling fluid) and so the load effect. Stress Analysis of drill pipe joints involving material  Valve manifolds , geometric nonlinearity and complexity of the contact friction conditions and other nonlinear problems, the establishment of a complete and accurate mathematical model, seeking analytical solution is very difficult.