螺杆马达与提速工具失效机理及动力学分析

基于实际作业工况,建立了螺杆马达定转子和复合冲击器提速工具动力学特性的有限元分析模型,对其服役期间的动力学失效机理进行了研究,得到了螺杆马达和提速工具的动力学强度薄弱环节,并对其进行了参数敏感性分析。结果表明:螺杆马达应力集中处位于定子橡胶衬套齿根处,随着定转子装配过盈量和井底温度增加,螺杆马达失效风险增大; 复合冲击器强度薄弱点位于外筒螺纹底部退刀槽和齿根凹键处; 复合冲击器外筒的疲劳损伤主要取决于转矩的变化情况,钻压和转矩的波动都会对复合冲击器凹键处的疲劳损伤产生较大影响。

Failure Mechanism and Dynamics Analysis of Screw Motor and Drilling Speed-Raising Tool

The finite element analysis model of the dynamic characteristics of the screw motor stator and rotor and the drilling speed-raising tool of the composite impact was established based on the actual working conditions. The dynamic failure mechanism of the screw motor and the composite impactor was studied. The dynamic strength weak part of the screw motor and the composite impactor was obtained, and a parameter sensitivity analysis was carried out. The analysis results show that the stress concentration of the screw motor is located at the root of the stator rubber bushing. With the increase of interference of stator rotor and bottom hole temperature, the risk of screw motor failure increases. The weak point of the compound impactor is located at the bottom of the outer cylinder thread and the concave bound of the tooth root. The fatigue damage of the outer cylinder of the composite impactor is mainly determined by the variation of torque, and the fluctuation of weight on bit(WOB)and torque will have a great influence on the fatigue damage of the concave bound of the composite impactor.