油套管特殊螺纹接头上扣扭矩理论分析

油套管特殊螺纹接头上扣扭矩及其构成对于提高接头结构完整性和密封完整性至关重要。在分析典型上扣
扭矩曲线基础上，采用弹性力学厚壁圆筒理论和旋转台肩扭矩公式，建立了特殊螺纹接头上扣扭矩理论计算方法，研
究了不同过盈量和螺纹脂摩擦系数对接头总上扣扭矩及其构成的影响规律。结果表明：过盈量和螺纹脂摩擦系数越
大，总上扣扭矩越大；螺纹径向过盈量、密封面径向过盈量、螺纹脂摩擦系数越小，台肩面轴向过盈量越大，作用到台
肩面扭矩与总扭矩比值越大。总体上，台肩扭矩比值主要受螺纹径向过盈量和台肩轴向过盈量控制，而螺纹脂摩擦系
数主要影响总上扣扭矩。建议加强优化公差配合、提高接头加工精度、严格控制上扣圈数并注重优选螺纹脂。研究结
果对于确定特殊螺纹接头合理上扣扭矩以及强度计算提供了理论依据。

Theoretical Analysis on Makeup Torque in Tubing and Casing Premium Threaded Connections

The makeup torque and its composition of premium threaded connections are of great importance for improving
mechanical and sealing integrity of tubing and casing. On the basis of analysis on typical makeup torque vs. turns curve，
the theoretical calculation method of makeup torque for premium threaded connections has been established with the elasticity
mechanics theory of thick-wall cylinder and rotary shoulder torque formula. The influences of different interferences and
thread compound friction coefficient on the total torque and the ratio of torque acting on shoulder to total torque has also
been investigated and the results show that the larger the interferences and thread compound friction coefficient，the higher the
total makeup torque. The smaller the thread tooth radial interference，sealing surface radial interference and thread compound
friction coefficient or the larger of the shoulder axial interference，the higher the ratio of torque acting on shoulder to total
torque. Generally，the ratio is mainly influenced by thread tooth radial interference and shoulder axial interference，while the
thread compound friction coefficient mainly affects the total torque. We suggest that enhancement of tolerance matching be
optimized，processing precision be improved，makeup turns be strictly controlled and attention to thread compound optimized
should be carried out. The study results provide theoretical basis for determining reasonable makeup torque of premium threaded
connections and calculating its strength.