特殊扣石油套管接头上扣扭矩计算方法

Calculation Method of Make-up Torque on Premium Threaded Casing Connection

研究了特殊扣石油套管接头上扣扭矩的构成,利用厚壁圆筒理论,推导了特殊扣石油套管接头上扣扭矩的计算方法,确定了螺纹牙径向过盈量,分析了螺纹脂摩擦因子对上扣扭矩的影响。结果表明,在螺纹过盈量一定的情况下,所用螺纹脂的摩擦因子越大,螺纹牙径向过盈扭矩所占总扭矩的比值越大,并逐渐趋于一定值。在进行特殊扣接头加工时,应优化公差配合,优先保证密封结构的加工精度和表面粗糙度,并注重螺纹脂的选择。利用本文给出的计算方法,可以较好地估算特殊扣接头的上扣扭矩。

The composition of the make-up torque on the premium threaded casing connection was studied,and a calculation method based on the thick-wall cylinder theory was established.The radial interference of the screw thread was determined and the effect of the friction coefficient of screw thread on the torque of the upper button was analyzed.The results show that in the case of a certain interference fit,the greater the friction coefficient of the screw thread fat,the greater the ratio of radial interference torque to the total one,and the ratio gradually tends to a certain value.In the process of premium threaded casing connection,the tolerance and fit should be optimized,priority given to ensure the machining accuracy and surface roughness of the sealing structure,and attention payed to the choice of thread compound.By using the calculation method given in this paper,the make-up torque on premium threaded casing connection can be estimated better.