异锥度气密特殊螺纹油管接头密封特性研究

Study on Sealing Characteristics of Air Tight Special Threaded Joint with Different Tapers

基于虚位移原理,建立了异锥度气密特殊螺纹接头(简称接头)的连接控制方程,并建立三维有限元模型,分析其在不同的机紧转矩和井下复杂工况条件下的力学响应特性。结果表明:在常见的工况下,接头的最大应力均小于材料的屈服应力;对于接头的密封结构,其主密封面的密封性能优于次密封面的密封性能;随着机紧转矩的增加,接头密封结构的平均接触压力与机紧转矩呈线性关系;轴向拉力和弯矩对接头密封结构的主、次密封面有不同程度的影响,但当机紧转矩值大于一定值后,其影响力将缓慢减弱并最终趋于稳定。分析结果对于接头的现场应用具有参考意义。

Based on the virtual displacement principle,the connection control equation of a special air-tight threaded joint with the different tapers was established.A three-dimensional finite element model was established to analyze the mechanical response characteristics under different tightening torques and complex downhole conditions.The results show that under common conditions,the maximum stress of joint is less than the yield stress of material.For the joint sealing structure,the sealing performance of the main sealing surface is better than that of the secondary sealing surface.With the increase of tightening torque,the average contact pressure of joint seal structure shows a linear relationship with tightening torque.Axial tension and bending moment have different effects on the primary and secondary sealing surfaces of joint sealing structure,but when the value of mechanical tightening torque is greater than a certain value,its influence will weaken slowly and finally stabilize.The analysis results can be used as reference for field application of joint.