锥度设计对套管特殊螺纹接头密封性能影响

Effect by Taper Design on Sealing Performance of Casing Premium Connection

为进一步研究锥度设计对套管特殊螺纹接头密封性能的影响,利用ABAQUS有限元分析软件对不同锥度设计的套管特殊螺纹接头进行了上扣、拉伸、压缩条件下密封接触压力及接触长度的数值模拟。结果表明:内螺纹收尾处平切处理可有效提高密封面的接触压力和接触长度,扩大螺纹锥度的取值范围,但会减少全顶螺纹数量,平切深度越大,全顶螺纹数量越少,设计平切深度值时应全面考虑,避免影响接头连接强度;设计退刀槽可增加密封面接触压力和长度,但需注意其结构设计,避免造成配合螺纹的划伤或粘扣。

In order to further study the influence of taper design on the sealing performance of the special thread joint of casing,ABAQUS finite element analysis software is used to simulate the sealing contact pressure and the contact length of the special thread joint of casing with different taper designs under the conditions of screwing on,stretching and compressing.The results show that the flat cutting at the end of the internal thread can effectively improve the contact pressure and contact length of the sealing surface,enlarge the value range of the thread taper,but reduce the number of full top threads.The larger the flat cutting depth is,the less the number of full top threads is.The design of the flat cutting depth should be fully considered to avoid affecting the joint connection strength.The design of the undercut can increase the contact pressure and length of the sealing surface,but it is necessary to avoid the scratch or sticking of the mating thread.