钻铤内螺纹接头断裂原因分析  

Fracture Analysis of Internal Screw Joint of Drill Collar

作　　者：赵江[1] 赵映辉[1] 张凤娟[2] 李平全[1] 佟琳[1] 薛燕[1] 

机构地区：[1]西安摩尔石油工程实验室,西安710065 [2]西安应用光学研究所,西安710065

出　　处：《失效分析与预防》2011年第3期160-163,共4页Failure Analysis and Prevention

摘　　要：采用宏观观察、金相检查、SEM形貌观察、EDS能谱分析等方法,对钻铤内螺纹接头断口及其断口附近螺纹根部的小裂纹进行分析,结果表明:该钻铤主要是由于上扣扭矩过大或在钻井过程中发生二次上扣,从而导致钻铤内螺纹接头在螺纹根部萌生疲劳裂纹;该钻铤接头材料的抗拉强度偏低、硬度值偏低、弯曲强度比BSR值偏低、钻井液中O含量较高等因素加速了钻铤内螺纹接头发生疲劳失效;通过采取一些改进措施,有效预防了钻铤的断裂失效。The internal screw of drill collar for oil fractured during serving.In order to find out the failure mode and cause,macro and micro observation,microstructure examination and EDS analysis were carried out.The results show that the fracture mode of the joint is fatigue fracture.Because of the greater fitting torque,fatigue crack initiated at the bottom of the screw.The lower tensile strength,hardness,flexural strength ratio as well as the high O content in the drilling fluid promoted the fatigue failure of the joint.Certain measures can be taken to prevent the failure of the drill collar.

关 键 词：钻铤 内螺纹接头 疲劳失效 弯曲强度比 上扣扭矩 

分 类 号：TH131.3[机械工程—机械制造及自动化]