某井N80-Q油管粘扣及脱扣的分析

对Φ73.02 mm×5.51 mm N80-Q外加厚油管发生的粘扣及脱扣事故进行了现场调查,对粘扣及脱扣样品进行宏观分析;对该批油管螺纹接头加工质量进行了全面检测;对油管材质进行了理化检验；对油管上、卸扣性能和拉伸性能进行了系统试验.分析认为,油管螺纹加工质量和材质符合标准要求,粘扣是由不符合规范的操作所引起的,脱扣...

Analysis of Causes for Thread Galling and Jump-out of N80-Q Tubings as Used in a Certain Oil Well

An on-the-site investigation is made into the failures of the thread galling and jump-out of the Φ73.02 mm×5.51 mm N80-Q externally-upset tubings as used in a certain oil well,while visual analysis of the samples taken from the faulty pipes is also conducted. An all-round inspection is made to the processing quality of the thread connections of the said tubings,and relevant physical-chemical tests of the tubings’ material are performed,too. Moreover,systematic tests are carried out to the make & break performance and the tensile property of the tubings. Base on the results of the above mentioned analysis and tests,it is identified that the galling fault is caused by maloperation,and the jump-out fault is resulted in by reduction of the connection strength as following the galling,which has nothing to do with the thread processing quality and material of the tubings that are in compliance with applicable standard requirements.