110 ksi钢级连续油管刺漏失效分析

为了探寻连续油管刺漏失效的原因，以某油田110 ksi钢级Φ50.8 mm×5.2 mm连续油管刺漏样品为研究对象，进行了微观组织分析、化学成分分析、力学性能试验、金相检验和断口分析。结果显示，失效连续油管的化学成分、拉伸性能、硬度检验结果等均符合API SPEC 5ST的要求，夹杂物等级较低，金相组织为铁素体+珠光体+粒状贝氏，组织均匀，无异常。分析指出，刺漏失效是连续油管在使用过程中，机械损伤和疲劳循环载荷共同作用的结果；油田现场应加强作业过程的管理和监控，避免因操作不当造成连续油管损伤，是防止连续油管失效，提高连续油管使用寿命的关键。

Failure Analysis of 110 ksi Coiled Tubing Leakage

In order to explore the causes of the failure of the coiled tubing leakage, taking coiled tubing leakage samples with 110 ksi grade steel Φ50.8 mm×5.2 mm in certain oilfield as the research object, the microstructure, chemical composition analysis, mechanical property test, metallographic examination and fracture analysis have been carried on it. The results showed that the chemical composition, tensile properties and hardness test results of the failed coiled tubing all met the requirements of API SPEC 5ST. The inclusion level was low. The microstructure was ferritic+pearlitic+granular bainite. Leakage failure is the result of the mechanical damage and fatigue cyclic loading of the coiled tubing. It is the key to prevent the coiled tubing failure and improve the service life of the coiled tubing that the management and monitoring of the operation process should be strengthened to avoid the coiled tubing damage caused by the improper operation.