Φ38.1 mm ST90连续油管断裂原因分析
Fracture Analysis of Φ38.1 mm ST90 Coiled Tubing

针对连续油管在泰国海上油田用于钻磨(Milling)时发生断裂问题，采用扫描电镜、直读光谱仪和各项力学性能测试设备等，对失效的连续油管的成分及力学性能进行分析。结果表明：失效的主要原因是油管壁厚整体减薄、外表面多处损伤导致断口位置壁厚严重减薄和局部弯曲变形，最终引起断裂发生。
In view of the fracture of coiled tubing when it is used in milling, which is in offshore oil field, the composition and mechanical properties of the failed coiled tubing are analyzed by using a scanning electron microscope, direct reading spectrometer and various mechanical property testing equip-ment. The results show that the main causes of the failure are the overall thinning of the wall thick-ness of the tubing, the multiple damages of the outer surface, the serious thinning of the wall thick-ness at the fracture position and the local bending deformation, which finally lead to the fracture.