某油田侧钻深井油管的刺穿失效原因分析

Analysis on Pierced Failure Causes of Sidetrack Deep Well Tubing in an Oilfield

某油田侧钻深井使用的N80-1 EU油管在服役期间发生刺穿事故。为查明该油管刺穿原因,采用体视显微镜、金相显微镜、扫描电子显微镜、X射线衍射和能谱分析等方法对失效油管进行了分析。结果表明:油管刺穿失效的主要原因是点蚀,CO_2、Cl^-、O_2、S^(2-)和输送介质的内压协同作用加速了油管的刺穿。

N80-1 EU tubing of sidetrack deep well used in an oilfield was pierced in service. In order to find out the reasons, the failure tubing was analyzed by stereomicroscope, optical microscope, scanning electron microscopy, X-ray diffraction and energy dispersive spectrometer. The results show that the main reason for the pierced tubing is pitting corrosion. The synergistic effect of CO2, Cl-, O2, S2 and internal pressure synergistic effect of conveying medium can accelerate the tubing piercing.