海上某油田井口输送管线发生局部泄漏, 泄漏部位集中在焊缝附近。对选取的典型管段样品进行宏观分析、材质理化检验、腐蚀产物X射线衍射分析、金相分析和能谱分析, 并对焊缝沟槽腐蚀敏感性进行了评价试验。结果表明, 湿环境下的CO2腐蚀破坏是该井口管线泄漏的原因, 而导致直管和弯管焊接处优先发生泄漏的主要原因是焊缝处具有较高的沟槽腐蚀敏感性。

An offshore oilfield wellhead crude oil pipeline system leaked locally, and the leaking locations were near the welds of the pipelines. A typical sample was taken from the leaked pipes and the sample was analyzed by means of macro examination, tests of chemical and mechnical properties, X-ray diffraction(XRD), microstructure examination, energy-dispersive spectroscopy(EDS) and assessment of grooving corrosion to find out the corrosion and leakage reason. The results show that the reason of the pipeline corrosion was wet CO2 corrosion, and the grooving corrosion promoted and accelerated the whole corrosion process. Some protective measures were proposed according to the corrosion analysis results.