桩11-8井外输管线腐蚀与防护

Corrosion of Delivery Pipeline of Zhuang-8 Oil Well and Prevention

利用材质分析、金相检验、腐蚀速率测试等手段对中国石化胜利油田有限公司桩西采油厂桩11-8井外输管线样品进行了测试分析,最终确定腐蚀原因为:该管线输送介质腐蚀性极强,20钢不适用于输送该介质,且1号管线存在的D3e级大块非金属夹杂物为引起1号管线局部腐蚀穿孔的主要原因。治理措施为:对该环境下的新建管线应采取适宜的内防腐蚀技术,推荐采用表面处理技术或添加缓蚀剂;对于目前已投入运行、尚未出现穿孔的管线,应采用非开挖内涂衬技术,以提高管线运行可靠性。

The samples of delivery lines of Zhuang - 8 oil well in Zhuangxi Oil Production Plant of Shengli Oil Field was tested and analyzed by material analysis, metallographic analysis and corrosion rate testing, and the corrosion causes were found out. They are ： the media transported by the pipeline is very corrosive. Whereas, the selected 20# steel is not a proper material for this media. The presence of D3e level big piece of non - metallic inclusions is the major culprit for the corrosion failure of 1# line. Corrosion control measures are recommended such as provision of internal corrosion protection for the new pipelines for this environment, application of surface treatment technique and addition of corrosion inhibitor and application of non - excavated internal coating technology for the existing operating pipelines which have not experienced corrosion failures so as to improve pipeline operation stability.