某海洋平台注水立管腐蚀穿孔失效分析

针对某海洋平台注水立管腐蚀穿孔失效问题，通过宏观分析、尺寸测量、材质性能评价、微观分析及腐蚀产物分析等技术手段，并结合该立管实际工况，分析立管穿孔失效原因。结果表明，立管安装造成部分防腐涂层破损，由于立管与护管连接结构所致，使得立管涂层破损部位长期处于海洋大气环境，造成局部腐蚀严重，导致穿孔失效。针对该类管线，建议避免类似立管结构，立管与护管之间环空应与海水或海洋大气隔绝；考虑采用气胀封堵加疏水水泥的防护技术，外部切口处采用补强包覆技术。

Failure Analysis of Corrosion Perforation of Water Injection Riser of an Offshore Platform

In view of the corrosion perforation failure of the water injection riser of the offshore platform, the causes of the perforation failure of the riser are analyzed by means of the macro analysis, size measurement, material performance evaluation, micro analysis and corrosion product analysis, combined with the actual working conditions of the riser. The results show that the installation of the riser results in the damage of some anti-corrosion coating, and the damaged part of the riser coating is in the marine atmospheric environment for a long time due to the connection structure between the riser and the protective pipe, which causes the serious local corrosion, leading to the perforation failure. For this kind of pipeline, it is suggested to avoid the similar riser structure, and the annulus between the riser and the protective pipe should be isolated from the sea water or the marine atmosphere; the protective technology of the air expansion plugging and the hydrophobic cement should be considered, and the reinforcement coating technology should be used at the external incision.