某气田地面工艺管线的腐蚀失效原因

Causes of Corrosion Failure of Surface Process Pipelines in a Gas Field

某气田工艺管线近期发生多起腐蚀穿孔失效,为了明确管线腐蚀失效的原因及机理,为今后管线的腐蚀管控工作提供有效指导,对失效管件进行了宏观形貌观察、化学成分分析、力学性能测试和腐蚀形貌观察、腐蚀产物分析等。结果表明:腐蚀产物主要为铁的氧化物及硫化亚铁,硫酸盐还原菌腐蚀是管线发生腐蚀失效的主要原因。建议加强水质管理,控制硫酸盐还原菌的含量或采用涂层或阴极保护技术、定期对工艺管道进行清管处理等,减轻管线腐蚀。

Recently, several corroded perforation failures occurred in the process pipeline of a gas field. In order to clarify the cause and mechanism of pipeline corrosion failure and provide effective guidance for future pipeline corrosion control work, macroscopic morphology observation, chemical composition analysis, mechanical property testing, corrosion morphology observation, and corrosion product analysis were carried out on the failed pipe. The results show that the corrosion products were mainly iron oxides and ferrous sulfide, and sulfate-reducing bacteria corrosion was the main cause of pipeline corrosion failure. It was recommended to strengthen water quality management, control the content of sulfate-reducing bacteria or adopt coating or cathodic protection technology, and regularly perform pigging operation of process pipelines to reduce pipeline corrosion.