油气管道SRB腐蚀研究新进展

由硫酸盐还原菌(SRB)引发的腐蚀是造成管道材料破坏和失效的重要原因,研究微生物腐蚀机制和防控措施具有重要的科学意义和经济价值.首先通过介绍国内外油气管道微生物腐蚀的失效案例,说明SRB对油气管道破坏的严重性.接着介绍了管道表面微生物膜的微观形成过程和结构特点,梳理了微生物膜作用下管材发生局部腐蚀的机理,主要对当前较为流行的微生物电化学腐蚀(EMIC)理论和管道微生物腐蚀预测模型做了深入探讨.综合考虑管道运行实际工况,结合模拟试验结果,进一步阐述了管线钢即使处于正常阴极保护条件下,由于受SRB生命代谢活动的影响,管道表面Fe中的电子通过细菌的新陈代谢作用直接获取,从而导致管材依然发生局部腐蚀甚至更为严重.而焊缝及其附近热影响区是管道发生腐蚀穿孔的薄弱区.最后全面总结了油气管道工业中抗SRB腐蚀防护前沿的理念和方法,分析了当前各种防护技术在实际应用中的不足,对微生物腐蚀如何更有效地防治提供了富有价值的参考,为管道工程SRB腐蚀防护技术的未来发展指明了方向.

Research Progress on Oil & Gas Pipeline Corrosion Induced by SRB

Corrosion induced by sulfate-reducing bacteria (SRB) is an important cause of damage and failure of pipeline materials. It is of great scientific significance and economic value to study the mechanism of microbial corrosion and the control measures. In this work, the failure cases of microbiologically influenced corrosion (MIC) on oil &gas pipelines both in and outside China were firstly cited to illustrate the serious damage effect of SRB on pipelines. Formation process and structural characteristics of the biofilm on the surface of pipes were introduced and the localized corrosion mechanism of pipes under the action of biofilm was also sorted out, especially the electrical microbially influenced corrosion theory and relevant corrosion predicting model were discussed in depth. According to the operation conditions and the simulation experiment result, SRB could directly acquire electron from Fe by its metabolism resulting in localized corrosion or much severer corrosion even though pipeline was under normal cathodic protection. The weld and its adjacent heat affected zone are the weak area of corrosion perforation. Finally, the latest prevention philosophy and technologies against SRB of oil &gas pipelines were summarized, the existing problems and development direction were pointed out in order to provide valuable reference for more effective method of MIC prevention.