高硫高盐油气混输管线腐蚀因素分析

Corrosion Factor Study on Gas/Liquid Mixture Transportation Pipeline Under High Sulfide and High Salinity Condition

输送油、气、水混合介质的伊朗某油田集输管线发生了多起腐蚀泄漏生产事故,泄漏点主要集中在管线低位处、水平段及上坡处。通过对流体介质、腐蚀类型分析并对腐蚀产物进行化验测试得知,介质中高含硫化氢、氯化物和盐类物质是产生腐蚀的主要因素,这些物质溶解在水中加速了碳钢管线的腐蚀。微生物的存在也是产生腐蚀的因素之一,微生物腐蚀(MIC)是一个复杂的腐蚀过程,材料上常见的微生物如细菌、真菌、藻类和酵母等造成直接或间接的腐蚀。许多类型的细菌都能引起腐生物腐蚀,而常见的细菌腐蚀是硫酸盐还原菌(SRB)腐蚀,SRB的存在加速了点蚀泄漏的进程。

Many corrosion leakage accidents occur in oil/water/gas multiphase pipeline in oilfield in Iran. The leakage points usually locate at the low points, the horizontal sections and the uphill sections of a pipeline. By analyzing fluid composition, corrosion forms and testing corrosion products, high sulfur, high chlorine and high salinity are found to be the main reasons to cause the corrosion.These elements dissolved in the water will speed up the corrosion of carbon steel pipe.Also the microorganism is one of the factors which cause corrosion. The microorganism corrosion（MIC） is a complex corrosion process. The common MIC is bacteria,fungi,algae and yeast,etc.They will cause direct or indirect corrosion.Many kinds of bacteria can cause microorganism corrosion and the most common one is sulfate reducing bacteria（SRB）,which can accelerate pitting corrosion and leakage.