为了确保油田集输管线的安全运行和生产，提前做好腐蚀防护工作，对塔河油田某失效油气集输管线进行分析，对油气集输管线腐蚀穿孔处进行宏观形貌观察，通过直读光谱仪对材料成分进行分析，使用扫描电镜观察试样腐蚀微观形貌，利用X射线衍射仪和能谱仪对腐蚀产物进行分析，并进行电化学测试，以明确油气集输管线穿孔原因。结果表明：腐蚀介质的矿化程度高，原油中含有大量的CO2和H2S，且向地层灌注的为注入水，导致管壁内部发生了二氧化碳腐蚀。介质中含有大量的可溶性钙盐，钙盐和CO2发生化学反应生成碳酸钙结垢，结垢物与腐蚀产物在管道上坡段沉积，导致金属基体发生了严重的垢下腐蚀，介质中高含氯离子加速了腐蚀的发生，最后造成管线底部穿孔失效。
关键词：
集输管线; 腐蚀; 失效; 结垢; 穿孔
In order to ensure the safe operation and production of oilfield gathering pipelines and to provide corrosion protection in advance,a failed oil and gas gathering pipeline in Tahe Oilfield was analyzed.The macro morphology observation of the corrosion perforation of such pipeline,the material composition analysis by direct reading spectrometer,the micro morphology observation of the sample corrosion by scanning electron microscope,the corrosion products analysis by X-ray diffractometer and energy disperse spectrometer,and the electrochemical testing were carried out to determine the cause of the perforation of the oil and gas gathering pipeline.Results showed that the highly mineralized corrosion medium,the crude oil containing a lot of CO2 and H2S,and the injected water poured into the stratum led to an CO2 corrosion inside the pipe wall.There were a lot of soluble calcium salts in the medium,and the chemical reaction between calcium salts and CO2 resulted in calcium carbonate scaling.The scaling and corrosion products were deposited on the uphill section of the pipeline,which led to serious corrosion of the metal matrix under scaling.The high-chloride ion accelerated the corrosion,and finally caused the perforation failure at the bottom of the pipeline.
