青海油田集输管线电化学腐蚀及防护

Electrochemical Corrosion and Protection of Gathering and Transportation Pipelines in Qinghai Oilfield

针对青海油田油气集输管线设计了动态、静态腐蚀试片试验,确定集输系统的腐蚀原因。分析了介质温度、Cl^-和HCO_3^-浓度、矿化度及pH值等因素对腐蚀速率的影响。结果表明:动态腐蚀速率实验结果更符合实际情况,且各介质腐蚀均为均匀腐蚀,未见点蚀;从能谱分析结果可以看出,20~#钢发生了较为严重的腐蚀,腐蚀形态以均匀腐蚀为主;Cl^-、HCO_3^-浓度及介质温度是影响该地区集输管道腐蚀的主要因素。为此提出了相应的腐蚀防护措施:掺水钢质管线可采用环氧粉末涂层作为内防腐涂层;对于腐蚀性强的重点部位可选用3RE60作为管线材质。

Dynamic and static corrosion test pieces of oil and gas gathering and transportation pipeline in Qinghai oilfield are designed, and the corrosion causes of the gathering and transportation system are confirmed.The effects of temperature,Cl^-,HCO_3^-,salinity and p H value on the corrosion rate were analyzed.The results show that the experimental results of the dynamic corrosion rate are more practical, and the corrosion of the medium is uniform,and no pitting corrosion is found.The energy spectrum analysis shows that the corrosion of 20~#steel is more serious, and the corrosion is mainly caused by uniform corrosion.The concentration of HCO_3^-, Cl-and temperature are the main factors for the corrosion in the gathering and transportation pipelines in this area. And put forward the corresponding protective measures to restrain the corrosion, such as water pipeline steel can be used as epoxy powder coating anticorrosion coating; corrosion resistance for key parts of the 3RE60 can be chosen as the pipeline material.