温度对油田注水管道内电化学腐蚀的影响

Effect of Temperature on Electrochemical Corrosion of Internal Injection Pipe in an Oil Field

采用电化学腐蚀试验,X-射线衍射和X-射线能谱仪等方法对20号管线钢在不同温度中延长油田注水水质进行腐蚀模拟试验验。结果表明,随着注水温度的升高,20号管线钢延长油田注水水质中的腐蚀速率先增加后减小;腐蚀过程趋于以氧扩散过程控制;20号管线钢表面腐蚀产物成分主要是FeCO3和Fe2O3,腐蚀产物中含有大量的垢样,结垢的主要成分为CaCO3,注水管道存在垢下腐蚀,通过腐蚀模拟试验确定延长油田注水管道在55℃时腐蚀速率最大。

The corrosion simulation test of 20 steel pipelines with injection water of an oilfield was carried out at different temperatures adopting the methods of electrochemical test, X-ray diffraction and X-ray energy dispersive spectrometer. The results showed that with the increase of temperature of injection water, the corrosion rate of 20 steel increased firstly and then decreased, the corrosion process tended to be controlled by oxygen diffusion. The composition of the corrosion products on the surface of 20 steel were mainly FeCO3 and Fe2O3. The corrosion products contained a large number of scale and the main component of the scale was CaCO3. There was corrosion under the scale of water injection pipeline. The simulation experiment showed that the maximum corrosion rate of Yanchang oil field water injection pipe was at 55 ℃.