油田回注水系统金属腐蚀机理的研究

Study on Corrosion Mechanism of Metal in Water Injrction System

根据注水水质分析和腐蚀检测结果,应用灰色关联分析方法对油田注水生产系统的腐蚀状况进行了分析。根据计算结果得知:硫化物、总铁、溶解氧、pH值、腐生菌、游离CO_2、硫酸盐还原菌为主要腐蚀因素。同时通过XRD结构分析腐蚀产物成分,腐蚀产物主要成分为CaCO_3、Fe_2O_3、FeS_2、Fe_2C、FeCO_3、Fe_9S_(10)。将二者相互结合,灰色关联分析方法为腐蚀因素提供分析方法,找到影响腐蚀的主要因素,同时XRD分析结果又为灰色关联分析结果得到验证。而腐蚀产物中的铁氧化物与碳酸亚铁、结垢产物碳酸钙镁垢,这主要是由溶解氧与游离CO_2引起的电化学腐蚀造成的,且垢下腐蚀明显。

According to the results of water injection analysis and corrosion test,the corrosion relation of oilfield water injection production system was analyzed by gray relational analysis method. According to the calculated results,sulfide,total iron,dissolved oxygen,pH,saprophytic bacteria,free CO2 and sulfate reducing bacteria were the main corrosion factors. At the same time,the corrosion products were analyzed by XRD structure. The main components of the corrosion products were CaCO3,Fe2O3,FeS2,Fe2C,FeCO3 and Fe9S10. The gray correlation analysis method is used to analyze the corrosion factors,and the main factors affecting the corrosion are found. The results of XRD analysis are also verified by gray correlation analysis. And corrosion products in the iron oxide and ferrous carbonate,fouling products calcium carbonate scale,which is mainly caused by dissolved oxygen and free CO2 caused by electrochemical corrosion,and the scale of corrosion significantly.