胜利海上埕岛油田注水系统腐蚀机制

Corrosion mechanism for water injection system of Chengdao Offshore Oilfield

采用标准失重法和电化学方法研究胜利海上埕岛油田注水体系金属腐蚀状况。结果表明:挂片在注入水中腐蚀速率随温度改变呈抛物线形态变化,50～60℃时腐蚀速率最高,腐蚀速率与水中的溶解氧含量呈正相关关系;挂片在3种水样中的腐蚀速率由高到低依次为水源井水、采出水、海水;3种水样中的腐蚀过程主要受阴极控制,在海水中的腐蚀类型为全面腐蚀,在采出水和水源井水中存在孔蚀,且在采出水中的孔蚀反应电阻远大于水源井水的;配伍性良好的回注水体系可在一定程度上降低挂片的腐蚀速率。

Standard test method for weight loss and electrochemical methods were used to investigate the corrosion of metal in water injection system of Chengdao Offshore Oilfield. The results show that the corrosion rate of coupon is parabolic shape against time and it comes to its maximum at 50-60 ℃. Besides, the corrosion rate increases with the soluble oxygen content increasing. The water samples are well water, produced water, sea water in diseending order of corrosion rate of coupon. The corrosion processing in three water samples is mainly dependent on the negative electrode. The corrosion of coupon in seawa- ter is uniform Cotxosion, while pitting corrosion happens in well water and produced water. In addition, the corrosion rate of coupon in produced water is smaller than that of well water. The water re-injection system with good compatibility can reduce the corrosion rate of coupon to a certain extent.