江汉油区注入水中二氧化碳腐蚀与指标控制

Corrosion Mechanism and Indicator Control for CO2 in Injection Waters of Jianghan Oil Region

二氧化碳腐蚀是导致油田套管和其他设备过早损坏的一个重要因素,针对二氧化碳腐蚀问题,通过对江汉油区水质状况分析和二氧化碳室内挂片实验,探讨了二氧化碳腐蚀机理及影响因素,确定了有效控制腐蚀的二氧化碳含量的界限值,指出当溶氧量一定时,二氧化碳含量越大,腐蚀性越强;溶解氧与二氧化碳共存时,溶解氧对腐蚀起主导作用,且加剧腐蚀;注入清水的二氧化碳值30mg/L和注入污水的二氧化碳值200mg/L分别作为其界限值,可有效控制腐蚀。

CO_2 corrosion is an important factor for rapid damage of oilfield casing and other equipment. Aiming at some problems of CO_2 corrosion,through analysis on water quality in Jianghan Oilfield and hanging-up experiment on CO_2 corrosion,the paper has discussed CO_2 corrosion mechanism and influence factors, determined the thresholds of CO_2 contents effectively inhibiting the corrosion.And it has indicated that given a constant dissolved oxygen content, the corrosion is intensified with increased CO_2 content; when it occurs simultaneously with CO_2, dissolved oxygen is predominant over and will intensify CO_2 corrosion; and that CO_2 corrosion can be effectively controlled when thresholds of CO_2 contents are 30 mg/L for CO_2 injected in clear water and 200 mg/L in sewage.