地层原生菌对J55钢腐蚀行为的影响

Effect of Native Bacteria on Corrosion Behavior of J55 Steel

目前关于地层原生菌对碳钢的腐蚀研究鲜见报道,利用高温高压釜对含有地层原生菌的采出水进行杀菌处理,通过配制不同比例的地层水和杀菌水获得了不同原生菌浓度的水溶液。采用自主研发的试验装置和烘箱开展了J55钢挂片腐蚀试验,研究了地层原生菌对J55钢腐蚀行为的影响规律,特别是地层原生菌浓度对碳钢腐蚀速率的影响。通过扫描电镜(SEM)分析对比了挂片腐蚀特征,利用失重法测试了腐蚀速率。结果表明:J55钢腐蚀速率随地层原生菌浓度增加而增大,增大幅度最大为14.8%;挂片试样表面有一层很薄的均匀腐蚀产物,呈黑色和棕黄色,试样表面均出现局部腐蚀特征,存在明显坑点;J55钢在含有地层原生菌溶液中的腐蚀是多种因素共同作用造成的,Cl-和地层原生菌是造成点腐蚀较为严重的重要原因。

Sterilization of raw water containing native bacteria was carried out by using high temperature autoclave, and the aqueous solution with different native bacteria concentrations was obtained by configuring formation water and bactericidal water with different proportions. The corrosion test of J55 steel was carried out by using homemade experimental apparatus and oven, and the influences of native bacteria on the cor- rosion behaviors of J55 steel, especially the concentration of native bacteria on corrosion rate were studied. In addition, the characteristics of the chip were analyzed by scanning electron microscopy （SEM）, and the corrosion rate was measured by weight loss method. Results showed that the corrosion rate of J55 steel increased with the increase of the primary bacteria concentration in the ground layer, and the maximum was 14.8%. On the surface of samples, a thin layer of uniform corrosion products with black and brown colors formed, and local corrosion charac- teristics with obvious corrosion pits emerged. It was concluded that the corrosion of J55 steel was caused together by various factors. Among them, C1- and native bacteria were the important factors which led to pitting corrosion, and the concentration of native bacteria was positively related to the corrosion rate of J55 steel.