新型离子液体缓蚀剂在油田采出水中的应用研究

Application of Novel Ionic Liquid Corrosion Inhibitors to Oilfield Produced Water

目的研究离子液体在钢铁防腐方面的缓蚀效果。方法采用静态失重和动态失重法比较4种离子液体的缓蚀速率,利用电化学测试、扫描电镜和EDS手段对N80碳钢进行表征,评价了产品的缓蚀性能。结果油田采出水中添加微量的离子液体复配型缓蚀剂后,试样表面生成以铁碳氧元素为主的保护膜,当4种缓蚀剂添加量达到150 mg/L时,N80碳钢的腐蚀速率下降趋势变化缓慢,B型缓蚀剂缓蚀效果最好,其用量为150 mg/L时腐蚀速率降低到0.0087 mm/a,自腐蚀电位由0.8112 V提高到?0.7446 V,自腐蚀电流由77.79μA下降到5.03μA,缓蚀率可达到93.5%。结论 4种复配型离子液体缓蚀剂对N80碳钢均有较好的缓蚀性能,缓蚀效果大小顺序为B﹥C﹥D﹥A,其中B的缓蚀效率最好,缓蚀率为94.1%。

The work aims to study corrosion inhibition effects of four novel ionic liquids on N80 steel. The corrosion inhibition rate of the ionic liquids was compared by virtue of static weight-loss and dynamic weight-loss methods. The N80 carbon steel was characterized by electrochemical test, scanning electron microscope and EDS to evaluate corrosion inhibition of the products. The protective film, which was mainly composed of iron, carbon and oxygen elements, took shape on the surface of the iron sample after composite ionic liquids were added to the oilfield produced water. The corrosion rate decreased slowly as 150 mg/L of 4 corrosion inhibitors was added. The inhibition efficiency of type B corrosion inhibitor was the best of all. When 150 mg/L was consumed, the corrosion rate decreased to 0.0087 mm/a; the self-corrosion potential increased from 0.8112 V to 0.7446 V; the self-corrosion current decreased from 77.79 ktA to 5.03 pA; and the inhibition rate amounted to 93.5%. The 4 ionic liquid corrosion inhibitors provide favorable inhibiting effects for N80 steel in oilfield produced water with inhibition efficiency as B〉C〉D〉A. The inhibition performance of B is the best and can be up to 94.1% when measured by virtue of weight loss method.