J55油管钢抗CO_2腐蚀复配缓蚀剂的制备及其缓蚀性能

Preparation and Inhibition Efficiency of Compound Corrosion Inhibitor for J55 Tubing Steel in CO_2 Corrosion Environment

目前,对油田常用油管材料J55钢抗CO_2腐蚀复配缓蚀剂研究不足,以油酸咪唑啉季铵盐和喹啉季铵盐为缓蚀剂主剂,配以辅助剂和表面活性剂配制了3种复配缓蚀剂,利用失重试验、扫描电子显微镜测试和电化学测试研究了3种复配缓蚀剂在油田采出水介质中对J55油管钢的缓蚀性能。结果表明:这3种复配缓蚀剂均有良好的抗CO_2腐蚀效果,其中喹啉季铵盐与硫脲复配缓蚀效果最好,高压失重试验中,缓蚀剂浓度为100 mg/L时缓蚀率可达85%以上,常压电化学测试中,缓蚀剂浓度为40 mg/L时,缓蚀剂可达97.91%;油酸咪唑啉季铵盐与硫脲复配、喹啉季铵盐与硫脲复配的缓蚀剂为抑制阳极型缓蚀剂,喹啉季铵盐与六亚甲基四胺复配的缓蚀剂为混合型缓蚀剂。

Three kinds of compound inhibitors were prepared by using imidazolinium quaternary ammonium salt and quinolinium quaternary ammonium salt as main agents of corrosion inhibitor and adding surfactant as accessory agent. The corrosion inhibition behavior of compound in- hibitors for J55 tubing steel in oilfield-produced water was studied by weight-loss test, scanning electron microscope test and electrochemical test. Results showed that three kinds of composite inhibitors had excellent effect on anti - CO2 corrosion. Among them, the mixture of quinoline quaternary ammonium salt and thiourea compound was the most effective, and the inhibition efficiency could reach more than 850 with the inhibi- tor dosage of 100 mg/L in the high-pressure weight loss test and reach 97.91% with the inhibitor dosage of 40 mg/L in the constant-pressure elec- trochemical test. Moreover, the mixture of oleie acid imidazoline quaternary ammonium salt and thiourea compound belonged to anodic corrosion inhibitors, while the mixture of quinoline quaternary ammonium salt and six methylene amine belonged to mixed-type corrosion inhibitors.