Lin Hai, Chen Xiaorong, Luo Zhongming, Xu Jun, Lu Ping, Xie Tianyi, Tang Jiayi, Wang Hu
CCDC Drilling Engineering Technology Research Institute, Xi'an 710018, China.
National Engineering Laboratory for Exploration and Development of Low-Permeability Oil & Gas Fields, Xi'an 710018, China.
Molecules. 2024 Jun 1;29(11):2611. doi: 10.3390/molecules29112611.
Under-deposit corrosion is widely present in the pipelines of oil and gas production, causing significant corrosion damage. In this paper, a novel electrochemical cathodic-polarization method was carried out to accelerate the formation of CaCO scale on a X65 steel surface in a simulated solution containing scaling ions. Subsequently, pre-scaled X65 steel was placed in a high temperature and pressure autoclave to conduct corrosion weight-loss experiments and in situ electrochemical measurements. The study mainly compared the corrosion inhibition behavior of four quaternary ammonium salt corrosion inhibitors, pyridinium quaternary salt (BPC), quinolinium quaternary salt (BQC), 8-hydroxyquinolinium quaternary salt (BHQ) and pyridinium (1-chloromethyl naphthalene) quaternary salt (1-CPN), in a simulated oilfield scale under corrosive conditions. The results of the weight-loss experiments demonstrated that the inhibition efficiencies of the corrosion inhibitors from high to low were as follows: 1-CPN < BHQ < BQC < BPC. The in situ electrochemical measurements showed that the immersion time and type of corrosion inhibitor had a pronounced influence on the corrosion and corrosion inhibition behavior of X65 steel with CaCO coating. It was also proved using both EIS and PC that 1-CPN shows the best inhibition performance in all. Lastly, the inhibition mechanism of corrosion inhibitors at under-deposit conditions was analyzed via a surface morphology observation of SEM.
垢下腐蚀广泛存在于油气生产管道中，会造成严重的腐蚀破坏。本文采用一种新型电化学阴极极化方法，在含有结垢离子的模拟溶液中加速X65钢表面CaCO₃垢的形成。随后，将预先结垢的X65钢置于高温高压釜中进行腐蚀失重实验和原位电化学测量。该研究主要比较了四种季铵盐缓蚀剂，即吡啶季铵盐（BPC）、喹啉季铵盐（BQC）、8-羟基喹啉季铵盐（BHQ）和吡啶（1-氯甲基萘）季铵盐（1-CPN）在模拟油田垢腐蚀条件下的缓蚀行为。失重实验结果表明，缓蚀剂的缓蚀效率由高到低依次为：1-CPN＜BHQ＜BQC＜BPC。原位电化学测量表明，浸泡时间和缓蚀剂类型对涂覆有CaCO₃涂层的X65钢的腐蚀和缓蚀行为有显著影响。通过电化学阻抗谱（EIS）和极化曲线（PC）也证明，1-CPN总体表现出最佳的缓蚀性能。最后，通过扫描电子显微镜（SEM）对表面形貌的观察分析了垢下条件下缓蚀剂的缓蚀机理。
