不同碳链长度咪唑啉缓蚀剂在CO_(2)驱采油环境中的腐蚀防护作用  

Corrosion Protection of Imidazoline Corrosion Inhibitors with Different Carbon Chain Length in CO_(2) Driving Oil Environment

作　　者：倪小龙 李欢 李云飞 郝卫国 杨庆 林冰 郑宏鹏 唐鋆磊[2,3] NI Xiao-long;LI Huan;LI Yun-fei;HAO Wei-guo;YANG Qing;LIN Bing;ZHENG Hong-peng;TANG Jun-lei(Xinjiang Oilfield No.2 Oil Production Plant,Xinjiang Karamay 834008,China;School of Chemistry and Chemical Engineering,Southwest Petroleum University,Chengdu 610500,China;Carbon Neutral Research Institute,Southwest Petroleum University,Chengdu 610500,China)

机构地区：[1]新疆油田采油二厂,新疆克拉玛依834008 [2]西南石油大学化学化工学院,成都610500 [3]西南石油大学碳中和研究院,成都610500

出　　处：《表面技术》2023年第8期278-289,共12页Surface Technology

摘　　要：目的合成制备适用于CO_(2)驱油环境中井筒材料的腐蚀防护的咪唑啉缓蚀剂,探究碳链长度对咪唑啉缓蚀剂腐蚀防护性能的影响机制。方法以辛酸、月桂酸、硬脂酸和二乙烯三胺等为原料,经酰胺化和环化后制备得到3种碳链长度(C7、C11和C17)的咪唑啉缓蚀剂。通过傅里叶变换红外光谱、量子化学计算、失重法、电化学方法以及表面观察技术,对合成缓蚀剂在CO_(2)驱油环境中对井筒材料的腐蚀防护性能进行了评价。结果红外测试观察到3种链长(C7、C11和C17)的咪唑啉缓蚀剂的特征吸收峰,表明3种链长咪唑啉缓蚀剂成功制备。量子化学计算表明,合成的C17咪唑啉缓蚀剂具有最优的供电子能力和最佳的疏水能力。腐蚀失重和电化学测试结果显示,所合成的3种不同碳链长度的咪唑啉缓蚀剂均对CO_(2)驱腐蚀环境中N80钢具有良好的腐蚀防护作用,随着缓蚀剂浓度的提升,其缓蚀效率逐渐增高。其中含有17个碳链的咪唑啉缓蚀剂(C17)在10 mg/L时缓蚀效率达到了90%以上。拉曼光谱观察到N80钢表面C=N和C—N的吸收峰,表明合成的3种缓蚀剂在N80表面上吸附。SEM结果发现,添加C17咪唑啉的N80表面腐蚀最为轻微,其腐蚀防护效果最优。结论合成的C17碳链的咪唑啉缓蚀剂具有优异的腐蚀防护效果,随着碳链长度的增加,碳链的推电子能力增强,使得咪唑啉缓蚀剂更容易在N80钢表面吸附,同时长碳链形成的缓蚀剂膜层也具有更好的疏水作用,导致咪唑啉中缓蚀剂越长其缓蚀效果越好。The work aims to synthesize three imidazoline corrosion inhibitors with different carbon chain length for corrosion protection of N80 carbon steel and explore the effect mechanism on the corrosion protection performance in carbon dioxide miscible oil displacement environment.The imidazoline corrosion inhibitors with C7,C11 and C17 carbon chains were synthesized by amidation and cyclization reaction with octanoic acid(OA),lauric acid(LA),stearic acid(SA)and diethylenetriamine(DETA),respectively.Fourier transform infrared spectroscopy(FTIR),quantum chemical calculation,weight loss method,electrochemical measurements including electrochemical impedance spectroscopy(EIS)and potentiodynamic polarization curve(PDP),Raman spectroscopy and surface observation technologies were employed to study the anti-corrosion mechanism of the synthesized three corrosion inhibitors.FT-IR results proved that imidazoline corrosion inhibitors with different carbon chains were successfully prepared.Quantum chemical calculations showed that the synthesized C17 imidazoline corrosion inhibitor had the best electron donating ability and hydrophobic ability.The results of weight loss indicated that all the synthesized inhibitors had good inhibition effect on N80 steel in CO_(2)miscible oil displacement corrosion environment.The inhibition effect of inhibitors increased as the inhibitor concentration and carbon chain length increased,and reached over 90%for imidazoline inhibitor with 17 carbon chain at 10 mg/L.The EIS results indicated that the capacitive arc radius increased with the increase of imidazoline concentration and carbon chain length.The polarization curve results suggested that the imidazoline corrosion inhibitor behaved as an anodic corrosion inhibitor in the test environment,and its self-corrosion current density decreased sharply with the increase of imidazoline concentration and carbon chain length.It could be seen that the same trend of inhibition efficiency was obtained by the method of weight loss and electrochemical test.Ra

关 键 词：CO_(2)驱油 咪唑啉缓蚀剂 碳链长度 缓蚀效率 理论计算 

分 类 号：TG172[金属学及工艺—金属表面处理]