三聚氰胺衍生物在高温油田采出水中的缓蚀作用及其机制

以三聚氰胺为基体，通过2步反应制备了三聚氰胺衍生物——三聚氰胺缩甲醛丁二酸钠(MFSS)。采用质量损失法、极化曲线法、交流阻抗法和量子化学计算考察了MFSS在高温模拟油田采出水中对X80钢的缓蚀性能及其缓蚀机制。质量损失分析表明，当MFSS缓蚀剂质量浓度为180 mg/L时，在60 ℃和80 ℃下X80钢的缓蚀率分别可达91.9%和93.7%，说明MFSS可有效地抑制X80钢在油田采出水中的腐蚀；电化学分析表明，MFSS缓蚀剂对X80钢腐蚀的阴、阳极反应过程均有抑制作用，但其抑制阳极反应更为显著，属于以抑制阳极反应为主的混合型缓蚀剂；量子化学计算表明，MFSS分子的HOMO轨道主要集中在胺基基团以及—C=N基团上，三嗪环通过π电子与Fe的螯合作用而平行吸附于Fe(001)面上，缩甲醛丁二酸酯取代基则在Fe(001)面的竖直方向。

Inhibition Performance and Mechanism of a Melamine Derivative in High Temperature Oilfield Produced Water

Melamine formal sodium succinate (MFSS), a melamine derivative, was prepared by a two-step reaction using melamine as the matrix. Mass loss, polarization curve and AC impedance methods were used to study the inhibition performance and mechanism of MFSS for X80 steel in simulated oilfield produced water at high temperature. The results of mass loss analysis show that the inhibition efficiency for X80 steel reaches 91.9% and 93.7% respectively, with a MFSS mass concentration of 180 mg/L at 60 ℃ and 80 ℃, indicating the high efficient corrosion inhibition performance of MFSS for X80 steel in the simulated oilfield produced water at high temperature. The electrochemical results indicate that the MFSS has an inhibitory effect on both the cathode and anode processes, but changes the anode reaction to a greater extent than the cathode process, which can be classified into mix-type inhibitor with mainly inhibition of anodic processes. Quantum chemical calculations demonstrate that the HOMO of the MFSS molecule is mainly concentrated on the amino and —C=N group, and the triazine ring is adsorbed on the Fe(001) surface in parallel by the chelation of π electrons with Fe, while the formal succinate group is the vertical orientation of the Fe(001) plane.