超临界CO2广泛存在于碳捕捉与封存、油气开采等环境中。超临界CO2与水形成的混相流体对碳钢具有极强的腐蚀性。在超临界CO2-水混相流体中，常规CO2缓蚀剂的缓蚀性能急剧下降，甚至失效。超临界CO2可能对缓蚀剂在介质中的溶解、金属/溶液双电层构造、界面缓蚀剂的补充与修复、缓蚀剂分子与金属间的作用力、缓蚀/腐蚀复合膜结构与组成等产生影响。本项目分析、计算CO2-水混相流体的相平衡及不同类型缓蚀剂在混相介质中的溶解与分配；采用动态高压电化学测试技术，结合表面微观分析手段，研究在不同流速的超临界CO2-水混相流体中，缓蚀剂对碳钢腐蚀电化学行为的影响，探讨缓蚀剂在碳钢表面的吸脱附行为。同时结合量子化学计算，阐明缓蚀剂在金属表面的吸附状态及缓蚀剂的极性、官能团等对其溶解、分配、缓蚀性能的影响。从本质上揭示超临界CO2-水混相流体中缓蚀剂的作用机理，为超临界CO2-水混相流体中的缓蚀剂开发提供理论依据。

Supercritical CO2 widely exists in carbon capture and storage, oil–gas exploiting situation. Supercritical CO2–H2O miscible flooding is very corrosive to carbon steel. The corrosion inhibition efficiency of conventional CO2 corrosion inhibitors declined greatly when they were applied in supercritical CO2–H2O miscible flooding. Many key factors may be changed by supercritical CO2, such as the dissolution of inhibitors, construction of double layer, repairing process of the inhibition film, the interaction between inhibitor and metal, structure and constituents of corrosion/inhibition multiple film. The phase equilibrium of supercritical CO2–H2O miscible flooding and the solubility/partition coefficients of different inhibitors are calculated. High pressure electrochemical tests and surface micro-analysis techniques are applied in this study. The effect of some different inhibitors on the corrosion electrochemical behavior of carbon steel and the adsorption-desorption behavior of the inhibitors on carbon steel in supercritical CO2–H2O miscible flooding are studied. Quantum chemistry calculation is applied to reveal the adsorption of inhibitors and study the effect of functional group and molecule polarity on the dissolution and inhibition efficiency of inhibitors. It is anticipated that this research would reveal the inhibition mechanism of inhibitors in supercritical CO2–H2O miscible flooding and provide an essential insight into development of corrosion inhibitors in supercritical CO2–H2O miscible flooding.