目的 探究咪唑啉与油酸的协同效应。方法 采用失重法和电化学技术，研究咪唑啉与油酸缓蚀剂对N80钢在饱和CO2油田地层水中的协同增效缓蚀效果。用SEM技术对腐蚀形貌进行了观察。通过测量金属表面膜的接触角，评价金属表面膜的疏水性能，并建立吸附模型以及拟合吸附曲线，分析了2种缓蚀剂单一作用时和混合后的缓蚀机理。结果 咪唑啉和油酸单独使用时均能够使腐蚀电位正移，添加量为100 mg/L时，缓蚀效率分别为82.89%和78.51%。二者复配后，缓蚀效率有一定提高，在油酸咪唑啉与油酸的复配比为25∶75时，缓蚀效率最大，相较于单独添加相同浓度的油酸咪唑啉，缓蚀效率提高了约15%，达到98.07%。在添加单一缓蚀剂时，金属表面的腐蚀程度随浓度的增加而减轻，在添加复配的缓蚀剂后，对比相同浓度下添加单一缓蚀剂后的腐蚀形貌，点蚀坑数量减少且尺寸减小。两缓蚀剂复配后，金属表面接触角较单独使用时增大，表明其在金属表面形成的缓蚀剂膜的疏水能力较单独使用时强。经计算单独使用油酸咪唑啉和油酸时体系的吉布斯自由能ΔG0分别为?48.578、?48.319 kJ/mol。结论 油酸咪唑啉与油酸之间有良好的缓蚀协同效应。单一油酸咪唑啉或油酸缓蚀剂通过化学吸附作用于金属表面。油酸咪唑啉与油酸复配后的缓蚀机理可归因于两者复配后改变了混合膜的结构，使缓蚀剂膜更致密，从而达到更好的缓蚀效果。

The synergistic effect of imidazoline and oleic acid corrosion inhibitor on corrosion inhibition of N80 steel in formation water containing CO2 saturated oilfield was studied by weight loss method and electrochemical technology. The corrosion morphology was observed by SEM. By measuring the contact Angle of the metal surface film, the hydrophobic performance of the metal surface film was evaluated, and the adsorption model was established and the adsorption curve was fitted. The corrosion inhibition mechanism of the two corrosion inhibitors was analyzed when the two inhibitors acted alone and after mixing. The results showed that when imidazoline and oleic acid were used alone, the corrosion potential could be positively moved, and the inhibition efficiency was 82.89% and 78.51%, respectively, when the addition amount was 100 mg/L. When the imidazoline:oleic acid was 25∶75, the inhibition efficiency was the highest. Compared with the imidazoline with the same concentration alone, the inhibition efficiency was increased by about 15% (98.07%). When a single corrosion inhibitor was added, the corrosion degree of the metal surface decreased with the increase of the concentration. After the addition of the compound corrosion inhibitor, the number and the size of pitting decreased compared with the corrosion morphology after the addition of a single inhibitor at the same concentration. The contact angle of the metal surface increased after the combination of the two inhibitors, which indicated that the hydrophobic ability of the corrosion inhibitor film formed on the metal surface was stronger than that when the two inhibitors were used alone. The Gibbs free energy ΔG0 imidazoline and oleic acid were calculated as ?48.578 kJ/mol and ?48.319 kJ/mol, respectively. There is a good synergistic effect between imidazoline and oleic acid. A single imidazoline or oleic acid corrosion inhibitor acted on the metal surface through chemical adsorption. The corrosion inhibition mechanism after the combination of imidazoline and oleic acid could be attributed to the change of the structure of the mixed film which made the corrosion inhibitor film denser, thus achieving a better corrosion inhibition effect.