CO₂ 环境中碳钢的腐蚀产物垢下腐蚀及缓蚀剂研究进展

In the environment of CO₂- containing oil and gas fields, the addition of corrosion inhibitors was the most effective and practical method to inhibit corrosion under the scale. The effect of corrosion inhibitors depended not only on their own structural properties, but also on the scale of corrosion products in pipelines. For the carbon steel covered by existing corrosion products, the influence of corrosion products, the inhibition effect of corrosion inhibitors and the interaction mechanism between the two were summarized in items of corrosion products and corrosion inhibitors aspects. Studies had found that when the composition and distribution of corrosion products varied, the mechanism of corrosion under the scale also changed, and the accumulation of corrosion products not only promoted corrosion under the scale but may also inhibit it. Some corrosion inhibitors were blocked by the scale layer, which resulted in less contact with the metal matrix and made it difficult to exert the corrosion inhibition effect. Alternatively, too much corrosion inhibitor was adsorbed on the surface of the scale layer, causing more serious local corrosion. There were also corrosion inhibitors that could interact well with corrosion product scale by filling pores, chemical adsorption, bonding to form hybrid structures, etc., thus effectively inhibiting corrosion under the scale. Finally, the future research directions of corrosion under the scale were prospected, including using the natural formation of corrosion products to slow down corrosion, developing corrosion inhibitors that could produce a mixed structure of corrosion products and corrosion inhibitors, or using the synergistic effect of corrosion inhibitors and corrosion products to provide better protection for carbon steel.