Research progress of corrosion inhibitors for high-temperature hydrochloric acid acidification

As exploration and development to the ultra-deep layer continue to advance, bottom hole temperatures have gradually increased, aggravating acid corrosion of the downhole pipe string and greatly challenging the safety of reservoir reconstruction. Hydrochloric acid (HCl), an inorganic acid with strong acidity, is widely used in common acid systems in oil fields. Therefore, the prevention of corrosion by HCl under high temperature is an important task. In this study, we analyze the molecular structure, synergistic effect, and inhibition mechanism of imidazoline, Mannich base, quaternary ammonium salt, and other high-temperature HCl inhibitors and green inhibitors to explore the temperature resistance of inhibitors from the perspective of molecular microstructure and provide guidance for the development of ultra-high-temperature acidification inhibitors. Finally, the advantages and disadvantages of various HCl corrosion inhibitors are compared and summarized, and the knowledge gap and future research direction in the development field of high-temperature HCl corrosion inhibitors are pointed out.