Research on Indoor Experimental Technology of Ultra-High Temperature Acidizing Corrosion Inhibitors Containing N-Heterocyclic Quaternary Ammonium Salts

In the process of acidizing operation, especially in ultra-high temperature wells, metal components such as wellbore tubing and surface equipment are severely corroded by acid fluids, leading to operational challenges in oilfield production. At present, the ad-dition of corrosion inhibitors is one of the most effective methods to mitigate metal corrosion. Pyridine residues, quinoline quaternary ammonium salts, aldehyde ketone amine condensates, acetylenic methyl ammonia and imidazoline corrosion inhibitors have been widely studied in the industry. Among them quaternary ammonium salts are widely used in oilfield production due to their excellent corrosion resistance, low toxicity and good water solubility. However, their limited heat resistance makes them unsuitable for ultra-deep exploration wells or scientific research wells. This study fo-cuses on N-heterocyclic quaternary ammonium salt-based corrosion inhibitors (alkyl quinolinium quaternary ammonium salts), which can withstand temperatures up to 200°C, meeting the requirements of ultra-high temperature wells.