Development of alginic acid salt gel embedded with imidazoles: A novel solid corrosion inhibitor for deep oil well applications

Directly injected corrosion inhibitors have a short action time and are difficult to penetrate oil wells to protect underground equipment. To solve this, long-lasting gel-loaded corrosion inhibitors have been developed. Two imidazole molecules were loaded into crosslinked alginate gel to prepare solid inhibitor spheres, which were tested in terms of structural feature, responsive release, and corrosion inhibition performance, to pursue the function of long-lasting metal protection effect. The corrosion inhibition efficiencies reach >90% in acidic and neutral environments. The alginate gel release rapidly in 10 h and continuously for 60 h, independent of environment temperature and pH, enabling corrosion inhibitors to protect metallic wellbore over longer distances. The alginate gel minimally impacts the environment but prolongs the lasting time of corrosion inhibitors under oil wells.