Evaluation of the efficiency of inhibitor protection of metal surfaces in aggressive water and oil environments

The article analyzes the problems associated with the occurrence of corrosion processes of equipment during oil and gas production. The main anti-corrosion methods and means used in modern conditions are considered. In the vast majority of cases, the corrosion of industrial equipment proceeds by an electrochemical mechanism when the metal is in contact with an aqueous mineralized environment, therefore it is advisable to use the inhibitory protection of the equipment against corrosion processes. It is known that corrosion inhibitors are substances, the introduction of which in relatively small quantities into an aggressive environment causes a noticeable slowing down of metal corrosion. In fact, it is a substance that inhibits the corrosion process due to competitive adsorption with particles of activators and the formation of protective adsorption or phase films on the metal surface, sometimes with barrier properties. Corrosion inhibitors affect the kinetics of electrode processes that occur during corrosion, and are also characterized by the ability to form oxide, hydroxide or other films on the metal and transfer the metal to a passive state. Taking into account the mechanism and conditions of corrosion processes during the extraction and transportation of oil-containing products and gas condensate, a chemical method of equipment protection was chosen for research. Known inhibitors based on phosphonic acids, as well as synthesized substances based on sulfonates, imidazolines, and diamines, were used as chemical agents in the research. As a result of the research, the effectiveness of protecting metals from corrosion was evaluated depending on the composition of the highly mineralized environment, the type of metal, the type of inhibitor and its concentration, and the effectiveness of the developed scale stabilizer (sodium nitrile dimethyl sulfonate) was evaluated in comparison with known reagents. It is shown that the effectiveness of protecting metals from corrosion in water-oil mixtures using alkylimidazoline inhibitors and inhibitors developed on the basis of sunflower oil and polyalkylene polyamine (AC-1), ethylenediamine (AC-2) reaches 90% in doses of 5 - 50 mg/dm3.