Study of the effectiveness of inhibiting corrosion processes in mineralized water-oil environments

Abstract

Corrosion is a phenomenon that strongly affects many industries. Everything related to metallurgy, shipbuilding, or the oil industry is negatively affected by corrosion processes. This is a big problem, because the number of industrial accidents due to corrosion reaches more than 75%. Therefore, in this work, the effectiveness of inhibition of corrosion processes in mineralized water-oil environments was investigated in detail. The main goal of the article is to study the regularity of corrosion processes in water-oil media of different composition and at different temperature regimes for effective selection of the inhibition mechanism and type of corrosion inhibitor.
 An effective method of reducing the impact of corrosion processes today is the use of inhibitors. This is expedient not only from the point of view of the effectiveness of the action, but also from the point of view of economic expediency. Inhibitors are added to corrosive environments in order to stop or reduce corrosion processes. They can be used as protective barriers that form a protective layer, and as absorbers that prevent oxidation processes. In the future, the type of inhibitor is selected depending on the type of metal and the conditions of the reactions responsible for the occurrence and course of corrosion.
 Currently, the use of corrosion inhibitors is recognized as the most effective way to reduce the intensity of corrosion destruction of metal structures. At the same time, it is impossible to obtain a universal inhibitor that meets the requirements of high efficiency, manufacturability, toxicological safety, and at the same time is obtained in an economically feasible way. Among various corrosion inhibitors, organic ones have shown their effectiveness in protecting low-alloy steels of oil industry equipment.
 Metal samples of St20 steel, the most widely used for the manufacture of oil pipelines and oil production equipment, were used as corroding materials in the study. The pH was changed by adding a solution of acetic acid. The degree of corrosion was determined by the massometric method. The volume of the test solution was 150 cm3, the pH of the solution was adjusted with a 5% acetic acid solution. Alkylimidozoline was used as an inhibitor.
 Judging by the research results, the mineral composition of the aqueous solution largely affects the rate of corrosion. The presence of oil significantly reduces the rate of corrosion due to both blocking the access of oxygen to the system by the oil film and due to the corrosion inertness of the chemical components of the oil. However, it was also found that with an increase in the content of carboxylic acids, the presence of oil does not affect the corrosion rate in any way. Arguably, the alkylamidazoline inhibitor showed a high degree of protection at room temperature, in contrast to studies at high temperatures.