In the oil production industry, economic losses and ecological damage caused by corrosion stem from the very large amounts of metal equipment and structures that come into contact with highly aggressive media. The most important tasks in the development of an oilfield are reliable operation and long life of equipment and pipeline systems. The presence of corrosive components in transported fluids negatively affects metal in oil production, refinery, transportation and processing operations. The degree of corrosive damage to oil production equipment is determined by the degree of heterogeneity of the extracted fluid, the content of corrosive gases (carbon dioxide [CO2] and/or hydrogen sulphide [H2S]), the degree of mineralisation in the aqueous phase and the variability of the corrosion activity of technological media in the course of exploration of a given deposit.
Under such conditions, a technically justified and efficient method of protection is the use of inhibitors that adsorb as protective films on a metal to prevent its corrosion. At the same time, inhibitor protection seems to be one of the most appropriate and costefficient ways to address this problem. The inhibitors applied during the operation of oil equipment and pipelines should satisfy a number of engineering requirements: they should be soluble or dispersible in water or brine, they should pass to an organic phase in insignificant amounts only, they should not create emulsions in water and condensates, they should be easily separable, they should ensure a highly protective effect, they should prevent the formation of pitting, they should prevent the hydrogenation of steel (in the case of the presence of H2S), they should be non-toxic and they should have strong after-effects.
Along with strong protective properties, another important requirement for inhibitors is that their foaming and emulsifying abilities should be low, since foaming and emulsification may impair the operating process of oil treatment: a corrosion inhibitor might cause a working solution to foam, which would disturb the operation of the system. Systems for complex oil treatment for transportation separate hydrocarbons–water liquid mixtures to isolate an oil fraction. The corrosion inhibitors used to protect equipment and pipelines should not decelerate the separation of the oil–water mixture.
Modern sanitary, hygienic and ecological requirements make it imperative to replace toxic corrosion inhibitors with equally effective inhibitors that are safe in terms of their production and application. In addition, it is vital to produce inhibitors from less expensive raw materials. In this context, the development of ecologically safe and highly effective organic compounds with simple synthesis from widely available raw materials remains a matter that must be addressed.
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