Study of Technological and Protective Properties of Corrosion Inhibitors at Gas Field Facilities

At many gas and gas condensate fields, the extracted products contain increased levels of carbon dioxide, which in the presence of condensation or formation water leads to carbon dioxide corrosion on carbon and low-alloy steels, characterized by dangerous local defects. One of the main methods of protecting steel equipment and pipelines at gas facilities from internal corrosion, including carbon dioxide corrosion, is inhibitor protection. The article considers the main requirements for corrosion inhibitors used at gas and gas condensate fields in terms of technological and protective properties. Among the important technological parameters of corrosion inhibitors, the following were studied: solubility in various solvents, emulsion formation, resistance of the commercial form and solutions of inhibitor reagents to low temperatures. They are important both for the possibility of using corrosion inhibitors (dosing, use in real operating conditions, etc.), and for eliminating negative consequences in the processes of processing gas and gas condensate and separating them from the produced fluids. The possibilities of using chemical and physical methods for separating the emulsion «gas condensate - water» formed due to high concentrations of corrosion inhibitors in operating environments have been studied. To reduce the negative impact of emulsion formation, optimal concentrations and modes of application in such conditions of demulsifiers and elevated temperatures, respectively, were studied. To protect against carbon dioxide corrosion, protective properties were studied for two main technologies of applying corrosion inhibitors: constant and variable dosing in working environments. A comparative analysis of the effectiveness of protection against general and local corrosion and the aftereffect of the inhibitor film was carried out under these two modes of inhibitor application.