CORROSION INHIBITOR AND METHOD OF ITS PRODUCTION Russian patent published in 2020 - IPC C23F11/14 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to corrosion inhibitors, which are used in oil and gas industry, in particular, to compositions used as corrosion inhibitors in mineralized media. Method involves preparing an active base by reacting triethylene tetramine and fatty acids of tall oil to form a mixture of aminoamides and imidazolines with weight ratio of (13–30):(70–87). After that stabilizer is introduced into it and stirred at 100–110 °C. A mixture of ethylene glycol and pentaerythritol, taken in weight ratio (10–20):1, is used as stabilizer, with weight ratio of stabilizer : active base (0.52–0.55):1. Stabilized active base is cooled down; a solvent and a modifier are added while stirring until homogeneous. Solvent used is methanol or a mixture of methanol and water with a weight ratio of 0.6–1.2. Inhibitor contains, wt%: active base 10–20, stabilizer 5.5–10.5, modifier – acetic acid 5.1–7 and mercaptoethanol 0.5, solvent – methanol or mixture methanol/water – balance. Inhibitor has high degree of protection in media with high degree of salinity, has low pour point (below minus 50 °C), physical and chemical characteristics (density, viscosity, pH), which meet operating requirements, has complete compatibility with the inhibited medium and can be used in high mineralization of formation water.

EFFECT: maintaining stability of the phase composition of the inhibitor at low temperatures, improving compatibility with formation waters of different degree of salinity, which improves its anticorrosive properties in the oil-water system.

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