Petroleum refining is characterized by the largest amount of systems exposed to corrosion compared to any other sector of the oil industry. Corrosion problems occur everywhere, from the points of raw materials delivery up to removal and transportation of the refined products. Corrosion control measures shall be taken at crude oil distillation plants and units for alkali treatment of oil, gas plants, reformer and cracking units, straight run deisobutanizers, units for adsorption of hydrogen sulphide from aqueous solutions, furfural treatment units etc. Liquid composition may vary depending on a particular stage of the oil refining cycle – from sulphurous, acid oil-water mixtures fed to refineries to final products (e.g., gasoline) with negligible water content. It is hardly possible to use any “universal” corrosion inhibitor due to the variety of process mechanisms that may cause intense corrosion of equipment used in the oil sector. The need to ensure property package determining processability and compatibility of the inhibitor with corrosion medium components necessitates development of an inhibitor that would be functional in different corrosive conditions. Oilfield water containing large amounts of chloride ions, oxygen, carbon dioxide and hydrogen causes and promotes further development of local electrochemical processes, which represent the most dangerous type of corrosion and failure of metal. Oilfield practice shows that the most dangerous local corrosion damages also occur in the presence of microorganisms. In order to protect oil equipment against chemical and bacterial corrosion, Karvan-L company designed efficient and cost-effective water-soluble and oil-soluble corrosion inhibitors. Corrosion inhibitors are nitrogen-containing surfactants, produced based on natural acids with addition of film-forming admixtures and biocides.
