Corrosion remains a significant challenge in the oil and gas industry, adversely impacting all stages of the production cycle, including exploration, extraction, transportation, and refining. This review provides a comprehensive analysis of corrosion mechanisms, classification systems, and the practical application of corrosion inhibitors, with particular emphasis on their effectiveness in protecting oilfield and refinery equipment. Special attention is given to organic corrosion inhibitors, specifically those based on imidazolines, phosphonates, and urotropine. These compounds are known for their ability to form protective films that reduce corrosion rates in harsh environments characterized by high concentrations of H₂S, CO₂, and other aggressive agents. Imidazoline-based inhibitors are recognized for their capacity to establish hydrophobic barriers on metal surfaces, while phosphonates are particularly effective under high-temperature conditions. Urotropine, in turn, demonstrates considerable efficiency in acidizing operations commonly employed in well stimulation. The review also explores the synergistic effects achieved through the combined use of different corrosion inhibitors, resulting in improved overall protection. In addition, it addresses critical challenges such as the environmental impact and toxicity of certain conventional inhibitors, underscoring the urgent need for the development of sustainable and environmentally friendly alternatives. This analysis aims to support the optimization of corrosion control strategies, thereby enhancing operational reliability and extending the service life of vital infrastructure in the oil and gas sector.

The voltammetry method of analysis is used to investigate the electrochemical behavior of zinc(II) and thiosulfate (\(\text{S}_{2}\text{O}_{3}^{2-}\)) ions in acidic solutions and their electrochemical deposition onto glass coated with a conductive layer of tin oxide. It is found that electrodeposition conducted according to the two-electrode scheme using the pulse current generated by the industrial alternating current produces sound zinc sulfide deposits. Physical and chemical properties of obtained zinc sulfide films have been characterized by using scanning electron microscope and UV spectroscopy. The "cross-section" method is used to determine the thickness of zinc sulfide film, which is equal to 140–160 nm. The obtained films have n-type conductivity.

This study investigates, for the first time, the influence of polyvinylpyrrolidone (PVP) concen­tration in the precursor solution on the structural, morphological, and photoelectrochemical (PEC) properties of BiSI/Bi13S18I2 thin films synthesized via one-step chemical bath depo­sition. By varying the PVP content from 0 to 3.0 wt.%, a clear correlation is established bet­ween polymer-assisted precursor stabilization, phase formation pathways, and the result­ing PEC performance. SEM and XRD analyses reveal that 2.5 wt.% PVP yields dense, uniform, and highly crystalline heterophase BiSI/Bi13S18I2 films with minimized grain-boun­dary den­sity, whereas insufficient polymer leads to discontinuous coatings and excess PVP induces surface passivation and suppressed crystallization. The optimized film (2.5 wt.% PVP) exhibits the highest photocurrent density (15.7 ± 0.31 μA cm-2) and quantum efficiency (IPCE at 465 nm = 2.62 ± 0.04 %) in 0.5 M Na2SO4. To elucidate interfacial charge-transfer kinetics and operational stability, the PEC behaviour was further investigated in electrolytes with varying redox activity: Na2SO4, Na2SO3, and a mixed electrolyte of Na2SO3 + Na2SO4. The inert sulphate electrolyte reflects intrinsic semiconductor performance and provides the highest stability, whereas sulphite-containing solutions reveal defect-mediated pathways, accelerated hole extraction, and increased susceptibility to photocorrosion. The mixed electrolyte yields the highest photocurrent (25.21 ± 0.38 μA cm-2) but also demonstrates amplified dark currents and gradual degradation. These results establish a structure-property-performance relationship for Bi-based chalcohalide photoanodes and provide practical guidelines for tuning polymer concentration and electrolyte composition to enhance PEC efficiency and stability in aqueous solar-driven systems.

Антикоррозионные праймерные покрытия на основе акрилатных триалкоксисиланов

In this study, a high molecular weight epoxy resin (ELM-NG 900Z) based on diglycidyl ether of bisphenol A was cured with different types of hardeners to examine their impact on the physical and mechanical properties of the epoxy resin. The hardeners used were G-5022X70 (140-170 mg KOH/g), G-A0533 (310-350 mg KOH/g), and G-0930 (280-320 mg KOH/g). The results indicated that the hardener G-A0533 provided the best mechanical properties for the epoxy resin compared to other hardeners. Furthermore, various additives including silica fume, talc, barium sulfate, ferric oxide, and pigments were mixed with the epoxy resin in the presence of the hardener G-A0533 to enhance its mechanical properties. It was observed that the addition of 3% silica fume, 10% ferric oxide, and 3% inorganic pigments improved the mechanical properties, while the addition of 5% talc decreased most mechanical properties and only increased hardness. The incorporation of barium sulfate into the epoxy resin enhanced adhesion and flexural strength but decreased tensile strength and hardness. The inclusion of organic pigment had no significant effect on the mechanical properties of the epoxy resin. This enhancement in mechanical properties is attributed to the type of hardener used as well as the types and amounts of additives mixed with the epoxy resin.

The formation of phosphate conversion coatings on St20 low-carbon steel was studied in order to evaluate the effect of organic accelerators on coating formation and protective performance. The influence of pH, temperature, treatment time, and stirring rate on coating formation was studied by gravimetry and SEM-EDS, the influence of accelerators was studied by Raman spectroscopy, salt spray testing, polarization measurements, EIS, and dynamic LPR monitoring. Efficient coating formation was achieved at an initial pH of 3.0, elevated temperature, and intensive stirring; the process showed diffusion-controlled behavior with an apparent activation energy of 28 kJ/mol. Sodium nitrite accelerated coating formation but did not increase the limiting coating mass. Among the organic additives, catechol provided the most pronounced improvement in corrosion resistance, which was attributed to lower effective porosity and possible incorporation of catechol-derived oxidized fragments into the phosphate layer. The catechol-modified coating also improved electrochemical resistance and did not impair the adhesion of subsequent acrylic paint. These results indicate that catechol is a promising organic modifier for zinc phosphate intermediate pretreatment layers.