Papers by Keyword: Inhibitor

Abstract: The inhibition effect of Cefalexin on the corrosion of mild steel in sodium chloride has been examined with the use of weight loss and potentiodynamic polarization methods at ambient temperature. Cefalexin showed good protection ability by adsorbing on the mild steel surface. The mixed inhibition characteristics of Cefalexin were revealed by the Potentiodynamic polarization results. The inhibitor efficiency was found to be above 65% obeying the Langmuir and Freundlich isotherm law with correlation regression coefficients of R² = 0.9984 and R² = 0.9488, respectively. The closeness of these R² values to unity established the reliability of Cefalexin as an inhibitor.

Abstract: Currently, inhibitory protection is one of the most effective and common methods of protecting the inner surface of oil field equipment from corrosion. The work explores the mechanism of protective action of new inhibitors based on quaternary ammonium compounds and assesses feasibility of their practical application in oil fields of OJSC Surgutneftegas. Studies were conducted on samples made of pipe steels A 568M, A 516-55 and 13CrV (rus 13ХФА) in a model produced water solution. Three corrosion inhibitors were tested. Parameters of the mechanism of protective action of reagents were determined by potentiodynamic analysis.

Abstract: The adsorption behavior and inhibition mechanism of (1, 4, 7-Tris [hydrogen (6-methylpyridin-2-yl) phosphonate] -1, 4, 7-triazacyclononane) (TPP) on the corrosion of mild steel in 1 M HCl were investigated by weight loss technique, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) methods for different concentrations at 25°C. The results show that the inhibition efficiency values depend on the amount of immersion times and the concentration. A 90% efficiency is found at the highest concentration of the studied compound according to weight loss measurements. The adsorption of the investigated inhibitor on the mild steel surface was well supported using an AFM study. For the assignment of the absorption sites, we performed quantum chemical calculations with (DFT) method. The interaction between the inhibitor and iron surface were performed by molecular dynamic (MD) simulations. In this paper, experimental methods and results used to assess the efficiency of the studied compound are presented.

Abstract: The failure analysis of 110S tubing during acidizing process was addressed. Results showed that serious pitting corrosion occurred on the outer wall of tubing, and there was no obvious pitting on the inner wall. The maximum pitting depth on the outer wall was 1019 μm. According to the results of simulation corrosion test, needle-shaped pitting appeared on the sample surface in the test without inhibitor, the maximum depth of pitting was 158 μm; and no pitting was found on the sample surface in the test within 1.5% TG501 inhibitor; the original pitting were deepened after spent acid test, and the sample with no pitting at the beginning also showed deep pitting corrosion after 96 hours spent acid test. It was indicated that the spent acid accelerated the development of pitting significantly. The external surface corrosion of the 110S tubing was caused by the chemical reaction between the high-concentration acidifying liquid and the outer wall of the tubing. There is a gap between the tubing and coupling threaded connection, which caused the acid solution entered into the thread position, and hence the severe corrosion of the thread and pin end of the tubing happened, the joint strength was continuously reduced with corrosion development till the tripping of the coupling, and then the lower string dropped. Some suggestions were proposed for avoiding or slowing down this kind of failure based on this study.

Abstract: Corrosion is the main problem in the processing of crude oil containing soap emulsion by using acetic acid based demulsifier. This study aims to analyze corrosion of API 5L Gr B steel pipe in the solution of 90% brine and 10% crude oil with addition of 2000 ppm of acetic acid based demulsifier at various concentration of amine based organic inhibitor. Corrosion testing was conducted using weight loss coupon. SEM and EDS analysis were performed to investigate corroded specimen. The weight loss results indicate that amine based organic inhibitor made the steel resistant to corrosion with an inhibitor effectiveness of up to 96.67% at a concentration of 40 ppm. SEM observation following with EDS analysis identifying the presence of inhibitor and corrosion product protection layer.

Abstract: This paper deals with the investigation of the corrosion situation of oil wells on site. On the basis of water quality analysis, the corrosion status of the site was studied on J55 steel used in the field. The most severe water sample was selected as the medium for electrochemical evaluation and on-site. The screening of four corrosion inhibitors was conducted in our study. Results showed that the salinity of the produced water is relatively high (average value of 29819 mg/L), the chloride ion content is high (average value of 17762.8 mg/L), and the corrosion rate is up to 0.1345 mm/a. Scanning electron microscopy (SEM) was used to analyze the corrosion products and morphology of the studied samples. In the electrochemical evaluation test, the TS-001 corrosion inhibitor has a good corrosion inhibition rate, which can reach up to 97.75% when the dosage is 100 mg/L.

Abstract: The influence of ultrasonic impact treatment on the corrosion resistance of 17G1S steel has been studied. It has been ascertained that the treated surface passivation effectiveness is determined by the optimal combination of ultrasonic treatment mode and choice of a corrosion inhibitor in the corrosion sites treatment. It is shown that ultrasonic impact treatment has a double action: increasing of corrosion resistance and hardening of steel.

Abstract: In this work, the effect of different inhibitors on the thermal stability of the magnetic properties in Fe_73.5Cu₁M₃Si_13.5B₉ nanocrystalline alloys, where M = Nb, W, Mo, was investigated. Nanocrystalline alloy with tungsten has the greatest thermal stability. The change in the magnetic properties in the ageing process was associated with vacancies and vacancy clusters, the formation of which is facilitated by large atoms of inhibitory elements occupying free positions in the substitution solid solution.

Abstract: Inhibitor is a chemical compound which commonly used to control corrosion in a tank or a pipelines. Organic inhibitor recently developed because of the availability and the ability to act like commercial inhibitor. The performance of mixed inhibitor was studied on St 41 carbon steel immersed in NaCl solution containing CO₂ gas. Research parameter used were pH 4 and 6, rotation speed of 150 and 250 rpm, with mixed inhibitor volume ratio of 1 (imidazoline) : 2 (paracetamol), 1:1, also 2:1. The Weight loss measurement, isotherm adsorption calculation, FTIR, and XRD measurement have also been done. Based on weight loss test, the highest inhibitor efficiency was 61.412 % at pH 6, 150 rpm, with inhibitor volume ratio of 2:1, adsorption isotherm calculation indicate the adsorption mechanism of the mixed inhibitor is physical adsorption. Tafel test result showed the tendency of inhibitor worked anodically. The FTIR spectrum result found functional group of N-H from the inhibitor precipitated on the metal surface after ten days of immersion Based on the EIS result, there was an increase value of polarization resistance value and decrease on CPE (constant phase element) value. While X – ray diffraction (XRD) result from the volume ratio of 1:2 confirm the CO₂ corrosion product FeCO₃ and Fe₂O₃ formed on metal surface. With volume ratio of 2:1 mixed inhibitor, it was confirmed that iron nitride (Fe₂₄N₁₀) compound was formed on steel surface because of the chemisorption reaction between Fe and nitrogen atom from pyridine at the imidazoline inhibitor. The inhibition mechanism was physisorption for entire parameters, based on calculation of Langmuir adsorption theorem.

Abstract: The article analyses corrosive stock in an oil and gas field, and the protection method for the equipment in boreholes and in oil pipelines is discussed. Subsurface pumping equipment corrosion rate monitoring method has been improved. In an oil and gas field, the inhibitor is pumped into the oil pipeline directly into the oil-gathering line and into the production boreholes with different dosages. Pilot testing was carried out to optimize the corrosion inhibitor dosage.