ISSN 2305-6894

2014, Vol. 3, Issue 1 (pp. 1–77)

Comparison of the protective efficiency of corrosion inhibitors in oilfield pipelines

      • I. S. Sivokon1 and N. N. Andreev2
1 OJSC Transenergostroi, Derbenevskaya nab. 7, bldg. 10, Moscow, 115114 Russian Federation
2A. N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Leninskii pr. 31, Moscow, 119071 Russian Federation

Abstract: This paper is the final article in the series published by the International Journal of Corrosion and Scale Inhibition. The series is dedicated to efficiency evaluation of protection provided by carbon dioxide corrosion inhibitors at oilfield pipelines in West Siberia where the inhibitor selection and efficiency supervision system issues are common in field-wide applications. Laboratory testing is an easy way to properly select corrosion inhibitors by performing a comprehensive set of procedures instead of making a couple of isolated tests trying to simulate most obvious corrosion environment features.

Int. J. Corros. Scale Inhib., 2014, 3, no. 1, 1–11 (PDF 828 K)
doi: 10.17675/2305-6894-2014-3-1-001-011

 

Corrosion inhibition of 1018 carbon steel in hydrochloric acid using Schiff base compounds

      • I. A. Zaafarany
Chemistry Department, Faculty of Sciences, Umm Al-Qura University, Makkah, Saudi Arabia

Abstract: The inhibition effect of some Schiff base compounds toward the corrosion of 1018 carbon steel in hydrochloric acid solution was studied using weight loss, galvanostatic polarization, and electrochemical impedance spectroscopy measurements. The percentage inhibition efficiency increased with increasing inhibitor concentration and with decreasing temperature. The polarization measurements indicated that the inhibitors are of mixed type and inhibit corrosion by adsorption on the steel surface. The adsorption process is described by the Freundlich adsorption isotherm. The activation energy and some activation thermodynamic parameters were calculated and explained. From the impedance data it is found that the corrosion of carbon steel is controlled by the charge transfer process at all concentrations of inhibitors.

Int. J. Corros. Scale Inhib., 2014, 3, no. 1, 12–27 (PDF 1105 K)
doi: 10.17675/2305-6894-2014-3-1-012-027

 

Cationic polymeric chemical inhibitors and multifunctional blends for the control of silica scale in process waters

      • E. Neofotistou and K. D. Demadis
Crystal Engineering, Growth and Design Laboratory, Department of Chemistry, University of Crete, Voutes Campus, Crete, GR-71003, Greece

Abstract: Water is used globally for cooling purposes in industry. During its re-use, scaling and deposition can develop due to the high content of dissolved species. Among the toughest to combat is silica scale, or amorphous silicon dioxide. In this paper, we present how certain chemical interventions in the water chemistry can be beneficial for inhibiting silica polycondensation. Specifically, we have used chemical additives known as dendrimers. These are dendrimeric molecules based on polyaminoamide backbones that possess amine moieties as surface groups. These become protonated at circumneutral pH, hence charging the dendrimer molecules cationically. Their blends with anionic polymers such as polyvinylphosphonic acid are also studied for their silica scale inhibition efficiency.

Int. J. Corros. Scale Inhib., 2014, 3, no. 1, 28–34 (PDF 724 K)
doi: 10.17675/2305-6894-2014-3-1-028-034

 

Calcium sulfate dihydrate (gypsum) scale inhibition by PAA, PAPEMP, and PAA/PAPEMP blend

      • Z. Amjad, R. T. Landgraf and J. L. Penn
Walsh University, Division of Mathematics and Sciences, North Canton OH 44720, USA

Abstract: The effects of poly(acrylic acid), PAA, polyamino polyether methylene phosphonic acid, PAPEMP, and PAA/PAPEMP blend on calcium sulfate dihydrate (gypsum) are reported in this paper. It has been found that gypsum inhibition by PAA increases with increasing PAA concentration. Among the various phoshonates (i.e., aminotris(methylene phosphonic acid), AMP; hydroxyphosphono acetic acid, HPA; hydroxyethylidene 1,1-diphosphonic acid, HEDP; 2-phosphonobutane 1,2,4-tricarboxylic acid, PBTC; and polyether polyamino phosphonic acid, PAPEP) evaluated, PAPEMP shows the best inhibition for gypsum precipitation. It has also been observed that presence of PAPEMP exhibits synergistic effect on the performance of PAA. Results on calcium ion compatibility of various phosphonates show that PAPEMP compared to other phosphonates tested show higher tolerance to calcium ions.

Int. J. Corros. Scale Inhib., 2014, 3, no. 1, 35–47 (PDF 921 K)
doi: 10.17675/2305-6894-2014-3-1-035-047

 

Study of steel corrosion inhibition in media containing H2S
and CO2 by impedance spectroscopy and polarization resistance methods

      • L. E. Tsygankova,1 M. N. Esina,1 V. I. Vigdorovich2 and N. V. Shel2
1Derzhavin State University, Internatsyonalnaya Str., 33, Tambov, 392000, Russian Federation
2Tambov State Technical University, Sovetskaya Str., 106, Tambov, 392000, Russian Federation

Abstract: Inhibition of carbon steel corrosion by “INCORGAS” compositions in a NACE medium containing hydrogen sulfide and carbon dioxide was studied by electrochemical impedance spectroscopy and linear polarization resistance methods. Contribution of the inhibitor to the total protective effect of the “corrosion product film/inhibitor” system was calculated. Polarization measurements testify that the anodic process is hindered in the presence of the inhibitors. The same conclusion was made from the data of electrochemical impedance spectroscopy.

Int. J. Corros. Scale Inhib., 2014, 3, no. 1, 48–58 (PDF 871 K)
doi: 10.17675/2305-6894-2014-3-1-048-058

 

Inhibition of copper pitting corrosion in alkaline sulphate media by benzotriazole at elevated temperatures

      • E. A. Skrypnikova,1 S. A. Kaluzhina2 and L. E. Agafonova2
1MESC Air Force Military Air Academy named after N. E. Zhukovsky and Yu. A. Gagarin, ul. Staryh bolshevikov 54a, Voronezh, 394000 Russian Federation
2Voronezh State University, Universitetskaya pl. 1, Voronezh, 394006 Russian Federation

Abstract: Using complex physical and chemical methods (voltammetry, chronoamperometry, microscopy), the inhibitive action of benzotriazole (BTAH) on copper pitting corrosion (PC) was investigated in alkaline–sulphate solutions in a range of temperatures (20–60°C). It was found that in the background electrolyte (1×10–2 M NaOH + 1×10–2 M Na2SO4 (pH 12)), the intensity of copper PC increases with a temperature growth, whereas addition of an adsorptive inhibitor, namely BTAH, increases the resistance of copper to PC at all the temperatures studied and that the effect is the stronger, the higher the temperature is. Full suppression of PC occurs at C(BTAH) = 8×10–4 M (20°C) and at C(BTAH) = 5×10–7 M (60°C). An explanation of the observed effects was suggested from the viewpoint of modern theories of pitting initiation, adsorption and complex formation phenomena.

Int. J. Corros. Scale Inhib., 2014, 3, no. 1, 59–65 (PDF 875 K)
doi: 10.17675/2305-6894-2014-3-1-059-065

 

Hydrocarbon soluble metal corrosion inhibitors.
I. Physicochemical aspects of the choice of starting products and synthetic reactions

      • A. I. Altsybeeva, V. V. Burlov, E. A. Tronova, T. M. Kuzinova and G. F. Palatik
All-Russia Research Institute of Petrochemical Processes, Zheleznodorozhnyi pr. 40, St. Petersburg, 192148 Russian Federation

Abstract: The relationship between the physicochemical and electronic characteristics of inhibitors that allows one to forecast the efficiency of metal corrosion inhibitors in water-hydrocarbon media is discussed. It has been shown that the main molecular characteristics of aliphatic acid amides obtained from nitrogen-containing compounds with one amino group and an N-methylolcaprolactam ester make it possible to forecast that they should have high efficiency as corrosion inhibitors in hydrocarbon media.

Int. J. Corros. Scale Inhib., 2014, 3, no. 1, 66–77 (PDF 713 K)
doi: 10.17675/2305-6894-2014-3-1-066-077