Unraveling effects of CO2 and H2S on the corrosion behavior of electroless Ni-P coating in CO2/H2S/Cl- environments


Generally, various materials and structural components are susceptible to failures. For example, corrosion is a cause of failure in carbon steel, which is used in most steam-assisted gravity drainage operations. This can be attributed to the presence of corrosive species in the well, such as carbon dioxide, hydrogen sulfide, and chlorine compounds. This has led to the deployment of various anti-corrosion measures like corrosion-resistant alloys. Unfortunately, application of these measures is limited considering the high initial investment required. Therefore, developing cost-effective corrosion prevention measures is highly desirable.

Among the available anti-corrosion coatings, electroless Ni-P coating has attracted significant attention from researchers, owing to its favorable mechanical and corrosion resistance properties. Corrosion performance of Ni-P coating has been investigated in various environments. For example, in acidic environments, high-phosphorous Ni-P coating exhibits superior corrosion resistance. However, most of the previously conducted research concerning the corrosion performance of Ni-P coating relied mainly on the presence of chlorine, acids, carbon dioxide, and hydrogen sulfide mostly at room temperature. Therefore, assuming the same results for corrosion performance at an elevated temperature may not give the desired outcome. As such, understanding the corrosion performance of Ni-P at high temperatures is highly desirable.

To this note, University of Alberta researchers Dr. Chong Sun, Professor Hongbo Zeng, and Professor Jing-Li Luo studied the corrosion mechanism in Ni-P coating, specifically in harsh environments. Their main objective was to ascertain the feasibility of using Ni-P coating as a corrosion-preventive measure in high-temperature and -pressure environments. Generally, their work was based on both theoretical and experimental approaches for analyzing the corrosion behaviors of Ni-P coatings. Consequently, it was necessary to investigate the defects in Ni-P coatings and their influence on corrosion resistance.

Various methods (i.e., weight loss test, water chemistry analysis, and surface characterization) were used to investigate the effects of carbon dioxide and hydrogen sulfide on the corrosion behavior of Ni-P coating. This entailed conducting laboratory scale and on-site corrosion tests under varying environmental conditions. Eventually, they proposed a corrosion model to analyze the degradation effects of Ni-P coatings in harsh environments.

The authors observed that the Ni-P coating exhibited significant corrosion resistance in a carbon dioxide environment as compared with hydrogen sulfide and H2S-CO2 environments. On the other hand, the coexistence of H2S-CO2 resulted in remarkable effects on the degradation of the coating. This was attributed to blocking the formation of the protective oxide film by the sulfide species. Alternatively, hydrogen sulfide significantly enabled electrolyte penetration in the micro-defects, thus resulting in the corrosion of the substrate.

In summary, the Canadian scientists reported the effects of carbon dioxide and hydrogen sulfide on the corrosion behavior of electroless Ni-P coatings in different environments. Considering the obtained results, the study provides vital information that will advance corrosion prevention in structures and materials, thus ensuring durability and excellent functionality.

The work was published in March 2019 in the Corrosion Science journal. The samples were provided by RGL Reservoir Management Inc., an international oil and gas engineering, manufacturing, and service company specializing in sand control and flow control technologies. RGL Reservoir Management Inc. also provided industrial insight for the research project and testing material and condition. Research funding was provided by Natural Sciences and Engineering Research Council of Canada/RGL Reservoir Management Inc. Collaborative Research and Development Grants.

Unraveling the effects of CO2 and H2S on the corrosion behavior of electroless Ni-P coating in CO2/H2S/Cl- environments at high temperatures and high pressure - Advances in Engineering

About the author

Chong Sun is a Postdoctoral Fellow in the Department of Chemical and Materials Engineering at University of Alberta, Canada. He received his PhD in Materials Science and Engineering at China University of Petroleum (East China) in 2016. He mainly conducts research on corrosion and prevention of oil & gas equipment and CO2 transport pipeline in carbon capture and storage. He has published over 20 papers in refereed journals and holds seven China patents.

He was a recipient of Excellent Doctoral Dissertation Award of Shandong Province in China (2018), Ten Academic Elites of China University of Petroleum (East China) (2016), National Scholarship for China PhD Student (2016), 2st Prize in the 3rd Petroleum Equipment Innovative Design Competition for China Postgraduate (2016), Yanchang Petroleum Group Scholarship for China PhD Student (2015, 2014), Excellent Bachelor Dissertation Award of Shandong Province in China (2012), Outstanding Undergraduate of Shandong Province in China (2011) and National Scholarship for China Undergraduate (2010).

About the author

Hongbo Zeng is a Professor in the Department of Chemical and Materials Engineering at the University of Alberta, a Tier 1 Canada Research Chair in intermolecular forces and interfacial science, a Member of the Royal Society of Canada’s College of New Scholars, and a Fellow of the Canadian Academy of Engineering. He received his BSc and MSc at Tsinghua University and PhD at the University of California, Santa Barbara.

His research interests are in colloid and interface science, functional materials & nanotechnology, with a special focus on intermolecular and surface interactions in soft matter (e.g., polymers, biopolymers, biological systems) and engineering processes. He has published 245 peer-reviewed articles in top journals, 7 book chapters, and coauthored/edited a book “Polymer Adhesion, Friction and Lubrication” (Wiley). He was a recipient of the Petro-Canada Young Innovator Award (2013), Martha Cook Piper Research Prize (2016), The Canadian Journal of Chemical Engineering Lectureship Award (2016), Engineering Research Award (2018) and Engineering Undergraduate Teaching Award (2018) of the University of Alberta, Hatch Innovation Award of The Chemical Institute of Canada (2018), Great Supervisor Award of The University of Alberta (2019), NSERC E.W.R. Steacie Memorial Fellowship (2019).

About the author

Dr. Jing-Li Luo is a professor in the Department of Chemical and Materials Engineering at the University of Alberta, Canada and Follow of Canadian Academy of Engineering. Dr. Luo received her B. Eng. Degree from University of Science and Technology Beijing in 1982 and her Ph.D from McMaster University, Canada in 1992 under the supervision of Professor Brian Ives. She joined the University of Alberta in 1995 with the Women’s Faculty Award funded by Natural Sciences & Engineering Research Council of Canada. She has served as a council member of International Corrosion Council since 2005, Editorial Board member of Corrosion Science, Editorial Board member of Electrochemical Energy Reviews (EER) (Springer-Nature publishing group), Board Committee Member of Fuel cells, the International Academy of Electrochemical Energy Science (IAOEES), Canadian Research Chair in Alternative Fuel Cells (2004-2015).

Dr. Luo has conducted extensive research on corrosion mechanism of erosion corrosion of pipeline in flowing slurry, corrosion of nuclear materials, corrosion control and prevention, the development of new alternative fuel cell processes and electrocatalysts, CO2 conversion and energy storage. She has published over 300 papers in refereed journals and holds six US patents. Dr. Luo is the recipient of a number of awards including; Canadian Metal Chemistry Award in 2014; McCalla Professorship, University of Alberta in 2003; and Morris Cohen Award in 2002.


Sun, C., Zeng, H., & Luo, J. (2019). Unraveling the effects of CO2 and H2S on the corrosion behavior of electroless Ni-P coating in CO2/H2S/Cl environments at high temperature and high pressure. Corrosion Science, 148, 317-330.

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