Pessu, F, Barker, R and Neville, A (2015) Early stages of pitting corrosion of UNS K03014 carbon steel in sour corrosion environments: The influence of CO2, H2S and temperature. In: NACE - International Corrosion Conference Series. Corrosion Conference and Expo 2015, 15-19 Mar 2015, Dallas, Texas. NACE International ISBN 9781510801882
Abstract
The challenges in managing localized corrosion failures in oilfields are of serious concern. In environments containing both CO2 and H2S gas, pitting corrosion of carbon steel is considered to be a common occurrence and particularly complex. The actual mechanisms and sequence of electrochemical activities for pitting corrosion in these environments is still not fully understood. The film formation characteristics and morphology in CO2 and H2S-containing systems is also known to influence the pitting corrosion behavior of carbon steel. However, questions still remain as to how the combined presence of CO2 and H2S gas both influence the corrosion mechanisms, as well as pit initiation and propagation. This paper presents part of an ongoing parametric study to investigate pitting corrosion behavior of carbon steel in CO2/H2S-containing environments. The work presented explores the impact of changes in two key process parameters (namely; temperature, absence/presence of 10% H2S and absence/presence of CO2 in the gas phase) on the early process of pitting corrosionon carbon steel in NaCl brines. A pit initiation study is conducted up to 7 hours based on changes in temperature and presence/absence of H2S gas. Corrosion film properties and morphology are studied through a combination of electrochemical and surface analysis techniques which include scanning electron microscopy (SEM) and X-ray diffraction (XRD). The extent of corrosion damage of the carbon steel is evaluated through the implementation of surface interferometry to study discrete pit geometry; namely, the size and depth. The results show that the depths of pits initiated after 7 hours were higher in H2S-containing environments (10% H2S in the gas phase), while general corrosion rates dominate the degradation mechanism when CO2 gas is solely present.
Metadata
Item Type: | Proceedings Paper |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2015, NACE International. This is an author produced version of a paper published in Proceedings of the Corrosion Conference 2015. |
Keywords: | Carbon dioxide corrosion, hydrogen sulfide corrosion, Iron sulfide, uniform corrosion, pitting, localized corrosion |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Mechanical Engineering (Leeds) > Institute of Functional Surfaces (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 07 Dec 2015 15:19 |
Last Modified: | 18 Jan 2018 09:38 |
Status: | Published |
Publisher: | NACE International |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:92551 |