Top-of-line (TOL) corrosion is a concern for carbon steel pipelines that transports full well stream wet gas, when these pipelines operate in stratified flow regime. Water may condense at the upper portion of the pipeline, which then becomes corrosive through absorbing acid gases (CO2 and/or H2S) in the environment. The condensed water is generally devoid of corrosion inhibitors that are usually present in the bottom fluids but have difficulty reaching the top-of-line. Previous studies have shown that TOL corrosion mechanisms are different between sweet (CO2 only) and sour (CO2 and H2S) systems. Thus, for TOL corrosion prediction, it is important to determine the threshold environmental conditions where the TOL corrosion switches from sweet to sour. To gain this understanding, experimental studies were performed using a unique TOL autoclave in slightly sour environments. Experimental results presented in this paper will demonstrate the effects of H2S concentration, top-of-line temperature, and condensation rate on TOL corrosion in slightly sour environments.

Subject
Water, Corrosion rate, Sour environments, Pipelines, Condensation rates, Partial pressures, Condensed water, Corrosion scales, Iron carbonate scale, Scale formation, Wet gas, Corrosion coupons, Corrosion mechanisms
Keywords:
Top of line corrosion, condensation, sour corrosion, slightly sour, sweet corrosion
© 2012 Association for Materials Protection and Performance (AMPP). All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means (electronic, mechanical, photocopying, recording, or otherwise) without the prior written permission of AMPP. Positions and opinions advanced in this work are those of the author(s) and not necessarily those of AMPP. Responsibility for the content of the work lies solely with the author(s).
2012
Association for Materials Protection and Performance (AMPP)
You do not currently have access to this content.