PART I - CORROSION CONTROL PROCEDURES AND FAILURE INVESTIGATION

The corrosion control procedures used in an attempt to protect a sour gas pipeline from metal loss corrosion and sulphide stress cracking are described. A combination of pretreatment, inhibition and dehydration was successful in preventing metal loss corrosion but after 18 months operation three failures occurred. Failure analysis revealed that areas of martensite in the inside, harder than normal, weld bead were the origins of this cracking. The resulting martensite and hard inside weld bead were caused by an incorrect combination of welding consumables.

PART II - INHIBITOR INVESTIGATIONS

Investigations into the suitability of a combined liquid phase, vapour phase inhibitor mixture are described. The main thrust of this part of the paper is the successful development of a procedure to analyze residual inhibitor which is present in samples of debris and on pipe surfaces. Also investigated was the persistency of the inhibitor film when exposed to large volumes of water and alcohol.

Subject
Pipe surfaces, Corrosion failures, Materials, Piping, Metal surfaces, Inhibitor films, Walls, Sour gas, Pipelines, Mixtures, Chemical inhibition, Corrosion inhibitors, Samples
© 1987 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).
1987
Association for Materials Protection and Performance (AMPP)
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