Raw seawater injection is an increasingly used technology in oil production. The injection of water allows more oil to be retrieved from a well. A large advantage of using raw seawater compared to treated seawater is that no surveillance is needed, and hence, the manning can be reduced. However, raw seawater requires the use of more corrosion resistant alloys than treated seawater. UNS S33207 is a newly developed hyperduplex stainless steel for umbilicals. It has a minimum PREN of 50. Recently, large diameter tubing has been developed with minimum yield strength of 101 ksi in the solution annealed condition, which results in a high strength material with a low level of anisotropy for the mechanical properties. The crevice corrosion resistance was evaluated by laboratory testing. In addition, crevice corrosion testing of UNS S33207 in natural seawater with severe crevices was performed, demonstrating very good crevice corrosion resistance. Furthermore, no indications of stress corrosion cracking in SSRT-testing in synthetic seawater at 80°C were found. The mechanical properties of the large diameter tubing and the results from the corrosion testing show that UNS S33207 is a good candidate tubing material for raw seawater injection.

Subject
Test methods, Materials, Tubes, Seawater injection, Synthetic seawater, Seawater, Mechanical properties, Tubing, Crevice corrosion, Corrosion resistance, Yield strength, Corrosion potential, Stress corrosion cracking
Keywords:
Hyperduplex, Raw seawater injection, Crevice corrosion, Stress corrosion cracking, Tubing
© 2011 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).
2011
Association for Materials Protection and Performance (AMPP)
You do not currently have access to this content.