The Armada complex of gas condensate fields located in the UK North Sea is to be developed. The corrosive nature of the produced fluids required the selection of corrosion resistant alloy tubular materials. The corrosion and sulphide stress cracking resistance of a standard 13 Cr stainless steel and a 13 Cr steel with a higher nickel and molybdenum content were investigated in simulated Armada field environments. The steels were exposed to simulated formation and condensed water, up to 1.46 MPa (212 psi) CO2 and up to 0.001 MPa (0.15 psi) H2S. Neither steel suffered from sulphide stress cracking. The modified 13 Cr steel remained passive in the simulated field environments. The standard BCr steel showed more complex behaviour. In low chloride simulated condensed water, low rates of corrosion and no localised attack were found. In high chloride simulated formation water, pitting attack was observed at 20°C while at temperatures above 70°C scales formed on the metal surface. The results indicate that in these conditions pitting attack is a more significant threat than sulphide stress cracking.

Subject
Water, Materials, Corrosion rate, Aqueous environments, Partial pressures, General corrosion rate, Condensed water, Corrosion attacks, Corrosion scales, Scale formation, Steel, Pitting, Sulfide stress cracking
Keywords:
martensitic stainless steel, 13% Cr steel, sulphide stress cracking, pitting corrosion, carbon dioxide, hydrogen sulphide, tubulars, autoclave testing, simulated field conditions
© 1995 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).
1995
Association for Materials Protection and Performance (AMPP)
You do not currently have access to this content.