Iron is soluble in reservoir waters which have high salinity and high hydrogen sulfide content. As the well produces, iron sulfide is precipitated due to the drop in pressure with the resultant increase in pH. The crystallites attach to the lower portion of the tubing, where either bimetallic or crevice corrosion occur beneath the crystallites. Gas condensate wells will deposit a high molecular weight material, such as asphaltene, on the iron sulfide crystallites as they deposit. Under these conditions the scale cannot be removed by hydrochloric acid, surfactants, or chelating agents. Corrosion of the metal continues if the combination layer of iron sulfide and "asphaltene" is cracked, porous, or spalls, but stops if the layer is dense and non-friable. The layer of scale can be removed only by mechanical means, or by removing the binder chemically.

Subject
Water, Materials, Asphaltenes, Iron sulfides, Condensates, Iron, Reservoirs, Corrosion scales, Tubing, Metals, Scale, Deposit corrosion, Hydrocarbons
© 1988 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).
1988
Association for Materials Protection and Performance (AMPP)
You do not currently have access to this content.