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Title: Chemical structure of cement aged at normal and elevated temperatures and pressures

Journal Article · · Cement and Concrete Research
 [1];  [2];  [2];  [3]
  1. Institut Francais du Petrole, 1-4 av de Bois Preau, 92852 Rueil-Malmaison (France) and Laboratoire de Physique et Mecanique des Milieux Heterogenes UMR CNRS 7636, Ecole Superieure de Physique et Chimie Industrielles, 10 rue Vauquelin, 75231 Paris Cedex 05 (France)
  2. Institut Francais du Petrole, 1-4 av de Bois Preau, 92852 Rueil-Malmaison (France)
  3. Laboratoire de Physique et Mecanique des Milieux Heterogenes UMR CNRS 7636, Ecole Superieure de Physique et Chimie Industrielles, 10 rue Vauquelin, 75231 Paris Cedex 05 (France)

The prime objective of the plug-and-abandon operations is to provide zonal isolation for infinite time. Cement-based materials are generally used as plugging materials. Therefore, it is important to understand the physical and chemical processes causing cement degradation in the downhole environment. In this study, we have characterised a Class G oilwell cement immersed for 1 year in brine at T=293 K, p=10{sup 5} Pa and T=353 K, p=7x10{sup 6} Pa using NMR and XRD techniques. In order to have a better understanding of the {sup 27}Al NMR spectra, selective dissolution has been performed. The results show that after 1 year of immersion in brine at T=293 K, p=10{sup 5} Pa, monosulfate is converted to Friedel's salt. Leaching resulted in the disappearance of portlandite and the formation of calcite and a more polymerised calcium silicate hydrates (C-S-H). In the T=353 K, p=7x10{sup 6} Pa mineralogy, ettringite is converted to hydrogrossular.

OSTI ID:
20793265
Journal Information:
Cement and Concrete Research, Vol. 36, Issue 1; Other Information: DOI: 10.1016/j.cemconres.2004.09.018; PII: S0008-8846(04)00425-9; Copyright (c) 2004 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0008-8846
Country of Publication:
United States
Language:
English