Insight into Carbon Black and Silica Fume as Cement Additives for Geoenergy Wells: Linking Mineralogy to Mechanical and Physical Properties

Thomas Sammer, Arash Nasiri, Nikolaos Kostoglou, Krishna Ravi, Johann Raith

Research output: Contribution to journalArticleResearchpeer-review

Abstract

The geoenergy industry has challenging demands on cements used as downhole materials. Once placed in the annular space, the cement sheath must be very low permeability and mechanically durable. Its characteristics are strongly influenced by its microstructure. A holistic approach, including combined mineralogical, physical, and mechanical investigations, provides a better understanding of how these characteristics interplay. Class G cement was investigated and compared to cement formulations containing carbon black or silica fu me, trying to tailor its performance. The addition of carbon black and silica fume has some effect on the modal and chemical phase composition and results in a much denser microstructure. Furthermore, porosity is reduced while the pore size distribution remains similar. Samples containing carbon black have a reduced Young’s modulus, indicating a more plastic behavior. The addition of silica fume increased both mechanical strength and permeability. However, comparable results can also be achieved by carefully tuning the water/cement ratio of the initial slurry.
Original languageEnglish
Article number71
Number of pages22
JournalC – journal of carbon research
Volume10.2024
Issue number3
DOIs
Publication statusPublished - 8 Aug 2024

Bibliographical note

Publisher Copyright: © 2024 by the authors.

Keywords

  • carbon black
  • geoenergy well cement
  • mechanical properties
  • microstructure
  • mineralogy
  • physical properties
  • silica fume

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