TY - JOUR

T1 - Insight into Carbon Black and Silica Fume as Cement Additives for Geoenergy Wells: Linking Mineralogy to Mechanical and Physical Properties

AU - Sammer, Thomas

AU - Nasiri, Arash

AU - Kostoglou, Nikolaos

AU - Ravi, Krishna

AU - Raith, Johann

N1 - Publisher Copyright: © 2024 by the authors.

PY - 2024/8/8

Y1 - 2024/8/8

N2 - 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.

AB - 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.

KW - carbon black

KW - geoenergy well cement

KW - mechanical properties

KW - microstructure

KW - mineralogy

KW - physical properties

KW - silica fume

UR - https://doi.org/10.3390/c10030071

UR - http://www.scopus.com/inward/record.url?scp=85205250851&partnerID=8YFLogxK

U2 - 10.3390/c10030071

DO - 10.3390/c10030071

M3 - Article

VL - 10.2024

JO - C – journal of carbon research

JF - C – journal of carbon research

SN - 2311-5629

IS - 3

M1 - 71

ER -