Lithology-specific influence of particle size distribution and mineralogical composition on thermal conductivity measurements of rock fragments

Beitrag in einer Fachzeitschrift


Details zur Publikation

Autorinnen und Autoren: Kämmlein M, Stollhofen H
Zeitschrift: Geothermics
Jahr der Veröffentlichung: 2019
Band: 80
Seitenbereich: 119-128
ISSN: 0375-6505
Sprache: Englisch


Abstract

Thermal conductivity data from
reservoir rocks are key parameters for the analysis of heat transfer
processes and heat flow patterns in geothermal exploration. Laboratory
measurements of regional sample sets still provide the most reliable
database. Since well cores are rarely available, rock fragments (e.g.,
drill cuttings) are the most common sample type for laboratory thermal
conductivity measurements. However, the effects of the particle size of
the rock fragments on the determination of thermal conductivity have not
yet been discussed in a systematic study for different rock types.

In
this study, we used a line source device to investigate the influence
of the particle size distribution of rock fragments and powder samples
from different rock types on thermal conductivity measurements. The
study focuses on three main objectives:

1.

Does
the particle size distribution of rock fragments impact thermal
conductivity measurements of sample–water mixtures with a line source?

2.

Are there lithology-specific differences in suitable particle sizes for measurements of thermal conductivity?

3.

Is there an ‘ideal’ or an inappropriate particle size for measurements of rock fragments?

Our
study demonstrates that particle size effects on thermal conductivity
determination of rock fragments and powders are unequivocal and that the
accuracy of thermal conductivity determination can be improved by
consideration of suitable, lithology-specific particle size ranges. The
accuracy of measurement is related to the particle size distribution,
mineralogical composition, competence under mechanical stress, and
porosity of the sample–water mixtures during the measurement. For almost
monomineralic limestones without significant clay volume fractions,
powder samples with particle sizes ≤0.063 mm are most appropriate. In
the case of argillaceous sandstone,
powder samples are an inappropriate sample type, and instead, coarse
rock fragment samples with mean particle sizes of 0.9–1.3 mm are
recommended.


FAU-Autorinnen und Autoren / FAU-Herausgeberinnen und Herausgeber

Kämmlein, Marion
Lehrstuhl für Geologie (Exogene Dynamik)
Stollhofen, Harald Prof. Dr.
Lehrstuhl für Geologie (Exogene Dynamik)


Forschungsbereiche

Tiefe Geothermie
Lehrstuhl für Geologie (Exogene Dynamik)
Klima und Ressourcen
Forschungsschwerpunkt einer Fakultät: Naturwissenschaftliche Fakultät


Zitierweisen

APA:
Kämmlein, M., & Stollhofen, H. (2019). Lithology-specific influence of particle size distribution and mineralogical composition on thermal conductivity measurements of rock fragments. Geothermics, 80, 119-128. https://dx.doi.org/10.1016/j.geothermics.2019.03.001

MLA:
Kämmlein, Marion, and Harald Stollhofen. "Lithology-specific influence of particle size distribution and mineralogical composition on thermal conductivity measurements of rock fragments." Geothermics 80 (2019): 119-128.

BibTeX: 

Zuletzt aktualisiert 2019-26-04 um 08:48