Thermal conductivity from core and well log data

Abstract

The relationships between thermal conductivity and other petrophysical properties have been analysed for a borehole drilled in a Tertiary Flysch sequence. We establish equations that permit us to predict rock thermal conductivity from logging data. A regression analysis of thermal conductivity, bulk density, and sonic velocity yields thermal conductivity with an average accuracy of better than 0.2 W(m K) -1 . As a second step, logging data is used to compute a lithological depth profile, which in turn is used to calculate a thermal conductivity profile. From a comparison of the conductivity-depth profile and the laboratory data it can be concluded that thermal conductivity can be computed with an accuracy of less than 0.3 W(m K) -1 from conventional wireline data. The comparison of two different models shows that this approach can be practical even if old and incomplete logging data is used. The results can be used to infer thermal conductivity for boreholes without appropriate core data that are drilled in a similar geological setting.

Colloquium 2016: Assessment of subsurface thermal conductivity for geothermal applications

“…Empirical approaches can, on the other hand, directly relate a well log signal to thermal conductivity (Pribnow et al 1993;Kukkonen and Peltoniemi 1998;Popov et al 2003;Hartmann et al 2005;Goutorbe et al 2007;Sundberg et al 2009;Gegenhuber and Schoen 2012;Fuchs and Förster 2013;Gasior and Przelaskowska 2014). Limited well logs signals can be used for that purpose.…”

Influence of depth, temperature, and structure of a crustal heat source on the geothermal reservoirs of Tuscany: numerical modelling and sensitivity study

“…Here, we use the geometric mixing law which has been proven to be a good theoretical description of the effective thermal conductivity of a rock/water mixture (Hartmann et al 2005(Hartmann et al , 2008. The thermal conductivity profiles derived from the logs are calibrated with the laboratory measurements (Fig.…”

Does hydrologic circulation mask frictional heat on faults after large earthquakes?

“…Thermal conductivity varies with density, porosity, grain size, degree of cementation, and mineral composition [e.g., Brigaud and Vasseur, 1989;Hartmann et al, 2005]. Low values of thermal conductivity associated with fault gouge or highly fractured rock may locally perturb temperatures and could be misinterpreted as a very small frictional heat signal [e.g., Tanaka et al, 2007].…”