  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). 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)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.
