Empirical relationships of thermal conductivity and petrophysical properties in the German basin
Presenter: Shin-Ting Ding Advisers: Tien-Shun Lin, Wu-Lung Chang
Abstract
Rock thermal conductivities are one of the essential parameters for determining crustal heat flows. If drill cores are not retrieved from boreholes no direct laboratory measurements of thermal conductivity can be made for subsurface rocks/sediments. In this case, petrophysical properties obtained from well logging can be used to determine thermal conductivities. We firstly establish empirical relationships between thermal conductivities and other petrophysical properties, such as density, porosity, and sonic velocity from direct measurements at the same dry rock samples in German basin. A regression analysis of thermal conductivity, bulk density, and sonic velocity yields thermal conductivity with an average accuracy of better than 0.2W(mK)-1. As a second step, logging data are used to compute a lithological depth profile, which in turn is used to calculate a thermal conductivity profile. We comparison of two kinds of thermal conductivity, the average error is 5-9%. If the database is enough to separate different lithotypes, the average error is 4-9%. And the empirical equation could be used in the other study area.
Reference
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Sven et al., 2013. Evaluation of common mixing models for calculating bulk thermal conductivity of sedimentary rocks: correction charts and new conversion equations