New approaches for the relationship between compressional wave velocity and thermal conductivity

Thermal conductivity is an important property for geothermal and geological applications. In most cases thermal conductivity is determined by laboratory techniques, due to difficult measuring directly in the field or borehole. Therefore relationships between thermal conductivity and properties, like compressional wave velocity or resistivity, available from field or borehole measurements are of special interest. In this study we present two models that can describe the correlation between thermal conductivity and compressional wave velocity depending on the rock type. Each starts with a solid matrix model and followed by a second step to implement defects and inclusions. The two important factors for thermal conductivity - mineral composition and cracks/fractures, are expressed in both models. The models show equally good correlation with measured data and the few outliers can be explained through the mineral composition.

► We model the correlation of compressional wave velocity and thermal conductivity. ► Two simple models are used, a defect and an inclusions model. ► Both can demonstrate the coupled influence of mineral composition and cracks. ► They worked really well for magmatic rocks.