Influence of anisotropic rock properties on the regional temperature distribution in the Thuringian Basin, central Germany: A numerical simulation study

Temperature distribution in the geological subsurface of sedimentary basins is controlled by conductive and advective heat transport processes. The efficiency of these mechanisms is largely governed by the petrophysical properties of the rocks present in a sedimentary basin, with thermal conductivity being of primary importance for conductive heat transfer and permeability for advective heat transport. Sedimentary rocks exhibit a stratification-related anisotropy of both thermal conductivity and permeability, which plays a crucial role in the numerical assessment of thermal conditions in sedimentary basins.

In this study, numerical 3D simulations are carried out using the Thuringian Basin in central Germany as a case study to investigate the influence of anisotropic thermal conductivity and permeability of its Permo-Triassic sedimentary infill on the regional temperature distribution. The modeled results are compared with available temperature measurements in drill holes to evaluate the predictive capability of the simulations. In addition, sensitivity analyses are performed to validate and contextualize the results by quantifying the significance of anisotropic parameters relative to other controlling factors.

The simulation results indicate that accounting for the directional dependence of thermal conductivity and permeability has a significant impact on the regional temperature distribution. In particular, permeability anisotropy exerts a strong control on both the spatial position and the lateral extent of thermal anomalies. Models employing isotropic parameters may significantly underestimate the influence of stratification-induced anisotropy on the subsurface temperature distribution.