Thue S. Bording

Regional Geothermal 3D Modeling in Denmark

We present first results of a 3D model of the subsurface temperature in Denmark. Updated temperatures are contoured for the Gassum formation which is currently utilized for geothermal energy production. The Gassum formation of Upper Triassic/Lower Jurassic age is present in most of Denmark with sufficient net sand thickness and temperatures between 50oC and 80oC in large areas. This makes this formation of particular interest for further geothermal exploration. The regional geothermal model is expected to aid decision makers in future prospecting of geothermal resources in Denmark.

The Thermal Properties of the Subsurface – Key Parameters for Geothermal Energy Utilization

Often the investigation of petrophysical properties is far behind the capabilities of sophisticated modelling techniques applied in basin and geothermal modelling and for which these data serve as an input. Therefore, more in-depth investigations especially of thermal properties are requested. We evaluate different methods and devices for measuring rock thermal properties including thermal conductivity and thermal diffusivity and will compare the results to assure a high quality of these important key parameters.

Improved Inversion of Needle Probe Data for the Determination of Rock Thermal Properties

Heat flow, thermal conductivity and thermal diffusivity are essential properties in subsurface temperature modelling. We present initial results of a novel inversion approach for laboratory measurements of rock thermal conductivity and thermal diffusivity by the needle probe method. Instead of analytical expressions, we use a numerical finite element procedure for the forward temperature response. A Markov Chain Monte Carlo Metropolis Hastings inversion procedure produces estimates of rock thermal parameters with uncertainties.

Estimating thermal conductivity from geophysical well logs: Selected boreholes in Danish sedimentary basins

Estimating temperatures in sedimentary basins and geothermal reservoirs requires knowledge of heat flow, thermal conductivity, heat production, and the surface temperature history. Contrary to heat flow, thermal conductivity typically shows large local variability, both on vertical and horizontal scale, resulting in large variations in temperature gradients. Accurate estimates of thermal conductivity are thus of paramount importance.