Component parts of the World Heat Flow Data Collection

Component parts of the World Heat Flow Data Collectio

Estimating deep temperatures in the Soultz‐sous‐Forêts geothermal area (France) from magnetotelluric data

International audienceAn indirect electromagnetic geothermometer is used for deep temperature estimations in the Soultzsous-Forêts geothermal area (France) using magnetotelluric sounding data. Validation of temperatureassessment carried out by comparison of the forecast temperature profile with temperature log fromthe deepest borehole has resulted in the relative extrapolation accuracy of less than 2%. It is foundthat the resistivity’s uncertainty caused by magnetotelluric inversion errors and by possible effects ofexternal factors very weakly affects the resulting temperature, with the latter being influencedmainly by the ratio between the borehole length and the extrapolation depth. The temperature crosssectionconstructed up to the depth 5000 m manifests local temperature maxima at large depthsbeneath the wells GPK2 and RT1/RT3. The analysis of the temperature profile in GPK2 locationbeneath 5000 m indicates that its behaviour continues to be of the conductive type (as in the depthrange of 3700 m–5000 m) up to the depth 6000 m, while manifesting convective type below thisdepth. Finally, application of the indirect electromagnetic geothermometer for the deep temperatureforecasting in the Rittershoffen site enabled us to constrain the location for future drilling