Geothermal 3-D Modell for the City of Hamburg and surrounding areas

Temperature prediction down to 6 km Depth


By order of the geological survey of the city of Hamburg we developed a numerical 3-D model to evaluate the geothermal potential of the subsurface. The geothermal model is based on a geological 3-D model which was provided by the geological survey of Schleswig-Holstein. The objective was to simulate the undisturbed temperature field affected by the tectonic setting. 


The geological model represents all important lithological units down to the Rotliegend including the existing salt structures. The corresponding regional numerical model extends over an area of 35 km x 28 km down to a depth of 6 km. For a reliable temperature prediction it was necessary to define the thermal properties precisely, in particular thermal conductivity. For this purpose we compiled existing borehole data, and in combination with other data from the North German basin we were able to assign representative values of thermal properties to each geological unit. Undisturbed temperature logs of deep boreholes in the regarded area could be used for model calibration. These data agree well with the steady-state simulations, using the derived thermal properties. The model results show the significant influence of the salt structures due to their comparable high thermal conductivity: at reservoir depths of approximately 3.5 km horizontal temperature variations of more than 35 K are possible.


Thus, this regional model allows to reliably predict temperatures for any target area or reservoir within the model domain. The model provides the basis for further reservoir simulations to predict the long term production behaviour of deep installation such as a geothermal doublet.


Model results can be requested by Behörde für Stadtentwicklung und Umwelt (U), Geologisches Landesamt Hamburg