Evaluation of Sandstone Aquifers of the North German Basin: a Contribution to the "Geothermal Information System of Germany'

Abstract

Numerous boreholes were drilled for the exploration for hydrocarbons in the eastern part of the North German Basin (NGB). These data and the results of geophysical investigations are used for the characterization of the geothermal potential of Mesozoic sandstone layers in NE Germany. Important aquifers for geothermal applications are the sandstones of the Middle Bunter, the Schilfsandstein (Middle Keuper), the sandstone complex of the Rhaetian and Liassic, the Dogger-? sandstone (Aalenian) and the Lower Cretaceous sandstones. These horizons are distributed basin-wide and reach often the required thicknesses. They display good geothermal properties with temperatures > 60?C, porosities > 20% and permeabilities > 500mD. The utilization of geothermal energy of deep aquifers is currently performed in several localities in NE Germany. Geothermal heating plants operate successful for more than 10-20 years. Further installations use thermal water for balneological purposes or they are established as deep seasonal heat storage.