Quantitative assessment of geothermal resources in the Oslo and Bergen Regions

Abstract

The geothermal potential of Norway mainland remains unknown. One of the major outcomes of the Kontiki project (2004-2007) was that heat flow values in southern Norway were, at least, 10 mW\/m2 higher than previously thought, opening the perspective for a future use of geothermal energy. A very first attempt was made to estimate underground temperatures well below the deepest levels reached by the scientific drillholes. The study suggested favourable conditions mostly in the Oslo Region but the error bars associated with the temperature determinations were deemed large. In the present project we aim to explore the potential for use of geothermal energy in the most populated areas of Norway: Oslo\/Asker and BergenIMongstad. A relatively large amount of data has already been collected in the Oslo Region in the course of various NGU projects. In contrast, the Bergen and Mongstad areas were not covered by any kind of geothermal data at the start of the present project. We conducted the very first gamma spectrometry study in the Bergen and Mongstad areas in order to assess the heat productivity of the basement. For the Oslo Region we used and completed the existing data in order to model the 3D thermal state at depth.