3D subsurface modelling of Lychen community considering geothermal aquifers

(bachelor thesis 2011)

The town of Lychen in the north of Brandenburg (NE-Germany) decided to contribute to a sustainable decrease of CO2-emission and to switch to a geothermal energy source to satisfy its heat demand. Proir to building the heat plant, a detailed evaluation of the geology and heat potential is necessary, in order to find an optimal positioning for the drill holes. The bachelor thesis is a part of this prospection work and aimed in the creation of a 3D geological model of the subsurface of the Lychen community.

The data set used for the model was provided by 6 older exploration drills and 8 seismic sections. Based on this data, the geometry of 10 subsurface geological boundary surfaces was modelled using the gocad software. Additionally, the properties of the geothermal aquifer were modelled on an S-grid. A simple linear equation incorporating the local geothermal gradient was applied to calculate the temperature within this aquifer. Since the region is affected by salt-tectonics, the development of surrounding salt-pillows was analyzed and reconstructed from the thickness distribution of several stratigraphic horizons. A risk-assessment of faults was made and revealed a salt-tectonic-related faulting with no significance for the drillings. Finally, the model was compared to older thickness maps derived from seismic data in order to determine the accuracy of the model.

The model delivers a very useful tool to visualize the underground situation of the community and can be used to evaluate the optimal drilling locations. In addition, it provides the basis for further research and hydraulic modelling.

Voigtland

3D model of the ground surface and subsurface of Lychen comprising boundary surfaces of Mesozoic and Cenocoic stratigraphic horizons. The horizons were folded by salt tectonics.

Team

  • Emanuel Buchheim
  • Peggy Hielscher
  • Heiko Fritz