Seismic surveys also help define drilling locations for reservoir development. The exploration of petrothermal reservoirs is determined by the position of various crystalline rock complexes and complex, usually steeply dipping fault systems. The existing geological models are used to extrapolate the structures known from the shallow geology, and the findings from mining activities, down to great depths. Because the target depth is around 5 to 6 km, extrapolations have to be supported by seismic surveys because these surveys can provide a significant amount of structural information on the geological structure of deep underground formations.
In addition to determining the complex 3D underground structure, the other challenges to be solved by the seismic exploration of geothermal reservoirs in crystalline rocks include the very steeply lying structures within the fault zone, and quantifying the degree of fracturing in the reservoir. These questions are to be solved by three research projects undertaken as part of a joint project under the overall management of the Leibniz Institute for Applied Geophysics (LIAG) and the involvement of the University of Hamburg and the Bergakademie Applied Science University in Freiberg: