The construction of a geothermal power plant requires the exploration of the underground geothermal reservoir at an early stage. The resource must be explored using indirect methods. In addition to the location of the underground reservoir, further characteristics such as structure, temperature and geology of the reservoir must be determined. Once the first boreholes have been drilled, further exploration measures of the reservoir are required.
Our working group uses various geophysical methods for exploration:
- Magnetotelluric measurements to allow statements about fluid movement in the subsurface and the occurrence of impermeable clay formations.
- The monitoring of induced microseismicity allows the evaluation of the reservoir volume and statements about tectonic stresses in the reservoir.
- Borehole logging methods allow the calculation and determination of reservoir parameters by indirect access to the reservoir. This allows to develop an understanding of the processes taking place in the reservoir in order to optimize the management of the resource.
- The interpretation of seismic data sets allows the determination of layer thicknesses and the location of fault zones.
- Hydraulic tests allow statements about the permeability, the storage capacity and, if necessary, also about the extent and type of the reservoir.
In addition, we use geochemical methods in close cooperation with the AGW Division for Geochemistry to identify processes in the reservoir. Analysis of dissolved fluid components (geothermometry) allows estimatiom of the reservoir temperature and characterization of the water-rock interactions. Reservoir characterization is also supported by isotope analysis.
We carry out our exploration activities in different geological regions. Among others, we are active in rift systems (Upper Rhine Graben), in the granitic basement (Black Forest) and in high-enthalpy regions.