In geothermal energy generation from deep reservoirs one needs to handle with fluids, which are mostly highly saline. These solutions get reinjected into the reservoir under new pressure and temperature conditions. The circulation of the thermal fluid in the reservoir is indispensable to ensure a sustainable, long-term operation at economically reasonable pressure conditions. In the course of this reinjection, it can precipitate minerals in the fracture, pore and crack network of the geothermal reservoir (reservoir scaling). With the reservoir scaling, the hydraulic and mechanical properties of the mountains change, so that the mountain permeability could be reduced significantly. Within the scope of this sub-project, models for describing the variable deformation behavior of discontinuity surfaces are developed based on the investigations of the network partners. The derived models are implemented in an existing software environment (roxol) and then used to describe the changing geomechanical behavior of the region near the drilling.
In NRW, carbonates are widely available at depths with temperatures sufficient for geothermal heat utilisation. The KarboEx project is dedicated to this. In contrast to the Bavarian Molasse, the carbonates in NRW have not yet been sufficiently explored. Exploration is basically a cost-intensive task, especially when large areas are involved. The proposed project is therefore initially based exclusively on the processing of existing data with this new objective. These are about 1,000 km of 2D seismic, 29 3D seismic measurements and 1,300 deep boreholes from hard coal exploration and findings from hard coal mining. Other existing data, e.g. from analogue surveys, are taken into account. The results of this research project can be used to estimate the geothermal potential of the carbonates of the Carboniferous and Devonian in NRW (at comparatively low cost compared to the usual costs of new exploration) and to control further exploration activities. The ultimate goal is to create the conditions for the construction of a larger number of heating plants at suitable locations (neighbourhood solutions) and the replacement of fossil heat sources such as coal or gas cogeneration with a renewable heat source.
Within the StimTec-X project, geomecon is developing a statistics module for the extended evaluation of the crack mechanics results of the R&D software roxol. These results will help the project partners to evaluate the stimulations carried out in the Reichen Zeche (Freiberg).
go to project website