The use of geothermal energy in Bavaria increased considerably in recent years, and practical experience in geothermal plant operation for heat and power generation has shown a primary need for research. To answer questions related to deep geothermal energy and to concentrate and link operating experience of the operators, the Geothermie-Allianz Bayern (GAB) was founded.
Bavaria has a unique geothermal potential in Germany. In particular, the South-German Molasse Basin south of Munich offers ideal conditions for the development of hydrothermal geothermal energy. The present project aims to reduce the risk of geothermal search in the South German Molasse Basin and to optimize reservoir engineering. For this purpose, the hydraulic effectiveness of disturbances will be investigated by a structure-stress analysis (Reinecker 2010). The disturbance zones near drilled holes will be characterized geologically, seismically and geomechanically. The results provide data for a reference model of the southern Molasse basin. In addition, the local stress situation around the borehole will be evaluated and a geomechanical reservoir model will be constructed using data from the geomechanical near-field analysis (Seithel et al. 2015). In order to complete the database of the mechanical properties of representative types of rock, extensive investigations will be carried out in the laboratory. This will be done with samples from geothermal drillings as well as with so-called analogue samples, which come from geologic or petro-graphic explorations, e.g. quarries.
Furthermore, petrothermal potential in crystalline rocks is focused in the northern part of Bavaria (Riemer 2011). The development and use of this future technology initially requires extensive research, but then it has an outstanding future potential, since the use of geothermal energy is not limited to water in depth (Bauer 2000). Considering local geology, natural stress conditions and geomechanical laboratory parameters, numerical modeling approaches shall show in which part of the investigation area hydraulically division surfaces of defined orientation will appear with priority in case of stimulation measurements. The results will be validated using the above mentioned borehole and exploration analogue data and will serve to predict existing rock anisotropies after stimulation measurements. The slip-tendency analysis is used here to investigate the behavior of already existing interfaces / disturbance zones in a defined stress field. It is used to identify potentially re-activatable faults and to selectively prevent seismic events during fluid injections.
