Petrothermal Energy Generation in Crystalline Rocks (Germany)

Abstract

The growing interest in the provision of geothermal energy as part of an energy mix has caused the German government to provide higher subsidies for the development of heat-mining projects. However, to increase the number of geothermal power plants, it is necessary to exploit resources beyond conventional hydrothermal systems and to use the Earth’s huge energy potential. This is possible by developing Enhanced (or engineered) Geothermal Systems (EGS) in hard rock formations to install a so called Petrothermal System. The way to construct such a heat exchanger has not yet been satisfactorily resolved. The proposed project in crystalline rocks is similar to other projects conducted worldwide, so that cross correlations are expected. From an initial phase we will report results from the exploration based on 3D-seismic investigations including thermal rock parameters, thermal models, the modern stress field, and geo-mechanical parameters. In 2014 we plan, in close cooperation with research institutions within a research network, to sink a 6000 m deep exploration well with the aim of establishing a deep-petrothermal reservoir. The principle idea of this procedure is to utilize one or more geological faults or fault zones as a natural heat exchanger to avoid fracturing operations with induced seismicity. The research well should provide comprehensive and fundamental information in order to address the many technical and technological issues that are presently relevant for the implementation of deep geothermal systems in the Federal Republic of Germany.