The GeoTief EXPLORE 3D Project – an Innovative Deep Geothermal Exploration for a Future Sustainable Heat Supply for the City of Vienna

Abstract

The Southern Vienna Basin possesses up to 60 % of Austria’s estimated resource of deep geothermal energy potential. In addition, the metropolitan area of Vienna has one of the largest district heating (DH) systems in Europe, which is highly applicable for the distribution of geothermal energy (hydrothermal systems) and thus may contribute to the reduction of greenhouse gas emissions in a large scale. Therefore, geothermal energy could play a key role in the future energy supply for Austria’s largest city, the Vienna metropolitan area. The potential geothermal reservoirs, underneath the city of Vienna and its surroundings, comprise Neogene basin sediments and the complex and steep dipping nappes of Triassic carbonates at depths of approximately 2,500 – 6,500 m. Although the Triassic basement of the Vienna Basin has been target of extensive exploration by the hydrocarbon industry, the knowledge about the geothermal reservoir properties is poor. The future development of this renewable heat source depends on efficient exploration and implementation concepts and methods considering technical, economic and regulatory conditions. As a result, several experts from various Austrian universities, research institutions and companies are working together in the research project “GeoTief Wien“. The project’s aim is to develop and implement extensive concepts and methods for the exploration and utilization of deep geothermal energy in the Southern Vienna Basin resulting in a stepwise exploitation of all reservoirs. Furthermore, establishing the City of Vienna as a model region for a sustainable and economic heat supply based on geothermal energy should lead to an increasing use of geothermal energy even throughout Austria and neighbouring countries. As a first step, the project aimed to expand the knowledge about the geothermal reservoirs by collecting, evaluating and preparing geological/geophysical and seismic data. The project team already carried out an innovative geophysical exploration concept, including 2D and 3D seismic acquisition, partly in the urban area of Vienna.