| Abstract |
Meeting the heat demand with renewable energy constitutes a joint endeavor made by many countries to reduce the carbon footprint in the energy sector. Since heat consumption represents more than 50% of the total energy consumption, providing a sustainable solution to the heat demand with renewable energy is of upmost importance. Specifically, deep geothermal energy utilization can significantly contribute to the decarbonization of district heating networks in urban cities where a considerable geothermal potential coincides with a large heat demand. The Bavarian Molasse Basin and in particular the so-called Greater Munich region, Germany has experienced in recent years one of the most dynamic developments in deep geothermal energy utilization. Remarkable efforts have been taken to provide heat to several villages in the outskirts of the city of Munich, where considerable heat is demanded. The successful case of geothermal energy development in the Greater Munich region evidences that substantial heat demand together with significant accessible geothermal resources and an economic, technological and political commitment to renewal energy are key elements for a sustainable and decarbonized district heating development. To accomplish this, major public or private companies such as the municipal energy supplier of Munich (Stadtwerke München - SWM) as well as central financial institutions extensively contributed. Based on the SWM’s district heating vision, the heat demand of the city of Munich should be met by 2040 completely by renewable energy. To attain this goal, geothermal energy extracted from the Upper Jurassic carbonates should contribute most to the heat transition in the city of Munich. Multiple geothermal extraction and production wells are planned by 2040 in the city of Munich. The Greater Munich region is located in the Bavarian Molasse Basin, which classifies as a foreland basin and is one of the most studied foreland basins in the World. Because of recent geothermal exploration and production as well as previous intensive hydrocarbon exploration, extensive and detailed data on the subsurface has been collected to build a 3D thermal-hydraulic reservoir model. During the lifecycle of field development, as new static and dynamic data becomes available the reservoir model requires updating and refining. Subdomains of the reservoir, which have been modelled with less resolution at a regional scale due to lack of data, can be updated with more resolved and reliable data. Based on the 3D seismic survey conducted in southern Munich (GRAME-project) and subsequent interpretation of data, simplified structural, facies and property models fit for dynamic finite-element simulation have been constructed for that region. Besides, an optimized geothermal reservoir management involves the study of possible interferences of neighboring geothermal facilities. Ultimately, history matching of production and injection data with modelling and simulation results is a key ingredient in understanding the inter-well permeability structure and dynamics of the reservoir and thus hints at optimization aspects of field development. The occurrence of earlier than predicted temperature and/or pressure decline at production wells helps to study the possible causes of a premature thermal breakthrough and reservoir compartmentalization. This work concentrates on the study of the Poing, Taufkirchen and Kirchstockach geothermal doublets in order to examine the transferability and comparability of thermal-hydraulic modelling and simulation results in similar reservoir settings. A series of worst-case scenarios focused on the 3D thermal-hydraulic behavior of the reservoir by varying the permeability structure and under different exploitation schemes have been modelled and simulated. 3D thermal-hydraulic modelling and simulation results can be explained by the assumption of breached relay ramp structures that may have been further reworked by karstification processes, providing the permeability structure required. 3D modelling and simulation findings hint at channeled fluid flow between injection and production wells by high-permeability zones. |