Geothermal Potential Analyses using Virtual Drilling into CityGML Models The content of this presentation is provided by Thomas H. Kolbe, Robert Kaden, Julia Offer Chair of Geoinformatics, TU München The presentation is given by Andreas Donaubauer Chair of Geoinformatics, TU München, andreas.donaubauer@tum.de March 14 OGC TC Meeting, Crystal City, Arlington, Virginia

Motivation Feasibility studies for geothermal energy systems must take into account constraints from: Earth surface: local energy demand, existing utilities networks, free space for building a geothermal plant … Subsurface: meso-scale information on geological structures with specific physical properties CityGML can be used as an information model for both Earth surface and subsurface constraints Image Source: J. Sippel, O. Kastner, GFZ Potsdam 24.03.2014 Donaubauer, Kolbe, Kaden, Offer: Geothermal Potential Analyses using Virtual Drilling into CityGML Models

Geothermal Potential Model for Berlin Image Source: J. Sippel, O. Kastner, GFZ Potsdam 24.03.2014 Donaubauer, Kolbe, Kaden, Offer: Geothermal Potential Analyses using Virtual Drilling into CityGML Models

Berlin Geothermal Energy Potential Analysis Transformation of the surface model into 3D cells. Each 3D cell is 500m x 500m x thickness of the rock layer at the respective location. Representation in CityGML as GenericCityObjects with generic attributes. Estimation of the Berlin underground model and the geothermal potential by J. Sippel, O. Kastner, GeoForschungsZentrum Potsdam 24.03.2014 Donaubauer, Kolbe, Kaden, Offer: Geothermal Potential Analyses using Virtual Drilling into CityGML Models

What information do we represent and use? 3D model of the deeper underground (-25m to -3,826m) CityGML GenericCityObjects with LOD2 solid geometries. Resolution: 500m x 500m x variable height. Rich thematic information for every 3D object. Fluid density on top surface [kg/m3] Fluid pressure on top surface [MPa] Mean salinity of fluid on top surface [kg/l] Porosity Energy in the rock [TWh], Rock surface energy density [MWh/m2] Energy in the brine [TWh], Brine surface energy density [MWh/m2] Mean temperature on top surface [K] CityGML CityObjectGroups grouping the GenericCityObjects with respect to the rock layers (Jurassic, Keuper etc.) 24.03.2014 Donaubauer, Kolbe, Kaden, Offer: Geothermal Potential Analyses using Virtual Drilling into CityGML Models

Virtual Drilling into the CityGML Model Analyses based on CityGML objects on Earth surface Determination of all buildings in an area Summing up the heating energy demand of the buildings Comparison with the amount of usable geothermal energy If more energy is available, increase size of region Virtual Drilling / Well Parameters: location, target rock layer (depth), specifics of geothermal plant Estimation: Sustainably producable geothermal energy; usable energy; Technical efforts 24.03.2014 Donaubauer, Kolbe, Kaden, Offer: Geothermal Potential Analyses using Virtual Drilling into CityGML Models

Implementation of the Virtual Drilling Machine: Data Flow 3 Geothermal potential estimator Geological Modeling Tool Geoforschungs-zentrum Potsdam 2 4 1 24.03.2014 Donaubauer, Kolbe, Kaden, Offer: Geothermal Potential Analyses using Virtual Drilling into CityGML Models

Input Parameters of the Geothermal Potential Estimator Geothermal potential model Position(s) of drill hole(s) Target rock layer Specifics of geothermal plant 24.03.2014 Donaubauer, Kolbe, Kaden, Offer: Geothermal Potential Analyses using Virtual Drilling into CityGML Models

Workflow behind the Geothermal Potential Estimator ArcGIS ModelBuilder Model which carries out the following steps: Select all rock layers at drill hole position 24.03.2014 Donaubauer, Kolbe, Kaden, Offer: Geothermal Potential Analyses using Virtual Drilling into CityGML Models

Workflow behind the Geothermal Potential Estimator ArcGIS ModelBuilder Model which carries out the following steps: Select all rock layers at drill hole position Select target rock layer 24.03.2014 Donaubauer, Kolbe, Kaden, Offer: Geothermal Potential Analyses using Virtual Drilling into CityGML Models

Workflow behind the Geothermal Potential Estimator ArcGIS ModelBuilder Model which carries out the following steps: Select all rock layers at drill hole position Select target rock layer Extract minimal and maximal depth from selected 3D object min depth max depth 24.03.2014 Donaubauer, Kolbe, Kaden, Offer: Geothermal Potential Analyses using Virtual Drilling into CityGML Models

Workflow behind the Geothermal Potential Estimator ArcGIS ModelBuilder Model which carries out the following steps: Select all rock layers at drill hole position Select target rock layer Extract minimal and maximal depth from selected 3D object Calculate thermal output of a specific geothermal plant and depth of drill hole based on attributes of 3D object and specifics of geothermal plant Temperature of fluid at production well / injection well Temperature of fluid at production well / injection well delivery capacity 𝑄 = 𝑚 𝐹 𝑐 𝑝 𝑇 𝐼 − 𝑇 𝐹 thermal output specific thermal capacity 24.03.2014 Donaubauer, Kolbe, Kaden, Offer: Geothermal Potential Analyses using Virtual Drilling into CityGML Models

Workflow behind the Geothermal Potential Estimator ArcGIS ModelBuilder Model which carries out the following steps: Select all rock layers at drill hole position Select target rock layer Extract minimal and maximal depth from selected 3D object Calculate thermal output of a specific geothermal plant and depth of drill hole based on attributes of 3D object and specifics of geothermal plant Store results of calculation as attributes of a „virtual well“ feature  semantic enrichment of 3D City Model 24.03.2014 Donaubauer, Kolbe, Kaden, Offer: Geothermal Potential Analyses using Virtual Drilling into CityGML Models

The Geothermal Potential Estimator as part of the Urban Analytics Toolkit 24.03.2014 Donaubauer, Kolbe, Kaden, Offer: Geothermal Potential Analyses using Virtual Drilling into CityGML Models

Conclusions The virtual drilling tool allows for estimating the geothermal energy potential based on a geological model, location, target rock layer and other specifics of a geothermal plant Integrating the virtual drilling tool with a semantic model which represents not only geological formations but also relevant features on the Earth surface with their energy-related properties supports well-informed site selection decisions for geothermal plants Interoperability is key for information integration and reusability of developed tools OGC‘s CityGML defines the semantic model + exchange format 24.03.2014 Donaubauer, Kolbe, Kaden, Offer: Geothermal Potential Analyses using Virtual Drilling into CityGML Models