Effiziente und sichere Nutzung der Geothermie Was kann das GeoLaB dafür leisten?, KIT Geothermal Laboratory in the crystalline Basement for Large scale monitoring of THMC coupled processes KIT University of the State of Baden-Württemberg and National Large-scale Research Center of the Helmholtz Association www.kit.edu
Challenges of geothermal energy use 2
cluffgeothermal.com Advantages of geothermal energy use Can provide base-load power is independent of weather/seasons Low in CO 2 Huge energy potential High availability Low space demand Decentralized energy production Sustainable Combined heat and power production Shallow geothermal is fully competitive 3
Long-term goals for EGS Science Impact of massive hydraulic flow in fractured medium Characterization of coupled processes, Insheim Research Economics facility for in situ experiments is needed! Necessity for the underground research Soultz lab - GeoLaB Optimized reservoir engineering Achieving >50 L/s, long time reliability, Landau Rittershoffen Gr.Gerau Weinheim Brühl Bruchsal Society Strasbourg Increase public acceptance Mitigate the environmental impact Riehen 4
Necessity of an URL Observation of processes in situ 3D/4D Laboratory experiments not transferrable Experiments on ~reservoir scale Bundling of knowledge International Science + industry 5
Ideal conditions for GeoLaB What criteria to use for site assessment? Hydraulically undisturbed fracture zones Site Alteration, conditions transmissivity, must be known close boundary to conditions, in low environmental impact of experiments typical reservoir rocks (crystalline basement) High differential stress (tectonic forces) Depth ~500m Accessibility / Infrastructure and low environmental impact 6
Feasibility Study - URL Concepts Build up a new gallery or extend an existing one? 7
Feasibility Study - URL Concepts Build up a new gallery or extend an existing one? Name Criterion 1: Criterion 2: Criterion 3: Criterion 4: fractured and fracture controllable comparable suitable stress rather transmissivity > hydraulic alteration (clay condition homogenous 10-4 m 2 s -1 boundary minerals) crystalline condition matrix sufficient overburden Grimsel Test Site YES NO partly NO NO YES Äspö Hard Rock Laboratory YES YES YES YES limit YES Mizunami URL YES limit YES NO NO YES Josef URL NO NO YES NO YES limit Mine Reiche Zeche YES limit NO YES YES limit Lindau Test Site YES YES YES n/a (NO) YES NO 8
Feasibility Study Black Forest Remote sensing techniques Outcropping crystalline rocks Lineament mappings Morphotectonic parameters Hydrographic parameters Fieldwork Stress field characterization Geomechanical modelling Reactivation potential of faults topographically induced perturbations 9
Feasibility Study Black Forest Criteria Fault zones / tectonic lineaments? 10
Feasibility Study Black Forest Criteria Reactivation potential of fault zones? Slip tendency Dilation tendency 11
Feasibility Study Black Forest Criteria Topographic induced stress perturbations? 12
Feasibility Study Black Forest Criteria Topographic induced stress perturbations? 13
Feasibility Study Black Forest Criteria Maximum overburden for gallery? 14
GeoLaB experiments Reservoir engineering Scaling inhibitors Spatial and temporal heterogeneity Earthquake mechanics Scale dependency Flow in 3D fracture network Novel THMC coupled models Longevity of materials Exploration for dynamic processes 15
Organization & Structure Management by Helmholtz institutions (KIT / GFZ / UFZ) Supported by DFG and international partners International advisory board Technical management Scientific management BMWi BMBF Land EU Industry DFG GeoLaB platform Helmholtz infrastructure 16
Summary GeoLaB Is essential for systematic large scale research Complements existing large-scale projects and laboratory experiments Offers a common platform for international community (University and Industry) Boosts technological innovation Requires competences of the whole geo-community 17
Thank you for your attention. 18
Perspectives of GeoLaB Deep fractured crystalline Hugh potential High temperatures / partly high natural permeability Applicable to thermal storage systems Existing Learning Curve HDR EGS From Rosemanowes over Soultz to Landau/Insheim Power and/or heating Technology Transfer Can be accessed in most parts of Central Europe Applicable to other Geoenergies (e.g. Shale Gas) 19
Geothermal Energy EGS Concept What is EGS? Usage of low-permeable rock formations Improving productivity by stimulation Why EGS? Application in low-enthalpy regions possible Independent of highly permeable rock formations Higher temperatures in deep boreholes >2km Ref.: GEIE 2011 20
Hydraulic stimulation H 1 2 3 4 h Hydraulic Stimulation 1) Initial fracture in ambient stress field 2) Pressurizing => fracture compliance (normal opening) 3) Further pressurizing => shearing 4) remaining fracture aperture higher than initial 21
Example: Scale dependency Hydraulics and mechanics are strongly scale dependent Failure determined by weakest structures Flow dominated by single structures (Bandis et al., IJRMMS, 1981) 22
GeoLaB Concept: Controlled High Flow Rate Experiments - CHFE Effects of massive injection in fractured rock Parameter distribution and variability f(x, t) Transmissivity Tracer permeability Electric conductivity Clay content Geochemistry Size / extension Micro seismicity Rock mechanical parameters Stress field 23