Hydrothermal systems in deep carbonate bedrock are among the most promising low-enthalpy geothermal plays across Europe. Apart from a few areas where viability of hydrothermal heat and power generation has been proved, most deep carbonate bedrock has received relatively little attention, because such rocks are perceived as ‘tight’. Exploration and development of the deep subsurface is an acknowledged high-risk investment, particularly in low-enthalpy systems, where tapping suitable temperatures for geothermal energy commonly requires drilling to depths of more than 3 km. In order to de-risk these challenging geothermal plays, it is crucial to improve our understanding of geological conditions that determine the distribution and technical recoverability of their potential resources. The efficacy of carbonate bedrock geothermal plays is crucially dependent on groundwater yield controlled by fracture conduits and karstification. This project identifies the generic structural controls in deep carbonate formations, through a comparison of geological situations and their structural inventory, as well as collation of deep borehole data and their petro- and hydro-physical characteristics. A consistent assessment and the sharing of knowledge – bringing all partners to a common high level – result in uniformly applicable best practice workflows for estimation, comparison and prospect-ranking of hydrothermal resources in deep carbonate bedrock. Applied in eleven target areas by means of 2D or 3D mapping and characterization, these spatial assessments help in de-risking the setup or maturation of regional plays, reveal possible cross-domain implications, and support sustainable subsurface management.
Dissemination and accessibility of Hotlime’s results
HotLime’s results of mapping and characterization, estimation, comparison and prospect ranking of hydrothermal resources in deep carbonate are provided in two principal synopses:
The results of mapping and characterization of the geothermal reservoirs after finalizing WP2 by the end of 2019, are summarized and compared in the HotLime Midterm Summary Report.
Based on these findings, play and prospect evaluation (WP3) has been implemented and deep carbonate play development strategies and impact (WP4) have been deduced, summarized in map sets on each of the eleven HotLime Case Study areas and supplemented by the hyperlinked knowledge base featuring cross-sections, reports, factsheets and the comprehensive LOD concepts vocabulary, the HotLime Geothermal Atlas.
Direct access to HotLime’s public deliverables:
D2.0 Summary report of resources mapping and characterization
D3.1 Report on play and prospect evaluation
D4.1 Report on deep carbonate play development strategies and impact
D5.1.1 HotLime partners’ legislation synopsis
All maps presented in the HotLime Geothermal Atlas and more spatial representations of the geothermal base assessment are also available as georeferenced, queryable, combinable and downloadable map layers, retrievable via the EGDI Metadata Catalogue, and visualized in the GIS viewer for Hotlime results:
Budget and partners
Having had available a total budget of 1,658,728.23 € (1,166,086.52 € partners’ share and 492,641.71 € EC grants), 15 national and regional Geological Survey Organizations from 10 European countries contributed knowledge and experience for the implementation of HotLime – to identify the generic controls and for their spatial representation in the respective areas of responsibility as presented in the HotLime map viewer and HotLime Geothermal Atlas.
|Partner short name||Participant Legal Name||Country||Person Months|
|LfU (Project Lead)||Bayerisches Landesamt für Umwelt||Germany||44.0|
|GSI||Department of Communications, Climate Action and Environment (GSI)||Ireland||38.0|
|TNO||Nederlandse Organisatie voor Toegepast-Natuurwetenschappelijk Onderzoek||The Netherlands||19.25|
|VITO||Vlaams Instituut voor Technologisch Onderzoek acting as a third party of Vlaams Planbureau voor Omgeving (VLO)||Belgium||10.0|
|ISPRA||Istituto Superiore per la Protezione e la Ricerca Ambientale||Italy||21.5|
|GeoZS||Geološki zavod Slovenije||Slovenia||7.2|
|RER-SGSS||Servizio Geologico, Sismico e dei Suoli della Regione Emilia Romagna||Italy||11.0|
|HGI-CGS||Hrvatski geološki institut – Croatian Geological Survey||Croatia||20.0|
|MFE-CSD||Ministry for Finance and Employment, Continental Shelf Department||Malta||4.0|
|ARPAP||Agenzia Regionale per la Protezione Ambientale del Piemonte||Italy||11.0|
|CGS||Česká geologická služba||Czech Republic||4.0|
|RU||Regione Umbria – Servizio Geologico||Italy||4.0|
|ICGC||Institut Cartogràfic i Geològic de Catalunya||Spain||13.86|
The HotLime partners and stakeholder visiting hot lime E&P drillings in southern Bavaria on occasion of the September 17-19, 2018 WP2 workshop in Augsburg. Picture credit: HotLime, G.W. Diepolder (LfU).