https://www.peren-revues.fr/annales-sgn/2653 Publications de Auteurs Frédéric Lacquement fr 0 https://www.peren-revues.fr/annales-sgn/2700 La région des Hauts-de-France, marquée par un riche passé minier, recèle en profondeur des roches calcaires datées du Dévonien (Givétien-Frasnien) et du Carbonifère (Dinantien) présentant un potentiel géothermique largement inexploité. Cette étude examine les perspectives offertes par ces réservoirs fracturés et karstifiés, en particulier les calcaires dinantiens, favorables aux applications géothermiques directes dans des systèmes hydrothermaux. Les récents résultats issus des travaux de retraitement et d’interprétation de données sismiques historiques des campagnes d’exploration pétrolières des années 80 et leur intégration au sein d’un modèle géométrique 3D conduisent à affiner la compréhension des réservoirs, de révéler leur complexité structurale et d’identifier des zones fracturées majeures associées aux grandes failles régionales. Des anomalies thermiques locales ont été rencontrées mais n’ont pas fait l’objet d’étude permettant de développer un potentiel géothermique largement sous-exploré. À l’instar de ce qui se fait de l’autre côté de la frontière franco-belge, les initiatives menées dans des contextes urbains tels que la métropole lilloise (ou MEL, Métropole Européenne de Lille), le Douaisis et le Valenciennois illustrent la faisabilité d’intégrer cette ressource dans des solutions énergétiques durables, contribuant à l’indépendance énergétique régionale et à la revitalisation économique. Les résultats obtenus soulignent l’importance de poursuivre les efforts d’exploration et de caractérisation, et de recourir à des approches interdisciplinaires et à des techniques de forage adaptées pour favoriser le développement durable de la géothermie profonde dans les Hauts-de-France. The Hauts-de-France region, with its strong mining legacy, contains deep Devonian (Givetian–Frasnian) and Carboniferous (Dinantian) limestone formations with significant yet largely untapped geothermal potential. This study assesses the geothermal prospects of these fractured and karstified reservoirs, particularly the Dinantian limestones, which provide favourable conditions for direct-use hydrothermal applications. Recent reprocessing and interpretation of historical seismic data, integrated into a 3D geometric model, have refined the understanding of these reservoirs, revealed their structural complexity, and identified major fractured zones associated with regional fault systems. Local thermal anomalies have been reported, but they have not yet been studied in detail, leaving the regional geothermal potential largely under-explored. Similar to initiatives across the Belgian border, urban projects in Lille Metropole, Douai, and Valenciennes illustrate the feasibility of integrating this resource into sustainable energy systems, contributing both to regional energy independence and economic revitalization. These results highlight the importance of pursuing further exploration and characterization, and of relying on interdisciplinary approaches and advanced drilling techniques, to support the sustainable development of deep geothermal energy in the Hauts-de-France region. mer., 26 nov. 2025 14:44:32 +0100 mer., 10 déc. 2025 15:22:24 +0100 https://www.peren-revues.fr/annales-sgn/2700 https://www.peren-revues.fr/annales-sgn/2637 In Northwestern Europe, the Dinantian limestone formation, could be a promising geothermal reservoir from 1 kilometer deep for heat production in densely populated regions. In the 1970s and 1980s, scientific drilling in Belgium encountered hot water at high flow rates in this layer, turning these wells into productive geothermal sources for district heating (e.g., Saint-Ghislain, Douvrain, and Ghlin). However, similar wells in France (Jeumont and Condé-sur-l'Escaut) were not productive enough for economic viability due to the heterogeneous nature of the Dinantian reservoir, influenced by the region’s complex geological history.To enhance understanding of this formation, an interdisciplinary study was conducted under the INTERREG NWE DGE-Rollout project. This study involved creating a cross-border map of the Dinantian structure and building a lithological chart to represent variations across the region, including Belgium, France, Germany, and the Netherlands. The formation is mainly composed of carbonate rocks but also contains significant heterogeneities, such as sedimentary breccias within the middle Visean (Livian), identified as a geothermal reservoir in Belgium's Mons region.Seismic surveys and petrophysical analyses were conducted across Belgium, France, and Germany. Results showed five main facies in the Dinantian: limestone, dolomite, anhydrite, sandstone, and clay. The Epinoy 1 well, for instance, revealed low porosity in dolomitic facies, while Jeumont 1 showed higher porosity levels in dolomitic intervals. Seismic data reprocessing further identified key geothermal targets, with dolomitic zones offering better reservoir properties in the north and east.Temperature data from wells in the region are scarce, though the Epinoy 1 well shows a normal geothermal gradient of 30°C/km. Favorable areas for geothermal development were identified based on energy demand and geothermal resource availability. The largest zone is located between Douai and Valenciennes, with significant heat demand and an existing district heating network. Another zone, around Maubeuge, also holds potential despite deeper Dinantian depths. jeu., 26 juin 2025 16:59:09 +0200 mar., 09 déc. 2025 11:54:59 +0100 https://www.peren-revues.fr/annales-sgn/2637