Hydrological constraints on the potential of enhanced geothermal systems in the ductile crust
Rattachement africain : is, ch, de. Niveau de preuve : code pays fourni par la source.
Le résumé fourni par la source
Abstract Continental crust at temperatures > 400 °C and depths > 10–20 km normally deforms in a ductile manner, but can become brittle and permeable in response to changes in temperature or stress state induced by fluid injection. In this study, we quantify the theoretical power generation potential of an enhanced geothermal system (EGS) at 15–17 km depth using a numerical model considering the dynamic response of the rock to injection-induced pressurization and cooling. Our simulations suggest that an EGS circulating 80 kg s−1 of water through initially 425 ℃ hot rock can produce thermal energy at a rate of ~ 120 MWth (~ 20 MWe) for up to two decades. As the fluid temperature decreases (less than 400 ℃), the corresponding thermal energy output decreases to around 40 MWth after a century of fluid circulation. However, exploiting these resources requires that temporal embrittlement of nominally ductile rock achieves bulk permeability values of ~ 10–15–10–14 m2 in a volume of rock with dimensions ~ 0.1 km3, as lower permeabilities result in unreasonably high injection pressures and higher permeabilities accelerate thermal drawdown. After cooling of the reservoir, the model assumes that the rock behaves in a brittle manner, which may lead to decreased fluid pressures due to a lowering of thresholds for failure in a critically stressed crust. However, such an evolution may also increase the risk for short-circuiting of fluid pathways, as in regular EGS systems. Although our theoretical investigation sheds light on the roles of geologic and operational parameters, realizing the potential of the ductile crust as an energy source requires cost-effective deep drilling technology as well as further research describing rock behavior at elevated temperatures and pressures.
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Le contrôle bibliographique ouvert
DOI retrouvé dans Crossref DOI retrouvé ; titre concordant.
- Titre Crossref
- Hydrological constraints on the potential of enhanced geothermal systems in the ductile crust
- Date Crossref
- 29/03/2024
- Éditeur
- Springer Science and Business Media LLC
- Type
- journal-article
Ce recoupement confirme des métadonnées liées au DOI. Il ne confirme ni la méthode ni les conclusions de l’étude, et il ne compte pas comme une seconde source scientifique indépendante.
Où se fait cette recherche
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University of Iceland Institute of Earth Sciences pays non établi dans la noticeUniversité ou école supérieure
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Institute of Earth Sciences pays non établi dans la noticeUniversité ou école supérieure
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ETH Zurich pays non établi dans la noticeUniversité ou école supérieure
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Institute of Geochemistry and Petrology pays non établi dans la noticeStructure de recherche
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GFZ Helmholtz Centre for Geosciences pays non établi dans la noticeStructure de recherche
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GFZ Potsdam German Research Center for Geosciences pays non établi dans la noticeStructure de recherche
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Quaise Energy pays non établi dans la noticeInstitution
Institute of Earth Sciences — University of Iceland, Institute of Earth Sciences et ETH Zurich, avec 4 autres affiliations.
Une affiliation ne permet pas de déduire la nationalité d’un auteur.