Interdisciplinary fracture network characterization in the crystalline basement: a case study from the Southern Odenwald, SW Germany
<p>The crystalline basement is considered a ubiquitous and almost inexhaustible source of geothermal energy in the Upper Rhine Graben (URG) and other regions worldwide. The hydraulic properties of the basement, which are one of the key factors in the productivity of geothermal power plants, ar...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2022-06-01
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| Series: | Solid Earth |
| Online Access: | https://se.copernicus.org/articles/13/935/2022/se-13-935-2022.pdf |
| _version_ | 1811232392325627904 |
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| author | M. Frey C. Bossennec L. Seib K. Bär E. Schill E. Schill I. Sass I. Sass |
| author_facet | M. Frey C. Bossennec L. Seib K. Bär E. Schill E. Schill I. Sass I. Sass |
| author_sort | M. Frey |
| collection | DOAJ |
| description | <p>The crystalline basement is considered a ubiquitous and almost inexhaustible source of geothermal energy in the Upper Rhine Graben (URG) and other regions worldwide. The hydraulic properties of the basement, which are one of the key factors in the productivity of geothermal power plants, are primarily controlled by hydraulically active faults and fractures. While the most accurate in situ information about the general fracture network is obtained from image logs of deep boreholes, such data are generally sparse and costly and thus often not openly accessible. To circumvent this problem, an outcrop analogue study was conducted with interdisciplinary geoscientific methods in the Tromm Granite, located in the southern Odenwald at the northeastern margin of the URG. Using light detection and ranging (lidar) scanning, the key characteristics of the fracture network were extracted in a total of five outcrops; these were additionally complemented by lineament analysis of two different digital elevation models (DEMs). Based on this, discrete fracture network (DFN) models were developed to calculate equivalent permeability tensors under assumed reservoir conditions. The influences of different parameters, such as fracture orientation, density, aperture and mineralization, were investigated. In addition, extensive gravity and radon measurements were carried out in the study area, allowing fault zones with naturally increased porosity and permeability to be mapped. Gravity anomalies served as input data for a stochastic density inversion, through which areas of potentially increased open porosity were identified. A laterally heterogeneous fracture network characterizes the Tromm Granite, with the highest natural permeabilities expected at the pluton margin, due to the influence of large shear and fault zones.</p> |
| first_indexed | 2024-04-12T11:02:25Z |
| format | Article |
| id | doaj.art-75d4417660d54d7d90098f4fd829ba12 |
| institution | Directory Open Access Journal |
| issn | 1869-9510 1869-9529 |
| language | English |
| last_indexed | 2024-04-12T11:02:25Z |
| publishDate | 2022-06-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Solid Earth |
| spelling | doaj.art-75d4417660d54d7d90098f4fd829ba122022-12-22T03:35:54ZengCopernicus PublicationsSolid Earth1869-95101869-95292022-06-011393595510.5194/se-13-935-2022Interdisciplinary fracture network characterization in the crystalline basement: a case study from the Southern Odenwald, SW GermanyM. Frey0C. Bossennec1L. Seib2K. Bär3E. Schill4E. Schill5I. Sass6I. Sass7Technical University of Darmstadt, Institute of Applied Geosciences, Department of Geothermal Science and Technology, Schnittspahnstraße 9, 64287 Darmstadt, GermanyTechnical University of Darmstadt, Institute of Applied Geosciences, Department of Geothermal Science and Technology, Schnittspahnstraße 9, 64287 Darmstadt, GermanyTechnical University of Darmstadt, Institute of Applied Geosciences, Department of Geothermal Science and Technology, Schnittspahnstraße 9, 64287 Darmstadt, GermanyGeoThermal Engineering GmbH, An der Raumfabrik 33c, 76227 Karlsruhe, GermanyTechnical University of Darmstadt, Institute of Applied Geosciences, Department of Geothermal Science and Technology, Schnittspahnstraße 9, 64287 Darmstadt, GermanyKarlsruher Institut für Technologie, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, GermanyTechnical University of Darmstadt, Institute of Applied Geosciences, Department of Geothermal Science and Technology, Schnittspahnstraße 9, 64287 Darmstadt, GermanyGFZ German Research Centre for Geosciences, Section 4.8: Geoenergy, Telegrafenberg, 14473 Potsdam, Germany<p>The crystalline basement is considered a ubiquitous and almost inexhaustible source of geothermal energy in the Upper Rhine Graben (URG) and other regions worldwide. The hydraulic properties of the basement, which are one of the key factors in the productivity of geothermal power plants, are primarily controlled by hydraulically active faults and fractures. While the most accurate in situ information about the general fracture network is obtained from image logs of deep boreholes, such data are generally sparse and costly and thus often not openly accessible. To circumvent this problem, an outcrop analogue study was conducted with interdisciplinary geoscientific methods in the Tromm Granite, located in the southern Odenwald at the northeastern margin of the URG. Using light detection and ranging (lidar) scanning, the key characteristics of the fracture network were extracted in a total of five outcrops; these were additionally complemented by lineament analysis of two different digital elevation models (DEMs). Based on this, discrete fracture network (DFN) models were developed to calculate equivalent permeability tensors under assumed reservoir conditions. The influences of different parameters, such as fracture orientation, density, aperture and mineralization, were investigated. In addition, extensive gravity and radon measurements were carried out in the study area, allowing fault zones with naturally increased porosity and permeability to be mapped. Gravity anomalies served as input data for a stochastic density inversion, through which areas of potentially increased open porosity were identified. A laterally heterogeneous fracture network characterizes the Tromm Granite, with the highest natural permeabilities expected at the pluton margin, due to the influence of large shear and fault zones.</p>https://se.copernicus.org/articles/13/935/2022/se-13-935-2022.pdf |
| spellingShingle | M. Frey C. Bossennec L. Seib K. Bär E. Schill E. Schill I. Sass I. Sass Interdisciplinary fracture network characterization in the crystalline basement: a case study from the Southern Odenwald, SW Germany Solid Earth |
| title | Interdisciplinary fracture network characterization in the crystalline basement: a case study from the Southern Odenwald, SW Germany |
| title_full | Interdisciplinary fracture network characterization in the crystalline basement: a case study from the Southern Odenwald, SW Germany |
| title_fullStr | Interdisciplinary fracture network characterization in the crystalline basement: a case study from the Southern Odenwald, SW Germany |
| title_full_unstemmed | Interdisciplinary fracture network characterization in the crystalline basement: a case study from the Southern Odenwald, SW Germany |
| title_short | Interdisciplinary fracture network characterization in the crystalline basement: a case study from the Southern Odenwald, SW Germany |
| title_sort | interdisciplinary fracture network characterization in the crystalline basement a case study from the southern odenwald sw germany |
| url | https://se.copernicus.org/articles/13/935/2022/se-13-935-2022.pdf |
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