3D Modelling of the Northern Upper Rhine Graben Crystalline Basement by Joint Inversion of Gravity and Magnetic Data

2021 ◽  
Author(s):  
Matthis Frey ◽  
Sebastian Weinert ◽  
Kristian Bär ◽  
Jeroen van der Vaart ◽  
Chrystel Dezayes ◽  
...  
Keyword(s):  
High Resolution ◽  
Heat Transport ◽  
Joint Inversion ◽  
Transport Processes ◽  
Crystalline Basement ◽  
Magnetic Data ◽  
Moho Depth ◽  
Upper Rhine Graben ◽  
Rhine Graben ◽  
Upper Rhine

<p>The crystalline basement of the Upper Rhine Graben presents an attractive target for deep geothermal projects due to its favourable temperatures and its high potential as a fractured and faulted reservoir system. It is already exploited at several sites, e.g. Soultz-sous-Forêts or Landau, and further projects are currently planned or under development. The crystalline units are furthermore the main source of radiogenic heat production and thus, together with the shallow Moho depth and convective heat transport along large fault zones, significantly contributing to the crustal temperature field. For these reasons, we developed the most detailed 3D geological model of the basement in the northern Upper Rhine Graben to date within the Interreg NWE DGE-ROLLOUT and Hesse 3D 2.0 projects. Due to the small number of very deep boreholes as well as seismic profiles reaching the basement beneath the locally more than 5 km thick sedimentary cover, we additionally used high-resolution magnetic and gravity datasets. In contrast to common deterministic modelling approaches, we performed a stochastic joint inversion of the geophysical data by applying a Monte Carlo Markov Chain algorithm. This method generates a large set of random but valid models, which enables a statistical evaluation of the results, e.g. concerning the model uncertainties. For a realistic attribution of the model, we used existing petrophysical databases of the region and measured the magnetic susceptibility of more than 430 rock samples. As a result of the inversion, high-resolution voxel models of the density and susceptibility distribution were generated, allowing conclusions about the composition and structure of the crystalline crust, which leads to a reduction of uncertainties and risks associated with deep geothermal drillings in the northern Upper Rhine Graben. Furthermore, our model will serve as a basis for realistic simulations of heat transport processes in the fractured basement and a meaningful assessment of the deep geothermal potential in the future.</p>

Influence of fluid flow and heat transport on predictions of geothermal potentials in sedimentary layers of Hesse (Germany)

2020 ◽  
Author(s):  
Nora Koltzer ◽  
Maximilian Frick ◽  
Magdalena Scheck-Wenderoth ◽  
Björn Lewerenz ◽  
Kristian Bär ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Heat Transport ◽  
Thermal Model ◽  
Transport Processes ◽  
Heating Power ◽  
Upper Rhine Graben ◽  
Reservoir Temperature ◽  
Rhine Graben ◽  
Geothermal Potential ◽  
Upper Rhine

<p>For the sustainable utilization of deep geothermal resources it is essential to predict the exploitable potential thermal energy from the subsurface. One main parameter influencing the geothermal potential is the reservoir temperature that may vary locally or regionally in response to fluid flow and heat transport processes.</p><p>This study aims at combining highly complex 3D thermo-hydraulic numerical simulations of heat transport and fluid flow with predictions of the geothermal potential for the application case of a hydrothermal doublet. Quantifying the influences of conductive, advective and convective heat transport mechanisms on the thermal field and moreover on the predicted heating power requires fundamental numerical investigations. We use the Federal State of Hesse in Germany as study area where heat transport processes have been quantified in recently published studies. There, the heterogeneous geology consists of outcropping Variscan Crust and up to 3.8 km and 1.8 km thick sedimentary deposits of the Upper Rhine Graben and the Hessian Depression, respectively. This geological complexity is expressed by areas of different hydraulic and thermal configurations: in the flat, but tectonically active Upper Rhine Graben high heat flow from below the graben sediments is in contrast to the variable topography of the Hessian Depression with low heat input from the Rhenohercynian Basement.</p><p>The heating power in the three reservoir units (I) Cenozoic, (II) Buntsandstein and (III) Rotliegend is only predicted to be high in the Upper Rhine Graben. There the reservoir temperature is high enough and varies between 50 °C in the convective thermal model of the Cenozoic reservoir and 170 °C in the conductive thermal model of the Buntsandstein reservoir. Predicted low temperatures in the Hessian Depression lead to negligible low heating power, but as production mass flux is above ~6 kg s<sup>-1 </sup>investigations should continue to assess the geothermal potential for other applications like seasonal energy storage or low enthalpy geothermal utilization.</p>

scholarly journals Integrated 3D geological modelling of the northern Upper Rhine Graben by joint inversion of gravimetry and magnetic data

2021 ◽  
pp. 228927
Author(s):  
Matthis Frey ◽  
Sebastian Weinert ◽  
Kristian Bär ◽  
Jeroen van der Vaart ◽  
Chrystel Dezayes ◽  
...  
Keyword(s):  
Joint Inversion ◽  
Magnetic Data ◽  
Upper Rhine Graben ◽  
Geological Modelling ◽  
Rhine Graben ◽  
Upper Rhine

scholarly journals Preliminary studies for an integrated assessment of the hydrothermal potential of the Pechelbronn Group in the northern Upper Rhine Graben

2018 ◽  
Vol 45 ◽  
pp. 251-258 ◽  
Author(s):  
Meike Hintze ◽  
Barbara Plasse ◽  
Kristian Bär ◽  
Ingo Sass
Keyword(s):  
Gamma Ray ◽  
Joint Inversion ◽  
Tectonic Setting ◽  
Rock Properties ◽  
Upper Rhine Graben ◽  
Petrophysical Parameters ◽  
Core Samples ◽  
Rhine Graben ◽  
Model Unit ◽  
Upper Rhine

Abstract. The northern Upper Rhine Graben is due to its tectonic setting and the positive geothermal anomaly a key region for geothermal heat and power production in Europe. In this area the Upper Eocene to Lower Oligocene Pechelbronn Group reaches depths of up to 2800 m with temperatures of locally more than 130 ∘C. In order to assess the hydrothermal potential of the Pechelbronn Group a large dataset is compiled and evaluated. Petrophysical parameters are measured on core samples of eight boreholes (courtesy of Exxon Mobil). Additionally, 15 gamma-ray logs, 99 lithology logs as well as more than 2500 porosity and permeability measurements on cores of some of these boreholes are available. The Lower Pechelbronn Beds are composed of fluvial to lacustrine sediments, the Middle Pechelbronn Beds were deposited in a brackish to marine environment and the Upper Pechelbronn Beds consist of fluvial/alluvial to marine deposits. In between the western and eastern masterfaults of the Upper Rhine Graben several fault blocks exist, with fault orientation being sub-parallel to the graben shoulders. During the syntectonic deposition of the Pechelbronn Group these fault blocks acted as isolated depocenters, resulting in considerable thickness and depositional facies variations on the regional and local scale (few tens to several hundreds of meters). Laboratory measurements of sonic wave velocity, density, porosity, permeability, thermal conductivity and diffusivity are conducted on the core samples that are classified into lithofacies groups. Statistically evaluated petrophysical parameters are assigned to each group. The gamma-ray logs serve to verify the lithological classification and can further be used for correlation analysis or joint inversion with the petrophysical data. Well data, seismic sections, isolines and geological profiles are used to construct a geological 3-D model. It is planned to use the petrophysical, thermal and hydraulic rock properties at a later stage to parametrize the model unit and to determine, together with the temperature and thickness of the model unit, the expected flow rates and reservoir temperatures and thus the hydrothermal potential.

Quaternary faulting in the Upper Rhine Graben revealed by high-resolution multi-channel reflection seismic

2006 ◽  
Vol 338 (8) ◽  
pp. 574-580 ◽  
Author(s):  
Guillaume Bertrand ◽  
Philippe Elsass ◽  
Gunther Wirsing ◽  
Alex Luz
Keyword(s):  
High Resolution ◽  
Upper Rhine Graben ◽  
Reflection Seismic ◽  
Rhine Graben ◽  
Upper Rhine

scholarly journals Locating Geothermal Resources: Insights from 3D Stress and Flow Models at the Upper Rhine Graben Scale

Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-24 ◽  
Author(s):  
Antoine Armandine Les Landes ◽  
Théophile Guillon ◽  
Mariane Peter-Borie ◽  
Arnold Blaisonneau ◽  
Xavier Rachez ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Transport Processes ◽  
Upper Rhine Graben ◽  
3D Flow ◽  
Geothermal Resources ◽  
Thermal Anomalies ◽  
Rhine Graben ◽  
Upper Rhine ◽  
Fault Network

To be exploited, geothermal resources require heat, fluid, and permeability. These favourable geothermal conditions are strongly linked to the specific geodynamic context and the main physical transport processes, notably stresses and fluid circulations, which impact heat-driving processes. The physical conditions favouring the setup of geothermal resources can be searched for in predictive models, thus giving estimates on the so-called “favourable areas.” Numerical models could allow an integrated evaluation of the physical processes with adapted time and space scales and considering 3D effects. Supported by geological, geophysical, and geochemical exploration methods, they constitute a useful tool to shed light on the dynamic context of the geothermal resource setup and may provide answers to the challenging task of geothermal exploration. The Upper Rhine Graben (URG) is a data-rich geothermal system where deep fluid circulations occurring in the regional fault network are the probable origin of local thermal anomalies. Here, we present a current overview of our team’s efforts to integrate the impacts of the key physics as well as key factors controlling the geothermal anomalies in a fault-controlled geological setting in 3D physically consistent models at the regional scale. The study relies on the building of the first 3D numerical flow (using the discrete-continuum method) and mechanical models (using the distinct element method) at the URG scale. First, the key role of the regional fault network is taken into account using a discrete numerical approach. The geometry building is focused on the conceptualization of the 3D fault zone network based on structural interpretation and generic geological concepts and is consistent with the geological knowledge. This DFN (discrete fracture network) model is declined in two separate models (3D flow and stress) at the URG scale. Then, based on the main characteristics of the geothermal anomalies and the link with the physics considered, criteria are identified that enable the elaboration of indicators to use the results of the simulation and identify geothermally favourable areas. Then, considering the strong link between the stress, fluid flow, and geothermal resources, a cross-analysis of the results is realized to delineate favourable areas for geothermal resources. The results are compared with the existing thermal data at the URG scale and compared with knowledge gained through numerous studies. The good agreement between the delineated favourable areas and the locations of local thermal anomalies (especially the main one close to Soultz-sous-Forêts) demonstrates the key role of the regional fault network as well as stress and fluid flow on the setup of geothermal resources. Moreover, the very encouraging results underline the potential of the first 3D flow and 3D stress models at the URG scale to locate geothermal resources and offer new research opportunities.

scholarly journals Influence of the Main Border Faults on the 3D Hydraulic Field of the Central Upper Rhine Graben

Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-21 ◽  
Author(s):  
Jessica Freymark ◽  
Judith Bott ◽  
Mauro Cacace ◽  
Moritz Ziegler ◽  
Magdalena Scheck-Wenderoth
Keyword(s):  
Heat Transport ◽  
Structural Model ◽  
Fluid Velocity ◽  
Three Dimensional ◽  
Upper Rhine Graben ◽  
Rhine Graben ◽  
Dimensional Interaction ◽  
Geothermal Potential ◽  
Hydraulic Regime ◽  
Upper Rhine

The Upper Rhine Graben (URG) is an active rift with a high geothermal potential. Despite being a well-studied area, the three-dimensional interaction of the main controlling factors of the thermal and hydraulic regime is still not fully understood. Therefore, we have used a data-based 3D structural model of the lithological configuration of the central URG for some conceptual numerical experiments of 3D coupled simulations of fluid and heat transport. To assess the influence of the main faults bordering the graben on the hydraulic and the deep thermal field, we carried out a sensitivity analysis on fault width and permeability. Depending on the assigned width and permeability of the main border faults, fluid velocity and temperatures are affected only in the direct proximity of the respective border faults. Hence, the hydraulic characteristics of these major faults do not significantly influence the graben-wide groundwater flow patterns. Instead, the different scenarios tested provide a consistent image of the main characteristics of fluid and heat transport as they have in common: (1) a topography-driven basin-wide fluid flow perpendicular to the rift axis from the graben shoulders to the rift center, (2) a N/NE-directed flow parallel to the rift axis in the center of the rift and, (3) a pronounced upflow of hot fluids along the rift central axis, where the streams from both sides of the rift merge. This upflow axis is predicted to occur predominantly in the center of the URG (northern and southern model area) and shifted towards the eastern boundary fault (central model area).

scholarly journals Rock and palaeomagnetic evidence for the Plio-Pleistocene palaeoclimatic change recorded in Upper Rhine Graben sediments (Core Ludwigshafen-Parkinsel)

2008 ◽  
Vol 87 (1) ◽  
pp. 41-50 ◽  
Author(s):  
C. Rolf ◽  
U. Hambach ◽  
M. Weidenfeller
Keyword(s):  
Global Climate ◽  
Groundwater Resources ◽  
Primary Objective ◽  
Magnetic Data ◽  
Characteristic Change ◽  
Upper Rhine Graben ◽  
Sedimentary Environments ◽  
Rhine Graben ◽  
Wide Range ◽  
Upper Rhine

AbstractThis paper summarizes results of magnetostratigraphic and rock magnetic investigations performed on fluvial sediments from the Ludwigshafen-Parkinsel drilling project (Upper Rhine Graben (URG) Germany). The drilling penetrated into Pleistocene gravel, sand, silt and clay, and unconsolidated Pliocene deposits. Its primary objective was the exploration of groundwater resources in the area of Ludwigshafen. Our rock magnetic investigations together with results of heavy mineral analyses (see Hagedorn & Boenigk, 2008) show a clearly structured sediment profile. It was possible to identify the change from mainly locally controlled sedimentation from the Graben margins to a more distinct Alpine controlled sedimentation at a depth of 177 m by magnetic data. Based on lithostratigraphic correlation with other sedimentary records from the URG and also based on palynological evidence, this event happened at the end of Late Pliocene during a time of normal polarity of the Earth's magnetic field (Gauss Chron?). The well-documented characteristic change in magneto-mineralogy from goethite to greigite almost at the same stratigraphic level, we interpret solely as a climatic signal which can be correlated with the global climate change at ∼2.5 Ma that is well documented in a wide range of sedimentary environments (e.g. deep-sea sediments, loess).

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