Characterization of conditions and fluid flow paths in the Buntsandstein Gp. sandstones reservoirs, Upper Rhine Graben

Deeply buried sandstone reservoirs are targeted in the Upper Rhine Graben (URG) for geothermal and hydrocarbon resources. These reservoirs, which are located at the top of the geothermal convective cells, have a complex diagenetic and structural history recorded by paragenesis. Here the focus is made on the characterization of carbonates and barite cementations which trace paleo geothermal circulations within the fracture network affecting the sandstones. These mineralizations are studied with a double approach on geochemistry and structural, faults and associated fracture network, to characterize fluid-flow episodes on different structural positions in the rift basin and its shoulders. Barite sulphur isotopic ratios suggest a common signature and source for all the locations. REE patterns, oxygen isotopic ratios, and fluid inclusion study suggest though two regimes of fluid flow forming barite, depending on their location. On the graben shoulders the barite have a higher content in total REE and contain non-saline fluids inclusions, suggesting that fluid circulations at the graben border faults interact with sulphate rich layers, and precipitate at high temperatures .In -deep-seated sandstones, fluid inclusions in barites show a wide range of salinities, suggesting a higher contribution of sedimentary brines, and precipitation at lower temperatures. These barite mineralizations are associated with carbonates and apatite with a diagenetic origin, according to their REE signature. These data are used to build a model for fluids circulation within the graben: Fast and deep down- and up-flows are taking place along the major border faults, which are leaching evaporitic horizons, and precipitates from geothermal fluid during fault activity. A part of these deep-down meteoric waters is reaching the centre of the basin. In this central part of the basin, fluid circulation is slower and restricted to the bottom of the basin, where fluid-mixing with sedimentary brines occurs. This new understanding of fluid pathways in the targeted reservoir brings new insights on the compartmentalization of geothermal circulations at the basin scale.

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

10.5194/egusphere-egu2020-4685 ◽

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

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.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.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 &#176;C in the convective thermal model of the Cenozoic reservoir and 170 &#176;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-1 investigations should continue to assess the geothermal potential for other applications like seasonal energy storage or low enthalpy geothermal utilization.

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Structure of hydrothermal convection in the Upper Rhine Graben as inferred from corrected temperature data and basin-scale numerical models

Journal of Volcanology and Geothermal Research ◽

10.1016/j.jvolgeores.2013.02.008 ◽

2013 ◽

Vol 256 ◽

pp. 29-49 ◽

Cited By ~ 49

Author(s):

Laurent Guillou-Frottier ◽

Clément Carrė ◽

Bernard Bourgine ◽

Vincent Bouchot ◽

Albert Genter

Keyword(s):

Numerical Models ◽

Temperature Data ◽

Upper Rhine Graben ◽

Rhine Graben ◽

Hydrothermal Convection ◽

Basin Scale ◽

Upper Rhine

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Characterization of the organic matter and its maturity in four boreholes of the middle Upper Rhine Graben; estimation of the paleogeothermal gradients

International Journal of Coal Geology ◽

10.1016/0166-5162(80)90013-0 ◽

1980 ◽

Vol 1 (1) ◽

pp. 86

Keyword(s):

Organic Matter ◽

Upper Rhine Graben ◽

Rhine Graben ◽

Upper Rhine

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

Geofluids ◽

10.1155/2019/8494539 ◽

2019 ◽

Vol 2019 ◽

pp. 1-24 ◽

Cited By ~ 2

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.

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Structural characterization of naturally fractured geothermal reservoirs in the central Upper Rhine Graben

Journal of Structural Geology ◽

10.1016/j.jsg.2021.104370 ◽

2021 ◽

pp. 104370

Author(s):

Carole GLAAS ◽

Jeanne VIDAL ◽

Albert GENTER

Keyword(s):

Structural Characterization ◽

Upper Rhine Graben ◽

Geothermal Reservoirs ◽

Rhine Graben ◽

Naturally Fractured ◽

Upper Rhine

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Global sensitivity analysis to optimize basin-scale conductive model calibration – A case study from the Upper Rhine Graben

Geothermics ◽

10.1016/j.geothermics.2021.102143 ◽

2021 ◽

Vol 95 ◽

pp. 102143

Author(s):

Denise Degen ◽

Karen Veroy ◽

Jessica Freymark ◽

Magdalena Scheck-Wenderoth ◽

Thomas Poulet ◽

...

Keyword(s):

Sensitivity Analysis ◽

Model Calibration ◽

Global Sensitivity Analysis ◽

Upper Rhine Graben ◽

Global Sensitivity ◽

Rhine Graben ◽

Basin Scale ◽

Upper Rhine

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

Netherlands Journal of Geosciences – Geologie en Mijnbouw ◽

10.1017/s0016774600024033 ◽

2008 ◽

Vol 87 (1) ◽

pp. 41-50 ◽

Cited By ~ 12

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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Structural heritage, reactivation and distribution of fault and fracture network in a rifting context: Case study of the western shoulder of the Upper Rhine Graben

Journal of Structural Geology ◽

10.1016/j.jsg.2017.09.006 ◽

2018 ◽

Vol 108 ◽

pp. 243-255 ◽

Cited By ~ 8

Author(s):

Lionel Bertrand ◽

Jessie Jusseaume ◽

Yves Géraud ◽

Marc Diraison ◽

Pierre-Clément Damy ◽

...

Keyword(s):

Fracture Network ◽

Upper Rhine Graben ◽

Rhine Graben ◽

Upper Rhine

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Influences of hydraulic boundary conditions on the deep fluid flow in a 3D regional model (central Upper Rhine Graben)

Environmental Earth Sciences ◽

10.1007/s12665-021-10111-z ◽

2022 ◽

Vol 81 (1) ◽

Author(s):

Nora Koltzer ◽

Giulia Kommana ◽

Mauro Cacace ◽

Maximilian Frick ◽

Judith Bott ◽

...

Keyword(s):

Fluid Flow ◽

Boundary Conditions ◽

Groundwater Flow ◽

Flow Dynamics ◽

Upper Rhine Graben ◽

Local Flow ◽

Regional Flow ◽

Rhine Graben ◽

Deep Fluid ◽

Upper Rhine

AbstractKnowledge of groundwater flow is of high relevance for groundwater management or the planning of different subsurface utilizations such as deep geothermal facilities. While numerical models can help to understand the hydrodynamics of the targeted reservoir, their predictive capabilities are limited by the assumptions made in their setup. Among others, the choice of appropriate hydraulic boundary conditions, adopted to represent the regional to local flow dynamics in the simulation run, is of crucial importance for the final modelling result. In this work, we systematically address this problematic in the area of the central part of the Upper Rhine Graben. We quantify how and to which degree different upper boundary conditions and vertical cross-boundary fluid movement influence the calculated deep fluid flow conditions in the area under study. Robust results, which are insensitive to the choice of boundary condition, are: (i) a regional groundwater flow component descending from the graben shoulders to rise at its centre and (ii) the presence of heterogeneous hydraulic potentials at the rift shoulders. Contrarily, results affected by the chosen boundary conditions are: (i) calculated flow velocities, (ii) the absolute position of the upflow axis, and (iii) the evolving local flow dynamics. If, in general, the investigated area is part of a supra-regional flow system—like the central Upper Rhine Graben is part of the entire Upper Rhine Graben—the inflow and outflow across vertical model boundaries need to be considered.

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