Deep reservoir analysis and characterisation of the earth’s surface (TRACE)

Geochemical and isotopical multi-method-concept to characterise deep aquifers in the upper Rhein Graben

Grundwasserprobennahme im Oberrheingraben

Geothermal energy is an eco-friendly energy source and provides base load capable regenerative low-carbon energy. Certainly there are still huge research and development needs to use the vast potential of deep geothermal energy economically.

It is state of the art in geothermal exploration to use various geophysical methods (eg. 3D-seismic) to identify adequate fault zones and the geometry of a geothermal aquifer, which is rather expensive. However this analysis does not allow for an estimation of an active fault’s hydraulic permeability nor provides a characterisation of the chemical properties of the deep aquifer fluid. Both factors play an important role in optimising siting of geothermal wells and operation of a geothermal power plant.

The TRACE project presents a low cost strategy characterizing deep hydrogeochemical reservoirs in the Upper Rhine Graben using a combination of methods from hydrogeochemistry and isotope hydrology in hot springs and near surface groundwater. The main goal is to confine the area of interest for further, indirect geophysical investigation. For this purpose natural geochemical tracers as well as rare earth elements, 3He/4He ratios, and radiogenic isotopes (Sr, Nd, Pb) are investigated.

Edelgasprobe wird im Feld von Florian Freundt genommen

The project is set for a duration of three years and is being funded by the German Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety (BMUB). The project is an interdisciplinary effort, combining the expertise of two Heidelberg University research groups of and the engineering company GeoT from Karlsruhe, which acts as project coordinator and possesses a wide expertise regarding the geology of the upper Rhein Graben and hydrogeothermal exploration.

The research group Hydrogeochemistry and Hydrogeology of Prof. Dr. Isenbeck-Schroter aim is to conclude from the chemical composition of ground waters to the origin and flow paths through the reservoir. Beside standard methods a main scope will be put on trace analysis like uranium, arsenic, lead, yttrium and the rare earth elements. In addition the working group on isotope geology will analyse strontium-, neodymium- and lead isotopes in ground- and thermal waters as well as in bedrocks.

The research group of Prof. Dr. Aeschbach-Hertig is working on the analysis and interpretation of helium isotopes in ground and thermal waters. Increased 3He/4He rates show the presence of mantle fluids and therefore a deep circulation shall be identified and researched in detail. The helium analysis will be complemented with complete noble gas measurements (Ne, Ar, Kr, Xe) and the analysis of the stable isotopes of waters (2H and 18O). Additionally a set of dating methods (3H-3He, 222Rn, CFCs, SF6, 14C) for groundwater is deployed.

Grundwasserprobennahme in der Nähe von Freiburg, nach Sonnenuntergang

 

Contact:

Dr. Florian Freundt
Prof. Dr. Werner Aeschbach

Resulting Dissertations

  • Freundt, F., 2017. Application of Helium Isotopes in Shallow Groundwaters for Geothermal Energy Exploration in the Upper Rhine Graben. Dissertation, Universität Heidelberg. DOI: 10.11588/heidok.00023245
     
  • Al Najem, S., 2016. Hydrogeochemische Charakterisierung von Grundwässern des Oberrheingrabens zur Identifizierung störungsbedingter Tiefenwasser‐Einflüsse. Dissertation, Universität Heidelberg. DOI: 10.11588/heidok.00021612

Conference abstracts

  • Goldschmidt 2013, TRACE: A Multi-Tracer Analysis of Shallow Aquifers to Improve Geothermal Potential Assessment, Freundt F, Al Najem S, Aeschbach-Hertig W, Isenbeck-Schroeter M, Kober B, Kraml M, Grobe R & Wenke A (2013) Mineralogical Magazine, 77(5) 1111 (http://goldschmidt.info/2013/abstracts/abstractView?abstractId=1871)

  • Goldschmidt 2013, Deep Geothermal Reservoir Analysis in the Upper Rhine Graben Using a Geochemical and Isotopical Multi-Tracer Method – First Results, Al Najem S, Freundt F, Isenbeck-Schroter M & Aeschbach-Hertig W (2013) Mineralogical Magazine, 77(5) 580 (http://goldschmidt.info/2013/abstracts/abstractView?abstractId=1845)

  • EGU General Assembly 2014, A multi-tracer approach for the exploration of deep geothermal energy potential and fault zone characterisation, applied in the Upper Rhine Graben, F Freundt, S Al Najem, W Aeschbach-Hertig, M Isenbeck-Schroter, G Schmidt, R Grobe, and M Kraml, Geophysical Research Abstracts, Vol. 16, EGU2014-13059, 2014 (http://meetingorganizer.copernicus.org/EGU2014/EGU2014-13059.pdf)