Geothermal Exploration of Upper Triassic Deposits in the Paris Basin: Comparison of the Sedimentary Records and Petrophysical Properties between In-Situ and Analogue Site (Ardeche, France)

Xavier Sengelen, Philippe Robion, Sylvie Bourquin, Jean-Baptiste Regnet, Christophe Barnes, Béatrice Ledésert
2021 Zenodo  
The Triassic formations of the Paris Basin present a good geothermal potential with their 80-125°C reservoir temperature, making them excellent candidates for energy co-production. In order to explore such opportunity, several aspects are investigated to provide an in-depth knowledge of the Triassic formations: (1) Establish a robust sedimentological frame of the Triassic sandstone and dolomite reservoirs. (2) Highlight potential reservoirs using rock physics properties (porosity,
more » ... .). (3) Combine those characteristics and properties into the regional stratigraphic framework of the Paris Basin, providing a better understanding of the Triassic formations at a larger scale. The comprehension of the geothermal prospects within Triassic formations implies to evaluate the degree of horizontal and vertical connectivity between the reservoir levels, which is assessed based on a sedimentological approach. Regarding the petrophysical input, new sets of properties are characterized for key horizons that represent a good flow potential identified in hydrocarbon exploration. The porosity, permeability and P/S wave velocity are analyzed for each reservoir. Along with the study of subsurface data from the deep Paris basin, a Triassic analogue is chosen in Ardèche (France), where fluvio-lacustrine sediments have been deposited along the passive margin of the Tethys Ocean. This formation is an equivalent to the one observed in the Paris Basin, in terms of facies and textures. Its sedimentary features are described along several sections in order to realize sequence stratigraphy correlations and to analyze the rock physical properties from various lithologies along these sections. The dual settings of the Paris basin and its analogue in Ardèche provides a unique opportunity to understand the vertical stacking and horizontal continuities of clastic deposits and dolomites, for both in-situ and exposure conditions. This approach would bring insights on the capacity of Triassic deposits to bear new geothermal pro [...]
doi:10.5281/zenodo.5786792 fatcat:ibqsadjevbc55ibg3gd5s6k43i