[en] The REPRESS project aims to collect, bank, analyze and disseminate thermal response test (TRT) reports, and to develop a method for estimating the energy potential of vertical geothermal probes at regional level. A total of 192 TRT reports were analysed. At national level, a regression was established for calculating initial ground temperature as a function of coordinates, probe head altitude and probe depth. This regression provides a more reliable prediction of initial temperature than an estimate based on RT2012 regulatory temperatures, particularly at higher altitudes corresponding to lower temperatures. A lithological cross-section was established for 64 boreholes. Conductivity values per lithology defined by Swiss standard SIA-384/6 were established. The results show that for the five most represented lithologies, namely limestone, marl, water-saturated clay, water-saturated sand and granite, in decreasing order of drilled length, the estimated conductivity is within the range of values suggested by SIA-384/6. In particular, these values appear reliable for the two main lithologies: the thermal conductivity of limestone is slightly lower (2.4 W.K^-1.m^-1) than the value recommended by SIA-384/6 (2.8 W.K^-1.m^-1), while the difference for marl is less than 0.2 W.K^-1.m^-1. A database was developed to store and disseminate test results. The main banked test results, in particular thermal conductivity and initial temperature, can be consulted in a dedicated layer on the map area of the 'geothermal perspectives' website. A method for estimating the energy potential of geothermal probes has been developed and applied to the Centre-Val de Loire and Poitou-Charentes regions, for which thermal conductivity models are available at depths of 0-50 m, 0-100 m and 0-200 m respectively. The initial temperature was estimated using the regression method described above. This method makes it possible to estimate the amount of heat that can be extracted from a probe while complying with a set minimum evaporator outlet temperature criterion, in this case - 3.0 deg. C, the regulatory limit for boreholes drilled under the Small-scale geothermal energy regulations. Solicitation dynamics are determined by regulatory climate zone. Extractable energy per linear drilled section ranges from 70 to 150 kWh.ml^-1.yr^-1. Finally, a comparison with ten available TRTs shows that the difference between the minimum temperature of the heat transfer fluid estimated by the map data and that estimated by the TRT can be as much as 4 deg. C, which is not negligible. So energy maps and the underlying temperature and conductivity maps are no substitute for TRT for large-scale projects

[en] In view of the constant development of Vertical Geothermal Probe (VGP) installations, it has become essential to have cartographic documents evaluating the geothermal potential for VGP in the 0-200 m depth range, and providing data such as thermal conductivity and ground temperature, in order to be able to dimension these installations at the feasibility study level. The first step is to take stock of the thermal data potentially available in mainland France from existing thermal response tests (TRT), which have yet to be collected, and of the methods used to draw up the potential maps already produced. At the end of this initial survey and data collection work, a more precise method for assessing the national geothermal potential for VGP is proposed. The implementation of this method could be the subject of a future project

[en] The CARTODIM project aims to continue collecting, banking, analyzing and disseminating thermal response test (TRT) reports, and to continue developing the closed-loop geothermal exchanger sizing platform for professionals. 122 TRT technical reports were collected, complementing the 192 reports collected during the previous study: REPRESS project (2018-2019). In REPRESS, a regression for calculating initial ground temperature as a function of coordinates, probe head altitude and probe depth had been established. This regression has been validated using the new test sample, in the sense that it reproduces a comparable error distribution. The lithological cross-sections established for 248 boreholes in the DIALOG lexicon were used to determine average thermal conductivity values by major lithological classes (limestone, marl, etc.). The closed-loop geothermal heat exchanger sizing platform has also been modified to take vertical geothermal probe fields into account. These are initial developments, which still need to be improved. Nevertheless, a first version was presented at six training courses in Marseille, Lyon (two courses), Lille, Chalon-sur-Saone and Metz, attended by a total of 77 professionals

[en] The CARTODIM project aims to continue collecting, banking, analyzing and distributing thermal response test (TRT) reports, as well as developing the closed-loop geothermal exchanger sizing platform for professionals. By the end of March 2023, 96 additional TRT reports had been banked, bringing to 511 the number of TRT results available online at www.geothermies.fr. The interface of the probe field sizing platform has been improved. Users can now load their own water law and calculate the initial ground temperature based on the geographical coordinates of their project. Nearly 90 professionals were trained to use this tool during 10 training sessions

[en] The aim of the CARTODIM project is to continue collecting, banking, analyzing and disseminating thermal response test (TRT) reports, as well as developing the closed-loop geothermal exchanger sizing platform for professionals. As of April 2021, 363 TRT results have been banked. An analysis by the Heat Fund revealed that 184 Heat Fund files could not be associated with a TRT reference. The operations financed by the Heat Fund therefore represent a significant pool of additional TRT reports, and specific requests will be made to local ADEME agencies in 2021-2022. The compilation of borehole lithological sections in the Dialog lexicon, begun in 2019-2020, has been continued and now covers all 363 boreholes. Average thermal conductivity values by lithology were determined and compared with the Swiss standard SIA-384/6. With the notable exception of limestone, where the trend is the opposite, the values determined are generally higher than those of SIA-384/6. The probe field dimensioning tool drafted in 2019-2020 has been successfully tested against EED and TRNSYS software. This tool has evolved to take into account active cooling and the automatic calculation of the make-up required to complement the heat pump. Its interface has also been improved. 108 professionals were trained in this tool, including 59 from design offices, and awarded an overall average score of 4.3/5 to the training and the tool

[en] A first report presents the model of development of geothermal energy in the Parisian Basin by capitalising on the experience acquired in the Ile-de-France region on the Dogger aquifer, but also on some old operations in Trias during the 1980's in France, and more recent experiences in Denmark and the Netherlands. The second one reports the development of 3D geological model of the Dogger with a presentation of the geological and structural context of the Orleans Metropole territory with respect to the Dogger and Trias, the presentation of the model, of available data and of methods, and an assessment of the geothermal potential of the studied territory. The third document reports the elaboration of a cartography of the potential of development of surface geothermal energy, with assessments of the contribution of vertical geothermal probes, of the maximum theoretical number of doublets on aquifers to cover needs, an of the thickness of soft areas suitable for the installation of geothermal exchangers

[en] A first report aims at shedding a light on existing projects of geothermal valorisation in France and in Europe (Germany, Netherlands, UK, Norway, Spain, Poland) and on studies performed in France, and at identifying favourable conditions and potential deadlocks related to the valorisation of former mining sites. A second report outlines the context and stakes of the conversion of hydrocarbon exploration and exploitation drillings into geothermal works, discusses the associated risks, presents the different technologies of exploitation of the geothermal resource, reports returns on experience in France and abroad (Poland, Switzerland, Germany, New-Zealand, USA), states recommendations for these conversions, and proposes an overview of the situation and the implementation of a methodology of data analysis for such conversions. The third report reports a study of the regulatory framework of the conversion of oil drilling or mining sites into geothermal works, and the study of two potential cases of conversion in closed loop and in open loop. The next report presents the project of valorisation of former mining sites, proposes an inventory and a characterization of mining emergences and mine shafts in France