VDH-GT2 is the second well drilled within the framework of the geothermal project Geoven at Vendenheim. The well was drilled from August 2018 to February 2019 to 5308 m (4417m TVD), and prolongated between November 2019 and February 2020 to 6312m (5011m TVD). VDH-GT2 will be used as injection well. Location of the VDH-GT2 wellhead (in WGS84): Latitude: 48.66166457° Longitude: 7.77362583° Altitude: 134m At the present time, the Geoven project (https://cdgp.u-strasbg.fr/geonetwork/srv/fre/catalog.search#/metadata/VDHD) is still in development and this description may change.

GNSS data are recorded at REIC station at Vendenheim during VDHD Episode and are provided by the operator Fonroche. The data format is Rinex. The stations are described here (https://cdgp.u-strasbg.fr/geonetwork/srv/fre/catalog.search#/metadata/GNSS-Stations). See station location (https://cdgp.u-strasbg.fr/Obsnef-Gnss/situation.php) and data availability (https://cdgp.u-strasbg.fr/Obsnef-Gnss/teqc_heatmap.html?REIC).

VDH-GT1 is the first well drilled within the framework of the Geoven geothermal project at Vendenheim. The drilling of the well began in June 2017 and reached a final length of 5408 m in March 2018. A second leg at VDH-GT1 was drilled between February and September 2019 and a third between June and August 2020 to 5447 m (4644m TVD). VDH-GT1 will be used as production well. Location of the VDH-GT1 wellhead (in WGS84): Latitude: 48.66169796° Longitude: 7.77349337° Altitude: 134m At the present time, the Geoven project (https://cdgp.u-strasbg.fr/geonetwork/srv/fre/catalog.search#/metadata/VDHD) is still in development and this description may change.

Injection flow rate obtained during the operations of the 2020 hydraulic program at Vendenheim on the two wells GT1 and GT2 . Several operations were carried out from 19/08/2020 to 02/01/2021, for more details see the expert report (https://www.bas-rhin.gouv.fr/contenu/telechargement/47764/305601/file/Rapport%20du%20Comit%C3%A9_version%20int%C3%A9grale.pdf) The data parameters are the following: Column 1: Date (UTC) Column 2: Time (UTC) Column 3: Injection flow rate (m3/h) These data have been extrapolated from the figures in the expert report (https://www.bas-rhin.gouv.fr/contenu/telechargement/47764/305601/file/Rapport%20du%20Comit%C3%A9_version%20int%C3%A9grale.pdf)

Injected volume obtained during the operations of the 2019 hydraulic program at Vendenheim for the GT1 and GT2 wells. Several operations were carried out from 01/01/2019 to 01/01/2020, for more details see the expert report (https://www.bas-rhin.gouv.fr/contenu/telechargement/47764/305601/file/Rapport%20du%20Comit%C3%A9_version%20int%C3%A9grale.pdf) The data parameters are the following: Column 1: Date Column 2: Time (UTC) Column 3: Injected volume (m3) These data have been extrapolated from the figures in the expert report (https://www.bas-rhin.gouv.fr/contenu/telechargement/47764/305601/file/Rapport%20du%20Comit%C3%A9_version%20int%C3%A9grale.pdf)

Seismological signals acquired at Vendenheim during the development phase of the GEOVEN geothermal project. Waveforms from the permanent stations described in VDHD-Surface_network (https://cdgp.u-strasbg.fr/geonetwork/srv/fre/catalog.search#/metadata/VDHD-Surface_network) are provided for each event from VDHD-Catalogue (https://cdgp.u-strasbg.fr/geonetwork/srv/fre/catalog.search#/metadata/VDHD-Catalogue), (-30s, +90s). Data are automatically computed at request time

Surface seismic network used to study the Geoven Episode. The network consists of stations from several networks: Resif (https://www.resif.fr/) (FDSN code: FR), the French seismic network composed of high gain seismometers and accelerometers, French Accelerometric Network (FDSN code: RA), LRGB network (FDSN code: LE), the German network for Baden-Wuerttemberg, RaspberryShake network (FDSN code: AM) financed by the BCSF-Renass and the LabEx G-eau-thermie Profonde. Public stations from Fonroche network (ECK4 and VDH4) are included in the FR network. Data are automatically computed at request time

Description of GNSS stations set up around geothermal sites in Alsace. One station must be commissioned by the operator and its data are public. See target station locations and data availability (https://cdgp.u-strasbg.fr/Obsnef-Gnss/situation.php).

Geoven (http://www.geoven.fr) was a geothermal power plant project initially managed by Fonroche Géothermie, later taken over by Arverne (https://arverne.earth/wp-content/uploads/2023/02/Communique_Presse_Georhin_130223.pdf). Located at the Ecoparc Rhénan site in Vendenheim, north of Strasbourg, the project aimed to generate 6 MW of electrical energy and 40 MW of thermal energy. It relied on two deep wells to extract hot water and reinject it at depths exceeding 4,000 meters. The two wells VDH-GT1 and VDH-GT2 had been drilled and some tests had been conducted (5 injectivity and productivity cycles between 02/2018 and 11/2019). A first interruption occured after a first period of seismicity (11/2019 – 01/2020, MLv=3.0 max) at Strasbourg and Vendenheim, to allow a third-party scientific expertise. During this period, the well was deepened of 450m to reach 5000m. New tests were authorized starting 10/2020, but were stopped on 28/10/2020 after a new period of seismicity with quake reaching 3.6MLv (04/12/2020). Authority decided on 07/12/2020 to definitely stop the project. Another earthquake of 3.9 ML (https://www.franceseisme.fr/donnees/intensites/2021/210626_0300/Rapport_BCSF-RENASS_2021R1_EVT210626-DPT67.pdf) occured on 26/06/2021. Authorities set up a committee of experts that delivered a first report (https://www.bas-rhin.gouv.fr/Politiques-publiques/Environnement/Geothermie/Rapport-du-comite-d-experts-cree-en-appui-a-l-administration-sur-la-boucle-geothermique-GEOVEN). The Episode contains several datasets which you can find further down the page in "Links".

Geoven is a geothermal project initially managed by Fonroche Géothermie, then taken over by Arverne (https://arverne.earth/wp-content/uploads/2023/02/Communique_Presse_Georhin_130223.pdf). This project targets a deep reservoir (around 5km) close to a regional fault. Two wells were drilled, GT1 and GT2. From April to November 2019, several stimulation operations were carried out on the 2 wells GT1 and GT2. A first interruption took place after an initial period of seismicity (11/2019 - 01/2020, MLv=3.0 max) in Strasbourg and Vendenheim. Some of the data have been extrapolated from the Figures presented in the expert report, publicly available here: https://www.bas-rhin.gouv.fr/contenu/telechargement/47764/305601/file/Rapport%20du%20Comit%C3%A9_version%20int%C3%A9grale.pdf The Episode contains several datasets which you can find further down the page in "Links".