CE49 - Planétologie, structure et histoire de la Terre

Coupled beHavior undErstaNdIng of fauLts : from the Laboratory to the fiEld – CHENILLE

Submission summary

The understanding of the coupled thermo-hydro-mechanical behaviour of fault zones in naturally fractured reservoirs is of fundamental importance for a variety of societal and economic reasons, such as the sustainable energy transition for the safe use of natural resources (energy storage, nuclear waste disposal or geothermal energy). The overall objective of this project is to better understand the physical processes resulting from a thermal and hydric load on an existing, identified and characterized fault zone. The idea here is to carry out a thermally controlled in situ fluid injection experiment in one of the faults accessible from the Tournemire underground research laboratory (URL). A heating system will be installed around the injection area and enable a precise and controlled incremental increase of the thermal load. In addition, an important monitoring system will be installed to measure the seismic and aseismic events induced either by thermal or by hydraulic loading. The monitoring system will be composed of acoustic and broadband sensors that will measure low to medium magnitude events. Furthermore, it is also planned to install a fibre optic network to measure temperature and displacement in a distributed manner in the investigation area. The active seismic methods will be deployed before and after the experiment to determine the structural network but also to detect the appearance of new structures triggered from the hydro-thermal pressurisation of the fault. A series of laboratory experiments will be conducted to understand the chemical and structural evolution occurring within the fault zones during the thermal and hydraulic loading. Experiments in climatic chambers exposing the samples to the same heat treatment as that of the in situ experiment will be carried out in order to compare the mineralogical composition evolution of the samples with those taken from the field investigated zone. Finally, a rock mechanical study, from the microscopic to the centimeteric scale with monitoring of the acoustic properties will be carried out. This study will include experiments from Scanning Electron Microscope with Energy Dispersive Spectroscopy (SEM-EDS) allowing the identification of the micro-scale mechanisms of deformation localization to which it is planned to add an acoustic measurement system. In order to study the evolution of mechanical behaviour as a function of scale, experiments in triaxial press, again with acoustic monitoring, are planned.

Project coordination

Pierre DICK (Pôle Santé Environnement - Direction Environnement)

The author of this summary is the project coordinator, who is responsible for the content of this summary. The ANR declines any responsibility as for its contents.

Partner

Section 4.2 GFZ Potsdam / Section 4.2 Geomechanics and Scientific Drilling
LMS Laboratoire de mécanique des solides
LG-ENS Laboratoire de géologie de l'Ecole Normale Supérieure
PSE-ENV Pôle Santé Environnement - Direction Environnement
Seismology Freie Universität Berlin

Help of the ANR 748,235 euros
Beginning and duration of the scientific project: December 2021 - 36 Months

Useful links

Explorez notre base de projets financés

 

 

ANR makes available its datasets on funded projects, click here to find more.

Sign up for the latest news:
Subscribe to our newsletter