Description du sujet de thèse

The objective of this PhD is to answer the long-lasting and still pending question: how the injection of fluids in the subsurface is linked to the occurrence of earthquakes? It is well known that the object “fault” is the key ingredient. Faults act as major conduit during injection of fluids in the subsurface and faults ultimately host earthquakes.
In the recent years, substantial research progresses have addressed the role of pre-existing faults on the remote triggering of seismicity but little have considered the complexity that lies in the multiscale roughness of faults which controls both fluid flow and slip. Indeed, research activities have been pursued in silo. Either the focus was solely on the control of fault geometry on fluid flow, or the focus was solely on the control of fault geometry on slip. This PhD position on induced seismicity aims at breaking this suboptimal silo-type research and to jointly assess the hydro and mechanical behavior of a multi-scale deformable rough fault.
Foreseen new findings should help to reconciliate our physical models with currently unexplained observations, such as unexpected large, remote or delayed triggered seismicity when reservoirs are initially very close to failure pre-injection. Applications to the case of the deep geothermal sites (Vendenheim, Balmatt, Rittershoffen) will be considered.

The recruited PhD researcher will:
• Develop numerical (3DEC, ITASCA for Discrete Element approach and MOOSE/GOLEM for Finite Element approach) and analytical hydro and mechanical forward models of a deformable fault with multi-scale asperities in the context of fluid injection.
• Implement inverse scheme to assimilate real observations and calibrate the forward models.
• Present, publish (ISI peer-review) and communicate research results at scientific meetings and in scholarly journals.

The recruited PhD researcher must have:
• Knowledge in numerical and analytical modelling
• Knowledge of geophysics, seismology, geomechanics or geothermal systems will be considered a strong additional asset
• Proficiency in English level C2 (according to the European Framework for languages)

Contexte de travail

The successful candidate will work at ITES (Strasbourg Institute of Earth & Environment) in the numerical modeling group of the ITI GeoT (Interdisciplinary Thematic Institute for the energy system transition – J. Schmittbuhl and V. Magnenet) and in strong collaboration with the TNO (Geological Survey of the Netherlands – T. Candela).

The objective of this PhD is to answer the long-lasting and still pending question: how the injection of fluids in the subsurface is linked to the occurrence of earthquakes? It is well known that the object “fault” is the key ingredient. Faults act as major conduit during injection of fluids in the subsurface and faults ultimately host earthquakes.
In the recent years, substantial research progresses have addressed the role of pre-existing faults on the remote triggering of seismicity but little have considered the complexity that lies in the multiscale roughness of faults which controls both fluid flow and slip. Indeed, research activities have been pursued in silo. Either the focus was solely on the control of fault geometry on fluid flow, or the focus was solely on the control of fault geometry on slip. This PhD position on induced seismicity aims at breaking this suboptimal silo-type research and to jointly assess the hydro and mechanical behavior of a multi-scale deformable rough fault.
Foreseen new findings should help to reconciliate our physical models with currently unexplained observations, such as unexpected large, remote or delayed triggered seismicity when reservoirs are initially very close to failure pre-injection. Applications to the case of the deep geothermal sites (Vendenheim, Balmatt, Rittershoffen) will be considered.

The recruited PhD researcher will:
• Develop numerical (3DEC, ITASCA for Discrete Element approach and MOOSE/GOLEM for Finite Element approach) and analytical hydro and mechanical forward models of a deformable fault with multi-scale asperities in the context of fluid injection.
• Implement inverse scheme to assimilate real observations and calibrate the forward models.
• Present, publish (ISI peer-review) and communicate research results at scientific meetings and in scholarly journals.

The recruited PhD researcher must have:
• Knowledge in numerical and analytical modelling
• Knowledge of geophysics, seismology, geomechanics or geothermal systems will be considered a strong additional asset
• Proficiency in English level C2 (according to the European Framework for languages)

Contraintes et risques

Not applicable