Bérénice Vallier

PhD student - étudiante en thèse:

Subject of the PhD thesis:

Modeling of the Thermo-Hydro-Mechanical (THM) coupling during the exploitation of a deep geothermal reservoir in the Upper Rhine Graben.

Research interests:

  • Deep geothermal reservoir
  • Numerical modeling
  • Thermo-Hydro-Mechanical coupling
  • Hydro-thermal circulation and its exploitation

Context:

The progress in geothermal technology shows the necessity of numerical models as decision tools for drilling, stimulation and exploitation planning in the deep geothermal reservoirs ( 2.5-5.0 km deep). The numerical models including Thermo-Hydro-Mechanical (THM) coupling are able to address some critical issues: what is the influence of the exploitation on the hydro-thermal circulation? How can be optimized the drilling planning? What are the conditions that initiate the induced seismicity? How optimize the reservoir exploitation in order to minimize the induced seismicity? How long does the operational life of geothermal reservoirs last?

Currently, the numerical simulations of reservoir encounter two major difficulties. First, the THM coupling leads to huge amount of calculation time. Secondly, the multiplicity of the scale adds complexity. In space, the high gradients of rock properties as fault permeability require specific meshing techniques. In time, the temporal scales ranges from the minute (to describe the exploitation) to millions years (to describe the reservoir-scale convection initialization).

The goal of my thesis is to develop a numerical code allowing to address these two issues. In particular, precise parametrization of the model using the in-situ measurements is expected followed by the review of exploitations of deep geothermal sites as Soultz-sous-Forêts ou Rittershoffen (France). The thesis takes place in the laboratory Labex G-eau-Thermie Profonde. Its funding comes from the EGS Alsace project (ES/EOST/ADEME).

Supervisors:

Vincent Magnenet (MCF, University of Strasbourg, ICUBE)

Christophe Fond (Pr, University of Strasbourg, ICUBE)

Jean Schmittbuhl (Dr, University of Strasbourg, CNRS)

Conference presentations:

  • Oral presentation

THM large-scale modeling of the hydro-thermal circulation in the deep geothermal reservoir of Soultz-sous-Forêts (France), Vallier B., Magnenet V., Schmittbuhl J. and Fond C., 5th European Geothermal Workshop 2017, Karlsruhe, Germany.

Influence of the geothermal fluid rheology in the large-scale hydrothermal circulation in Soultz-sous-Forêts reservoir, Vallier B., Magnenet V., Schmittbuhl J. and Fond C., EGU General Assembly 23-28 April 2017, Vienna, Austria.

Three-dimensional THM modelling of the Soultz-sous-Forêts geothermal reservoir, Vallier B., Magnenet V., Schmittbuhl J. and Fond C., European Geothermal Congress 19-23 October 2016, Strasbourg, France.

  • Poster presentation

Influence of the geothermal fluid rheology in the large scale hydro-thermal circulation in Soultz-sous-Forêts reservoir, Vallier B., Magnenet V., Fond C. and Schmittbuhl J., IMAGE Final Conference 4-6 October 2017, Akureyri, Iceland.

Fluid viscosity effect on the large scale hydro-thermal circulation in Soultz-sous-Forêts reservoir, Vallier B., Magnenet V., Fond C. and Schmittbuhl J., European Geothermal PhD Days, 1-3 March 2017, Bochum, Germany.

Two and three dimensional THM modelling of the Soultz-sous-Forêts geothermal reservoir: a comparison, Vallier B., Magnenet V., Schmittbuhl J. and Fond C., European Geothermal Congress 19-23 October 2016, Strasbourg, France.

Teaching:

Teaching assistant during 2016-2017:

  • Introduction to geosciences, L1 students.
  • Introduction to PETREL software for seismic interpretation, M1 - 2nd year EOST students.