Margaux Raguenel

Flow simulation in fractured reservoirs on unstructured meshes

 To well understand and predict the behaviour of complex geothermal systems, a double challenge must be taken up. On one hand, representing accurately the main physical phenomena that induce the flow and heat circulation, and on the other hand, identifying the impact of geological heterogeneities in those processes. Since the work of Kohl et al. (2003), major progresses have been made to model coupled processes. however, their application often remains limited to two dimensions or with simple geometry systems (Scott et al., 2015). It is for now very difficult to predict the impact of complex heterogeneities in the local or the global behaviour of geothermal systems.

The goal of this PhD thesis is to bring responses to this problem using realistic 3D descriptions of geological heterogeneities, by generating unstructured mesh which are describing those heterogeneities and then run numerical simulations on those mashes with finite elements/finite volumes hybrid methods.

This work will aim to develop a tool combining static and dynamic models of the geothermal reservoir. An important part will deal with the integration of relevant thermic and hydrodynamic properties of the mesh. This tool will for example allow to run sensitivity tests on the response of the geothermal system regarding the changing of the geology of the reservoir. On a larger scale, it will help answer fundamental or applied questions on the geothermal ressource.