Johanne KLEE, PhD student in ULS will defend her PhD thesis the 26th of November 2021 at 9:00 am (UTC+1 Paris) at UniLasse
Influence of fluid-rock interaction processes and strain on strike-slip zones properties: An analogue-based multidisciplinary approach. Fractured granitic geothermal reservoirs applications
ABSTRACT
This contribution aims at a better understanding of basement rock petrophysical properties evolution affected by progressive deformation along strike slip structures. The chosen approach is based on analogue studies, an analogue being a geological object dedicated to the understanding processes of particular interest. We have chosen a portion ofthe Southern Death Valley Fault Zone (Noble Hills, CA, USA) as an analogue.A comparison to structures found within the Upper Rhine Graben area and Soultz-sous-Forêts demonstration site is proposed. Our findings indicate that two stages of alteration can affect granitic basement rocks. A pervasive propylitic alteration, affecting the whole granitic body is overprinted by an argillic alteration mainly concentrated in the vicinity of fracture zones. At low to moderate strain a progressive increase of alteration degree, porosity values and calcite content are observed. Interestingly, the degree of alteration is not directly linked to the fracture density. It is demonstrated that high strain zones can but do not necessarily represent a barrier to geothermal brines circulation. Mechanical properties of high strained fault rocks play a crucial role in hindering the development of openings necessary to channel the flow within the reservoir. These properties are involving in time and space depending on accumulated deformation and fluid-rock interaction processes. A conceptual model of fault zone evolution and reservoir architecture is proposed. Geothermal exploration and exploitation must consider the role of geological heritage in order to warranty sustainable and safe operations.
KEYWORDS
Fractured granite, Fluid-rock interaction, Deformation gradient, Geothermal reservoirs, Analogue
LIVE ACCESS
If you are interested in following Johanne’s defense on live, you can access it by connecting to the following TEAMS link.
JUDGE PANEL
Gioia FALCONE
Professor, University of Glasgow
Judge–Rapporteur
Rafael FERREIRO-MÄHLMANN
Professor, Universität Darmstadt
Judge–Rapporteur
Domenico LIOTTA
Associate Professor Università di Bari
Judge–Examinateur
David BRUHN
Professor, Universität Delft
Judge–Examinateur
Juliet NEWSON
Director, Iceland School Energy
Judge–Examinateur
Ingo SASS
Professor, Universität Darmstadt
Judge–Examinateur
Pascal BARRIER
Associate Professor, UniLaSalle
Director
Ghislain TRULLENQUE
Associate Professor, UniLaSalle
Co-Director
Sébastien POTEL
Research Director, UniLaSalle
Collaborator–Guest
Béatrice LEDESERT
Professor, Cergy Paris University
Collaborator–Guest
Terry PAVLIS
Professor, University of Texas El Paso
Collaborator-Guest