1 Jul 2017
1 Dec 2017 (Extended to 10 Jan 2018)
15 Jan 2018
16 Apr 2018 (Extended to 15 Jun 2018)
From 16 July 2018
By 17 September 2018
ISRM Franklin Lecture
Department of Civil and Environmental Engineering, Ehime University
Thu-02 Nov 2018 | 08:30 – 09:15 | Summit 2
"Thermal-Hydraulic-Mechanical-Chemical Couplings that Define the Evolution of Flow and Transport Behavior in Fractured Rocks"
When considering the sequestration of the energy byproducts of radioactive wastes and anthropogenic CO2 and the efficient recovery of subsurface energy, it is of significant importance to examine the flow and the transport behavior in fractured rocks. In particular, the fluid flow within low-permeability rock masses is often dominated by transport in through-cutting fractures, and may cause hydraulic weakness. Changes in the ambient stress and temperature conditions should affect the transport characteristics of these conduits through combined mechanical and chemical interaction. We have been seeking a consistent understanding of coupled thermal, hydraulic, mechanical, and chemical controls on the hydraulic and transport properties of natural fractures and fractured rocks. In this lecture, the results are presented of water flow-through experiments in rock fractures under various confining pressure and temperature conditions. The experiments follow the progress of the fracture permeability mediated by the coupled processes. Phenomenological models are also presented to replicate the experimental measurements by accounting for the chemo-mechanical processes such as the pressure solution. Furthermore, coupled THMC numerical models are shown to predict the long-term change in rock permeability. Finally, a prospective view of our work is presented.
Hide Yasuhara is a Professor at Graduate School of Science and Engineering, the Ehime University in Japan. He received his Ph.D. in Energy and Geo-Environmental Engineering from the Pennsylvania State University, US in 2005, and then, moved to the Ehime University, Japan as an Assistant Professor. He has been a full Professor at the same university since 2016. Dr. Yasuhara’s research interests are mainly related to rock mechanics and engineering, earth physics, geochemistry, fault mechanics, computational mechanics, flow and transport in porous fractured rocks, in addressing coupled thermo-hydro-mechano-chemo problems such as sequestration of high level radioactive wastes and CO2, and recovery of subsurface energy (e.g., geothermal energy, unconventional oil and gas, methane hydrate). He is a recipient of the Rocha medal 2007 awarded by the International Society for Rock Mechanics.