Approaches to multi-scale analyses of mechanically and thermally-driven migration of fluid inclusions in salt rocks

Publication date: Available online 22 July 2019Source: Physics and Chemistry of the Earth, Parts A/B/CAuthor(s): Hua Shao, Yifeng Wang, Olaf Kolditz, Thomas Nagel, Torben BrüningAbstractFluid inclusions are found within mineral crystals or along grain boundaries in many sedimentary rocks, notably in evaporite formations, and can migrate along a thermal or hydro-mechanical gradient. Shale and salt rocks have been considered potential host rocks for radioactive waste disposal, due to their low permeability. Previously stagnant inclusions may become mobilised by a perturbation of the in situ state by a geotechnical installation or the emplacement of heat-generating waste. The migration of fluid inclusions can thus have important impacts on the long-term performance of a geologic repository for high-level radioactive waste disposal. As a part of the international research project DECOVALEX-2019, two aspects of fluid inclusion migration in rock salt are currently investigated under different boundary conditions: a) altered hydro-mechanical conditions as a consequence of tunnel excavation or borehole drilling and b) coupled thermo-hydro-mechanical-chemical conditions during the heating period of the post-closure phase of a repository.To obtain a mechanistic understanding of underlying physical processes for fluid inclusion migration, a multi-scale modelling strategy has been developed. Microscale hydraulic and time-dependent mechanical conditions related to the creep behaviour of ...
Source: Physics and Chemistry of the Earth, Parts ABC - Category: Science Source Type: research