Dynamic characterization and modeling of coupled structural - chemical - and transport pro-cesses: a multiscale approach – CATCH

We aim to implement a stepwise methodology starting with novel micro/nano-fluidics and column experiments, where we will characterize the macroscopic transport properties of porous media of increasing complexity combining time-resolved and post-mortem multi-scalar analysis techniques that cover the nanometer to centimeter scale ranges. The experimental results (e.g. porosity evolution as a function of time, pore network connectivity, pore-size/ interfacial energy controlled solubility) obtained on a limited number of fully characterized samples will be used as input parameters or constraints for the development of both pore and continuum scale modeling approaches. In terms of an integrative task, the most suitable upscaling techniques and methodologies will be explored in order to produce continuum models and relevant parameters for the future improvement of efficiency and safety evaluations for subsurface energy applications.

First results available soon

In progress

Tournassat, C.; Steefel, C.I. & Gimmi, T. Solving the Nernst-Planck equation in heterogeneous porous media with finite volume methods: Averaging approaches at interfaces Water Resources Research. 2020. 56, e2019WR026832. doi.org/10.1029/2019WR026832

J. Poonoosamy, C. Soulaine, A. Burmeister, G. Deissmann, D. Bosbach, and S. Roman, Microfluidic flow-through reactor and 3D Raman imaging for in situ assessment of mineral reactivity in porous and fractured porous media, Lab on a Chip, under review.

The CATCH project aims at estimating changes of transport parameters in geological media in response to porosity evolution. The long-term effectiveness of deep subsurface storage systems largely relies on our understanding and modeling capability of key relationships between natural media and engineered components. Changes in the mineral matrix due to dissolution-precipitation reactions following perturbations caused by geological applications can lead to changes in the macroscopic transport properties of the geological medium. Predictions can be made by considering transport processes coupled to chemical reactivity, but current reactive transport models (RTM) have severe limitations due to an incomplete understanding and quantification of the underlying mechanisms and processes. Using a combination of multiple methods and multi-scale characterizations, we aim at making a fundamental step forward in the predictive ability of RTM based on bridging the pore and continuum scales.