Logo Bedretto Lab and logo ETH Zurich
2022-01-01 - 2023-01-01

Bridging the gap between micro- and macro-scopic permeability and porosity evolution from natural and anthropogenic processes

The relationship between porosity and permeability at macroscopic scales, and how they couple to rock strength, is poorly understood. Current laboratory methodologies cannot be reliably upscaled to macroscopic field observations, and there exists no field method which yields permeability and porosity simultaneously. In the field, geophysical techniques offer a cost-effective and non-destructive approach to remotely assess these properties but only qualitatively. Perhaps the most promising method, when it comes to crystalline rock, is ground penetrating radar (GPR). GPR responses depend on the dielectric properties of the medium and are therefore greatly affected by changes in permeability and porosity. Still, the measured response from GPR cannot be calibrated properly, since it depends on several factors, including the coupling of the source to the host rock and the radiation pattern of the antenna. We propose a novel methodology to establish a link between permeability, porosity and dielectric properties, starting from the laboratory and moving into the field. We will achieve this by imposing and measuring transient responses from rock samples with a recently developed permeameter. We will simultaneously use a dielectric spectrometer and a high-frequency GPR device to monitor changes in properties as the permeability test evolves.

Project Leader Institution

ETH Zurich

Project Contact

Alexis Shakas

Funding

ETH Zurich

Partners

Dr. Peter Achtziger, Prof. Dr. Florian Amann (RWTH Aachen)

Dr. Jacek Scibek (Kyoto Univ.)

Tags: past project