oa Gas Migration into Low Permeability Callovo-Oxfordian Argillite

Gas migration into argillaceous formations is an important issue to evaluate the perturbation induced by gas in an underground radioactive waste repository. The mechanisms controlling gas entry and flow into clay media are not fully understood yet and have to be investigated. In that context, Andra and its partners developed an experimental program to characterize the gas behavior of the Callovo-Oxfordian argillite which is the host rock for the French radioactive waste repository. Gas entry pressure and some key parameters such as gas permeability have been measured. We present first the main experimental results obtained on argillite. Then, the analysis of the results leads to discussions about the two-phase flow model used to predict gas migration at the repository scale.