Propriétés hydrodynamiques du Callovo-Oxfordien dans lʹEst du bassin de Paris : comparaison des résultats obtenus selon différentes approches

Since 1994, Andra has carried out a series of research programs in order to determine the hydrogeological properties, including permeability, of the Callovo-Oxfordian argillaceous formation of the Paris Basin, and more specifically of the site of the underground laboratory located on the township of Bure, in the South of the Meuse district. Determining such a parameter in a very low permeability argillaceous rock raises a number of questions: theoretical (is the Darcy law still valid?), methodological as well as technical (how can values representative of the formation be obtained?). This article presents the approach and means adopted to achieve this goal, i.e., to obtain for this parameter a value as reliable and precise as possible, and to determine its uncertainty, its anisotropy and possible variability according to the lithology. The results obtained from measurements carried out on samples, as well as through a series of tests carried out in deep boreholes from the surface and short boreholes from the experimentation drift at 445-m depth, are coherent, although the methods and investigation scales are different. At the scale of the laboratory site, permeability is below 10 −12   m s −1 over the entire thickness of the argillaceous formation, with a minimum value estimated at 10 −14   m s −1 . The first results from tests carried out in the experimental drift of the underground laboratory at 445-m depth confirm the very low bulk permeability of the Callovo-Oxfordian formation. To cite this article: J. Delay et al., C. R. Geoscience 338 (2006).