Influencia de la anisotropía en las propiedades hídricas de rocas. Estudio de rocas dolomíticas brechoides de la Cordillera Bética (España)

Zusammenfassung

The purpose of this study is to determine the influence of anisotropy on hydrical properties of brecciated dolostones (BD). The present investigation involving BD has revealed, on the one hand, at meso-scale, four types of fractures. On the other hand, mercury intrusion porosimetry (MIP) has delimited two main porous families: pores of rock matrix and micro-fracture systems. Capillary transport and permeability tests were performed on four types of BD in order to establish the correlation between these parameters and the porous-fracture systems. The results show strong anisotropy in capillary absorption measured on prismatic samples in their three orthogonal directions. At the same time, our study has demonstrated that permeability correlates with both capillary absorption, as well as fracture density. Finally, the porous system of BD can be described in two ways: as a tri-continuum medium that consists of pores belonging to the pore matrix, fractures and cavities or as a dual-porosity model embedding fractures and vein intercrystalline porosities.