Permeability and electrical conductivity of rocks in the crust: laboratory experiments and theoretical models

This research thesis reports the study of transport mechanisms in crust rocks through the joint development of experimental studies performed in laboratory, and of theoretical models able to describe the main involved physical processes. The first part reports an experimental study of transport properties of different sandstones, with a particular attention to permeability under controlled pressure and at room temperature, and electric measurements in ambient conditions. The second part presents a synthesis of main approaches used to model transport properties in rocks. Benefits and limitations of these models are analysed and discussed. In the third part, the author reports the application of models to actual cases of rock physics, with notably a comparison of results predicted by these models with experimental results obtained on sandstones. The last part proposes a more general geophysical point of view on rock transport properties. The author examines the permeability-electric conductivity-porosity relationships within a diagenetic sequence, and addresses the problem of permeability of deep rocks submitted to very high pressures and for which transport properties are governed by asperities on crack walls or on fracture surfaces