Development and application of an innovative method for studying the diffusion of dissolved gases in porous saturated media

This thesis describes how the petrophyiscal properties of clayey samples influence the transport properties, with examples for the Boom Clay and Eigenbilzen Sands. Transport measurements (hydraulic conductivity and diffusivity of dissolved gases) have been performed on different samples from the Boom Clay and Eigenbilzen Sands. Afterwards, the samples were fully characterized by CT, µCT, mineralogy, grain size distribution, N2-BET measurements, light microscopy of thin section, … Results indicate an increase in hydraulic conductivity when samples become more sandy/silty, and also diffusivity increases. For the samples of the Eigenbilzen Sands, the geometric factor is constant while it increases with increasing size of the diffusing molecule for the clayey samples. Correlations are observed between mineralogy, grain size distribution, SSA, log(K), log(Deff) and the fraction of micro pores. Petrographical analyses showed that the compositions strongly influences the microstructure of the samples, but also the distribution of the mineral phases plays an important role.