Application of Non-toxic Yield Stress Fluids Porosimetry Method and Pore-Network Modelling to Characterize the Pore Size Distribution of Packs of Spherical Beads

Abstract

With X-ray computed tomography still being flawed as a result of limitations in terms of spatial resolution and cost, toxic mercury intrusion porosimetry (MIP) is nowadays the prevailing technique to determine PSDs of most porous media. Recently, yield stress fluids porosimetry method (YSM) has been identified as a promising clean alternative to MIP. This technique is based on the particular percolation patterns followed by yield stress fluids, which only flow through certain pores when injected at a given pressure gradient. In previous works, YSM was used to characterize natural and synthetic porous media, and the results were compared with MIP showing reasonable agreement. However, considerable uncertainty still remains regarding the characterized pore dimension with each method arising from the highly complex geometry of the interstices in real porous media. Therefore, a critical stage for the validation of YSM consists in achieving successful characterization of model porous media with well-known pore morphology and topology. With this objective in mind, a set of four packs of glass beads each with a given monodisperse bead size were characterized in the present work using different porosimetry methods: experimental YSM, numerically simulation of MIP and pore-network extraction from a 3D image. The results provided by these techniques were compared, allowing the identification of the pore dimensions being characterized in each case. The results of this research elucidate the causes of the discrepancies between the considered porosimetry methods and demonstrate the usefulness of the PSD provided by YSM when predicting flow in porous media.