Characterization of Fontainebleau Sandstone: Quartz Overgrowth and its Impact on Pore-Throat Framework

Abstract

Fontainebleau sandstone outcrop is a prime example of a simple natural porous medium because of its pure mineral composition (0.995 Quartz) and an almost constant grain size in large sample blocks. It is widely used to investigate the correlation between the simple petrophysical properties independently of other parameters. This paper shows an experimental evaluation of Fontainebleau sandstone properties and their characteristics to advance understanding on the quartz overgrowth and the petrophysical and electrical transport properties. In order to acquire the pore and grain frameworks, we measure and quantify spatial attributes of the grain and pore's matrix by Computed Tomography (CT) image analysis, associated to stereological measurements and statistical 2D/3D reconstructions. In addition, the regular petrophysical laboratory methods are applied and connected to the spatial results. Furthermore, our graphical methods are compared to pre-existing literature. The main contribution of this work is the impact of quartz overgrowth on the pore-throat framework. Our laboratory experimental measurements provide comprehensive information in petrophysical and petrological data of Fontainebleau sandstone. We conclude that Fontainebleau sandstone outcrop displays consistent and homogenous properties. The clay in the studied samples of Fontainebleau sandstone are almost not exists and does not play any role in the pore framework. This ensures repeatability and reproducibility of our flow experiments in porous media. It provides comparable core flow experimental in our study of the oil mobilization process in the porous media. We demonstrated that the quartz overgrowth (i.e. cementation) is playing a central role in the pore-throat geometry and impacts both permeability and porosity by reducing the pore-throats (i.e. coordination number).