Pore geometry and pressure dependence of the transport properties in sandstones : Geophysics V56, N4, April 1991, P436–446

Abstract

The model of the pore geometry of sandstones proposed in this paper is based on three‐dimensional qualitative observations of the pore structure of sandstones reported in the literature. Three categories of pores can be distinguished: large spherical pores at four‐grain vertices (or nodal pores); tube‐like throats at three‐grain edges; and narrow sheet‐like throats at two‐grain faces. As a first step, the model is limited to rocks with a low clay content and, therefore, pores and throats are supposed to be free of clay. In this model, the sheet‐like and tube‐like throats are in parallel and, because of their different shapes, respond differently to pressure. The transport properties can thus be split into two parts: a strongly pressure dependent part associated with the sheet‐like throats and an approximately constant part associated with the tube‐like throats and the equidimensional nodal pores. Following these remarks, a scheme to estimate the volume fraction of each category of pores using the pressure...