Statistical Synthesis of Imaging and Porosimetry Data for the Characterization of Microstructure and Transport Properties of Sandstones

Abstract

The microstructure of a suite of sandstone samples is quantitatively analyzed using a method which combines information from thin section micrographs of the pore space with mercury injection porosimetry in a statistical framework. This method enables the determination of a continuous distribution of pore sizes ranging from few nanometre to several hundred micrometre. The data obtained unify fractal and Euclidean aspects of the void space geometry, yield estimates of the pore-to-throat aspect ratio and challenge the ability of commonly used network models to describe fluid percolation in multiscale porous media. Application of critical path analysis to the prediction of flow permeability and electrical conductivity of sandstone core samples using the new information produces results comparable to those obtained by the classical approach-a fact attributed to the presence of macroscopic heterogeneity at the scale of several millimetres.

Using X-ray computed tomography in pore structure characterization for a Berea sandstone: Resolution effect

“…In addition, pore structure mapping directly from the real sample can provide the physical framework for pore-scale network models (Bryant et al, 1993;Bhattad et al, 2010), in which pore geometry and topology are incorporated explicitly, therefore no adjustable parameters, such as porosity, tortuosity, and relative permeability, are required for single-or multi-phase flow simulations (e.g., Blunt et al, 1992;Hilpert et al, 2000;Gladkikh and Bryant, 2005). Many efforts have been used to quantitatively characterize pore structure with different methods, which can be classified as direct imaging methods and various indirect methods as described by Amirtharaj et al (2011). The direct imaging methods, such as backscatter scanning electron microscopy (Ioannidis et al, 1996), X-ray computed tomography (XCT) with either conventional or synchrotron radiation (Brusseau et al, 2006;Dong and Blunt, 2009;Fredrich et al, 2006;Wildenschild et al, 2002), and Focus Ion Beam nanotomography (FIB-nt, Bera et al, 2011;Holzer and Cantoni, 2011;Keller et al, 2011), in recent decades have been used to construct the 3D pore structure and phase distributions in pore scale for natural and synthetic porous media.…”

“…Indirect pore geometry/structure probes include gas adsorption/condensation (such as N 2 or water vapor), mercury intrusion porosimetry (MIP), and nuclear magnetic resonance (NMR) relaxometry and imaging (Amirtharaj et al, 2011). Pore surface area, pore size distribution (PSD), and pore connectivity can be deduced from nitrogen adsorption-desorption curves (Barret et al, 1951;Seaton et al, 1989) or mercury intrusion-extrusion curves (Murray et al, 1999).…”

A method to calculate the multiphase flow properties of heterogeneous porous media by using network simulations

“…According to the critical path analysis of pore systems characterized by a broad range of pore throat sizes, 38,41,42 the hydraulic conductivity of each phase during drainage is governed by the permeability of the most permeable network spanning clusters of pores occupied by this phase. Given that in the heterogeneous synthetic pore network, oil starts occupying pores that are accessible through the largest throats, the oil relative permeability increases sharply as soon as a network spanning cluster of oil-occupied pores is established for a first time (Figure 8).…”

“…4 Up-scaling the transport properties A series of pore-structure characterization methods have recently been developed to probe pore sizes from several nanometers to several millimeters. 38,41,42 In this manner, the pore space of mineral soils and sedimentary rocks was analyzed in terms of the pore-and throat-size distributions of network models. 38 The autocorrelation function of back-scattered scanning electron microscope (BSEM) images was used to estimate the pore-size distribution over the range of large pore sizes, whereas high-pressure Hg intrusion data were used to extend the distribution to the range of small pore sizes.…”

Effects of micro-heterogeneity and hydrodynamic dispersion on the dissolution rate of carbon dioxide in water-saturated porous media

“…The micro-heterogeneity of reservoirs can be quantified by combining experimental techniques of pore structure analysis with inverse modeling optimization methods (Amirtharaj et al, 2011). It is worth mentioning that the hydrodynamic dispersion parameters of porous media of varying heterogeneity can be estimated with inverse modeling of solute concentration breakthrough curves measured during miscible displacement tests Tsakiroglou, 2007, 2008).…”