Microscopy and Microanalysis

Table of Contents - February 2012 - Volume 18, Issue 01  

Materials Applications

Characterization of Nanometer-Scale Porosity in Reservoir Carbonate Rock by Focused Ion Beam–Scanning Electron Microscopy

Bijoyendra Beraa1, Naga Siva Kumar Gundaa1, Sushanta K. Mitraa1 c1 and Douglas Vicka2

a1 Department of Mechanical Engineering, Micro and Nano-Scale Transport Laboratory, University of Alberta, Edmonton, AB T6G 2G8, Canada

a2 NRC-National Institute for Nanotechnology, Edmonton, AB T6G 2M9, Canada

Abstract

Sedimentary carbonate rocks are one of the principal porous structures in natural reservoirs of hydrocarbons such as crude oil and natural gas. Efficient hydrocarbon recovery requires an understanding of the carbonate pore structure, but the nature of sedimentary carbonate rock formation and the toughness of the material make proper analysis difficult. In this study, a novel preparation method was used on a dolomitic carbonate sample, and selected regions were then serially sectioned and imaged by focused ion beam–scanning electron microscopy. The resulting series of images were used to construct detailed three-dimensional representations of the microscopic pore spaces and analyze them quantitatively. We show for the first time the presence of nanometer-scale pores (50–300 nm) inside the solid dolomite matrix. We also show the degree of connectivity of these pores with micron-scale pores (2–5 μm) that were observed to further link with bulk pores outside the matrix.

(Received July 04 2011)

(Accepted September 23 2011)

Key words

Correspondence:

c1 Corresponding author. E-mail: sushanta.mitra@ualberta.ca