Advances in Computed Tomography for Geomaterials: GeoX 2010

In Situ Permeability Measurements inside Compaction Bands Using X-ray CT and Lattice Boltzmann Calculations

N. Lenoir — J. E. Andrade — W. C. Sun — J. W. Rudnicki

Northwestern UniversityDepartment of Civil and Environmental Engineering2145 Sheridan roadEvanston, IL [e-mail]

ABSTRACT. The paper presents some results of the characterization of microstuctural differences inside and outside compaction bands in natural sandstone. Specimens of Aztec sandstone were scanned at the synchrotron APS, at Argonne National Laboratory (USA). Porosity measurements obtained by image analysis show a sharp transition inside/outside the compaction band. Finally, preliminary permeability measurements were conducted via the lattice Boltzmann method and demonstrate the dramatic decrease in permeability caused by the reduced porosity inside the compaction band relative to the host rock.

 

KEYWORDS: compaction band, sandstone, permeability, lattice Boltzmann, synchrotron

1. Introduction

The study of deformation bands including compaction bands (CB) in granular porous rocks is an important topic for many applications ranging from oil and gas reservoirs to CO₂ sequestration to geologic repositories for nuclear waste. For instance, compaction bands have been found in sandstones typical of possible repository host rock for CO₂ sequestration. There is the question of how formation, presence or extension ...