Characterization of Permeability Distribution in Bioturbated Geological Media using X-Ray Microtomography and Spot-permeametry
Baniak, Greg; La Croix, Andrew D.; Polo, Camilo A.; Playter, Tiffany L.; Pemberton, S. George; Gingras, Murray K.
In recent years, great advancements have been made in sedimentology to understand the distribution of porosity and permeability in two- and three-dimensions (2-D and 3-D). Herein, X-ray microtomography (micro-CT) is discussed as a technique to evaluate the distribution of density contrasts associated with trace fossils at high resolutions (1 to 34 μm). Coupled with sedimentological data and spot-permeametry measurements, micro-CT proved valuable in mapping the distribution of permeability within bioturbated sediments. Carbonate datasets from Western Canada (Debolt Formation and Wabamun Group) and siliclastics datasets from offshore Norway (Ula Formation) are used as examples.
Within the studied datasets, spot-permeametry measurements indicated that the trace fossils are typically higher in permeability relative to the surrounding matrix. With knowledge of the lithological and sedimentological data, histograms of the attenuation coefficients for scanned samples within the micro-CT can be used to differentiate the matrix and trace fossils in 2-D and 3-D. As a result, the permeability measurements can be linked with micro-CT data to build a spatial model that predicts the distribution of permeability in 2-D and 3-D.
AAPG Search and Discovery Article #90163©2013AAPG 2013 Annual Convention and Exhibition, Pittsburgh, Pennsylvania, May 19-22, 2013