|
|
 |
|||||||||||||||||
|
|||||||||||||||||
 |
|||||||||||||||||
| JOURNAL HOME | HELP | CONTACT PUBLISHER | SUBSCRIBE | ARCHIVE | SEARCH | TABLE OF CONTENTS |
1 Department of Geology and Geophysics, University of Calgary, 2500 University Drive N.W., Calgary, Alberta T2N 1N4, Canada; meyer{at}geo.ucalgary.ca
2 Department of Geology and Geophysics, University of Calgary, 2500 University Drive N.W., Calgary, Alberta T2N 1N4, Canada; krause{at}geo.ucalgary.ca
Rudi Meyer earned his M.S. degree in structural geology from Michigan State University and then worked at Petróleos de Venezuela S.A., focusing primarily on development geology in the Maracaibo basin. He earned his Ph.D. in clastic reservoir sedimentology from the University of Calgary, receiving the 1998 Canadian Society of Petroleum Geologists Award for the most significant contribution to Canadian sedimentary and petroleum geology. His current research interests are integrated reservoir characterization, fractured reservoirs, and provenance, deposition, and diagenesis of sediments in the Alberta foreland basin.Fed Krause earned his B.S. and M.S.(honors) degrees from the University of Kansas and Ph.D. from the University of Calgary, Canada. He has worked in industry, government, and university. His research has focused mostly on applications to petroleum reservoir geology, including shorefaces and ravinement surfaces, paleosoils and unconformities, progradational estuaries, ancient muddy coastlines, and cool/cold water carbonates and methane clathrate hydrates. Field work commonly lands him in the Book Cliffs, southern Alberta/northern Montana, western Nevada, the Florida Keys, and the Basque Country.
In this article we compare permeability measured on radially confined cylindrical plugs to permeabilities measured using a millimeter-scale probe tip on unconfined end-faces of the same plugs. Our investigation focuses on directional attributes of probe permeametry data as a means to understand the differences between plug-scale and probe-scale permeability magnitudes. Horizontal and vertical plug and probe flow tests were carried out on fine- to medium-grained, three-dimensional (3-D) cross-bedded sandstones collected from estuarine channel successions within the Cretaceous-age Virgelle Member at Writing-on-Stone Provincial Park, southern Alberta, Canada. The sandstones are heterogeneous in that they contain thin, discontinuous micaceous/carbonaceous laminae and apparent bedding-parallel grain-scale fabric.
The resulting probe-derived permeabilities (0.4-3.5 d) are mostly higher than corresponding plug permeabilities (0.5-1.6 d), and mean probe-derived permeability anisotropy is significantly lower than that derived from plug-scale measurements, that is, plug kV/kH is less than probe-derived kV/kH. The results can be understood as a consequence of the model flow geometry of probe flow tests (Goggin et al., 1988), namely, that flow is preferentially directed parallel to the sample surface, radially outward from the probe tip.
On end-faces of vertical plugs the bedding-parallel fabric further enhances flow parallel to the sample surface, and probe measurements yield reliable estimates of horizontal permeability, having magnitudes comparable to the permeability of equivalent horizontal plugs. For probe measurements on end-faces of horizontal plugs, flow paths appear to be variably confined parallel to bedding as a function of grain-scale and laminae-scale fabric, systematically yielding an overestimate of horizontal permeability (kPRH > kPLH). Interpretation of probe data in this orientation, however, is very uncertain, due to partitioning of flow paths parallel to and at angle to bedding. Significantly, almost all probe permeameter core and outcrop studies are based on measurements of this type.
This article has been cited by other articles:
|
|
 |
|
  Geostatistical models for shales in distributary channel point bars (Ferron Sandstone, Utah): From ground-penetrating radar data to three-dimensional flow modeling AAPG Bulletin, December 1, 2003; 87(12): 1851 - 1868.
|
|
|
|
 |
|
 Assessing Textural Variation in Laminated Sands Using Digital Image Analysis of Thin Sections Journal of Sedimentary Research, January 1, 2003; 73(1): 133 - 143.
|
|
| JOURNAL HOME | HELP | CONTACT PUBLISHER | SUBSCRIBE | ARCHIVE | SEARCH | TABLE OF CONTENTS |
