ABSTRACT: Millimeter-scale Permeability Variations, Upper Devonian Gordon Reservoir Sandstone, West Virginia, USA

MCDOWELL, RONALD R., AVARY, K. L., HOHN, M. E., MATCHEN, D. L., and PACKER, M. D., West Virginia Geological and Economic Survey, Morgantown, WV

Based on geophysical log signature and perforated interval, selected portions of nine cores from the Jacksonburg-Stringtown field were subjected to direct permeability mea-surement using a TEMCO minipermeameter. Slabbed core from pay and non-pay sandstones and conglomerates from the Upper Devonian Gordon reservoir were sampled along a 10 x 10 grid with nodes spaced 0.635 cm (0.25 inches) apart and rows oriented parallel to observed bedding. Permeability was measured and recorded at each grid node. Data were mapped at a 1-to-1 scale and variograms of permeability were produced for each grid to help quantify observed variability.

Permeability data suggest that classification of core as pay sandstone based on log signature was successful. A single example of pay sandstone was found to have negligible permeability (all nodes <1 mD); other samples showed uniformly distributed permeabilities ranging from 10 to 200 mD. Non-pay samples were found with no permeability; negligible (<1 mD), "patchy" permeability; and distinct, bedding-parallel zones of low (1-5 mD) permeability adjacent to impermeable zones.

Several conglomerate samples showed permeabilities similar in magnitude and distribution to pay sandstones. Others displayed impermeable, "patchy", or strongly zoned permeability similar to non-pay. Importantly, conglomerates with different styles and ranges of permeability could not be readily differentiated on geophysical logs and may be inter-bedded with pay or non-pay sandstones. This work was funded by the U. S. Department of Energy under contract number DE-AC26-98BC15104.

Search and Discovery Article #90907©2000 AAPG Eastern Section Meeting, London, Ontario, Canada