Geology and Stratigraphy of Devonian and Lower Mississippian Sediments of Roaring Fork-Looney Creek Field, Wise County, Virginia, and Harlan County, Kentucky

Roswell Barranco

The Roaring Fork-Looney Creek field produces from the Devonian shale and the Berea, Sunbury, Injun or Weir, and Greenbrier ("Big Lime") formations.

The Devonian shale production is from the Cumberland Plateau fault block and the Pine Mountain (Cumberland) overthrust fault block. The Pine Mountain thrust fault courses through the lower members of the Devonian shale. Three different relationships are observed in the Devonian shale: (1) the section appears to be unfaulted, (2) some section appears to be missing, and (3) multiple occurrences of the same intervals are observed. Isopachs of the shale's total thickness are useful for determining the volume of reservoir rock in an area but not for depositional interpretation. Gas production from beneath the Pine Mountain thrust fault is an extension of the shale-gas production in the Big Sandy gas field of Kentucky. Although the shale has relatively low initial flow rates, its relatively long production life provides the largest gas reserves.

The Berea Formation is shale in the field area and, like the overlying Sunbury Shale, thins from east to west. The normal completion practice for these formations is to perforate the upper part of the Devonian, Berea, and Sunbury shales at the same time, as one overall shale interval.

The Injun or Weir is a sandstone-shale sequence that thins from west to east, and its sandstone members become siltstones and shale in the same direction. This sequence has provided the best high-sustained flow rates in the field.

The Greenbrier has sporadic porosity development, which typically develops in the lower half of the formation. This limestone thickens to the east. Although the Greenbrier has high initial production rates after treatment, the rate of decline is relatively steep.

From November 4, 1984, to December 31, 1987, Coastal Oil and Gas Corporation has produced a total of 19.78 bcf from 163 gas wells in the field, an average of 17.82 MMCFGD for 37 months.

AAPG Search and Discovery Article #91031©1988 AAPG Eastern Section, Charleston, West Virginia, 13-16 September 1988.