Greenbrier Limestone Reservoir Controls and Exploration Strategies – Central WV
Gregory R. Wrightstone, Texas Keystone, Inc., Pittsburgh, PA 15238
Oolitic zones in the Greenbrier Limestone provide a prolific producing reservoir throughout much of central and southern West Virginia, eastern Kentucky and southwestern Virginia. In the central West Virginia counties of Kanawha and Jackson, structure plays a dominant role in the geographic distribution of the productive oolite reservoirs. Also recognized in this area is the structural segregation of the reservoirs, with a small gas cap up-dip, large oil productive area and finally water downdip.
The Hicumbottom Oil Fields, located in northern Kanawha County, were discovered in the 1940s during drilling targeting the deeper Oriskany Sandstone. Cumulative production from the two fields exceeded 2.5 MMBO. Both oil fields were located on the crests of northward plunging anticlines and anticlinal noses. The present day structures were proposed to have been active during the deposition of the Greenbrier Limestone and provided topographically high areas above wave base, along which the oolitic shoals were accumulated.
A prospective oil productive area on trend with the existing fields was identified based on structural mapping. A soil gas survey was completed in this exploratory area in 1992 and led to the drilling of an exploratory well in 1994. This well flowed oil and water measured at 190 bbls/day and is interpreted to be on the downdip edge of a new oil field. It is likely that a significant oil field similar in size to the Hicumbottom Fields will be discovered by offsetting the exploratory well in a structurally higher location.
AAPG Search and Discovery Article #90059©2006 AAPG Eastern Section Meeting, Buffalo, New York