STRATIGRAPHY AND GAS PRODUCTION FROM THE MARCELLUS SHALE IN SOUTHERN WEST VIRGINIA

The Marcellus Shale is the only formation in the Middle Devonian Hamilton Group preserved in southern West Virginia. Most of the Hamilton Group, including the upper part of the Marcellus Shale, has been removed by the Middle Devonian Taghanic unconformity. Most often preserved is a thin, highly radioactive shale interval of the Marcellus Shale. To the west of the Warfield Anticline in Logan County, WV, in areas underlain by the Rome Trough, the Marcellus Shale is better developed/preserved. Included in this area are several discrete shale intervals separated by thinner limestone intervals. This is similar to the Marcellus Shale stratigraphy of northern West Virginia.

Recent activity in Marcellus Shale gas exploration has extended to southern West Virginia. In Logan County, WV, the Marcellus Shale ranges from zero to about 20 feet thick across most of the county with the western area ranging to about 30 feet. Temperature logs indicate that the thin Marcellus Shale is productive of natural gas but most wells are completed in the interval containing both the Marcellus Shale and the overlying organic-rich Rhinestreet Shale Member of the West Falls Formation that onlaps the Middle Devonian unconformity. Structure contours on the top of the Onondaga Limestone, immediately beneath the Marcellus Shale, indicate that areas of most active exploration lie along the axis of the Warfield anticline and in the eastern limb of the structure.