Baez, Noelia¹, Christopher S. Swezey², John E. Repetski², Robert L. Ripperdan¹, E. Charlotte Sullivan³
(1) University of Puerto Rico, Mayaguez, PR
(2) U.S. Geological Survey, Reston, VA
(3) University of Houston, Houston, TX

ABSTRACT: Extent of the Devonian Mandata Shale May Control Gas Production from the Silurian-Devonian Helderberg Group, West Virginia (U.S.A.)

Gas is present within carbonate strata of the Silurian-Devonian Helderberg Group in the Appalachian Basin. Most of this gas is from fields located along anticlines in northeastern West Virginia. Data from some of these fields (Jordan Run, Headsville, Headsville North, and Inkerman) indicate that the Helderberg reservoir interval is at depths of 4,000-9,000 ft (1,200-2,800 m) in the Lower Devonian Corriganville Limestone and possibly the underlying Devonian New Creek Limestone of the Helderberg Group. For two wells in the Jordan Run field, final open flow of gas from the Corriganville Limestone was 73 and 2,500 mcf per day, and reservoir pressures were 1,890 and 1,450 psi, respectively. In outcrops near the Helderberg gas fields, the Corriganville and New Creek Limestones are carbonate grainstones and packstones, and the combined thickness of these two formations is approximately 39-46 ft (12-14 m). The Corriganville and New Creek Limestones are overlain by the Lower Devonian Mandata Shale, which is thought to form a seal (and possibly a source) for the gas. Helderberg gas production is not present south of the Jordan Run field, which corresponds with the southernmost extent of the Mandata Shale. The extent of the Mandata Shale, therefore, may control the extent of gas production from the Helderberg Group in northeastern West Virginia.

AAPG Search and Discovery Article #90026©2004 AAPG Annual Meeting, Dallas, Texas, April 18-21, 2004.