Abstract: Petroleum Geology of the Scull and Voorhies Pools of Crawford County, PA and Their Relationship to Major Strike Slip Faulting in Northwestern Pennsylvania

ZAGORSKI, W. A.
Lomak Petroleum, Inc., Hartville, OH

Oil and gas production has been established from Cambrian Age reservoirs in northwestern Pennsylvania since 1964 coinciding with the discovery of the Scull and Voorhies Pools in Crawford County. The original Scull well tested 7,000 MCFPD natural and produced over 190 MMCF in its first 18 months on line. Limited understanding of the nature of the Knox Unconformity and local reservoir characteristics resulted in several dry holes offsetting the original Scull discovery and the area was abandoned by the late 1960s. Interest in the Scull and Voorhies Pools has increased recently as the Rose Run play extends into Pennsylvania from Ohio. Several new wells have been drilled in the study area since 1994 which have contributed considerably to the understanding of the interplay between stratigraphy and structure in the Scull and Voorhies Pools.

Analysis of log, sample, and stratigraphic data suggests that production established from the Scull and Voorhies Pools occurs primarily within a sandy zone occurring in the Beekmantown Dolomite and not the Rose Run Sandstone or its equivalents as proposed by earlier investigations. Review of seismic, surface, and subsurface data indicates that a major strike-slip fault system is located along a northwest trend including the Scull and Voorhies Pools. This fault system has a significant effect on the localization of hydrocarbons in the reservoirs associated with the Knox Unconformity as well as the Medina Sandstone Group (L. Silurian), Lockport Dolomite (Silurian), and the Oriskany Sandstone (L. Devonian). The presence of wrench faulting near the Scull and Voorhies Pools is significant since the study area has several similarities to the prolific East Randolph and Atwater Fields located on the northern side of the Akron Suffield Fault in Portage County, Ohio.

AAPG Search and Discovery Article #90930©1998 AAPG Eastern Section, Columbus, Ohio