WILSON, THOMAS H., LI ZHENG, and ROBERT C. SHUMAKER, West Virginia University, Morgantown, WV

ABSTRACT: Sequential Development of Structural Heterogeneity in the Granny Creek Oil Field of West Virginia

Analysis of Vibroseis and weight-drop seismic data over the Granny Creek oil field in the Appalachian foreland of West Virginia

indicates that the field's development has been effected by episodic Paleozoic reactivation of fault blocks rooted in the Precambrian crystalline basement. The imprint of structures associated with the Rome trough penetrates the overlying Paleozoic sedimentary cover. Reactivation histories of individual fault blocks vary considerably throughout the Paleozoic. In general, the relative displacement of these basement fault blocks decreases exponentially during the Paleozoic; however, this pattern is interrupted by periods of increased tectonic activity and relative inversion of offsets along some faults.

The distribution of late-stage detached structures during the Alleghenian orogeny also appears, in part, to be controlled by mechanical anisotropy within the detached section related to the reactivation of deeper structures in the crystalline basement. The net effect is a complex time-variable pattern of structures that partly controls the location of the reservoir and heterogeneity within the geometric framework of the reservoir.

Structural heterogeneity in the Granny Creek area is subdivided on the basis of scale into structures associated with variations of oil production within the reservoir. Variations of production within the field are related, in part, to small detached structures and reactivated basement faults.

AAPG Search and Discovery Article #90995©1993 AAPG Eastern Section Meeting, Williamsburg, Virginia, September 19-21, 1993.