ABSTRACT: Tectono-Structural Synthesis for an Integrated Modeling Study of Ellenburger and Clear Fork Reservoirs, Permian Basin

HOAK, THOMAS E., K. SUNDBERG, P. ORTOLEVA, and M. SHEBL

A cooperative analysis of the Central Basin Platform and eastern Midland Basin is being conducted by the Indiana University-Laboratory for Computational Geodynamics, Phillips Petroleum Company, and SAIC. The project is being funded by the U.S. Department of Energy (DOE) to understand the genesis of fractured carbonate oil reservoirs.

The primary objectives of the tectonic analysis for modeling input were: (1) delineating regional stress state evolution; (2) calculating regional shortening; (3) delineating basement and Ellenburger fault zones; (4) confirming structural style; (5) characterizing fractured zones; and (6) analysis of linear features on, satellite imagery and their correlation to deeper structures.

We have characterized the surficial and subsurface geology and have integrated this information into a coherent synthesis of regional tectonic evolution. We have calculated geologic boundary conditions for the modeling regime and integrated potential field geophysical data (aeromagnetics and gravity) to provide independent confirmation of regional structural trends, especially at deeper structural levels.

To assess basement and pre-Permian structural control on the permeability and fracture trends in Clear Fork reservoirs, we investigated the relationship between basement/Ellenburger structural trends, and surficial trends observed on LANDSAT imagery. Results indicate that Clear Fork fracture trends should parallel those observed at the Ellenburger and basement level because of the correspondence observed between surficial linears and deep structure. Work in progress involves completion of the regional shortening calculation integrating seismic and well data, and fracture characterization through core studies.

Given the historic interest in the large hydrocarbon reserves in West Texas carbonate reservoirs, results of this integrated modeling project will have tremendous implications for exploration and production strategies targeting vuggy, fractured carbonate systems not only in West Texas, but throughout the globe.

AAPG Search and Discovery Article #90947©1997 AAPG Southwest Section Meeting, San Angelo, Texas