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The AAPG/Datapages Combined Publications Database

AAPG Bulletin


Volume: 65 (1981)

Issue: 5. (May)

First Page: 960

Last Page: 961

Title: Subtle Porosity and Traps Within Frisco Formation (Devonian, Hunton Group): Geologic-Seismic Waveform Approach, Example from West El Reno Field, Canadian County, Oklahoma: ABSTRACT

Author(s): William A. Morgan, Richard E. Schneider

Article Type: Meeting abstract


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The Frisco Formation is a middle Lower Devonian limestone within the Hunton Group (Upper Ordovician-Lower Devonian). In the Anadarko basin, the Frisco Formation consists of skeletal packstones and grainstones, whose main components are pelmatozoans, brachiopods, and, locally, corals. Depositional intergranular porosity has been mostly obliterated through syntaxial cementation on pelmatozoans, and mechanical and chemical compaction. Only minor intrabryozoan primary porosity remains. Secondary porosity, which formed during subaerial exposure of the Frisco Formation during the late Early and Middle Devonian, occurs locally at the top of the formation in the form of partly leached grains, vugs, and solution channels. This secondary porosity is best developed close to areas where the forma ion was completely eroded; these areas commonly correspond to Middle Devonian paleostructures.

Hydrocarbon accumulations in the Frisco Formation are mainly in stratigraphic traps situated downdip of the areas where the formation has been severely truncated. The Woodford Shale (Upper Devonian-Lower Mississippian) unconformably overlies the Frisco Formation in the study area and provides a source, trap, and seal for Frisco Formation reservoirs.

Geophysical identification of Frisco Formation porosity is possible using Relative Amplitude (RAM) processing. Mapping of porosity and truncated margins, and identification of potential hydrocarbon traps, are facilitated by using these RAM processed seismic sections. The West El Reno field, Canadian County, Oklahoma, produces gas and condensate from an outlier of the Frisco Formation, and provides a template for this technique.

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Copyright 1997 American Association of Petroleum Geologists