Exploration for Hunton Production in Dewey and Blaine Counties, Oklahoma

Stacy L. Clark, Patrick S. Mulvany

Hunton reservoirs in the study area are structurally controlled. They occur where up-to-the-basin faults intersect anticlinal noses. The structures range in size from 640 to 800 ac, and vertical fault displacements are less than 100 ft. These structures appear to be small-scale versions of similar structures that occur in the nearby North Custer City and Aledo fields.

Hunton structures are identified using both seismic information and subsurface data from well control. Apparent seismic signatures include (1) subtle flexure or closure, (2) amplitude dimming of reflectors within the Hunton, (3) amplitude dimming or disruption of the Viola reflector, and (4) normal faulting. Amplitude dimming and/or disruption may indicate porosity development, dolomitization, faulting, fracturing, or presence of gas. In areas having sufficient shallow well control, Hunton structures are revealed by structure contour maps on the Chester and Inola. Contours close, nose, or separate over Hunton structures. The locations of faults can be inferred from these maps.

Time of structuring appears to be a controlling factor for the presence of hydrocarbon in the Hunton. Hunton production is found only where positive structural deformation occurred during Atoka-Morrow time. These structural events are expressed as thins on an Inola-Chester isochore map.

AAPG Search and Discovery Article #91025©1989 AAPG Midcontinent, Sept. 24-26, 1989, Oklahoma City, Oklahoma.