Sequence systems tract mapping in Desmoinesian Granite Wash, Anadarko Basin: Implications for reservoir geometry

Abstract

A fan delta facies architectural model for the Desmoinesian Granite Wash is developed from study of 8 cores some of which include spectral gramma ray and magnetic susceptibility scans. Architectural hierarchy spans scales from lithofacies to lithofacies association to facies. Depositional settings range from fan platform through fan apron to fan toe. Results of this study offer an alternative depositional model to the conventional basin-floor fan model for the Granite Wash in western Oklahoma and adjacent Texas panhandle. In the vicinity of northern Beckham County, parasequence- and parasequence-set-scale correlation of conventional well logs from vertical wells and stratigraphic mapping define geometries that should be considered in horizontal drilling strategies. For example, the upper Skinner Wash is dominated by falling stage and lowstand systems tracts. Isopach map patterns delimit broad, arcuate sandstone accumulations separated by thin areas that extend across some 2,500 acres; such geometries are in contrast to lobate patterns expected for basin-floor fan.

AAPG Datapages/Search and Discovery Article #90221 © 2015 Mid-Continent Section, Tulsa, Oklahoma, October 4-6, 2015