Stratigraphy, Seismic Characteristics, and Reservoir Properties of the Desmoinesian Granite Wash, Buffalo Wallow Field Area, Anadarko Basin, Texas

Abstract

The Desmoinesian Granite Wash is a productive oil and gas play of the southern Anadarko Basin. It includes a series of alluvial fans, fan-deltas, proximal turbidites, and debris flows deposited in association with the Amarillo-Wichita uplift. The deposits occur as several thousand feet of conglomerates, sandstones, carbonates, and shales that form complex low-permeability and generally low-porosity reservoirs. The stratigraphic and structural framework and reservoir characteristics of the Desmoinesian Granite Wash are established using a 28 mi2 (72 km²) 3-D seismic survey, logs from 450 wells, and petrophysical data derived from published cores. The lithologies and well-log signatures of the different reservoirs are highly variable. The dominant lithofacies include cross-bedded sandstone, parallel-stratified sandstone, planar-laminated sandstone, structureless sandstone, bioturbated sandstone, and silt-rich mudstone. Artificial-neural-network (ANN) techniques are used to estimate lithology logs in non-cored wells by utilizing core and well logs. Key stratigraphic surfaces are commonly related to laterally extensive shales. The Desmoinesian Granite Wash is subdivided into 10 intervals based on net-to-gross ratio, regional trends in well-log signatures, and seismic reflection character. Detailed interpretation of 3-D seismic data also illustrates that the Granite Wash interval exhibits several high-angle reverse faults with significant offset. Results from P-impedance inversion are used with the estimated lithology logs, and the established stratigraphic and structural framework to constrain the spatial distribution of lithology and petrophysical properties in 3-D reservoir models. The models illustrate the stratigraphic architecture, main structural elements, and their relationship to Granite Wash reservoir quality distribution for the study area.

AAPG Datapages/Search and Discovery Article #90259 ©2016 AAPG Annual Convention and Exhibition, Calgary, Alberta, Canada, June 19-22, 2016