Field Analysis of Stacked Granite Wash Reservoirs: Using Sequence Stratigraphy, Mineralogy, and Source Rock Analysis to Identify Play Fairways

The Granite Wash play in the deep Anadarko Basin of western Oklahoma and the Texas Panhandle has been a vertical drilling target for decades. Since late 2007 the play has been the focus of significant horizontal drilling with over four hundred (400) completions. Recent horizontal successes in Pennsylvanian age (Missourian and Desmoinesian series) Washes in the deep basin immediately proximal to the Amarillo-Wichita uplift are spurring a tremendous amount of activity. Multiple wells have had initial production rates greater than 1000 BOPD and 3 MMCFD. Immediately north of and proximal to the uplift the thickness and quality of Granite Wash reservoirs vary tremendously over short distances. Sediment supply, accommodation space, and sea level fluctuations all impact the patterns of deposition and likelihood of preservation of reservoir. Utilizing core data, imaging logs, and log data from hundreds of wells, we have developed a stratigraphic interpretation of the multiple stacked Desmoinesian and Missourian washes, focused on a four township area. Production in these washes is largely focused in deltaic, fan and bar systems with preserved clean sand in stratigraphic traps that laterally pinch into marine shale and are often encased in source rocks representing regional flooding surfaces. Understanding the sequences and depositional pattern of each wash, as well as the unique mineralogy of the source of sediment allows delineation of productive trends of multiple stacked reservoir units.  

AAPG Search and Discovery Article #90142 © 2012 AAPG Annual Convention and Exhibition, April 22-25, 2012, Long Beach, California