Distribution of Diagenetic Overprints and Reservoir Quality in Woodbine Sandstones, Double A Wells Field, Polk Co., TX

M. L. Barrett¹, C. Bresch¹, and T Kitchingham^2
1 Centenary College of Louisiana, Shreveport, LA
² Louisiana Tech University, Ruston, Louisiana

Four conventional cores were studied from the Woodbine interval of Double A Wells Field, Polk Co., TX. The objective was to characterize the distribution of diagenetic overprints and petrophysical properties in relation to lithologic units. The cores are from the Champion International C no. 1, 57 feet; the Alabama Coushatta no. 6, 58 feet; the W. T. Carter Battise GU no. 1, 119 feet; and the W. T. Carter no. 7, 118 feet. Cores were described, and lithologic units, lithofacies, and diagenetic overprints were characterized. Fifty thin-sections were also studied so as to verify and interpret the diagenetic overprints recognized initially by using a binocular scope. Measured core data and well log curves were compared to lithologic and diagenetic data to delineate reservoir-quality patterns.

The diagenetic overprints are calcite, quartz, quartz plus carbonate, and matrix. Quartz and carbonate cements and recrystallized depositional matrix vary at the finer scale of lithologic units, not lithofacies. The best reservoir properties, 16-22% porosity and permeability greater than 100 millidarcies, occur in clean sandstones of medium bed thickness or greater and have a quartz or quartz and carbonate overprint. There are also thin-bedded to laminated clean sandstones that alternate with argillaceous sandstones or shales. These clean sandstones have similar diagenetic overprints as medium-bedded clean sandstones but are extensively cemented. Other sandstones contain a depositional matrix, and this fabric limits the amount of later diagenetic products. These argillaceous sandstones may retain porosity up to 12-16 % but permeability values are often less than one millidarcy.

AAPG Search and Discovery Article #90032©2004 GCAGS 54th Annual Convention, San Antonio, Texas, October 10-12, 2004