Electrostratigraphy, thickness, and petrophysical evaluation of the Woodford Shale, Arkoma basin, Oklahoma

Scope and method of study. This study was intended to evaluate the gas-shale potential of the Woodford Shale in the Arkoma basin and address four questions: (1) Can well-logs be used to construct the informal stratigraphy of the Woodford? (2) What is the distribution of these informal units? (3) Can log-derived characteristics delineate higher gas-volume producing areas within the Woodford gas-shale play? (4) What other analyses are useful in evaluating Woodford production potential in untested areas? Well logs, especially resistivity and gamma-ray curves, provided necessary data. Wireline log characteristics were compared to production data. Thickness maps were generated for the total Woodford section and each informal stratigraphic unit.; Findings and conclusions. An informal stratigraphic framework was established for the Woodford Shale in the Arkoma basin from well-logs. Three informal units were defined and mapped. Log-derived characteristics were compiled and average thickness, density, and gamma-ray intensity were calculated for each unit. Specific resistivity and density criteria were identified that corresponded with higher volume gas production.