SEQUENCE STRATIGRAPHY AND RESERVOIR CHARACTERISTICS OF BOOCH SANDSTONES (MCALESTER FORMATION), IN SOUTHEASTERN OKLAHOMA
The middle Booch consists of three parasequences that record the period of maximum valley incision, progradation, and sand deposition. From an oil and gas perspective, this interval contains the best reservoirs. It separates the two lower Booch parasequences, which are sandstone poor and represented by mostly marine shale, from the three upper Booch parasequences that record periods of both widespread marine inundation and the subsequent progradation of large delta systems.
The Booch was deposited over a period of roughly two million years; a timeframe that provides an average of 250,000 years between the flooding surfaces that initiate the deposition of each parasequence. Although the cyclicity observed may have a eustatic component, it is thought that local variations in sediment influx and subsidence, mostly through sediment loading, were the primary factors driving changes in sea level. Large, post-depositional folds generated by Ouachita compression have brought the Booch to the surface and allowed a direct correlation of outcrops to nearby well logs. The recognition of Booch cyclicity through regional well log analysis has provided a framework into which unnamed and incorrectly identified sandstone outcrops can be placed.