ABSTRACT
Cherokee sandstone reservoirs west of, parallel with, and flanking the Central Kansas uplift produce oil primarily from structural traps. Of probable late Cherokee age, these sandstones are the products of the erosion of the nearby positive arch area. Several depositional environments probably are represented, although shallow-water marine conditions from the transgressing Cherokee seas are an obvious influence.
A basinward facies change to dominantly limestone and shale confines the maximum sandstone development within a northwest-southeast trend. This trend generally coincides with the truncated updip limit of the Mississippian, although the sandstones onlap rocks as old as Cambro-Ordovician (Arbuckle) on the pre-Pennsylvanian unconformity surface on which they are deposited.
Sandstones at nearly all levels in the interval produce. Correlation of individual sandstones can be accomplished only on a limited scale, indicating the lenticular nature of the section. Intraformational limestones are not widely persistent.
Pennsylvanian and Permian movements were most important in forming the producing structures. However, except on the pronounced structural trends, producing fields have no particular pattern where the underlying rocks are of Mississippian age. In a thinner updip interval are what commonly are called “conglomerate sands.” These also are productive and appear to be a product of the same transgression and as such are genetically related.
More than 5,000,000 bbls of oil has been produced from Cherokee sandstone pools. Additional reserves found during the past 2 years should increase the oil already produced by 30%. More prospecting will discover additional structural traps and furnish further control for the search for stratigraphic traps—a search which should not be neglected.
