Abstract

The Arenoso Sub-Basin, located on the western flank of the Central Basin Platform, contains a succession of hydrocarbon bearing carbonates and siliciclastics that have proven to be a complex series of reservoirs. Pennsylvanian sediments throughout the Permian Basin were largely controlled by sub-humid conditions and often rapid fluctuations in sea level. Sea level fluctuations caused cycles to begin and end abruptly as the shelf flooded with relative sea level rise and dropped below the shelf margin drastically as sea level fell exposing the shelf to erosion. 11 cores, available through the Bureau of Economic Geology, were examined and revealed 5 dominant depositional facies within the sub-basin: (1) fossiliferous wackestones and packstones, (2) grainstones, (3) phylloid algal boundstones, (4) mudstones/shales and (5) chert conglomerates. Analyzing these depositional facies provides a better understanding of the reservoir conditions within the sub-basin. The Arenoso Sub-Basin carbonates have largely been under-exploited, due to their complex nature, while the siliciclastics have proven to be more prolific hydrocarbon bearing reservoirs. With a better understanding of the stratigraphic framework, the carbonate reservoirs can be exploited more efficiently with newer drilling and hydraulic fracturing methods to increase the likelihood of communication with hydrocarbon-rich reservoirs.