| dc.description.abstract | The Desmoinesian Series Granite Wash at Buffalo Wallow Field represents deepwater
deposits including slumps, channels, and submarine fan lobes that consist of six major
lithofacies as mudstone, interbedded mudstone and sandstone, dark gray muddy
sandstone, sandstone with mudstone clasts, fining upward sandstone, and laminated
sandstone with mudstone. A combined artificial neural network and well-log cutoff
approaches was followed to estimate lithology logs for non-cored wells with 84%
accuracy. There are 10 stratigraphic intervals that, from top to bottom, include
Marmaton, Caldwell, Cherokee, and Granite Wash A through G. These intervals are
bounded by flooding surfaces which are capped by laterally extensive and distinctive
mudstone layers. Furthermore, using well logs, a vertical proportion curve, and seismic
data a sequence-stratigraphic framework was constructed and system tracts were
interpreted that consist of five third-order regressive-transgressive cycles. Detailed 3-D
lithological and effective porosity models that were constrained to cores, estimated
lithology logs, porosity logs, spatial statistics from variography, and 3-D seismic data
illustrate the stratigraphic variability in reservoir characteristics. Sandstone proportion
within the study area decreases basinward from southwest to northeast. Moreover, while
the sandstone proportion decreases stratigraphically upward, the muddy sandstone
increases. In terms of sequence stratigraphy, lowstand and transgressive system tract
deposits were combined and they contain a greater amount of sandstone and connectivity
when compared to highstand deposits. Highstand deposit thickness increases vertically
as well as the muddy sandstone occurrence, which represent more proximal deposits,
thus suggesting that there is an overall progradation within the study area. | en_US |
