Regional Grayburg Formation (Permian, Lower Guadalupian) Sequence Stratigraphy, Permian Basin, USA
Grayburg Formation (Permian, Lower Guadalupian) sequence stratigraphy was correlated along strike for 341 km (212 miles) from the Guadalupe Mountains (GMS) through the Northwest Shelf (NWS) and Central Basin Platform (CBP). The Grayburg type section and a nearby cored well reference section in the NWS were correlated with two reference sections in the GMS and two additional reference sections on the west and east sides of the CBP. All reference sections are part of dip-oriented sequence stratigraphic cross sections that utilized outcrops and/or cored wells.
The Grayburg is a carbonate-dominated mixed carbonate-siliciclastic succession that was deposited upon a ramp that distally steepened into the Delaware and Midland basins. The ramp contained inner ramp, ramp crest shoal, middle ramp, and outer ramp paleoenvironments. The outer ramp and part of the middle ramp were removed by erosion following Grayburg deposition and before deposition of the overlying middle Queen Formation.
The Grayburg is a composite sequence and contains two simple sequences, referred to as the Lower Grayburg (transgressive-dominated) and the Upper Grayburg (highstand-dominated). Each simple sequence contains five high-frequency sequences. The Grayburg contains approximately 21 cycle sets and 82 individual carbonate cycles that have been identified and correlated within fields and outcrops. Identification, description, and correlation of these sequences, cycle sets, and carbonate cycles enabled the construction of a high-resolution sequence stratigraphic framework for the Grayburg Formation that will aid in facies modeling, prediction of reservoir development, and reservoir compartmentalization.
AAPG Search and Discovery Article #90142 © 2012 AAPG Annual Convention and Exhibition, April 22-25, 2012, Long Beach, California