Vignali, Marco F.¹ 
(1) University of Oklahoma, Norman, OK

ABSTRACT: Seismic Stratigraphic Framework for the Upper Cretaceous in the NPRA

Seismic stratigraphic framework for the upper Cretaceous in the NPRA was completed utilizing 23,200 mi² covered by 2D seismic data, and well information. This study will include recognition of sediment depositional timing and direction within the basin to define the evolution of the upper Cretaceous in a stratigraphic framework. The seismic interpretation has 49 surfaces interpreted. Between every two surfaces 48 isochrone maps were created to define shelf breaks for each interpreted interval in order to define the shelf breaks map. This map was then used to determine depositional directions. This paleo-basin is deeping in a west to east direction following a series of prograding wedge depositional pattern. Wedges are seen progradational and aggradational that are due to very high sediment influx all over time. The basin area is divided into two areas, western and eastern NPRA, due to differences in the depositional patterns. The western NPRA deposition is related to more accommodation space with a N75°E depositional direction, and the Eastern NPRA is related to less sediment accommodation space. Therefore the Eastern NPRA has more surfaces in a reduced accommodation space following a N90°E depositional direction. The seismic startigraphic framework is based on a regional line of 252 miles of 2D seismic lines. Using interpreted seismic reflectors, a regional cross section with 5 wells was constructed to define a sequence stratigraphic framework. After defining this sequence stratigraphic framework the interpretation will be used to define prospective areas for sand accumulations associated with basin floor fans.

AAPG Search and Discovery Article #90026©2004 AAPG Annual Meeting, Dallas, Texas, April 18-21, 2004.