Wilcox Depositional Systems: Shelf to Deep Basin

Abstract

The Wilcox has long been recognized as an important petroleum resource, producing from deltaic, fluvial and shallow marine sandstone reservoirs since the 1930s. Recent drilling in the Perdido Fold Belt (Alaminos Canyon OCS area) has confirmed a new exploration play in the deep basin component of the Wilcox petroleum system, with significant discoveries in distal turbidite systems. The Wilcox Group in the Gulf of Mexico basin spans much of the Upper Paleocene and Lower Eocene. In outcrop the Wilcox is characterized by a variety of paralic and very shallow marine depositional settings, and is represented by interbedded sandstone and shale plus locally abundant lignite. Updip from the Lower Cretaceous shelf edge, relatively dense shallow subsurface well control allows documentation of fluvial, deltaic and open shelf depositional systems. Downdip from the Lower Cretaceous shelf edge the Wilcox comprises delta front, open shelf, estuarine and widespread prodelta depositional facies. Relatively sparse well control shows a mostly sand poor section for the prodelta and shelf depositional systems. Downdip from the shelf and prodelta, the next Wilcox well penetrations are 250 miles farther in the basin, in the southern Alaminos Canyon OCS area referred to as the Perdido Fold Belt (PFB) in the deepwater Gulf of Mexico. Recently released drilling data sheds new light on play concepts and hydrocarbon potential of the PFB. Located in the southern Alaminos Canyon OCS area and extending into Mexican waters, the PFB consists of a series of large, northeastsouthwest trending, saltcored box folds containing Middle Jurassic to Holocene clastic and carbonate sequences. Based on regional