The Jurassic Norphlet Formation of the deep-water Eastern Gulf of Mexico : a sedimentologic investigation of aeolian facies, their reservoir characteristics, and their depositional history.

Abstract

This study defined the sedimentary facies, reservoir architecture, and depositional history of the Jurassic aeolian Norphlet Formation in the deep-water Eastern Gulf of Mexico. Seven depositional facies were identified and grouped into four facies associations, three of which being primary aeolian facies: 1) Grainflow, exhibiting the highest permeability and dip angles; 2) Wind-Ripple, exhibiting moderate permeability and dip angles; and 3) Wet Interdune, exhibiting the lowest permeability and dip angles. Associated extradunal fluvial facies were identified in the lower Norphlet interval. All facies displayed heterogeneous attributes of porosity and permeability. Permeability has been reduced by various diagenetic cements in the Norphlet. Stratigraphically equivalent aeolian stabilization surfaces were identified within the Norphlet. The reconstructed Norphlet depositional model demonstrates a relatively dry, mature, northwestward migrating aeolian erg with the Middle Ground Arch highland sediment source to the east, and presumably an ancestral Gulf of Mexico to the west.