ABSTRACT: Sequence Stratigraphy, Structural Styles, and Reservoir Characterization of the Tuscaloosa Trend
BARRELL, KIRK A.
A multi-discipline, trend wide re-evaluation was conducted on the mature fields of the Tuscaloosa Trend. The utilization of emerging concepts such as sequence stratigraphy and new technology such as 3D seismic, resulted in a new interpretation for the regional and local geology of these prolific gas fields. Through the integration of regional cross sections, reprocessed 2D seismic, and paleotological data, the entire Tuscaloosa interval, from the base of the Austin Chalk to the top of the Washita, was segmented into four major sequences. Each sequence was then divided into systems tracts and parasequences on the field level. Structural styles were examined and categorized into four groups: aggradational-unexpanded four-way salt closures, expanded three-way fault closures, expanded four-way closures, and combination aggradational unexpanded/expanded four-way closures. Reservoirs were characterized by incorporating sand maps and facies interpretation through the integration of well logs and conventional cores. Geologic reservoir maps were then integrated with engineering analysis to determine original and remaining gas reserves. The regional sequence analysis and reservoir characterization has led to a significant increase in 3D seismic acquisition, drilling, and reserves. The multi-discipline team approach combined with emerging technologies has revitalized a trend that was once believed to be mature and depleting.
AAPG Search and Discovery Article #90941©1997 GCAGS 47th Annual Meeting, New Orleans, Louisiana