From Bureau of Economic Geology, The
University of Texas at Austin (www.beg.utexas.edu).
Bureau Seminar, April 13, 2007
Reservoir-Scale Depositional Facies, Trends, and Controls on Sandstone Distribution of the Lower Atoka Group ("Bend Conglomerate"), Fort Worth Basin, Texas
Bureau of Economic Geology, Jackson School of Geosciences, University of Texas at Austin.
Study of the largely siliciclastic lower Atoka Group established detailed reservoir-facies distribution of four chronostratigraphic units in a 900-mi2 area comprising all of Wise and adjacent easternmost Jack Counties (Boonsville field). Net-sandstone maps (~1-mi well spacing) representing the basal, medial, and upper parts of the lower Atoka, supplemented by core descriptions, reveal that (1) the unit comprises depositional facies that are far more heterogeneous than previously described, (2) syndepositional regional faulting was a significant control on sandstone distribution, and (3) primary source areas and related principal sediment-transport pathways vary systematically with age within the lower Atoka. These elements form a predictive model for locating primary sandstone fairways and for generally assessing the unitís additional infill and stepout potential. Such an effort is timely because of the aggressive development of the deeper Barnett Shale play in most of the Fort Worth Basin.