RESERVOIR COMPARTMENTALIZATION OF A DEEP-WATER OOID FAN, HAPPY FIELD, PERMIAN BASIN

JASON L. CLAYTON
CML Exploration LLC, Barton Oaks Plaza 1, Suite 430, 901 Mopac Expressway South, Austin, Texas 78746, USA
e-mail: ClaytonJ@cmlexp.com

AND

CHARLES KERANS
Department of Geosciences, Jackson School of Geosciences, The University of Texas at Austin, 1 University Station
C1100, Austin, Texas 78712, USA

ABSTRACT: The Permian (Leonardian) Upper Spraberry Formation in the Happy Field of Garza County, Texas, contains an excellent example of a reservoir composed of resedimented carbonates in a deep-water slope–basin setting. The field has one of the most complete data sets of any producing deep-water carbonate reservoir known, including 15 whole cores with matching full suites of electric logs, and high-resolution three-dimensional (3D) seismic data. Sequence stratigraphic analysis combined with detailed characterization of analogous outcrops, detailed core-based sedimentology, and well-log analysis indicate that the Happy Field ooid fans are positioned within the transgressive systems tract of the fifth composite sequence in the Leonardian. The main reservoir facies are resedimented ooid and skeletal grainstone hyperconcentrated density flows that were focused downslope through a probable reentrant in the shelf margin and deposited in a long-lived topographic depression at the toe-of-slope. Vertical heterogeneity is set up by laterally extensive shale and silt beds that punctuate the oolitic density flows. Lateral heterogeneity and compartmentalization within the reservoir are created by younger mixed carbonate–siliciclastic debris flows that are highly erosive and are characterized by relatively low permeability.

KEY WORDS: toe-of-slope, carbonate debris flow, ooid fan, reservoir, Leonardian

Clayton JL, Kerans C. 2013. Reservoir compartmentalization of a deep-water ooid fan, Happy Field, Permian Basin. In Verwer K, Playton TE, Harris PM (Editors). Deposits, Architecture, and Controls of Carbonate Margin, Slope, and Basinal Settings, Special Publication 105: SEPM (Society for Sedimentary Geology), Tulsa, OK. doi: 10.2110/sepmsp.105.07.