ABSTRACT: Wolfcampian Sequence Stratigraphy of the Eastern Central Basin Platform, Texas

CANDELARIA, MAGELL P., ARCO Oil and Gas Company, Midland, TX, J. F. SARG, Geological Consultant, Midland, TX, G. L. WILDE, GLW International, Midland, TX, and D. J. ENTZMINGER and F. H. BEHNKEN, ARCO Oil and Gas Company, Midland, TX

Integrated study of well logs, cores, high-resolution seismic data, and biostratigraphy has established the sequence framework of the Atokan (Early Pennsylvanian)-Wolfcampian (Early Permian) stratigraphic section along the eastern margin of the Central Basin platform in the Permian basin. Sequence interpretation of high-resolution, high-fold seismic data through this stratigraphic interval has revealed a complex progradational/retrogradational evolution of the platform margin that has demonstrated overall progradation of at least 12 km during early-middle Wolfcampian. Sequence stratigraphic study of the Wolfcamp interval has revealed details of the internal architecture and morphologic evolution of the contemporaneous platform margin.

The Wolfcampian across much of the Central Basin platform consists of up to seven third-order (3 degree) stratigraphic sequences. These sequences are characterized by thin transgressive systems tracts (TST), which overlie 3 degree sequence boundaries. Facies of the TST consist of mud-rich upward-shoaling parasequences overlain by thicker highstand deposits consisting of grain-rich upward shoaling progradational parasequences. Lowstand deposits are not present on the platform proper.

Two generalized seismic facies assemblages are recognized in the Wolfcampian. Platform interior facies are characterized by high-amplitude, laterally continuous parallel reflections; platform margin facies consist of progradational sigmoidal to oblique clinoforms and are characterized by discontinuous, low-amplitude reflections.

Sequence interpretation of carbonate platform-to-basin stratal geometries helps in predicting subtle stratigraphic trapping relationships and potential reservoir facies distribution. Moreover, this interpretive method assists in describing complex reservoir heterogeneities that can contribute to significant reserve additions from within existing fields.

AAPG Search and Discovery Article #91018©1992 AAPG Southwest Section Meeting, Midland, Texas, April 21-24, 1992 (2009)