Tucker F. Hentz1,
(1) University of Texas at Austin, Austin, TX
Abstract: Three-dimensional seismic facies imaging by stratal slicing of Miocene-Pleistocene sediments in the greater vermilion block 50-Tiger Shoal Field area, offshore Louisiana
A merged 3-D seismic volume, 23 x 14 mi, in the greater Vermilion Block 50-Tiger Shoal field area, offshore Louisiana, records an interval of Miocene-Pleistocene sediments in a 0.4- to 4.0 section. Except for in the two fields, most of the covered area has no well control. Between-well-scale, 3-D seismic facies imaging is needed there to help expand sequence-stratigraphic and reservoir study in the wells across the entire area and the whole section of interest. A test according to time- and horizon-slide approaches on the raw 3-D cube generated poor results because of the low accuracy of depositional surface pick in the seismic data. A stratal slicing of the 3-D volume among 18 reference (marine-flooding) reflections dramatically improved the facies imaging by revealing numerous high-quality, satellite-picturelike depositional facies patterns. Seismic-wavelet reconditioning and attribute application further refined the results. Guided by modern depositional models and available sequence-stratigraphic analysis in the wells, we have identified five major facies (groups) on the stratal slices of amplitude, continuity, and other attributes: (1) numerous channels (100 ft to 2 mi wide) in a coastal-plain setting, (2) subregional-scale (as wide as 10 mi) incised valleys developed on the paleo-shelf during lowstands, (3) shelf-edge deltas, (4) slope fans/wedges, and (5) channel-levee-system/basin-floor fans.
AAPG Search and Discovery Article #90914©2000 AAPG Annual Convention, New Orleans, Louisiana