Intraslope basin reservoirs deposited by gravity-driven processes: Ship shoal and ewing banks areas, offshore Louisiana

Journal Article · Thu Jun 01 04:00:00 EDT 1995 · AAPG Bulletin

OSTI ID:86611

Armentrout, J M; Malecek, S J; Mathur, V R ^[1]

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1. Mobil Oil Corp., Dallas, TX (United States); and others

Seismic facies and high-resolution biostratigraphic analysis provide a sequence stratigraphic framework for interpreting lateral distribution of sand-prone facies and reservoir connectivity in the Ship Shoal 351-358 to Ewing Bank 988 area, offshore Louisiana. The interval of interest is an isochron thick interpreted as a lowstand systems tract deposited at bathyal water depths within an intraslope-basin. This basin is approximately 50 kilometers from the age equivalent shelf/slope break. The D. pentaradiatus-D. brouweri sequence consists of the synclinal fill of a salt withdrawal basin forming an isochron thick that thins onto adjacent salt-cored structural highs. This isochron interval was subdivided into four seismic facies and each is calibrated with local well data. The seismic facies are: Facies (1) hummocky-mounded facies with an internal reflection character of discontinuous variable amplitude, calibrated to thick, flat-based blocky to fining-upward sandstones interpreted as local sheets deposited as channel-fed depositional lobes; Facies (3) clinoform-wedge facies are characterized by continuous, uniform amplitude reflections and are calibrated with mudstones interpreted as part of a downslope prograding complex that downlaps and onlaps the hummocky- mounded facies; and Facies (4) parallel-continuous facies of relatively uniform amplitude correlated with mudstones that drape the other three facies throughout the study area and are interpreted as hemipelagic mudstone. Mapped patterns of these seismic facies suggest a network of channel systems within a slope valley supplying sand by gravity-driven processes into a local salt withdrawal intraslope-basin. Following the above analysis, three wells and two side-tracks were drilled to further test the prospectivity of the area. Rock type and hydrocarbon predictions based on seismic facies analysis were confirmed by the wells.

• OSTI ID: 86611
• Report Number(s): CONF-9506190--
• Journal Information: AAPG Bulletin, Journal Name: AAPG Bulletin Journal Issue: 6 Vol. 79; ISSN 0149-1423; ISSN AABUD2
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
EXPLORATION
LOUISIANA
OFFSHORE DRILLING
PETROLEUM DEPOSITS
RESERVOIR ROCK
SEDIMENTARY BASINS
SEISMIC SURVEYS
STRATIGRAPHY
US GULF COAST