Transgressive valley-fill sequences: Implications to sequence stratigraphy and petroleum exploration

Conference · Sat Sep 01 04:00:00 EDT 1990 · AAPG Bulletin (American Association of Petroleum Geologists); (USA)

OSTI ID:5922182

Horne, J C; Devine, P E; Wheeler, D M; Scott, A J ^[1]

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1. RPI International, Boulder, CO (USA)

Large amounts of hydrocarbons have been discovered in association with valley-fill deposits. The lateral and vertical distribution of siliciclastic rock types in transgressive valley-fill deposits is governed by the stratigraphic sequence. The sequence stratigraphy is controlled primarily by the interaction of subsidence, eustacy, and volume of sediments. Reservoir-potential siliciclastics accumulate in valley-fill, estuarine, and wave-reworked transgressive deposits. Differences in the spectrum of transgressive deposits can be attributed to variations in the rate of eustatic sea-level rise, subsidence, and sediment supply. Rapid rates of subsidence and/or eustatic sea-level rise relative to sediment supply result in an abrupt landward shift in facies and valleys filled primarily with estuarine muds. Examples include the Opeche formation of the Powder River Basin and the lower Wilcox and Yegua formations of the Texas Gulf Coast. The valley-fill mudstones in these units trap hydrocarbons in laterally adjacent facies. Slower rates of relative sea-level rise, or increased sediment supply, result in valley-fill sequences with thicker basal fluvial deposits overlain by estuarine to marine sands and muds. Petroleum is produced from fluvial-estuarine reservoirs within this type of valley-fill in the Morrow Formation in southeast Colorado and southwest Kansas and the Doig Formation of western Alberta. Complex valley-fill sequences consisting of multiple backstepping progradational parasequences occur in association with varying rates of eustatic sea-level rise or subsidence relative to sediment supply Examples from the Muddy Sandstone of the Powder River basin illustrate such complexities. Petroleum has been produced from fluvial, bayhead-delta, and barrier island facies of the Muddy Sandstone valley-fills.

• OSTI ID: 5922182
• Report Number(s): CONF-9010204--
• Conference Information: Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (USA) Journal Volume: 74:9
• Country of Publication: United States
• Language: English

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02 PETROLEUM
020200* -- Petroleum-- Reserves
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58 GEOSCIENCES
580000 -- Geosciences
ALBERTA
ALLUVIAL DEPOSITS
CANADA
COLORADO
EXPLORATION
FEDERAL REGION VII
FEDERAL REGION VIII
GEOLOGIC DEPOSITS
GEOLOGIC FORMATIONS
GEOLOGIC HISTORY
GEOLOGIC STRUCTURES
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PETROLEUM DEPOSITS
POWDER RIVER BASIN
RESERVOIR ROCK
RESOURCES
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SEDIMENTARY ROCKS
SOURCE ROCKS
STRATIGRAPHY
USA
WYOMING