Regional paleotopographic trends and production, Muddy Sandstone (Lower Cretaceous), central and northern Rocky Mountains

Journal Article · Thu Feb 28 23:00:00 EST 1991 · AAPG Bulletin (American Association of Petroleum Geologists); (United States)

OSTI ID:6008478

Dolson, J ^[1]; Muller, D; Stein, J A ^[2]; Evetts, M J ^[3]

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1. Amoco Production Co., Denver, CO (United States)
2. Amoco Production Co., Houston, TX (United States)
3. Amoco Production Co., Tulsa, OK (United States)

The Muddy Sandstone and equivalent strata have produced more than 1.5 billion bbl of oil-equivalent hydrocarbons. Production is controlled principally by unconformities formed during a relative sea level low-stand. Reservoirs are found in paleohills of older marine sandstones, younger valley fills and associated alluvial plain channel sandstones, and transgressive marine deposits. At least ten paleodrainage basins existed at maximum lowstand. A regional drainage divide formed in southern Wyoming and separated southeast-flowing from north-west-flowing alluvial systems. Local tributaries stripped drainage divides of fine-grained detritus derived from the underlying Skull Creek Shale and older marine sandstones. In contrast, trunk streams carried medium- and coarse grained-sands eroded from eastern, southern, and western provenances of Paleozoic and Mesozoic strata. The best fluvial reservoirs are developed within these coarser grained trunk systems. Reservoir data display little or no correlation between depth and porosity due to secondary dissolution porosity developed at all depths. Valley fill and channel reservoirs have produced at least 359 MMBOE, onlap cycles another 315+ MMBOE, and older marine buried-hill reservoirs more than 268 MMBOE. The best per-field reserves are from marine sandstones. Regional production patterns reflect proximity to mature Skull Creek and Mowry shale source beds and favorable trapping conditions within individual paleodrainages. Future hydrocarbon exploration successes will require drilling to the Muddy Sandstone in deeper basin settings and a better understanding of the role of unconformities and diagenesis in controlling hydrocarbon accumulations.

• OSTI ID: 6008478
• Journal Information: AAPG Bulletin (American Association of Petroleum Geologists); (United States), Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (United States) Vol. 75:3; ISSN AABUD; ISSN 0149-1423
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
ALLUVIAL DEPOSITS
CRETACEOUS PERIOD
DEPOSITION
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC FORMATIONS
GEOLOGIC HISTORY
GEOLOGIC STRUCTURES
GEOLOGY
MESOZOIC ERA
MINERAL RESOURCES
MOUNTAINS
PETROLEUM DEPOSITS
PETROLEUM GEOLOGY
POROSITY
PRODUCTION
RESERVOIR ROCK
RESOURCES
ROCKS
ROCKY MOUNTAINS
SANDSTONES
SEDIMENTARY BASINS
SEDIMENTARY ROCKS
STRATIGRAPHY
TOPOGRAPHY