Development geology study of Weber sandstone, Rangely field, Colorado

Conference · Fri Sep 01 00:00:00 EDT 1989 · AAPG Bulletin (American Association of Petroleum Geologists); (USA)

OSTI ID:5699057

Jackson, W D; Bowker, K ^[1]

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1. Chevron U.S.A. Inc., Houston, TX

The Pennsylvanian-Permian Weber Sandstone formation is the major producing horizon at the giant Rangely field, Rio Blanco County, Colorado. The Weber has been separated into six lithofacies using core descriptions, core analyses, optical and scanning-electron microscopy, x-ray diffraction, and special-core analyses. Two of the lithofacies (eolian) are productive. The subarkosic laminated sandstones (which have the best reservoir quality) have an average Boyle's Law porosity of 9.7%. Permeability varies directionally on a small scale because of differential cementation within the graded laminae; the very fine-grained portion of the laminae is more tightly cemented by carbonate minerals than are the fine-grained portions. Permeability along the laminae averages 1.2 md; permeability across the laminae is less than 1 md. The second productive lithofacies is massive (bioturbated) and more thoroughly cemented than the first; it is also composed of fine and very fine-grained sandstones. These massive subarkosic sandstones have an average porosity of 7% and permeability averaging less than 1 md. Fractures alter permeability in portions of the field. The remaining four lithofacies (fluvial) are not productive and act as intraformational permeability barriers. Arkosic sandstones, arkosic siltstones, shales, and rare carbonates comprise this group. The relationship of the lithofacies to the depositional environment and the recognition of them on electric logs has allowed correlations across the field. This has proven an important contribution to the management of the current CO{sub 2} flood.

• OSTI ID: 5699057
• Report Number(s): CONF-8910195-; CODEN: AABUD
• Journal Information: AAPG Bulletin (American Association of Petroleum Geologists); (USA), Vol. 73:9; Conference: AAPG Rocky Mountain Section meeting, Albuquerque, NM (USA), 1-4 Oct 1989; ISSN 0149-1423
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
COLORADO
OIL FIELDS
GEOLOGY
CARBON DIOXIDE INJECTION
ENHANCED RECOVERY
GEOLOGIC FORMATIONS
LITHOLOGY
OIL WELLS
PENNSYLVANIAN PERIOD
PERMEABILITY
PERMIAN PERIOD
PETROLEUM
POROSITY
SANDSTONES
SCANNING ELECTRON MICROSCOPY
SILTSTONES
ELECTRON MICROSCOPY
ENERGY SOURCES
FEDERAL REGION VIII
FLUID INJECTION
FOSSIL FUELS
FUELS
GEOLOGIC AGES
GEOLOGIC DEPOSITS
MICROSCOPY
MINERAL RESOURCES
MISCIBLE-PHASE DISPLACEMENT
NORTH AMERICA
PALEOZOIC ERA
PETROLEUM DEPOSITS
RECOVERY
RESOURCES
ROCKS
SEDIMENTARY ROCKS
USA
WELLS
020200* - Petroleum- Reserves
Geology
& Exploration