Depositional environments and geometry of coal-bed natural gas reservoirs in the Raton basin, Colorado and New Mexico

Conference · Sat Jun 01 00:00:00 EDT 1991 · AAPG Bulletin (American Association of Petroleum Geologists); (United States)

OSTI ID:6127271

Close, J C; Dutcher, R R ^[1]

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1. Southern Illinois Univ., Carbondale (United States)

Recognition of the depositional environments, occurrence, and geometry of Raton basin coals and coal-bearing rocks is essential to the reliable estimation of potential gas-in-place reserves and profitability, optimum placement and operation of production wells, and effective completion design for all Raton basin coalbed degasification projects. This knowledge is needed for two reasons: (1) coals of the Vermejo and Raton Formations, coalbed gas reservoirs in the Raton basin, are laterally discontinuous and separated by significant innerburden. (2) Vermejo and Raton Formation coals have been naturally coked or replaced by middle Tertiary igneous sills and dikes in many areas of the basin. Diagnostic criteria for facies recognition indicate the major environments of peat deposition included generally northeast-trending Vermejo interdistributary bays, northwest-trending Vermejo distributary-mouth bars, and northeast-trending Raton alluvial plains. Stratigraphic, sedimentologic, and coal petrographic data indicate Raton basin coals are vitrinite rich, composed of discrete coal and shale interbeds 2-10 ft thick at drilling depths of up to 2,500 ft, present in a stratigraphic interval at least 1,000 ft thick, that collectively form net thicknesses of 15 to 70 ft and dramatically thicken, thin, pinch out, or abut against sills or dikes in distances of less then 5,000 ft. The data base for these conclusions is comprised of petrographic observations for approximately 200 coal crushed particle pellets, 54 measured sections, 294 paleocurrent measurements at 45 stations, geophysical logs for 50 wells, and observations of field depositional relationships at over 200 outcrops.

• OSTI ID: 6127271
• Report Number(s): CONF-9107109-; CODEN: AABUD
• Journal Information: AAPG Bulletin (American Association of Petroleum Geologists); (United States), Vol. 75:6; Conference: American Association of Petroleum Geologists (AAPG) Rocky Mountain Section meeting, Billings, MT (United States), 28-31 Jul 1991; ISSN 0149-1423
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
01 COAL, LIGNITE, AND PEAT
COAL DEPOSITS
STRATIGRAPHY
COLORADO
NATURAL GAS DEPOSITS
NEW MEXICO
CALCULATION METHODS
DEPOSITION
GEOLOGIC FORMATIONS
GEOMETRY
NATURAL GAS
PETROGRAPHY
RESERVES
RESERVOIR ROCK
SEDIMENTARY BASINS
DEVELOPED COUNTRIES
ENERGY SOURCES
FEDERAL REGION VI
FEDERAL REGION VIII
FLUIDS
FOSSIL FUELS
FUEL GAS
FUELS
GAS FUELS
GASES
GEOLOGIC DEPOSITS
GEOLOGIC STRUCTURES
GEOLOGY
MATHEMATICS
MINERAL RESOURCES
NORTH AMERICA
RESOURCES
USA
030200* - Natural Gas- Reserves
Geology
& Exploration
011000 - Coal
Lignite
& Peat- Reserves
Geology
& Exploration