Oil-source correlations between the Mississippian Heath Shales and the reservoired oils in the Pennsylvanian Tyler Sands, Montana

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

OSTI ID:6857549

Cole, G A; Drozd, R J ^[1]; Daniel, J A ^[2]

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1. BP Exploration, Houston, TX (USA)
2. Univ. of Minnesota, Morris (USA)

The Mississippi Heath Formation exposed in Fergus County, central Montana, is comprised predominantly of nearshore, marine, black, calcareous shales and carbonates with minor anhydrite and coal beds. The black shales and limestones have been considered as sources for shale oil via Fischer Assay and pyrolysis analysis. These shales are potential source units for the oils reservoired in the overlying Pennsylvanian Tyler Formation sands located 50 mi (80 km) to the east of the Fergus County Heath sediment studied. Heath Formation rocks from core holes were selectively sampled in 2-ft increments and analyzed for their source rock characteristics. Analyses include percent total organic carbon (%TOC), Rock-Eval pyrolysis, pyrolysis-gas chromatography, and characterization of the total soluble extracts using carbon isotopes and gas chromatography-mass Spectrometry. Results indicated that the Heath was an excellent potential source unit that contained oil-prone, organic-rich (maximum of 17.6% TOC), calcareous, black shale intervals. The Heath and Tyler formations also contained intervals dominated by gas-prone, organic-rich shales of terrestrial origin. Three oils from the Tyler Formation sands in Musselshell and Rosebud counties were characterized by similar methods as the extracts. The oils were normally mature, moderate API gravity, moderate sulfur, low asphaltene crudes. Oil to source correlations between the Heath shale extracts and the oils indicated the Heath was an excellent candidate source rock for the Tyler reservoired oils. Conclusions were based on excellent matches between the carbon isotopes of the oils and the kerogen-kerogen pyrolyzates, and from the biomarkers.

• OSTI ID: 6857549
• Report Number(s): CONF-900605--
• Conference Information: Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (USA) Journal Volume: 74:5
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
58 GEOSCIENCES
580000 -- Geosciences
ALKALINE EARTH METAL COMPOUNDS
ANHYDRITE
BITUMINOUS MATERIALS
BLACK SHALES
CALCIUM COMPOUNDS
CALCIUM SULFATES
CARBONACEOUS MATERIALS
CARBONIFEROUS PERIOD
CHATTANOOGA FORMATION
CHEMICAL REACTIONS
CHEMISTRY
CHROMATOGRAPHY
COAL DEPOSITS
COAL SEAMS
DECOMPOSITION
ENERGY SOURCES
FEDERAL REGION VIII
FOSSIL FUELS
FUELS
GAS CHROMATOGRAPHY
GEOCHEMISTRY
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC FORMATIONS
KEROGEN
MATERIALS
MINERAL RESOURCES
MINERALS
MONTANA
NORTH AMERICA
OIL SHALES
ORGANIC MATTER
OXYGEN COMPOUNDS
PALEOZOIC ERA
PETROLEUM DEPOSITS
PYROLYSIS
RESERVOIR ROCK
RESOURCES
SEPARATION PROCESSES
SOURCE ROCKS
SULFATE MINERALS
SULFATES
SULFUR COMPOUNDS
THERMOCHEMICAL PROCESSES
USA