Oil-source correlations between the Mississippian Heath Shales and the reservoired oils in the Pennsylvanian Tyler Sands, Montana
- BP Exploration, Houston, TX (USA)
- 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-; CODEN: AABUD
- Journal Information:
- AAPG Bulletin (American Association of Petroleum Geologists); (USA), Vol. 74:5; Conference: Annual convention and exposition of the American Association of Petroleum Geologists, San Francisco, CA (USA), 3-6 Jun 1990; ISSN 0149-1423
- Country of Publication:
- United States
- Language:
- English
Similar Records
Petroleum source rock evaluations of the Cretaceous Newark Canyon Formation in north-central Nevada
Vitrinite reflectance of coals from the Heath Formation, central Montana
Related Subjects
58 GEOSCIENCES
MONTANA
PETROLEUM DEPOSITS
SOURCE ROCKS
ANHYDRITE
BLACK SHALES
CARBONIFEROUS PERIOD
COAL SEAMS
GAS CHROMATOGRAPHY
GEOCHEMISTRY
GEOLOGIC FORMATIONS
KEROGEN
PYROLYSIS
RESERVOIR ROCK
ALKALINE EARTH METAL COMPOUNDS
BITUMINOUS MATERIALS
CALCIUM COMPOUNDS
CALCIUM SULFATES
CARBONACEOUS MATERIALS
CHATTANOOGA FORMATION
CHEMICAL REACTIONS
CHEMISTRY
CHROMATOGRAPHY
COAL DEPOSITS
DECOMPOSITION
ENERGY SOURCES
FEDERAL REGION VIII
FOSSIL FUELS
FUELS
GEOLOGIC AGES
GEOLOGIC DEPOSITS
MATERIALS
MINERAL RESOURCES
MINERALS
NORTH AMERICA
OIL SHALES
ORGANIC MATTER
OXYGEN COMPOUNDS
PALEOZOIC ERA
RESOURCES
SEPARATION PROCESSES
SULFATE MINERALS
SULFATES
SULFUR COMPOUNDS
THERMOCHEMICAL PROCESSES
USA
020200* - Petroleum- Reserves
Geology
& Exploration
580000 - Geosciences