Biomarkers and carbon isotopes of oils in the Jurassic Smackover trend of the Gulf Coast states, U. S. A

Journal Article · Fri Jan 01 04:00:00 EST 1988 · Organic Geochemistry; (UK)

DOI:https://doi.org/10.1016/0146-6380(88)90152-0· OSTI ID:7221217

Sofer, Z ^[1]

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1. Consultant, Austin, TX (USA)

The geochemistry of 25 oils from 23 fields in Alabama and the Mississippi and Louisiana-Arkansas Jurassic salt basins was evaluated. Results show that the oils were generated by a carbonate source rock which was deposited under highly anoxic conditions, and which contains mainly marine derived organic matter. The Mississippi and Louisiana-Arkansas oils are geochemically similar, indicating similar depositional environments for the source. Although the Alabama oils were also derived from a carbonate source rock, they are dissimilar to the Mississippi and Louisiana-Arkansas oils. Terpane biomarkers suggest that in addition to marine derived organic matter, the source for the Alabama oils had an organic input from a more near shore (paralic) environment, i.e. with a component of terrestrially-derived kerogen. Within each area the oils are similar. Therefore, the Norphlet and Upper Smackover oils in Alabama share a common source and the Upper Smackover, Cotton Valley and some of the Lower Tuscaloosa oils (where production is from faulted structures) in Mississippi also share a common source. Maturities of the oils in the three areas vary from low in the updip Mississippi salt basin, high in the Louisiana-Arkansas salt basin, to very high in portions of Alabama. Based on the maturity of oils in Mississippi, oil generation and migration commenced during the Cretaceous when the source was at modest levels of thermal maturity. Oils migrated relatively short distances into nearby reservoir rocks. Some oils reached high maturities in the reservoirs, resulting in abundant late-forming bitumen and pyrobitumen deposition in pore spaces.

• OSTI ID: 7221217
• Journal Information: Organic Geochemistry; (UK), Journal Name: Organic Geochemistry; (UK) Vol. 12:5; ISSN ORGED; ISSN 0146-6380
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
023000* -- Petroleum-- Properties & Composition
ALABAMA
ARKANSAS
BIOLOGICAL MARKERS
BITUMENS
BITUMINOUS MATERIALS
CARBON ISOTOPES
CARBONACEOUS MATERIALS
CARBONATE ROCKS
CHEMISTRY
COMPARATIVE EVALUATIONS
DEPOSITION
ENERGY SOURCES
ENVIRONMENTAL TRANSPORT
FEDERAL REGION IV
FEDERAL REGION VI
FOSSIL FUELS
FUELS
GEOCHEMISTRY
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC FAULTS
GEOLOGIC FRACTURES
GEOLOGIC HISTORY
GEOLOGIC STRUCTURES
GULF COAST
ISOTOPE RATIO
ISOTOPES
JURASSIC PERIOD
KEROGEN
LOUISIANA
MASS TRANSFER
MATERIALS
MATURATION
MESOZOIC ERA
MINERAL RESOURCES
MISSISSIPPI
NORTH AMERICA
ORGANIC COMPOUNDS
ORGANIC MATTER
ORIGIN
OTHER ORGANIC COMPOUNDS
PETROLEUM
PETROLEUM DEPOSITS
POROSITY
RESERVOIR ROCK
RESOURCES
ROCKS
SEDIMENTARY ROCKS
SOURCE ROCKS
TAR
USA