Generation, migration, and entrapment of Precambrian oils in the Eastern Flank Heavy Oil province, south Oman

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

OSTI ID:5895476

Konert, G; Van Den Brink, H A ^[1]; Visser, W ^[2]

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1. Petroleum Development Oman, Muscat (Oman)
2. Koninklijke/Shell Exploratie en Produktie Lab., Rijswijk, (Netherlands)

The prolific Eastern Flank Heavy Oil province east of the South Oman Salt basin is unique because of the widespread occurrence of Precambrian source rocks from which the hydrocarbons originated. Fission-track analysis and burial studies suggest that most of these source rocks became mature and generated hydrocarbons in the Ordovician; subsequently, the source beds were uplifted and did not re-enter the oil window. Its uniqueness is also based on the all-important role played by Precambrian salt. The traps in Palaeozoic clastics were initially structured by halokinesis, and subsequently by salt dissolution. The latter process gradually removed the salt from the area is largely responsible for the present-day structure with palaeo-withdrawal basins inverted in present-day turtles. Present-day traps are mainly post-Late Jurassic in age, significantly post-dating the time of oil generation. Detailed field studies indicate that charge phases appear to correlate with periods of increased salt dissolution in the Late Jurassic-Early Cretaceous, Late Cretaceous, and Tertiary. Oil was probably stored in intermediate traps below and within the salt. It was gradually released upon progressive tilting of the basin flank; it migrated updip toward the basinward retreating salt edge, and subsequently (back) spilled into the stratigraphically younger traps. Also, removal of the top seal of intra-salt and sub-salt traps by salt dissolution allowed upward remigration. It follows that charge concepts in the Eastern Flank Heavy Oil province depend on defining salt-edge-related hydrocarbon release areas, rather than on kitchen modeling.

• OSTI ID: 5895476
• Report Number(s): CONF-910978-; CODEN: AABUD
• Journal Information: AAPG Bulletin (American Association of Petroleum Geologists); (United States), Vol. 75:8; Conference: International conference and exhibition of the American Association of Petroleum Geologists (AAPG): the way ahead-hydrocarbons for the 1990s, London (United Kingdom), 29 Sep - 3 Oct 1991; ISSN 0149-1423
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
OMAN
PETROLEUM DEPOSITS
SALT DEPOSITS
PETROLEUM
ENVIRONMENTAL TRANSPORT
MATURATION
GEOLOGIC TRAPS
SOURCE ROCKS
FISSION TRACKS
PETROLEUM GEOLOGY
PRECAMBRIAN ERA
SEDIMENTARY BASINS
ASIA
DEVELOPING COUNTRIES
ENERGY SOURCES
FOSSIL FUELS
FUELS
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC STRUCTURES
GEOLOGY
MASS TRANSFER
MIDDLE EAST
MINERAL RESOURCES
PARTICLE TRACKS
RESOURCES
020200* - Petroleum- Reserves
Geology
& Exploration