Geochemical evaluation of oils and source rocks from the Western Siberian basin, U. S. S. R

Conference · Thu Feb 28 23:00:00 EST 1991 · AAPG Bulletin (American Association of Petroleum Geologists); (United States)

OSTI ID:7271876

Peters, K E; Huizinga, B J ^[1]; Moldowan, J M ^[2]; Kontorovich, A E; Stasova, O ^[3]; Demaison, G J

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1. Chevron Overseas Petroleum, Inc., San Ramon, CA (United States)
2. Chevron Oil Field Research Co., Richmond, CA (United States)
3. Siberian Scientific Research Institute for Geology, Geophysics and Mineral Resources, Novobsibirsk (Russian Federation)

Although the Western Siberian basin is among the most prolific in the world, there has been disagreement among Soviet geoscientists on the origin of the petroleum within this basin. Screening geochemical analyses were used to select several oils and potential source rocks for a preliminary study using detailed biomarker and supporting geochemistry. Possible sources for this petroleum include rocks of Middle Jurassic, Upper Jurassic, and Lower Cretaceous age. Results indicate that most of the analyzed Western Siberian oils, occurring in reservoirs from Middle Jurassic to Late Cretaceous in age, are derived from the Upper Jurassic Bazhenov Formation. The locations of the samples in the study generally correspond to the distribution of the most effective oil-generative parts of the Bazhenov Formation. Analyses show that the Bazhenov rock samples contain abundant marine algal and bacterial organic matter, preserved under anoxic depositional conditions. Biomarkers show that thermal maturities of the samples range from the early to late oil-generative window and that some are biodegraded. For example, the Salym No. 114 oil, which flowed directly from the Bazhenov Formation, shows a maturity equivalent to the late oil window. The Van-Egan no. 110 oil shows maturity equivalent to the early oil window and is biodegraded. This oil shows preferential microbial conversion of lower homologs of the 17{alpha}, 21{beta}(H)-hopanes to 25-nor-17{alpha}(H)-hopanes.

• OSTI ID: 7271876
• Report Number(s): CONF-910403--
• Journal Information: AAPG Bulletin (American Association of Petroleum Geologists); (United States), Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (United States) Vol. 75:3; ISSN AABUD; ISSN 0149-1423
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
023000 -- Petroleum-- Properties & Composition
ASIA
BIOLOGICAL MARKERS
CHEMICAL COMPOSITION
CHEMISTRY
CRETACEOUS PERIOD
DEVELOPED COUNTRIES
ENERGY SOURCES
EUROPE
FOSSIL FUELS
FUELS
GEOCHEMISTRY
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC FORMATIONS
GEOLOGIC STRUCTURES
JURASSIC PERIOD
MATURATION
MESOZOIC ERA
MINERAL RESOURCES
ORIGIN
PETROLEUM
PETROLEUM DEPOSITS
RESOURCES
SEDIMENTARY BASINS
SIBERIA
SOURCE ROCKS
USSR