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OIL GEOCHEMISTRY OF THE VERKH-TARSKOYE AND VOSTOCHNO-TARSKOYE OIL FIELDS (SOUTH OF WESTERN SIBERIA)

E. A. Fursenko 1,2, A. I. Burukhina 1,2

1 A.A.Trofimuk Institute of Petroleum Geology and Geophysics SB RAS; 2 Novosibirsk State University, Novosibirsk, Russia

We studied the oils of the Verkhtarskoye field (1 sample from the oil-and-gas-bearing horizon of the Mesozoic–Paleozoic contact zone, OGBHCZ, Pz; 2 samples from the Vasyugan Formation, J3o) and Vostochno-Tarskoye field (Vasyugan Formation, 1 sample). The biomarker geochemical parameters (prystane/phytane, prystane/ n-C17, phytane/n-C18, steranes C29/C27, ITC, hopanes C35/C34, steranes/terpanes, tri-/monoaromati c steroids, phenanthrenes/dibenzothiophenes, CPI, Ts/ Tm, isomeric ratios of the C29 steranes and C31–C32 homohopanes, maturity parameters based on the arenes composition) and the carbon isotope composition of the Vasyugan samples indicate their aquatic genotype and maturity corresponding to the main zone of oil formation. A potential source of these oils is the mature aquatic organic matter of the Bazhenov Formation. The Paleozoic oil sample, in accordance with the parameters listed above, can be classified as having mixed genotype, i. e. formed due to several sources: Paleozoic aquatic organic matter and Lower Jurassic organic matter enriched with terrestrial components.

Keywords: Western Siberia, organic geochemistry, oil, biomarker hydrocarbons, gas liquid chromatography, gas chromatography/mass-spectrometry.

DOI 10.20403/2078-0575-2022-11с-72-76

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