HOPANE HYDROCARBONS IN BITUMENS OF MESOZOIC DEPOSITS OF THE WESTERN YENISEI-KHATANGA REGIONAL TROUGH
N.S. Kim1, A.P. Rodchenko2,3
1A.A. Trofimuk Institute of Petroleum Geology and Geophysics, Siberian Branch of the Russian Academy of Sciences, pr. Akademika Koptyuga 3, Novosibirsk, 630090, Russia
2A.A. Trofimuk Institute of Petroleum Geology and Geophysics, Siberian Branch of the Russian Academy of Sciences, ul. Pirogova 2, Novosibirsk, 630090, Russia
3Novosibirsk State University
Keywords: Organic matter, Mesozoic deposits, biomarker hydrocarbons, 25-norhopanes, rearranged hopanes, West Siberian Basin, Yenisei-Khatanga regional trough
Abstract
We performed a chromato-mass-spectrometric study of the distribution of hopane hydrocarbons in the organic matter of Jurassic-Lower Cretaceous mudstones from wells drilled in the western Yenisei-Khatanga regional trough. A series of 25-norhopanes has been first identified; these hydrocarbons, often found in naphthides, are commonly related to biodegradation processes. We consider other hypotheses of formation of 25-norhopanes. Based on the examined distribution of rare rearranged hopanes, new biomarker parameters have been introduced, which ensure a more reliable estimation of the conditions of accumulation of organic matter in rocks and of its thermal maturity.
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