25th International Meeting on Organic Geochemistry IMOG 2011

P-063
Origin of crude oil with high concentration of dibenzothiophene
in Tarim Basin
Zhu Guangyou, Zhang Shuichang, Jiang Naihuang, Su Jin, Cui Jie, Gu Lijing
Research Institute of Petroleum Exploration and Development, PetroChina, Beijing, China (corresponding
author:zhuguangyou@petrochina.com.cn)
Dibenzothiophene series is one of the most important
compositions in crude oil, which generated under
multiple geological and geochemical processes. The
relationships between dibenzothiophene series and
other biomarker (C29 αα sterane 20R, C28 triaromatic
sterane 20R) , Combining with the research of TSR,
biodegradation, geological ages, and oil source in
Paleozoic oils in Tazhong area, indicate that there are
three factors for high concentration of
dibenzothiophene series. First, both oil source rocks,
no matter middle-upper Ordovician or lower
Ordovician-Cambrian, are marine carbonate
sediments which could produce abundant organic
sulfur compounds including dibenzothiophene series.
Second, biodegradation can result in the enrichment
of organic sulfur compounds. In addition, sulfate
reducing bacteria is able to transfer hydrocarbons and
S in SO4 2- in oil-bearing formation water into organic
sulfur compound. It might be a main path to produce
dibenzothiophene series. Third, sulfur compounds
might form by TSR reaction because S of SO4 2- in oilbearing
formation water could be also transfered to
H2S and organic sulfur compounds under high
temperature, which might result in increase of
dibenzothiophene series in crude oil.
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