Abstract:

Based on the field geological work, core observation and a lot of test data, the authors aim to develop comparative study on the characteristics of biomarkers of oil shale, including isoprenoid, steranes and terpanes, between Eocene Huadian Formation of Huadian basin in northeast China and Green River Formation of Uinta basin in western United States. The differences on the origin of organic matters and sedimentary environment of oil shale in the two places have been discussed. In GC spectra, the Pr/Ph of Huadian oil shale varies from 1.47 to 2.03, which shows that pristane is in dominated. However, the Pr/Ph of Green River oil shale varies from 0.34 to 0.44, showing phytane is in dominated. In the m/z217 GC-MS, the regular steranes C₂₇-C₂₈-C₂₉ of Huadian oil shale distributes with inverse “L” shape, and ∑(C₂₇+C₂₈)/∑C₂₉ ratio varies between 0.63 and 2.52, but Green River oil shale distributes with asymmetric “V” shape with obtuse angle, and ∑(C₂₇+C₂₈)/∑C₂₉ ratio varies between 0.96 and 1.20. In the m/z191 GC-MS, C₂₉ terpene in Huadian oil shale is most abundant, ββ configuration of hopane by the second, and then αβ configuration of hopane. But in Green River oil shale, C₃₀ hopane is most abundant, according to the relative abundance, pentacyclic triterpane are characterized by highest abundances, the tricyclic terpane by the second, and then tetracyclic terpane, and abundant gammacerane and βcarrotanes can also be detected. The characteristics parameters of biomarkers of oil shale in the two places reveals that the organic matters of Huadian oil shale are characterized by double origins from aquatic organisms and higher plants, but bacteria and algae are dominate, and the oil shale mainly forms in weak reduction environment with fresh water. However, the organic matters of Green River oil shale mainly are aquatic organisms, including bacteria and algae, and the oil shale forms in high reduction environment with salt water.

Key words: biomarker, oil shale, Huadian Formation, Green River Formation, Eocene