Genetic Typification of Paleozoic Oils in South-Eastern Western Siberia Based on a Complex of Geochemical Studies

Summary The work is devoted to geochemical studies of Paleozoic genesis oils in the south-east of Western Siberia. The work included studies of molecular and isotopic composition of 120 samples of Paleozoic oils from 15 fields. The study of oils was done by gas chromatography–mass spectrometry method in tandem with isotope mass spectrometry for more accurate interpretation of the results. Based on the results of molecular and isotopic analyses, three Paleozoic oil families were identified, the differences in which are due to sedimentation conditions of the oil-material rocks involved in their generation. The aryl isoprenoids have been identified in the Paleozoic oils. The presence of these compounds in the composition of oils indicates that the accumulation of organic matter of oil-material rocks occurred in conditions of anoxia of the photonic layer. The information obtained on the genetic type of Paleozoic oils and the identification of different groups among them indicate that at least three different intra Paleozoic sources were involved in their generation.