Application of Isotope Geochemistry Methods for Characterization of Unconventional Reservoirs on the Example of Bazhenov and Domanic Formations

Summary Isotope compositions of carbon, hydrogen, sulfur, nitrogen and oxygen have been measured for several hundred samples of rock, fluid and gases of Bazhenov and Domanic formations. Core samples and fluids have been sampled at the oilfields located in different regions of Western Siberia (Salym arch, Frolov depression, Elisarov depression, Nurolskaya depression) and South Ural (Tatar arch and Bashkir arch). Results of the isotope study have been used for the characterization of reservoirs and analysis of oil generation processes. It was shown that isotope data bring new insight into understanding sedimentation, diagenesis and catagenesis, including new knowledge on genesis of organic matter, changes of redox conditions during sedimentation, data on the level of catagenesis, conditions of accumulation and migrations of hydrocarbons in different lithotypes of studied cross sections.