Stable Isotope Ratios δ18O, δ13C in Petroleum Geology Application

Isotopic studies are currently among the most prioritized methods for addressing critical challenges in petroleum geology, particularly in determining the nature and sources of organic matter. This paper briefly presents the results of utilizing isotopic markers in addressing issues related to: stratigraphic correlation, geochemical characterization of organic matter, and fluid dynamic reconstruction. The isotopic effects (δ18О, δ13С) observed in the study of Meso-Cenozoic sections in Crimea and the Western Pre-Caucasus have enabled the identification of global events, facilitating detailed stratigraphic correlation. Analysis of the isotopic-geochemical characteristics (δ13С) of fluids from sedimentary formations of varying ages allowed for the determination of formation conditions, the genesis of organic matter, and its geochemical classification for a group of fields at Kamennaya Vershina (Western Siberia). By integrating geochemical vertical zonality, evidence of hydrocarbon mixing from different origins, and the detection of localized thermal anomalies based on isotopic parameters, a comprehensive fluid dynamic model was developed, incorporating previously acquired geological and geophysical data.