Characteristics of the structure and hydrocarbon prospectivity of the deeply buried strata in the eastern Precaspian basin

The article examines the geological structure and oil and gas prospects of the pre-salt complex in the eastern Precaspian Basin (PB). Based on the synthesis and comprehensive analysis of geological exploration (GE) results and the analysis of geological-geochemical criteria for hydrocarbon potential, the oil and gas geological zoning has been updated, and effective directions for GE have been identified. The justification of a new hydrocarbon resources base within the eastern PB margin can be ensured by further investigating of the deeply buried Devonian-Middle Carboniferous horizons in the known petroleum plays, as well as within the less explored Sakmar-Kokpektinsky segment of the Ural fold-and-thrust belt. Within the productive KT-I and KT-II formations, there is an unrealized hydrocarbon potential at depths of 5-6 km. Using the example of the Bozoba West area, the oil and gas prospects of the Visean-Bashkirian and Lower Permian strata are examined, highlighting the significance of faults as elements of the hydrocarbon system. The applied set of 3D seismic survey data and deep drilling allowed for the interpretation of deep seismic sections, up to depths of 7.0-7.5 km. The Middle-Upper Devonian strata are considered prospective but have not been extensively explored by deep drilling. To establish a new hydrocarbon resource base within the eastern Precaspian Basin margin, it is recommended to conduct advanced regional seismic surveys and parametric exploration drilling.