Geological structure and oil and gas potential of Domanik deposits in the central part of the Volga-Ural oil and gas basin

The paper describes the structure and depositional conditions of a domanicoid high-carbon formation (HCF) in the central part of the Volga-Ural oil and gas basin. The structure of the HCF depends on the structural relatedness and paleogeographic conditions of the Late Devonian period, where the time of maximum sea level standing within the basin led to deposition of high organic carbon content intervals. The structural-facies zonation of the HCF distribution area is associated with the zone of relatively deep-water depressions, the zone of slopes, highs and the shallow water shelf with numerous bioherm buildups. The boundaries of the zones were determined by the position of large structural elements of the Tatar and Bashkir arches and depressions of the Kama-Kinel system of troughs. These zones differ not only in the distribution of the thickness of HCF deposits, but also in the nature of the distribution of intervals of the section enriched in organic matter. The maximum number of interlayers enriched by organic matter of the siliceous-carbonate rocks is observed in the section of the Frasnian and Famennian deposits within the central part of the Kama-Kinel system of troughs. Numerous of oil shows from the HCF intervals indicate the potential for further study and spotting of promising areas for hard-to-recover hydrocarbon reserves exploration.