Based on the materials of geological and geophysical studies of the Middle Ob region in Western Siberia, areas of development of the «anomalous section» at the border of Jurassic and Lower Cretaceous deposits were identified. The results of deep wells’ tests confirmed the relationship between discovered oil/gas deposits in the Lower Cretaceous deposits and the location of the «anomalous section». The article presents the main hypotheses and models for the formation of «anomalous sections». Seismotectonic activity in the local areas with dimensions of a few hundred meters causes the formation of reverse fault and landslide types of sediment structures. Interpretation of 3D seismic surveys enables to identify subvertical zones of rock destruction on time sections associated with channels of deep degassing and fluid flows through which vertical migration of hydrocarbons and filling of traps occurs throughout the entire range of the geological section. The unity of the Achimov layers and Upper Jurassic deposits suggests their hydrodynamic connection, therefore, in areas of development of the «anomalous section», the reservoirs of the Achimov strata represent a promising formation for hydrocarbon exploration. Based on a complex analysis of the work carried out, models for the formation of hydrocarbon deposits were developed, the main patterns of the location of productive areas were proposed, and directions for further clarification of the geological structure of the territory and oil-bearing prospects were determined. The presence of «anomalous section» of Upper Jurassic deposits is a prospecting sign for the detection of hydrocarbon deposits in the Achimov strata.
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