The paper considers the different aspects of the oil and gas presence in a specific reservoir in the top of the Middle Jurassic sequence of the West Siberian sedimentary cover. They allow to identify regional patterns of hydrocarbon accumulations distribution in the Yu2-Yu4 horizons of Bathonian reservoir within the entire territory of the West Siberian basin. Based on the latest results of the regional studies, the structural and facies control, trap type control have been established.

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... ent to the certain parts of the reservoir section in various regions of the petroleum province have been described. Additionally changes in the hydrocarbons phase, pressure-and-temperature conditions, the physical and chemical properties of fluids have been identified. The revealed features of the oil-and-gas accumulations distribution make it possible to carry out a reasonable forecast of new findings in the Yu, Yu and Yu productive horizons within the promising areas. This is of great practical importance and application for the reserve replacement, as well as the effective selection of the future exploration strategy and further on the creation of the optimal development plan.