This paper attempts to calculate hydrocarbon reserves in productive formations of the Buyaginskaya deep drilling area. Brief information on the lithologic-stratigraphic section and tectonic structure of the Buyaginskaya structure, which is located in the western part of the Suntar uplift of the Siberian Platform, is given. Zonal and sectional features of the prospective Kharystan Vendian horizon are noted based on the history of the region’s development. The results of well testing in the intervals of occurrence of Kharystan and Osinsk productive horizons are presented. On the basis of the data obtained during the trial operation of the Kharystan productive horizon deposit, the reserves were estimated by the pressure drop method. The conclusion was made about low potential of the Kharystan horizon gas deposit within the studied area. Based on field geophysical data, the calculation parameters for the Osinsk horizon were substantiated and oil and gas reserves were calculated using the volumetric method. It is shown by calculation that the reserves of the Buyaginskaya area can be classified as shallow according to the current reserves classification. The results of prospecting and exploration works in the area of the junction of the Vilyuchanskaya saddle and the Predpatomsky regional trough, showing high prospects of the Kharystan horizon in the regional plan, are presented. On the basis of the conducted studies, it is suggested that the Kharystan horizon may be distributed within the avlacogens, which are narrow and extended negative structures of the crystalline basement of northeastern strike along the northwestern and southeastern slopes of the Suntar uplift. Similar zones of oil and gas accumulation may be developed along the slopes of the Arbaisko-Sinskiy rampart. Alternative ways to monetize the available gas resources of the Buyaginskoye prospective field were proposed.