The relevance of the research is caused by the need to assess the current state of oil reserves quality in bottom-hole zones and to predict technological efficiency of the existing oil reserves production in selection of wells-candidates for bottom-hole zone processing, which meets the needs of global practices in finding the most effective methods of oil-gas field development. The majority of oil fields in West Siberia are at the late stage of development. In this regard, the development of remaining reserves becomes a priority. To make design decisions for predicted development period the assessment of remaining hydrocarbons in place is required, which determines the timeliness of the study and adaptation of field resources assessment methods. The aim of the research is to improve the efficiency of field development through the introduction of modern techniques which will effect the possibility of determining the values of changes in oil reserves by the example of the Severo-Orekhovskoe field and analyze the techniques used in the Severo-Orekhovskoe field enabling prediction of the technical efficiency of production and estimation of oil reserves in the selection of wells-candidates for bottom-hole zone processing.  Object of the research is the Severo-Orekhovskoe field as an energy complex, where not only traditional techniques of predicting the technological efficiency of oil reserves production are used, but absolutely new methods of oil reserves assessment in selection of wells-candidates for bottom-hole zone processing are tested. Methods: prediction making it possible to understand the technological efficiency of production and estimation of oil reserves in selection of wells-candidates for bottom-hole zone processing; method of determining the specific remaining reserves values stipulating the use of comparative analysis of the capacity of wells-donors and wells-acceptors; analysis and assessment of values resulting from the reserves drainage; evaluation of the current oil saturation. Results. The authors have applied the comparative analysis of existing methods of predicting the technological efficiency of production and estimation of oil reserves used in selection of wells-candidates for bottom-hole zone processing. They proposed the modified method for determining specific remaining reserves, which allows estimating the reserves and production of the entire facility for each producing well, as well as reservoir properties of the entire well stock. It was established that the method of determining specific remaining reserves involves identification of wells-donors and wells-acceptors. It was found out that the approach used in the selection of wells-candidates for bottom-hole zone processing is universal, as it allows identifying wells with insufficient production under the existing capacity. Moreover, this methodological approach involves the assessment of oil production relative dynamics and identification of oil rate drop incomparable with residual potential. It was shown that the methodological approach combining the properties of the expected technological efficiency prediction and the criterion justification is based on calculation of multiple regression analysis parameters. It was established that it is based on the assumption that measure technological efficiency (excluding success, random factor) is closely related to geological and technological parameters that characterize the potential of wells: remaining recoverable reserves, sand count, drainage area, permeability, etc. It was proved that this method does not only meet the selection of bottom-hole zone processing, but the groups of technologies for increasing oil recovery of different specificity (according to a mechanism of involvement of idle oil reserves) as well; the desired function is the technological efficiency of activities (per year or per month), and the arguments are a set of well stock geological-technological parameters on the date of the event. The technique of definition of well stock remaining oil reserves was suggested, which contributes to determining the oil reserves quality for a separate production well and allows estimating the reserves and production of the whole facility, as well as reservoir parameters of the whole well stock. Conclusions. It was established that the specific features of the existing techniques identified during the analysis allow solving a number of oilfield tasks: to determine the reserves volume coming out of the drainage area (selection of water-restriction methods to increase oil output, cement squeeze, well operation condition correction, well shut-off); to define the extent of idle oil reserves not involved in drainage (hydraulic fracturing, compaction); to analyze the reachability of recoverable reserves production, estimated according to the generally accepted characteristics of displacement in producing wells, that is, to make their correction.