The oil rim reserves development suggests complexity in maintaining the balance of gas and oil withdrawals from the reservoir, choosing the optimal well design and geosteering, justifying well operation conditions, etc. In addition, gas and oil reservoir can be complicated by diagenetic alterations of deposits, blocked structure, abnormal thermobaric conditions. The paper presents the results of conceptual approach to the Botuobinskiy horizon’s oil rim development design at the Chayandinskoye oil and gas condensate field with the presence of the above complications. This experience can be applied to assess the majority of fields in Eastern Siberia.

The article presents the experience of implementation of the oil deposit development project for U1 reservoirs of the Zapadno-Tarkosalinsky oil and gas condensate field. Key features of geological structure and development parameters are considered, also the main problems and ways of their solution are revealed, as well as the obtained results of geological and hydrodynamic modeling and adaptation of models are presented.

Background. The article considers the results of updating the geological model of the khamakinskii horizon reservoirs of the Chayandinskoe oid and gas field. The main aim is project the production of the oil rims and form a positive business case of the project. Materials and methods. Conceptual sedimentary model bases on the core of the 14 wells. Updating of the petrophysical model is the key to identify post-sedimentary transformations (like anhydritization and halitization) and the opportunity to correct the permeability trend. The tectonic pattern of the horizon based on the interpretation of 3D seismic data. There are two groups of faults were identified: certain and possible. Neural networks algorithm uses for a creating the predictive maps of anhydritization, which are used in the geological model. Results. Estuary sands influenced by fluvial and tidal processes dominate the khamakinskii horizon. The reservoir is irregular vertically: at the base of the horizon, there are sandstones of the delta front and there are alluvial valley with fluvial channels in the middle and upper parts. Eustary sands eroded by incised valleys (alluvial channels). According to the core and thin section analysis, the main uncertainty is sedimentary transformations of reservoir. It affects the net thickness and then the volume of oil in productive wells. 3D geological model includes the trends of anhydritization and halitization over the area, which makes it possible to obtain a more accurate production forecast. Conclusion. As part of the probability estimate of oil reserves, the main geological parameters that affect the volume of reserves were identified. Pilot project is planning to remove geological and technical uncertainties.