For the design of new technologies aimed at increasing the efficiency of the production of hard-to-recover reserves, it is necessary to take into account factors that may affect their implementation. These factors may include the pore structure, the physical and physicochemical properties of reservoir fluids, as well as their variability within the development object. The authors determined the basic laws of the variability of the molecular mass distribution of alkanes based on chromatographic studies of the composition of high-viscosity oil of the Bobrikovian-Radaevian horizon of the Vishnevo-Polyanskoe field. The object of the study is the Vishnevo-Polyanskoe high-viscosity oil field, which is located on the eastern side slope of the Melekess Depression and was put into development in 1988. The main object of development is the Bobrikovian-Radaevian horizon. The Vishnevo-Polyanskoe field is characterized by a rather low oil recovery factor of 0,09. Consequently, this highly viscous oil field can be considered as a priority object for the application of technologies aimed at increasing oil production. In connection with the above, for the selection of effective reservoir stimulation methods, it is necessary to study the patterns of manifestation of microprocesses occurring in the reservoir. The analysis for study the dynamics of the composition of the moving part of the remaining oil in place of the Vishnevo-Polyanskoe field of high-viscosity oil samples taken from 20 production wells with a frequency of 7 days was carried out. In general, the oil of the Bobrikovian-Radaevian horizon of the Vishnevo-Polyanskoe field is characterized by close molecular mass distribution curves of n-alkanes C10-C40. Analysis of the molecular mass distribution of n-alkanes is characterized by a monotonic decrease in hydrocarbon content from C14 to C34. The oil of the Vishnevo-Polyanskoe field has a single-mode character with a maximum in C14. The group of heavy components C21-C40 is characterized as heterogeneous, which may indicate a decrease in the stability of structural formations and precipitation of aggregates from high-molecular hydrocarbons, gums and asphaltenes in the reservoir and bottomhole zone due to changes in thermodynamic conditions.
1. Muslimov R.Kh., Abdulmazitov R.G., Khisamov R.B. et al., Neftegazonosnost' Respubliki Tatarstan. Geologiya i razrabotka neftyanykh mestorozhdeniy (Oil and gas bearing of the Republic of Tatarstan. Geology and development of oil fields), Part 2, Kazan': FEN Publ., 2007, 524 p.
2. Yusupova T.N., Ganeeva Yu.M., Romanov G.V., Barskaya E.E., Fiziko-khimicheskie protsessy v produktivnykh neftyanykh plastakh (Physical and chemical processes in the productive oil reservoirs), Moscow: Nauka Publ., 2015, 412 p.
3. Kayukova G.P., Romanov G.V., Lukyanova R.G., Sharipova N.S., Organicheskaya geokhimiya osadochnoy tolshchi i fundamenta territorii Tatarstana (Organic geochemistry of sedimentary strata and basement of the territory of Tatarstan), Moscow: GEOS Publ., 2009, 487 p.4. Surguchev M.L., Vtorichnye i tretichnye metody uvelicheniya nefteotdachi plastov (Secondary and tertiary methods of enhanced oil recovery), Moscow: Nedra Publ., 1985, 308 p.