The article considers the creation of a detailed geological model of the upper subformation sediments of the Tyumen formation to improve the accuracy of reservoir properties forecasting and reserves localization. Based on a detailed analysis of core material 2 sedimentation environments were identified: a meandering river system in the interval of the YuS3 formation and transitional delta deposits in the interval of the YuS2 formation. The sedimentation conditions are described by a complex of facies, combined into 4 macrofacies in the YuS2 formation interval (shelf, submarine ridges, marshes and swamps, sandbanks and gullies, delta channels) and into 3 macrofacies in the YuS3 formation interval (floodplains and swamps, crevasse glyph, river channel). The best poro-perm properties are in the facies of the delta channel and river bed, transitional properties - in the facies of underwater ridges, beaches, shoals and gullies, crested glyph, the worst - in the facies of floodplains, marshes and swamps. The high poro-perm properties are connected with the active dynamics of the aquatic environment in which the sediments accumulated. Macrofacies are characterized based on well logging data: average poro-perm parameters, boundary porosity values for identifying reservoirs are specified. The high poro-perm reservoir is concentrated in the facies of the river-bed, delta channel and underwater ridge. Facies maps of sediments are compiled using 3D seismic interpretation (spectral decomposition cube sections and other attributes). A detailed geological model with quantitative morphological parameters of facies was obtained which enables to develop hydrocarbon reserves of tight-oil deposits of the Tyumen formation.
References
1. Walker R.G , James N.P., Facies models: response to sea level change, Geological Association of Canada, 1992.
2. Baraboshkin E.Yu., Prakticheskaya sedimentologiya. Terrigennye rezervuary. Posobie po rabote s kernom (Practical sedimentology. Terrigenous reservoirs. On how to operate core samples), Tver: GERS Publ., 2011, 152 p.
3. Kontorovich A.E., Kontorovich V.A., Ryzhkova S.V. et al., Jurassic paleogeography of the West Siberian sedimentary basin (In Russ.), Geologiya I geofizika = Russian Geology and Geophysics, 2013, V. 54, no. 8, pp. 972–1012.
4. Isakova T.G., Persidskaya A.S., Khotylev O.V. et al., Typification of the deposits of the Tyumen Formation according to the degree of hydrodynamic conditions of sedimentation to create a petrophysical model and differentiated interpretation of well log data (In Russ.), Georesursy = Georesources, 2022, V. 24, no. 2, pp. 172–185,
DOI: https://doi.org/10.18599/grs.2022.2.16
5. Gabdullina G.T., Suleymanov E.D., Kararova A.Z., Fakhrutdinova A.M., Update of petrophysical and geological model of Middle Jurassic deposits during well monitoring (In Russ.), Neftegazovoe delo, 2024, V. 22, no. 3, pp. 8–18, DOI: https://doi.org/10.17122/ngdelo-2024-3-8-18
6. Muromtsev V.S., Elektrometricheskaya geologiya peschanykh tel – litologicheskikh lovushek nefti i gaza (Electrometric geology of sand bodies - lithological traps of oil and gas), Leningrad: Nedra Publ., 1984, 260 p.
7. Oreshkova M.Yu., Ol’neva T.V., Kompleksnyy podkhod k modelirovaniyu geometrizatsii otlozheniy paleoruslovykh sistem tyumenskoy svity Zapadno-Sibirskogo neftegazonosnogo basseyna (An integrated approach to modeling the geometrization of sediments of paleochannel systems of the Tyumen suite of the West Siberian oil and gas basin), Collected papers “Seysmorazvedka v Sibiri i za ee predelami” (Seismic exploration in Siberia and beyond), Proceedings of nauchno-prakticheskoy konferentsii, 2023, pp. 129–134.
