The article presents the results of the structural uncertainties assessment of sector geological models of the VK1 reservoir of the Kamennoe license area (Krasnoleninsky field, Krasnoleninsky arch, Western Siberia) according to production drilling data. The depth uncertainty of the reservoir top is the critical uncertainty of geological modeling. It is determined that it is described by a normal distribution with estimated parameters. The obtained distribution is of significant practical importance, since it enables to estimate the probability of the reservoir top to be above a certain depth in the oil-water zone. The uncertainty of the reservoir top angle significantly affects the selection of angles for horizontal wells drilling. To solve this problem, the authors formulated the concept of the critical zenith angle (CZA), which defines the corridor of the drilling angles. As a result, it was found that outside the fault zones, the CZA can be assumed to be equal to 1,1 degrees, and in the fault zones – 3,3 degrees. Erroneous definitions of the fault amplitudes lead to a decrease of a horizontal well drilling through the reservoir. Non-confirmation of the amplitude even at 2 m is critical. The probability of getting such an error is 33 %. Thus, comparing the results of geological modeling based on prospecting and exploration wells with the results of production drilling is a reliable source of information about the structural uncertainties of the initial geological model. The results obtained are recommended to be taken into account when setting up production drilling in neighboring areas.
References
1. Zakrevskiy K.E., Geologicheskoe 3D modelirovanie (3D geological modeling), Moscow: Publ of IPTs Maska, 2009, 376 p.
2. Kazanskaya D.A., Aleksandrov V.M., Belkina V.A., Geological modelling of vikulovskaya suite production deposits (In Russ.), Izvestiya Tomskogo politekhnicheskogo universiteta. Inzhiniring georesursov = Bulletin of the Tomsk Polytechnic University, 2019, V. 330, no. 7, pp. 195–207,
DOI: https://doi.org/10.18799/24131830/2019/7/2195
3. Likhoded I.A., Avdonin Yu.E., Reshetnikova D.S. et al., Efficient involvement in the development of remaining oil of the edge zones of the Vikulovskaya formation of the Krasnoleninskoye oil and gas condensate field (In Russ.), Territoriya Neftegaz, 2021, no. 3–4, pp. 66–74.
4. Ovcharova L.P., Justification of optimal parameters of development systems for horizontal wells in the Vikulov formation of the «K» field, Meridian, 2020, no. 12 (46), pp. 174–176.
5. Tsvetkova P.A., Fedulov V.V., Sautkin R.S., New approaches to the development of thin-layered undersaturated reservoirs (Vikulovskaya series of the Krasnoleninskiy dome of the Frolovskaya petroleum area) (In Russ.), Vestnik Moskovskogo universiteta. Ser. 4, Geologiya = Moscow University Geology Bulletin, 2021, no. 1,
pp. 71–78.
6. Dubrule O., Geostatistics for seismic data integration in Earth models, Tulsa, Society of Exploration Geophysicists & European Association of Geoscientists and Engineers, 2003, 281 p.
7. Yanevits E.A., Lapkovskiy V.V., Lebedev M.V., Stokhasticheskoe modelirovanie strukturnykh neopredelennostey kak osnova veroyatnostnoy otsenki resursov uglevodorodov (Stochastic modeling of structural uncertainties as a basis for probabilistic assessment of hydrocarbon resources), Proceedings of XXV scientific and practical conference “Puti realizatsii neftegazovogo potentsiala KhMAO” (Ways of realization of oil and gas potential of KhMAO), Khanty-Mansiysk, 23–26 November 2021, Khanty-Mansiysk, 2022, pp. 154-164.
