Standard procedures for determining the displacement coefficient assume a single value of this parameter for reservoirs with fixed filtration-capacity properties. For inhomogeneous formations, petrophysical relationships are usually constructed between the values of the displacement coefficients and the filtration and reservoir properties of the formation. However, the generally accepted standard approach does not take into account the structure and mobility of the residual oil. In the proposed article, the authors present the results of experiments showing significant changes in the oil displacement coefficient by water when the displacement conditions change, characterized by different values of the capillary number. Experimental dependences of the displacement coefficients on the capillary number are obtained. It is shown that the standard values of the displacement coefficients, at the maximum values of the capillary numbers, can change multiple times with varying values of the capillary number. This leads to changes in the values of displacement coefficients in the near-well and inter-well areas of the developed formations. Examples of the distribution of displacement coefficients in development elements with the same filtration and reservoir properties, but with changing well placement systems, are given. The influence of well placement systems on changes in the displacement coefficient is shown.
1. Gladkikh E.A., Khizhnyak G.P., Galkin V.I., The method for estimating the oil displacement coefficient based on standard core analysis (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2017, no. 8, pp. 90–93, DOI: 10.24887/0028-2448-2017-8-90-93.
2. Glazunov P.A., Fedorova A.B., Smetanin A.V. et al., The summary of oil displacement experiments in Tomsk region (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2016, no. 4, pp. 36–38.
3. Mikhaylov N.N., Ostatochnoe neftenasyshchenie razrabatyvaemykh plastov (Residual oil saturation of developed reservoirs), Moscow: Nedra Publ., 1992, 240 p.
4. Mikhaylov N.N., Tekhnologii dorazrabotki zavodnennykh plastov na osnove issledovaniya struktury i podvizhnosti ostatochnoy nefti (Technologies for further development of flooded formations based on the study of the structure and mobility of residual oil), Collected papers “Novye tekhnologii osvoeniya i razrabotki trudnoizvlekaemykh zapasov nefti i gaza i povysheniya neftegazootdachi” (New technologies of development and exploitation of stranded oil and gas and enhanced oil gas recovery), Moscow: Publ. of Institut neftegazovogo biznesa N, 2008, 344 p.
5. Mikhaylov N.N., Glazova V.I., Vysokovskaya E.S., Prognoz ostatochnogo neftenasyshcheniya pri proektirovanii metodov vozdeystviya na plast i prizaboynuyu zonu (Forecast of residual oil saturation in the design of methods of stimulation of reservoir and the bottom zone), Moscow: Publ. of VNIIOENG, 1983, 71 p.
6. Mikhaylov N.N., Dzhemesyuk A.V., Kol'chitskaya T.N., Sostoyanie i raspredelenie ostatochnoy nefti v zavodnennykh plastakh (Status and distribution of the residual oil in the flooded layers), Collected papers “Fundamental'nyy bazis novykh tekhnologiy neftyanoy i gazovoy promyshlennosti” (The fundamental basis of the new technologies of the oil and gas industry), Moscow: Nauka Publ., 2000, pp. 204–213.
7. Mikhaylov N.N., Melekhin S.V., Basic ideas about the curves of capillary displacement and their characteristics (review) (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2018, no. 8, pp. 24–28.
8. Mikhaylov N.N., Chumikov R.I., Experimental research of the capillary-pinched phases mobility (In Russ.), Vestnik TsKR Rosnedra, 2009, no. 5, pp. 42–48.
9. Gioia F., Alfani G., Andreutti S., Murena F., Oil mobility in a saturated water-wetted bed of glass beads, J. Hazard Mater., 2003, B97, pp. 315−327, doi: 10.1016/s0304-3894(02)00281-9.
10. Kamath J., Meyer R.F., Nakagawa F.N., Understanding waterflood residual oil saturation of four carbonate rock types, SPE-71505-MS, 2001, https://doi.org/10.2118/71505-MS
11. Saadapoor E., Bryant S. L., Sepehrnoori K., New trapping mechanism in carbon sequestration, Transp. Porous Media, 2010, V. 82, pp. 3−17.
12 Mikhaylov N.N., Polishchuk V.I., Khazigaleeva Z.R., Modeling of residual oil distribution in flooded heterogeneous formations (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2014, no. 8, pp. 36–39.
13. Zaitsev M.V., Mikhailov N.N., Effect of residual oil saturation on the ﬂow through a porous medium in the neighborhood of an injection well (In Russ.), Izvestiya RAN. Mekhanika zhidkosti i gaza = Fluid Dynamics, 2006, no. 4, pp. 93–99.14. Mikhaylov N.N., Varlamov D.P., Klenkov K.A., Modeling the impact of well placement systems on the residual oil saturation of flooded formations (In Russ.), Burenie i neft', 2004, no. 1, pp. 13–15.