Cyclic and polymer-cyclic flooding of fractured-porous reservoirs is investigated by the method of computational experiment. As a research tool, the Tempest-More software package from ROXAR was selected, which makes it possible to perform hydrodynamic modeling of fractured-porous systems taking into account dual porosity and dual permeability. It is shown that the dependence of the oil recovery factor on the proportion of fractures in the reservoir has a non-monotonic character. It was revealed that for the selected parameters of the simulated technologies, the highest final oil recovery factor under cyclic and polymer-cyclic impact is achieved with the smallest injection half-cycle. The combination of cyclic flooding with polymer flooding increases the final recovery factor, but at the same time, injectivity of injection wells may decrease due to the achievement of injection pressure limitation due to the increased viscosity of the fluid and, as a result, lower efficiency at the end of the effect compared to conventional polymer flooding. It is shown that the assessment of the results of the impact on the reservoirs significantly depends on at what point in time the assessment is made: at the end of the impact, at the end of the effect of the impact or when the maximum water content of the well production is reached.
References
1. Barenblatt G.I., Zheltov Yu.P., Kochina I.N., On the basic concepts of the theory of filtration of homogeneous fluids in fractured rocks (In Russ.), Prikladnaya matematika i mekhanika = Journal of Applied Mathematics and Mechanics, 1960, V. XXIV, no. 5, pp. 852–864.
2. Surguchev M.L., Cyclic (pulsed) impact on the reservoir as a method of increasing oil recovery during flooding (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 1965, no. 3, pp. 52–57.
3. Bokserman A.A., Zheltov Yu.P., Muzafarov K.E., Ogandzhanyants V.G., Eksperimental’noe izuchenie kapillyarnogo uderzhaniya vody v poristykh sredakh pri uprugo-kapillyarnom rezhime (Experimental study of the capillary retention of water in porous media in the elastic-capillary regime) Proceedings of VNII, 1967, no. 50, pp. 94–101.
4. Tsynkova O.E., On the issue of the mechanism of cyclic impact on oil reservoirs (In Russ.), Izvestiya AN SSSR. Mekhanika zhidkosti i gaza = Fluid Dynamics, 1980, no. 3, pp. 58–67.
5. Sharbatova I.N., Surguchev M.L., Tsiklicheskoye vozdeystviye na neodnorodnyye neftyanyye plasty (Cyclical effects on heterogeneous oil layers), Moscow: Nedra Publ., 1988, 121 p.
6. Muslimov R.Kh., Sovremennye metody povysheniya nefteizvlecheniya: proektirovanie, optimizatsiya i otsenka effektivnosti (Modern methods of enhanced oil recovery: the design, optimization and assessment of efficiency), Kazan’: Fen Publ., 2005, 688 p.
7. Akulshin A.L., Study of oil displacement from a fractured-porous reservoir using POLYCAR polymer (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2000, no. 1, pp. 36–38.