Carbonate reservoirs are characterized by a low degree of knowledge of the matrix and fractures parameters, the lack of the possibility to confidently identify typical objects and to evaluate numerical geological and physical parameters and the wettability of reservoirs. For carbonate reservoirs the reserves internal structure concept, the wettability correctness and related factors influence on the forecasting development design indicators and the choice of a method for extracting oil. The existence of a secondary porosity can be determined by pressure transient analysis, geophysical well logging (FMI, etc.) and core examinations. The secondary porosity in the pressure derivative curve is diagnosed by a particular change in the curve. In addition, the filtration characteristics of the medium are determined by well testing with pressure transient analysis. The entire complex of well testing data was reinterpreted. It was found that secondary porosity was impossible to determine using hydrodynamic tests. At the same time, according to FMI and core data, the presence of cracks is shown. As a result of detailed data processing and modeling, it was concluded that the effect of dual porosity is overlapped by the influence of the wellbore. The analysis of existing and possible displacement mechanisms is a necessary component in choosing the optimal development system and methods of exposure for all carbonate reservoirs, which are characterized by a high influence of the secondary porosity in the filtration process. In order to achieve maximum oil and gas production at a late stage of development, it is necessary to involve the displacement mechanism in the flooded zone from the matrix blocks.
References
1. Aguilera R., Naturally fractured reservoirs, Tulsa (Oklahoma): PennWell Books, 1980, 703 p.
2. Ambartsumyan R.A., Sayakhutdinov A.I., Rol' promyslovykh issledovaniy v protsesse sozdaniya kontseptual'noy modeli karbonatnogo plasta na primere Khasyreyskogo mestorozhdeniya (The role of field research in the process of creating a conceptual model of a carbonate reservoir on the example of the Khasyrey field), Collected papers “Geologiya, geoekologiya i resursnyy potentsial Urala i sopredel'nykh territoriy” (Geology, geoecology and resource potential of the Urals and adjacent territories), Ufa, 2019, pp. 141–142.
3. Amott E., Observations relating to the wettability of porous rock, SPE-1167-G, 1959, DOI: https://doi.org/10.2118/1167-G
4. Donaldson E.C., Thomas R.D., Lorenz Ph.B., Wettability determination and its effect on recovery efficiency, SPE-2338-PA, 1969, DOI: https://doi.org/10.2118/2338-PA5.
5. Nelson R., Geologic analysis of naturally fractured reservoirs, Gulf Professional Publishing, 2001, 352 p.
6. Golf-Racht T., Fundamentals of fractured reservoir engineering, Amsterdam, New York: Elsevier, 1982.
7. Aguilera R., Naturally fractured reservoirs, Tulsa (Oklahoma): PennWell Books, 1995, 521 p.
