Cavernous-fractured reservoirs are characterized by significant heterogeneity in the distribution of microfractures and cavernousness, which does not allow obtaining reliable data using traditional methods due to the presence of a scale effect. A partial solution of this problem is filtration studies on full-size core samples, however, mass sampling of cores in vertical and directional wells allows studies to be carried out on reservoir models oriented only perpendicular to the bedding or at a certain angle. This article discusses the experience of creating a technology for determining relative phase permeability and displacement coefficients for the gas –water and oil – water system for cavernous-fractured reservoirs, taking into account the above problems. The created technology is based on many years of experience in conducting filtration experiments in domestic and foreign research laboratories. As part of the development of this technology, the influence of the scale effect on the evaluation of reservoir filtration parameters was studied based on the results of flow experiments. In addition, a procedure was developed for determining the relative phase permeability and residual oil saturation both for a single full-size core sample and for the entire full-size core column related to a specific sedimentation environment based on tomography of this column and measurements using standard methods for determining relative phase permeability for a limited number of samples with a volume of 21–27 cm3 and more. The procedure is based on the use of a hydrodynamic model of a given reservoir interval, created based on the results of tomography of a column of full-size core samples of this reservoir interval and the results of measuring the filtration-capacitance properties, displacement coefficients and relative phase permeability of core samples cut from characteristic density zones of this column. The hydrodynamic model makes it possible to calculate the relative phase permeability in the volume of a full-size core sample (or an entire column belonging to a certain sedimentation environment) depending on the orientation relative to the selected directions (for example, along the bedding or perpendicular to the bedding).
References
1. Kheyfets L.I., Neymark A.V., Mnogofaznye protsessy v poristykh sredakh (Multiphase processes in porous media), Moscow: Khimiya Publ., 1982, 320 p.
2. Rodionov S.P., Sokolyuk L.N., Calculation and use of modified relative phase permeabilities when transforming a geological model into a hydrodynamic one (In Russ.), Trudy MFTI, 2010, V. 2, no. 2, pp. 130-136.
3. Cheremisin N.A., Shul’ga R.S., Zagorovskiy A.A. et al., Core modeling of oil penetration into the gas cap of complex-structured fields (In Russ.), Neftyanoe khozyaystvo = Oil Industry, 2022, no. 7, pp. 90-96, DOI: https://doi.org/10.24887/0028-2448-2022-7-90-96
4. Rassokhin S.G., Anisotropy of filtration properties of rocks and its effect on the relative phase permeability (In Russ.), Geologiya nefti i gaza = Oil and Gas Geology, 2003, no. 3, pp. 53-56.
5. Gurbatova I.P., Masshtabnye i anizotropnye effekty pri eksperimental’nom izuchenii fizicheskikh svoystv slozhnopostroennykh karbonatnykh kollektorov (Scale and anisotropic effects in the experimental study of the physical properties of complex carbonate reservoirs): thesis of candidate of technical science, Moscow, 2011.
6. Congcong Li, Shuoliang Wang, Qing You, Chunlei Yu, A new measurement of anisotropic relative permeability and its application in numerical simulation, Energies, 2021, V. 14, p. 4731, DOI: http://doi.org/10.3390/en14164731
