Features of experimental studies of dynamic characteristics of two-phase filtration in carbonate reservoirs

UDK: 622.276.43(470.57)

DOI: 10.24887/0028-2448-2025-12-46-49

Key words: core, relative permeabilities, wettability, hydrophobization, displacement efficiency, residual oil saturation, carbonate reservoirs

Authors: A.A. Kovalev (Samara State Technical University, RF, Samara); A.A. Kozhemyakin (Zarubezhneft JSC, RF, Moscow)

The article studies features of experimental studies of dynamic characteristics of two-phase filtration in carbonate reservoirs. The most important dynamic characteristics of two-phase flow are the relative permeabilities for fluids saturating the pore space. The objective of this study is to investigate the dynamic characteristics of two-phase flow in carbonate sediments of the Mendym horizon of one of fields in the Samara region, whose reservoir rocks are porous and cavernous organogenic-clastic limestones. There were selected standard and full-size samples with similar porosity and permeability in order to study the relative permeabilities. To facilitate comparison of the obtained results and further analysis, the total flow rate of fluids injected into the samples for each experimental series and for each flow regime was the same. Capillary measurements were additionally conducted to assess the pore size distribution to study pore structure. Analysis of the obtained results revealed differences in the conditions for the formation of residual oil saturation and the pace of change in relative oil permeability, which should be taken into account in further simulation modelling of reservoir development processes in complex carbonate reservoirs. Furthermore, for carbonate reservoir conditions, the dynamic characteristics should be studied comprehensively using additional studies, including capillary measurements, Nuclear Magnetic Resonance Logging, study of thin sections and other.

References

1. Kovalev A.A., Vliyanie anizotropii gornykh porod na fil'tratsionnye kharakteristiki produktivnykh plastov i effektivnost' protsessov dobychi nefti (The influence of rock anisotropy on the filtration characteristics of productive formations and the efficiency of oil production processes), Proceedings of Giprovostokneft, Samara, 1999,

pp. 58–65.

2. Kovalev A.A., Problems of identification of two-phase filtration process for hydrodynamic calculations (In Russ.), Izvestiya Samarskogo nauchnogo tsentra RAN, 2003, Special Issue “Problemy nefti i gaza” (Oil and Gas Problems), pp. 89–94.

3. Mikhaylov N.N., Physicogeological problems in
modeling of reserves assessment and hydrocarbon reservoir and production
engineering (In Russ.), Vestnik TsKR Rosnedra, 2014, no. 6, pp. 31–43.