The paper analyzes the lessons learned while using the Digital Core technology to obtain data on void space structure and minerals distribution, as well to estimate the flow properties of rocks.
The possibility to reconstruct the void space is considered based on the results of studying several core samples by micro-CT and FIB-SEM methods. The quality of the reconstruction is analyzed by comparing the laboratory and micro-CT porosities. It is demonstrated that the basic software settings to interpret the results of microtomography in the overwhelming majority of cases do not provide an acceptable match between the CT-simulated and laboratory-measured results. Moreover, the difference with laboratory data increases with increasing porosity of samples, regardless of their size.
The paper justifies the efficiency of the computational and experimental approach to build the relative permeability functions through a combination of digital micro-simulation and lab core flow studies. The simulated steady-state two-phase flow of oil and water is considered in the pore capillary channel system using the generalized Bernoulli’s equation for which the inter-phase interaction function can be described by regression equations obtained from laboratory studies. The relative permeability values calculated by the proposed method are in good agreement with the laboratory data.
The results of studies show that so far this technology is far from perfect, but it has a number of significant advantages as compared with traditional laboratory experiments, therefore it can be considered as promising and practically valuable.
References
1. Shandrygin A.N., Digital core analysis for flow process evaluation is myth or reality? (In Russ.), SPE 171216-RU, 2014.
2. Shiqi Liu, Shuxun Sang, Geoff Wang et al., FIB-SEM and X-ray CT characterization of interconnected pores in high-rank coal formed from regional metamorphism, Journal of Petroleum Science and Engineering, 2017, V. 148, pp. 21–31.
3. Andrew M., Bijeljic B., Blunt M., Pore-scale contact angle measurements at reservoir condition using X-ray microtomography, Advances in Water Resources, 2018, V. 68, pp. 24-31.
4. Blunt M.J., Flow in porous media – pore-network models and multiphase flow, Current Opinion in Colloid & Interface Science, 2001, no. 6, pp. 198 - 207.
5. White J., Borja R., Fredrich J., Calculating the effective permeability of sandstone with multiscale lattice Boltzmann/finite element simulations, Acta Geotechnica, 2006, no. 1, pp. 195–209.
6. Zaretsky Y., Geiger S., Sorbie K., Forster M., Efficient flow and transport simulations in reconstructed 3D pore geometries, Advances in Water Resources, 2010, V. 33, pp. 1508–1516.
7. Dem'yanov A.Yu., Dinariev O.Yu., Evseev N.V., Osnovy metoda funktsionala plotnosti v gidrodinamike (Fundamentals of the density functional method in hydrodynamics), Moscow: Fizmatlit Publ., 2009, 312 p.
8. Altunin A.E., Sokolov S.V., Stepanov S.V. et al., Calculation method of receiving relative phase permeability based on solution of Bernoulli generalized equations for a system of porous channels (In Russ.), Neftepromyslovoe delo, 2013, no. 8, pp. 40–46.
9. Shabarov A.B., Gidrogazodinamika (Fluid dynamics), Tyumen': Publ. of Tyumen State University, 2013, 460 p.
10. Bembel' G.S., Stepanov S.V., Mathematical modeling of slug two-phase flow in the system of capillary canals (In Russ.), Avtomatizatsiya, telemekhanizatsiya i svyaz' v neftyanoy promyshlennosti, 2015, no. 6, pp. 30–38.
11. Shabarov A.B., Shatalov A.V., Pressure drops in water-oil mixture flow in porous channels (In Russ.), Vestnik Tyumenskogo gosudarstvennogo universiteta. Fiziko-matematicheskoe modelirovanie. Neft', gaz, energetika, 2016, V. 2, no. 2, pp. 50–72.
