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Modelling multiphase flow through micro-CT images of the pore space. Ali Raeini , Branko Bijeljic and Martin Blunt. Department of Earth Science and Engineering Imperial College Consortium on Pore-scale Modelling. Objective. Relative permeability. Micro-CT image.
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Modelling multiphase flow through micro-CT images of the pore space • Ali Raeini, BrankoBijeljicand Martin Blunt Department of Earth Science and Engineering Imperial College Consortium on Pore-scale Modelling
Objective Relative permeability Micro-CT image Direct numerical simulation Capillary pressure Microscopic description of flow Macroscopic description of the flow
Previous studies Relative permeability Pore network model Pore network modelling Micro-CT image Capillary pressure
Methodology Relative permeability Numerical Simulation Finite volume mesh Micro-CT image Capillary pressure
Governing equations Advection of indicator function Capillary pressure equation Momentum balance Mass balance
Numerical code OpenFOAM: open source CFD toolbox www.openfoam.com interFOAM code: + our modifications ......
Test cases Modelling a static droplet Equilibrium solution Initial condition
Test cases Modelling a static dropletOriginalCSF formulation (m/s) • Presence of spurious velocities in CSF formulation makes the simulations impossible at low capillary numbers
Test cases Modelling a static droplet Sharp Surface Force (SSF) formulation (m/s) (Pa)
Test cases Modelling a static dropletCSF vs. SSF results Spurious currents Capillary waves
Test cases Droplet in contact with a flat plate Jagged solid walls Smooth solid walls (m/s) solid wall • Non-physical velocities are generated close to the jagged solid walls in both CSF and SSF formulations
Test cases Droplet in contact with a flat plate Filtering capillary forces parallel to the interface (Pa) (m/s)
Test cases Steady movement of a micro-scale droplet CSF formulation SSF formulation
Test cases Steady movement of a micro-scale droplet Filtering capillary fluxes • Filtering is necessary to obtain accurate results for the velocity field
Novel contributions in this study ..... Filtering capillary forces parallel to the interface Filtering capillary fluxes Sharp Surface Force formulation
Primarily pore-scale simulations Transient drainage experiment
Simulation time Single-phase flow High Capillary Numbers (>10-7) Low Capillary Numbers
Future work (Pa) (Pa) • Improving the efficiency of the numerical model for low capillary numbers • Obtaining Capillary pressure and relative permeability curves from transient experiments Pc Pd
Future work Transient experiments • Multiphase micro-CT images • Steady two-phase flow experiments, • using cyclic boundary conditions
Thanks to: • Stephen Neethling, • PeymanMostaghimi, • Christopher Pentland • and many other colleagues, for useful discussions • Sponsors of the project: • DTI, EPSRC, ENI, Saudi Aramco, BG, BHP, • JOGMEC, Schlumberger, Shell, Statoil and Total • and Thank you for your attention
References Brackbill, J. U., Kothe, D. B., and Zemach, C. A continuum method for modeling surface tension. J. Comput. Phys., 100(2):335–354, 1992