Control of Generalized Capillary Number on Immiscible Displacement Path: NMR Online and Network Simulation of Fluid Displacement Mechanism

Finger-like protrusions that form along fluid−fluid displacement fronts in porous media are often excited by hydrodynamic instability when low-viscosity fluids displace high-viscosity resident fluids. Such interfacial instabilities are undesirable in many natural and engineered displacement processes. We report a phenomenon whereby gradual and monotonic variation of pore sizes along the front path suppresses viscous fingering during immiscible displacement, that seemingly contradicts conventional expectation of enhanced instability with pore size variability. Experiments and pore-scale numerical simulations were combined with an analytical model for the characteristics of displacement front morphology as a function of the pore size gradient. Our results suggest that the gradual reduction of pore sizes act to restrain viscous fingering for a predictable range of flow conditions (as anticipated by gradient percolation theory). The study provides insights into ways for suppressing unwanted interfacial instabilities in porous media, and provides design principles for new engineered porous media such as exchange columns, fabric, paper, and membranes with respect to their desired immiscible displacement behavior.

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Coreflood planning criteria for relative permeability computation by Welge-JBN method

The APPEA Journal ◽

10.1071/aj17194 ◽

2018 ◽

Vol 58 (2) ◽

pp. 664 ◽

Cited By ~ 2

Author(s):

A. Al-Sarihi ◽

Z. You ◽

A. Behr ◽

L. Genolet ◽

P. Kowollik ◽

...

Keyword(s):

Relative Permeability ◽

Pore Volume ◽

Capillary Number ◽

Measurement Precision ◽

Petroleum Engineering ◽

Unsteady State ◽

Fluid Displacement ◽

Fluid Properties ◽

Water Cut ◽

Operational Criteria

Relative permeability computation is extensively applied in petroleum engineering through the Welge-JBN’s method in unsteady-state corefloods. The purpose of this work is to determine admissible coreflood parameters that could limit the application of the Welge-JBN method. These parameters are presented through theoretical and operational criteria. The theoretical criteria include capillary number and capillary–viscous ratio. The operational criteria consist of measurement precision for pressure, volume sampling for either of phases, water cut measurement precision, and number of samples taken during one pore volume injected. The minimum core length and fluid displacement velocity for specific rock and fluid properties could be determined through these criteria. A laboratory coreflood example was performed using the proposed parameters.

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INVASION PERCOLATION IN THE PRESENCE OF NANOPORES

International Journal of Modern Physics C ◽

10.1142/s0129183108013060 ◽

2008 ◽

Vol 19 (10) ◽

pp. 1515-1528

Author(s):

FATEMEH EBRAHIMI

Keyword(s):

Capillary Number ◽

Critical Value ◽

Percolation Model ◽

Immiscible Displacement ◽

Bond Percolation ◽

Invasion Percolation ◽

Nanoporous Media ◽

Size Restriction ◽

Mass Uptake ◽

Accessible Porosity

Site invasion percolation (IP) processes are combined with bond percolation model, to study the effects of size restriction on low capillary number immiscible displacement in heterogeneous nanoporous media. Both cases of compressible (NTIP) and incompressible defender fluid (TIP) are considered. It is found that in site IP the value of mass uptake increases with the size of invader particles, if the latter is not greater than a critical value. This occurs when the accessible porosity of the medium decreases as the size of fluid particles increases. We also investigate the effect of nanopore's concentration on the mass and the anisotropy of sample spanning cluster as well as the critical exponent of trap numbers.

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The surface conditions for viscous displacement in a homogeneous porous medium

Canadian Journal of Physics ◽

10.1139/p79-239 ◽

1979 ◽

Vol 57 (10) ◽

pp. 1738-1745 ◽

Cited By ~ 1

Author(s):

T. J. T. Spanos

Keyword(s):

Boundary Layer ◽

Porous Medium ◽

Continuum Theory ◽

Immiscible Displacement ◽

Surface Conditions ◽

Fluid Displacement ◽

Two Fluids ◽

Mathematical Abstraction ◽

Homogeneous Porous Medium ◽

Macroscopic Shape

The viscous surface conditions between two fluids are considered for fluid displacement in a homogeneous porous medium. The term viscous surface is defined here as a mathematical abstraction used to approximate the macroscopic shape of the boundary layer between two fixed saturations of displacing fluid by continuum theory. In the limit as the saturations approach each other, one then obtains a convergence of the viscous surface to a constant saturation contour. This yields a mathematical description of immiscible displacement in porous media which contains a theory of viscous fingering.

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