In all tests, the absolute permeability
is a diagonal tensor and the porous media are isotropic.
To investigate the effective stress effect, we consider the intrinsic permeability as absolute permeability
instead which is an effective strain-based model.
where [t.sub.DMK] is the dimensionless time (s), [alpha] a units conversion factor (3.16>[10.sup.-4]), k is the absolute permeability
(md), [sigma] is the interfacial tension (mN/m), and L is the characteristic length of the sample (cm).
of brine was measured on each sample in both horizontal and vertical flow orientations.
where [k.sub.0] is the absolute permeability
of the porous medium, [k.sub.ri] is the relative permeability of phase i, [[micro].sub.i] is the viscosity of phase i, and P represents phase pressure which are the same for different phases here.
Deutsch, "Calculating Effective Absolute Permeability
in Sandstone/Shale Sequences," SPE Formation Evaluation, vol.
The flow in these systems can easily be studied using, for example, the Hagen-Poiseuille approximation (for single-phase flows), which can then be used to estimate the absolute permeability
of the rock sample.
Bijeljic, "Computations of absolute permeability
on micro-CT image," Mathematical Geosciences, vol.
The relative permeability refers to the ratio between the effective permeability of each fluid type and the absolute permeability
of the rock itself, in the cases of saturated multiphase fluid in the rock pores.
Then the absolute permeability
is calculated in the following term :
Figure 6 shows the cross-sectional views of the initial hydrate saturation, porosity, and absolute permeability
in the model.
where [k.sub.n] is the absolute permeability
of grid n, as specified in data block ROCKS and [[zeta].sub.n] is the permeability modification coefficient which can be defined internally or externally and maybe provided as part of the geometry data in block ELEME and then employed to multiply the absolute permeability
[k.sub.n] for each grid in the subdomain.