One of the Absolute permeability models based on the pipe conduit or multigrain pack:
k = \frac{d^2}{72 \cdot \tau^2} \cdot \frac{(\phi_f -\phi_{f0})^3}{( 1 - \phi_f+\phi_{f0})^2} |
where
| absolute permeability | |
| effective formation porosity | |
| porosity cut-off | |
| grain size | |
| pore channel tortuosity |
k = 1014.24 \cdot FZI^2 \cdot \frac{\phi^3}{( 1 - \phi )^2} |
where
| effective porosity | |
| Flow Zone Indicator |
The Flow Zone Indicator is considered to be constant within a given lithofacies.
This correlation was historical the first physical permeability model, based on the fluid flow in porous media with simplified structure consisted of a bunch of independent capillaries with various diameters.
Later on it's been upgraded to percolation through inter-grain porous space which specifies the Flow Zone Indicator as a function of grains size distribution, grain shape and packing.
The most popular correlation with a mean grain size is given as:
FZI = a \cdot D_g |
where coefficient is a function of grain shape, packing, inter-grain clay and, as a consequence, of inter-grain effective porosity
.
Petroleum Industry / Upstream / Subsurface E&P Disciplines / Petrophysics / Absolute permeability / Absolute permeability @model
J. Kozeny, "Ueber kapillare Leitung des Wassers im Boden." Sitzungsber Akad. Wiss., Wien, 136(2a): 271-306, 1927.