Air-saturated formation permeability to air sweep with Klinkenberg correction or Knudsen correction:
There is a statistical correlation between absolute permeability
k_a and formation porosity
\phi which can be approximated by various permeability-porosity models.
(1)
k_a = k_{air}
Absolute permeability stays constant for small pressure variations but in a wide range of pressure variations the dependence on ambient pressure c_r(p) can not be neglected and should be tabulated from laboratory core tests or estimated from permeability-pressure correlations.
See also
Petroleum Industry / Upstream / Subsurface E&P Disciplines / Petrophysics
[Permeability] [Relative permeability] [Absolute permeability @model] [ Basic reservoir properties ]