In the majority of practical cases the low permeability values have very weak dependence on low porosity values.
This can be fairly discounted from potential production and considered as no-flow rocks with zero permeability thus leading to the following permeability modification:
| (1) | k = \left\{ \begin{aligned} k(\phi) , \, \phi> \phi_0 \\ 0 , \, \phi \le \phi_0 \\ \end{aligned} \right. |
where \phi_0 is minimal porosity contributing to flow.
See also
Petroleum Industry / Upstream / Subsurface E&P Disciplines / Petrophysics
[ Basic reservoir properties ]