| (1) | k = k_1 \, \phi^{m_1} + k_2 \, \phi^{m_2} |
where
This is a complex empirical model which does not directly rely on the Flow Zone Indicator.
Usually, the first component k_1 \, \phi^{m_1} dictates permeability values at low porosities while second component k_2 \, \phi^{m_2} takes over at high porosities.
This allows to cover a wider range of porosity variations comparing to single-component power law permeability @model.
This model was thought to be empirical for a very long time but later on it was shown that it has a physical meaning within the frame of fluid percolation through a porous medium with fractal structure.
See also
Petroleum Industry / Upstream / Subsurface E&P Disciplines / Petrophysics / Absolute permeability / Absolute permeability @model