k = k_1 \, \phi^{m_1} + k_2 \, \phi^{m_2}

where

	effective porosity

This is a complex empirical model which does not directly rely on the Flow Zone Indicator.

Usually, the first component dictates permeability values at low porosities while second component 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