k = permeability, cm2 (= 1013 x 108 Darcie)
Φ = effective porosity
Sv = total granular surface / unit volume of the reservoir, cm2/cm3
The following figure shows the ratio of grain size (Fig. 1) and classification (Fig. 2): porosity and permeability.
(Fig.1) Porosity, permeability and grain size. The porosity is not affected by grain size but the permeability increases with grain size.