Theory 32/Transport & flow/Permeability
Permeability Follows Pore Throats
The claim
The permeability of a porous medium is set by the ratio of pore throat to grain size, so two sands of equal porosity can differ by orders of magnitude.
01Mechanism
Flow is limited by the narrowest constriction along a path, not by average pore size.
02Prediction
Permeability should track the ratio.
03Refutation
Permeability tracking porosity would remove throat geometry.