Averaging Pore Statistics of Two-Dimensional Images for Predicting Permeability

Effective medium theory (EMT) was employed to estimate permeability of fine-grained estuarine sediments. X-radiographs were taken of sediment cores collected in the field and from laboratory aquaria, designed to mimic the benthic environment of an estuary. Image analysis of two-dimensional X rays provided values of pore parameters required by the EMT model, which include pore body and throat radii, pore throat length, porosity, and the interconnectivity of pores. Values of these parameters were used to quantitatively calculate permeability based upon Darcyʹs law. The EMT model with an arithmetic mean for averaging pore parameters predicted permeability 1 order of magnitude higher than measured values. The harmonic mean for averaging pore parameters in the EMT model provided estimates of permeability similar to measured values.