Permeability‐porosity relationship: A reexamination of the Kozeny‐Carman equation based on a fractal pore‐space geometry assumption

Received 4 November 2005; revised 15 December 2005; accepted 20 December 2005; published 31 January 2006. [1] The relationship between permeability and porosity is reviewed and investigated. The classical Kozeny-Carman approach and a fractal pore-space geometry assumption are used to derive a new permeability-porosity equation. The equation contains only two fitting parameters: a Kozeny coefficient and a fractal exponent. The strongest features of the model are related to its simplicity and its capability to describe measured permeability values of different non-granular porous media better than other models. Citation: Costa, A. (2006), Permeability-porosity relationship: A reexamination of the Kozeny-Carman equation based on a fractal pore-space geometry assumption, Geophys. Res. Lett., 33, L02318, doi:10.1029/2005GL025134. [2] Estimation of permeability is of pivotal importance for the description of different physical processes, such as hydrocarbon recovery, fluid circulation in geothermal systems and degassing from vesiculating magmas. Mainly due to the intricate geometry of the connected pore space and to the complexity of porous media, it has been very difficult to formulate satisfactory theoretical models for permeability. One of the most largely used methods remains the KozenyCarman approach. [3] In this study we briefly review the Kozeny-Carman model. Then, using the hypothesis of a fractal pore-space geometry and the empirically based Archie law, we reformulate that model without introducing the concept of hydraulic radius and obtain a new simple permeabilityporosity equation. As an application, we used the obtained equation to predict permeability of fiber mat systems and of vesicular rocks.