Characterizing average permeability in oil and gas formations Academic Article uri icon


  • Permeability in a formation frequently follows a unimodal probability distribution. In many formations, particularly sedimentary ones, the permeability distribution is similar to the log-normal distribution. Theoretical considerations, field cases, and a reservoir simulation example show that the medium, rather than the arithmetic mean, is the appropriate measure of central tendency or average value of the permeability distribution in a formation. Use of the correct estimate of average permeability is of particular importance in the classification of tight gas formations under statutes in the 1978 Natural Gas Policy Act (NGPA).

author list (cited authors)

  • Rollins, J. B., Holditch, S. A., & Lee, W. J.

complete list of authors

  • Rollins, JB||Holditch, SA||Lee, WJ

publication date

  • March 1992