Permeability from the
Wylie-Rose Method
This is one of the oldest permeability methods available, and
is reliable when calibrated to core data.
1:
PERMw = CPERM * (PHIe ^ DPERM) / (SWir ^ EPERM)
Where:
CPERM = permeability constant (fractional)
DPERM = porosity exponent (fractional)
EPERM = irreducible saturation exponent (fractional)
PERMw = permeability (millidarcies)
PHIe = effective porosity from any method (fractional)
SWir = irreducible water saturation (fractional)
COMMENTS:
Reference:
1. Using Log-Derived Values of Water Saturation and Porosity,
R.L. Morris, W.P. Biggs, SPWLA, 1967.
2. An Investigation of Permeability, Porosity, and Residual Water
Saturation Relationships,
A. Timur, SPWLA, 1968
Different researchers have found a variety of exponents based
on core analysis studies, and the analyst may find many more in
the literature or company files.
RECOMMENDED
PARAMETERS:
RESEARCHER CPERM DPERM EPERM
OIL GAS
Morris-Biggs 65000 6500 6.0 2.0
Timur 3400 340 4.4 2.0
NUMERICAL
EXAMPLE:
Assume data from Classic Example Sand B.
PHIe = 0.30
SWir = Sw = 0.25
Wylie-Rose formula / Morris-Biggs parameters:
CPERM = 62500
DPERM = 6.0
EPERM = 2.0
PERMw = 62500 * (0.30 ^ 6) / (0.25 ^ 2) = 730 md
Permeability from Morris - Biggs parameters
Permeability from Timur parameters
META/LOG "PERM" Compare
Permeability Calculated from Various Methods
Download this spreadsheet:
SPR-24 META/LOG PERMEABILITY CALCULATOR
Calculate and compare permeability derived from well
logs,
5 Methods.
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