Reservoir EngineeringPermeability

Binary Power-Average Effective Permeability Formula

k_{eff}=\left[p_{ss}k_{ss}^m+(1-p_{ss})k_{sh}^m\right]^{1/m}

Binary Power-Average Effective Permeability calculates binary power-average effective permeability for permeability workflows in reservoir engineering.

Calculate

How engineers use this formula

Use this formula when the listed inputs (p_ss, k_ss, k_sh, m_exp) are known and the assumptions behind the cited permeability relationship match the engineering case being checked.

Assumptions

Input values are representative for the well, reservoir, fluid, or equipment case being evaluated.
The declared units match the field-unit constants used in the formula.
The cited formula applies to the selected petroleum engineering workflow.

Limitations

The calculation does not replace a full engineering model or operating procedure.
Accuracy depends on the source correlation, assumptions, input quality, and unit consistency.

Common mistakes

Mixing unit systems without converting the inputs.
Using default example values as field recommendations.
Applying the formula outside the source assumptions.

Default example

Using the default inputs, k_eff equals 90.11185 mD.

p_ssfraction

0.7

k_ssmD

200

k_shmD

m_expdimensionless

0.25

Inputs

p_ss

fraction

Sand or High-Permeability Fraction

k_ss

Sand or High-Permeability Component

k_sh

Shale or Low-Permeability Component

m_exp

dimensionless

Power-Average Exponent

Outputs

k_eff

Binary Power-Average Effective Permeability

p_ss

fraction

Sand or High-Permeability Fraction

k_ss

Sand or High-Permeability Component

k_sh

Shale or Low-Permeability Component

Source and review

reviewed

Estimation of the Effective Permeability of Heterogeneous Porous Media by Using Percolation Concepts, Masihi, M., Gago, P.A., King, P.R. (2016)

Masihi, M., Gago, P.A., and King, P.R. 2016. Estimation of the Effective Permeability of Heterogeneous Porous Media by Using Percolation Concepts. Transport in Porous Media 114, 169-199.

Source