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Reservoir EngineeringPermeability and Flow

Relative Permeability from Effective Permeability Formula

kr=keffkk_r = \frac{k_{eff}}{k}

Relative Permeability from Effective Permeability calculates relative permeability for permeability and flow workflows in reservoir engineering.

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How engineers use this formula

Use this formula when the listed inputs (k_eff, k_abs) are known and the assumptions behind the cited permeability and flow 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_r equals 0.3 dimensionless.

k_effmd

60

k_absmd

200

Inputs

k_eff

md

Effective Permeability to the Flowing Phase

k_abs

md

Absolute Permeability

Outputs

k_r

dimensionless

Relative Permeability

k_eff

md

Effective Permeability to the Flowing Phase

k_abs

md

Absolute Permeability

Source and review

reviewed

DrillingFormulas.com. Effective and Relative Permeability.

Source

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