PetroCalcHubFree
Reservoir EngineeringPermeability and Flow

Corey Water Relative Permeability Formula

krw=krwo(Sw)nwk_{rw} = k_{rw}^o(S_w^*)^{n_w}

Corey Water Relative Permeability calculates water relative permeability for permeability and flow workflows in reservoir engineering.

Calculate

How engineers use this formula

Use this formula when the listed inputs (k_rw_end, S_wn, n_w) 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_rw equals 0.0375 dimensionless.

k_rw_enddimensionless

0.3

S_wnfraction

0.5

n_wdimensionless

3

Inputs

k_rw_end

dimensionless

Endpoint Water Relative Permeability

S_wn

fraction

Normalized Water Saturation

n_w

dimensionless

Corey Water Exponent

Outputs

k_rw

dimensionless

Water Relative Permeability

k_rw_end

dimensionless

Endpoint Water Relative Permeability

S_wn

fraction

Normalized Water Saturation

n_w

dimensionless

Corey Water Exponent

Source and review

reviewed

Petroleum Office. Corey and LET Relative Permeability Models.

Source

Related formulas and calculators

Average Permeability for Linear Flow in Layered Beds
Permeability
Average Permeability for Linear Flow - Series Beds
Permeability
Average Permeability for Parallel-Layered Systems
Permeability
Average Permeability in Radial Systems
Permeability
Klinkenberg Apparent Gas Permeability
Permeability
Jones-Owens Klinkenberg Slip Factor
Permeability