PetroCalcHubFree
Production EngineeringInjection Wells

Waterflood Mobility Ratio Formula

M=krw/μwkro/μoM=\frac{k_{rw}/\mu_w}{k_{ro}/\mu_o}

Waterflood Mobility Ratio calculates waterflood mobility ratio for injection wells workflows in production engineering.

Calculate

How engineers use this formula

Use this formula when the listed inputs (k_rw, mu_w, k_ro, mu_o) are known and the assumptions behind the cited injection wells 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, M equals 1.836735 dimensionless.

k_rwfraction

0.3

mu_wcP

0.7

k_rofraction

0.7

mu_ocP

3

Inputs

k_rw

fraction

Relative Permeability to Water at Residual Oil Saturation

mu_w

cP

Water Viscosity

k_ro

fraction

Relative Permeability to Oil at Initial Water Saturation

mu_o

cP

Oil Viscosity

Outputs

M

dimensionless

Waterflood Mobility Ratio

mu_w

cP

Water Viscosity

Source and review

reviewed

AAPG Wiki. Waterflooding, mobility ratio definition.

Source

Related formulas and calculators

Productivity Index and Straight-Line IPR
Inflow Performance
Vogel Inflow Performance Relationship
Inflow Performance
Rawlins-Schellhardt Gas Deliverability Rate
Inflow Performance
Gas Deliverability Pressure-Squared Drawdown
Inflow Performance
Rawlins-Schellhardt Absolute Open Flow Potential
Inflow Performance
Rawlins-Schellhardt Deliverability Coefficient from Test Point
Inflow Performance