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Reservoir EngineeringPermeability and Flow

Buckley-Leverett Saturation Front Velocity Formula

vS=utϕdfwdSwv_S = \frac{u_t}{\phi}\frac{df_w}{dS_w}

Buckley-Leverett Saturation Front Velocity calculates saturation front velocity for permeability and flow workflows in reservoir engineering.

Calculate

How engineers use this formula

Use this formula when the listed inputs (u_t, phi, dfw_dSw) 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, v_S equals 12.5 ft/day.

u_tft/day

1

phifraction

0.2

dfw_dSw1/fraction

2.5

Inputs

u_t

ft/day

Total Darcy Velocity

phi

fraction

Porosity

dfw_dSw

1/fraction

Fractional Flow Derivative with Respect to Water Saturation

Outputs

v_S

ft/day

Saturation Front Velocity

u_t

ft/day

Total Darcy Velocity

phi

fraction

Porosity

dfw_dSw

1/fraction

Fractional Flow Derivative with Respect to Water Saturation

Source and review

reviewed

Abushaikha et al. (2021). Buckley-Leverett Theory for a Forchheimer-Darcy Multiphase Flow Model with Phase Coupling. Mathematical and Computational Applications, 26(3), 60.

Source

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