Production EngineeringWell Performance
Stokes Law Droplet Settling Velocity Formula
Stokes Law Droplet Settling Velocity calculates terminal droplet settling velocity for well performance workflows in production engineering.
How engineers use this formula
Use this formula when the listed inputs (g, D_p, rho_p, rho_c, mu_c) are known and the assumptions behind the cited well performance 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_t equals 0.007301 m/s.
gm/s2
9.80665
D_pm
0.00002
rho_pkg/m3
700
rho_ckg/m3
30
mu_ccP
0.02
Inputs
g
m/s2Gravitational Acceleration
D_p
mDroplet Diameter
rho_p
kg/m3Droplet Phase Density
rho_c
kg/m3Continuous Phase Density
mu_c
cPContinuous Phase Viscosity
Outputs
V_t
m/s
Terminal Droplet Settling Velocity
g
m/s2
Gravitational Acceleration
D_p
m
Droplet Diameter
rho_p
kg/m3
Droplet Phase Density
rho_c
kg/m3
Continuous Phase Density
mu_c
cP
Continuous Phase Viscosity
Source and review
reviewedGPSA Engineering Data Book, Section 7 Separation Equipment, Eq. 7-5.
SourceRelated formulas and calculators
Effective Wellbore Radius of a Well in Presence of Uniform Flux Fractures
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Effective Wellbore Radius of a Horizontal Well – Method 1 (Anisotropic Reservoirs)
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Effective Wellbore Radius of a Horizontal Well – van der Vlis et al. Method
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