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Annular Velocity from Pump Output Calculator

AV=24.5QDh2Dp2AV = \frac{24.5Q}{D_h^2 - D_p^2}

Enter pump output and annular area or the required geometry inputs. The calculator returns average annular velocity.

Tabular solver

Inputs

Defaults provide a quick field-unit example for the equation.

3 variables

Your input values and calculation stay in this browser.

Engineering reference summary

Calculation context and source notes

Annular velocity from pump output estimates the average drilling-fluid velocity in the annulus from flow rate and annular area.

Use it for hole-cleaning checks, hydraulics reviews, and circulation planning before more detailed rheology calculations.

Solves for

AV (ft/min)

Formula reference

Formula, variables, and default calculation

AV=24.5QDh2Dp2AV = \frac{24.5Q}{D_h^2 - D_p^2}

Reproducible default result

With the default values shown below, the calculation returns AV = 311.111111 ft/min. Defaults demonstrate the implementation; they are not recommended field values.

Qgpm

600

D_hin

8.5

D_pin

5

Input definitions

Q

gpm

Circulation Rate

D_h

in

Hole or Casing Inside Diameter

D_p

in

Pipe Outside Diameter

Output definitions

AV

ft/min

Annular Velocity

Q

gpm

Circulation Rate

D_h

in

Hole or Casing Inside Diameter

D_p

in

Pipe Outside Diameter

Engineering use, assumptions, and limits

Use it for hole-cleaning checks, hydraulics reviews, and circulation planning before more detailed rheology calculations.

Assumptions

  • Flow rate is steady during the calculation.
  • The annular area represents the section being evaluated.
  • Velocity is an average value, not a local velocity profile.

Limitations

  • Does not account for eccentricity, cuttings bed development, or non-Newtonian velocity profiles.
  • Not a replacement for detailed hole-cleaning modeling in deviated wells.

Common mistakes

  • Using pipe ID instead of annular area.
  • Comparing average velocity directly to critical transport limits without considering inclination and rheology.

Source and record status

Source metadata identifies the relationship implemented by the calculator. Check the cited edition, unit basis, and scope against the engineering case before operational use.

reviewedguidance published

Lyons, W.C., Carter, T. and Lapeyrouse, N.J. 2012. Formulas and Calculations for Drilling, Production and Workover, 3rd Edition, Page 10.

Open source reference

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