Enter the pump output and the annular capacity into the calculator to determine the annular velocity.

Annular Velocity Formula

The following equation is used to calculate the Annular Velocity.

AV = PO * AC
  • Where AV is the annular velocity (ft/min)
  • PO is the pump output (bbl/min)
  • AC is the annular capacity (bbl/ft)

To calculate annular velocity, multiply the pump output by the annular capacity.

What is an Annular Velocity?


An annular velocity measures the linear rate of fluid (typically oil) moving through an annular drilling setup.

How to Calculate ?

Example Problem:

The following example outlines the steps and information needed to calculate the Annular Velocity.

First, determine the pump output. In this example, the pump output is found to be 12.5bbl/min.

Next, determine the annular capacity. In this case, the annular capacity is measured to be .25 bbl/ft.

Finally, calculate the Annular Velocity using the formula above:

AV = PO * AC

AV = 12.5 * .25

AV = 3.125 ft/min