Annular velocity
From Wikipedia, the free encyclopedia
Annular velocity is the speed of the drilling fluid's movement in a column called an annulus in oil wells.[1] It is commonly measured in feet per minute (ft/min) or meters per minute (m/min). Annular velocity is often abbreviated as AV, though this is not exclusively so, as AV also refers to apparent viscosity which is calculated from rheometer readings from tests that the mud engineer performs.
For this article, annular velocity is described, as used in drilling fluid applications in the oil exploration industry. There may be other applications in other fields of study such as fluid mechanics (the study of the movement of fluid) or fluid dynamics (the study of the flow of fluid).
Determination
The annular velocity can be calculated using one of the following formulas.
Or
Where:
- AV = annular velocity in Ft/min (feet per minute)
- PObpm = pump output in bpm (barrels per minute) 1 barrel = 42 gallons
- POgpm = pump output in gpm (gallons per minute) 1 gallon = 0.0238095238 barrels
- ID2 = inside diameter of the wellbore or casing, squared
- OD2 = outside diameter of the drill pipe or tubing, squared
- 1029.4 = A conversion factor constant used to calculate the volume between the outside of a tube within the inside of another tube, using barrels.
- 24.5 = A conversion factor constant used to calculate the volume between the outside of a tube within the inside of another tube, using gallons.
- Pump Output = Refers to the measurement of the quantity of a fluid (to put that fluid in motion).
