Annular Velocity for a Given Circulation Rate

Annular velocity is the speed at which the drilling fluid (mud) travels up the annulus between the drill pipe and the borehole wall.  

 

Annular Velocity for a Given Circulation Rate Formula
\( AV \;=\; \dfrac{ 24.5 \cdot Q }{ C_{id}^2 - C_{od}^2 } \)
Symbol	English	Metric
\( AV \) = Annular Velocity	\(ft\;/\;min\)	-
\( Q \) = Circulation Rate	\(gpm\)	-
\( C_{id} \) = Casing ID	\(in\)	-
\( C_{od} \) = Casing OD	\(in\)	-