Buoyancy Factor

In well drilling, the buoyancy factor, abbreviated as BF, a dimensionless number, is used to account for the buoyant effect of the drilling fluid on the drill string, casing, and other downhole equipment.  The buoyant force reduces the effective weight of the drill string in the wellbore, affecting both the load on the drilling rig and the downhole equipment's behavior.

 

Buoyancy Factor formula
\( BF \;=\;   65.5 - MW  \;/\; 65.5 \)     (English) \( BF \;=\;   7.85 - MW  \;/\; 7.85 \)     (Metric)
Symbol	English	Metric
\( BF \) = Buoyancy Factor	\(dimensionless\)	\(dimensionless\)
\( MW \) = Mud Weight (ppg)	\(lbm\;/\;gal\)	\(kg\;/\;l\)