
56
B
Breakout Block
B
reakout Block: A plate that ts in the rotary table and holds the drill bit
while it is being unscrewed from the drill collar.
Breakout Cathead: A device attached to the catshaft of the drawworks, used
as a power source for the tongs that is used in unscrewing the drill pipe; usu-
ally located opposite the driller’s side of the drawworks.
Breakout (Drilling): An enlargement of the borehole.
Break Point: The point in time when the efuent contaminant concentration
in a controlled air stream (usually an adsorption device) begins to increase
as the adsorbing device becomes saturated.
Breakthrough: (1) A ood front breaking