12 1/4" FA617G , Tricone Rock Bit, Medium hard with higher compressive strength as well as thick and streaks

RECOMMENDED DRILLING PARAMETERS FOR APPLICATION

ROLLER CONE BIT FLUID CIRCULATION 

Drilling fluid passes from the drillstring and out through nozzles in the bit.

As it passes across the face of the bit it carries the drilled cutting from the cones and into the annulus.

The original design for rock bits only allowed the drilling mud to be ejected from the middle of the bit .

This was not very efficient and led to a build up of cuttings on the face of the bit (bit balling) and cone erosion.

A more efficient method of cleaning the face of the bit was therefore introduced.

The fluid is now generally ejected through three jet nozzles around the outside of the bit body .

The turbulence created by the jet streams is enough to clean the cutters and allow efficient drilling to continue.