Pilot Mill
Pilot mills are used for milling the following equipment/ material: adapters, liners, casing, swaged casing, stuck drillpipe, wash pipe.
The procedure for milling with a pilot mill is as follows:
1. Rotate the string above the fish to establish the free rotating torque.
2. While rotating approximately 30 rpm, slowly enter the fish. Torque shall increase when the mill blades start milling on the fish.
3. Add approximately 2 000 lbs weight and stop rotating suddenly. A gradual slowdown or spin indicates that the mill has entered the fish . . .