Underreaming
Underreaming procedures vary from tool to tool. However, it shall be verified that:
- the tool is function tested with the mud pumps on surface before running in
- the cutters are secured inside the tool body with a small piece of rope or tape to ensure a safe trip in the hole without damage to the cutters
- pump pressure gradually increases while the tool is rotating until the cutter arms cut to the maximum diameter
- a constant drilling weight is maintained while underreaming. Do not slack off intermittently and do . . .