Standard Drilling Tools
Some of the standard drilling tools commonly used in drilling are briefly described here, together with procedures for, and information on, their use. More detailed descriptions and specifications of particular tools are to be found in the relevant manufacturer's literature.
1. Float Sub
Float subs are always used when drilling pilot holes, and can also be used when drilling 36", 26" (or 22"), and 17 1/2" (or 16") hole sections.
When using float subs, the following procedures shall be carried out:
1. When running in hole, break circulation . . .