Page 163 - Drilling Technology in Nontechnical Language

154 Drilling Technology in Nontechnical Language Second Edition

Leaving the bit in after cost per foot starts to increase should seldom, if
ever, be done.

Summary

All major types of drill bits were discussed in this chapter. The relative
advantages and disadvantages of each were covered, demonstrating the
many factors that have to be considered when deciding which drill bit to
use and what drilling parameters to recommend. Drilloff tests, drilling
hydraulics, and grading the dull bit were described. Drillbit economics
and how to calculate the end of the economic life of a bit were examined.

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