Page 431 - Practical Well Planning and Drilling Manual

Section 3 revised 11/00/bc 1/17/01 12:00 PM Page 407

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3.6

Drillbits

Section 2, “Well Programming,” examined offset bit runs: how to
analyze them to make the best bit choice for the next well and the
effect of BHA choice on bit choice. This section now deals with the
practical aspects of the bit run.
Even though we have done as much as we can at the well planning
stage, the final bit choice will normally be made on the wellsite. The
start of the run may be at a different place than was anticipated in the
drilling program. The performance and grading of the previous bit out
may cause a revision in thinking.

3.6.1. Alternative Bit Choices

If depth in is not as planned. If a bit is pulled before the planned
end of its run, then by reading the recommendations and examining
the hole section summary it may be clear what kind of bit will be best
to run next. (See Section 1.1.2, “Hole section summaries.”) Usually

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