Page 445 - Practical Well Planning and Drilling Manual

Section 3 revised 11/00/bc 1/17/01 12:00 PM Page 421

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3.7

Directional Drilling

This subject was covered in Section 2 from a well planning view-
point. There were many topics covered in Section 2 that are also rele-
vant to the wellsite operation (such as selecting the appropriate length
of monel drill collars for magnetic surveys). Refer to Section 2.3 for
information on directional drilling, or check the Table of Contents or
Index for related subjects.
The material presented here only concentrates on the directional
aspects of bottom hole assemblies. For questions of preventing down-
hole failures relating to tool joint damage, casing wear, and drillstring
fatigue, refer to Section 1.5.2, “Dogleg Severity Limits—Combined
Buildup and Turn Rate.”

3.7.1. Rotary Bottom Hole Assemblies—General Points

Most rotary drilling is done in a tangent section. In this situation,
designing a suitable BHA is straightforward. Where deviation work is
in hand there will usually be a directional driller on site who will rec-
ommend what to run in the bottom hole assembly.

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