Page 195 - Drilling Technology in Nontechnical Language

186 Drilling Technology in Nontechnical Language Second Edition

Fig. 8–8. Tangent rotary assembly

A locked assembly can also be run with a slightly undergauge second
stabilizer, which would give an increased build tendency.

Rotary steerables

The approach in each different tool is the same, though the mechanics
vary. The rotary steerable is run immediately above the bit, a kind of
replacement NB stab. Modern tools will have three blades positioned
close to the drill bit, much like stabilizer blades. These blades move in and

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