Bent Sub And Mud Motor In Directional Drilling
The most commonly used technique for changing the trajectory of the wellbore uses a piece of equipment known as a “bent sub,” which is used only in directional well drilling (Figure 1) with a Positive Displacement (mud) motor.

What is The Bent Sub In Directional Drilling

A bent sub (Drilling Subs) is a short length of pipe with a diameter approximately the same as the collars and threaded connections on either end.
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