Research Article

Study of Radial Vibration Impact on Friction and Torque of Rotary Drill String

Table 1

Section parameters of different joints models.

Tool modelSection parameters
Major radius a (×10−3m)Minor radius b (×10−3m)Ratio of major radius to minor radius of the joint elliptical section

Common joint16161
Drill pipe1617 joint17161.0625
Friction1618 joint18161.125
Reduction joints1619 joint19161.1875