Lead angle
In the old days (pre 1985) it was normal practice to allow a “lead angle”
when kicking off. Since roller cone bits used with rotary assemblies tend to
“walk to the right”, the wells were generally kicked off in a direction
several degrees to the left of the target direction. In extreme cases the lead
angles could be as large as 20°.
The greatly increased use of steerable motors and PDC bits for rotary
drilling have drastically reduced the need for wells to be given a “lead
angle”. Many wells today are deliberately kicked off with no lead angle
(i.e. in the target direction).
In the old days (pre 1985) it was normal practice to allow a “lead angle”
when kicking off. Since roller cone bits used with rotary assemblies tend to
“walk to the right”, the wells were generally kicked off in a direction
several degrees to the left of the target direction. In extreme cases the lead
angles could be as large as 20°.
The greatly increased use of steerable motors and PDC bits for rotary
drilling have drastically reduced the need for wells to be given a “lead
angle”. Many wells today are deliberately kicked off with no lead angle
(i.e. in the target direction).
No comments:
Post a Comment