Dogleg Definition



A particularly crooked place in a wellbore where the trajectory of the wellbore in three-dimensional space changes rapidly.

While a dogleg is sometimes created intentionally by directional drillers, the term also refers to a section of the hole that changes direction faster than anticipated or desired, usually with harmful side effects.

In surveying wellbore trajectories, a standard calculation of dogleg severity is made, usually expressed in two-dimensional degrees per 100 feet [degrees per 30 m] of wellbore length.

Generally, intentional doglegs are limited to 3-3.5 degrees/ 30m.

Higher doglegs may create problems , such as key seating or damage to the drillstring.