Apparatus and method for moving track guided equipment to and from a track

摘要

Apparatus and method for moving the top drive of a top drive subterranean drilling system from the drilling track extending along the length of the derrick includes a movable working track, a secondary track pivotably connected to the working track, and a power assembly. The working track is connected to the derrick and is transversely movable between a first position in which the working track is aligned with the drilling track and a second position in which the working track is transversely displaced from alignment with the drilling track. The secondary track is pivotable between a skewed position in which the secondary track is not transversely coplanar with the drilling track and working track and an in-line position in which the secondary track is about transversely coplanar with the drilling track and the working track. The secondary track is transversely movable with the working track so that the secondary track is aligned with the drilling track when the working track is in the second position. The power assembly pivots the secondary track from the skewed position to the in-line position and transversely moves the secondary track in the in-line position and the working track to the second position of the working track to align the secondary track with the drilling track; and reverses the sequence to return the working track to alignment with the drilling track.