摘要 |
A method and apparatus for aligning a wellhead or BOP stack with a mast assembly comprising a sensor which provides an initial alignment between a mast and a wellhead or BOP stack. A mast assembly is transported to a well site by a rig carrier which positions the mast assembly adjacent a wellhead, or BOP stack. The mast assembly is raised to an upright position whereby a rear portion of the mast extends over the wellhead. Sensors mounted to the top drive, crow, well head, or mast can be used to align the mast with the wellhead. |