Drilling rig is a metal facility placed over a wellhead for running a drilling tool, a downhole motor or casing pipes in the well and pulling them out.

There are tower and A-type (mast-type) drilling rigs. Most common drilling rigs are the ones of A-type, consisting of two supports, which are kept vertical by leg boxes or a portal facility and stabilizing guy lines. The height of a drilling rig depends on the projected well depth and varies between 9 and 58 meters. The main technical parameters of a drilling rig are height and load capacity.