A drilling rig is a mechanical device that drills holes in the ground, either as a large, outdoor water, oil, or gas well drilling rig or as a small, one-person, moveable piece of equipment called an auger. Augers can be used to sample underground deposits or for installing underground production equipment, such as underground machinery, instruments, pipelines, and shafts. They may be mobile units mounted on trucks, trailers, or tracks, or more permanently mounted on land or offshore structures (such as drilling rigs, commonly referred to as "offshore oil rigs", although not designed to contain drilling rigs). The term "drilling rig" generally refers to equipment that drills into the Earth's crustal layers.
