Types of Oil Rig and Drilling String ComponentsDrilling rigs like these bore or drill holes into the earth. Usually they drill to find oil or gas. They work both on land and offshore. Some are big and some are relatively small. Big rigs drill very deep holes, 20000 feet (ft), 3000 meters (m) or more; small rigs may only drill to a few thousand ft or meters. People in the oil land describe groups of rigs into 6 basic types: Land, Jack up, Platform, Submersible, Semi-Submersible and Drill Ship.A land rig drills on dry land. There is the most common rig. Light duty rigs drill holes from 3000-5000ft, or 1000-1500m; Medium duty rigs drill to depth ranging from about 4000-10000ft or 12000-3000m; Heavy duty rigs drill holes from about 12000-16000ft deep or 3500-5000m; Ultra-heavy duty rigs drill holes from about 18000-25000ft or more (5500-7500m or more).Crew members can move land rigs on trucks, tractors, trailers, barges, helicopters, heavy rolling gear, skids and in rare cases, on specialized air-pressurized equipment. Small light duty rigs are pretty simple to move.Ultra-heavy land rigs can be difficult to move.