1. Land rigs are used to drill wells on land. They are typically used in areas where the terrain is stable and the drilling depths are relatively shallow. Land rigs can be either portable or stationary, and they may be powered by diesel engines or electric motors.
2. Jack-up rigs are self-elevating rigs that are used to drill wells in relatively shallow waters. They are supported by a number of legs that can be raised or lowered to adjust the rig's height above the waterline. Jack-up rigs are often used in coastal areas or in areas with relatively calm waters.
3. Semi-submersible rigs are floating rigs that are used to drill wells in deep water. They are typically supported by a number of columns that are submerged in the water. Semi-submersible rigs are often used in offshore oil fields, where the water depths can be very deep.
In addition to these main types of rigs, there are also a number of other specialized drilling rigs that are used for specific purposes. These include:
* Drill ships: These are floating vessels that are used to drill wells in deep water. They are similar to semi-submersible rigs, but they do not have the same level of stability.
* Platform rigs: These are fixed structures that are used to drill wells in shallow water. They are typically used in coastal areas or in areas with relatively calm waters.
* Workover rigs: These are rigs that are used to perform maintenance and repair work on existing oil and gas wells. They are typically used on land or on shallow-water platforms.