Oil Rigs: Types and Where They're Used

When people say "oil rigs" they usually picture a big drilling derrick in the middle of a desert. But in reality, oil rigs come in many different types, each designed for a specific job and environment. The right rig for the job depends on where you're drilling, how deep you're going, and what you're drilling for.

Onshore Land Rigs

These are the rigs you see on land — in the Middle East, the North Sea's onshore fields, the Permian Basin in Texas, and oilfields all over the world. Onshore rigs range from small truck-mounted workover rigs to massive skid-mounted rigs that drill 6,000 meters deep. Most onshore rigs are mobile to some degree, because oil companies drill multiple wells in a field and need to move the rig around.

Offshore Rigs

Offshore drilling is a whole different world. Rigs here have to deal with saltwater, waves, wind, and the logistics of supplying an operation that's miles from shore. There are two main types: fixed platforms (which sit on the ocean floor) and floating rigs like drillships and semi-submersibles. Offshore rigs are much more expensive than onshore rigs — a single deepwater drillship can cost half a billion dollars.

Workover Rigs

Not all oil rigs are for drilling new wells. Workover rigs are used to service existing wells: pulling the tubing, repairing pumps, stimulating the reservoir, or plugging and abandoning old wells. These are usually smaller truck-mounted rigs, because they don't need the same capacity as a drilling rig. Workover rigs are busy all the time — every producing well needs maintenance sooner or later.

FAQ

Q: How many people work on an oil rig?
A: A typical onshore drilling crew is 8-15 people, working 12-hour shifts. Offshore crews are larger, usually 50-100 people, because of the extra logistics and safety requirements.