Equipment — Rig Classification

Types of Drilling Rigs

Different environments require fundamentally different rig designs. Water depth, geological conditions, and economics determine which type is deployed.

Land Rig

Onshore

Truck-mounted or skid-mounted rigs that drill on land. Range from shallow exploration wells to deep shale plays. The most common rig type worldwide.

Depth capacity500 – 35,000 ft

Mob cost$10K – $500K

Jack-up Rig

Shallow Offshore

Three or four retractable steel legs punch into the seabed, jacking the hull above wave height. The workhorse of shallow-water drilling.

Depth capacityup to 35,000 ft

Water depth≤ 400 ft

Day rate$80K – $180K/day

Semi-submersible

Deepwater

Pontoons flooded with seawater provide stability below the wave zone. Anchored or dynamically positioned. Used in deepwater plays.

Depth capacityup to 40,000 ft

Water depthup to 12,000 ft

Day rate$250K – $500K/day

Drillship

Ultra-deepwater

A purpose-built ship with a moon pool for the drill string. Dynamic positioning keeps it on location without anchors.

Depth capacity40,000+ ft

Water depthup to 15,000 ft

Platform Rig

Fixed / Production

Fixed to the seabed via steel jacket or concrete gravity base. Permanently installed, drilling dozens of wells from one location.

Water depthup to 1,500 ft

Well capacity20 – 60+ wells

Submersible / Barge

Swamp / Shallow

Flooded hull rests on the seabed in very shallow water — bays, swamps, and marshes. Common along the Gulf Coast and Southeast Asia.

Water depth≤ 70 ft

TerrainMarsh, bay, lake

Comparison

Jack-Up vs Semi-Submersible

The two most common offshore rig types are often compared directly since they can overlap in shallower water depths.

	Jack-up Rig	Semi-Submersible
Water Depth	Up to ~400 ft	400 – 12,000 ft
Stability Method	Legs rest on seabed	Floats, held by anchors or DP
Mobility	Towed, legs must jack down/up	Can reposition more easily
Day Rate	Lower ($80K–$180K)	Higher ($250K–$500K)
Best For	Shallow shelf drilling	Deepwater exploration & development