Rotary Table for Drilling Rigs: 10 FAQs on Specs, Sizes & Maintenance

1. What is a rotary table on a drilling rig?

A rotary table is a mechanical device on a drilling rig that provides rotational torque to the drill string through a master bushing and kelly bushing. While top drive systems are common on new rigs, rotary tables remain essential on conventional rigs and workover operations.

2. What sizes do rotary tables come in?

Common sizes: 17-1/2", 20-1/2", 27-1/2", 37-1/2", and 49-1/2" opening diameters. For standard oil wells to 5,000m, a 27-1/2" table suffices. Larger casing programs require 37-1/2" or 49-1/2".

3. What is the load capacity?

A 27-1/2" rotary table typically supports 5,850 kN static load and 1,340 kN dynamic load. Larger models support 700+ tons.

4. What are the main components?

Housing (cast steel), main bearing (roller bearings), spiral bevel gear set, master bushing, pin drive bushings, and locking mechanism.

5. What spare parts are commonly needed?

Master bushings, pin drive bushings, main bearing sets, pinion/main gear sets, oil seals, and locking mechanism parts. Gears are case-hardened 20CrMnTi or equivalent alloy steel.

6. How is maintenance performed?

Daily: oil level check. Weekly: bushing wear and bolt torque. Monthly: oil analysis. Quarterly: oil change and gear inspection. Annually: full teardown with bearing clearance and gear contact verification.

7. What lubrication system is used?

Splash lubrication or forced oil circulation in an oil bath. Oil changed every 1,000 hours. Forced circulation systems include pumps and filters for improved cooling.

8. Can a rotary table be used with a top drive?

Yes. With a top drive, the rotary table serves as backup rotation and for connection make-up. It can be locked during top drive operations.

9. How to select the right size?

Base selection on maximum casing/tool diameter and load requirements. For 5,000m wells, 27-1/2" is standard. For deep wells or large casing, use 37-1/2" or 49-1/2".

10. What is the lead time?

Standard lead time: 60-90 days depending on size and configuration, with optional master bushings, pin drive bushings, and hydraulic locking systems.