NOV TDS-11HD top drive

The TDS-11HD is the high-torque 500-ton drive in the TDS-11 family. Two 600 horsepower induction motors give it 1,200 horsepower and 58,800 ft-lb of continuous torque at 110 rpm. You buy it when the well needs more torque than an 800 horsepower TDS-11SA, not when you need more than 500 tons of hoisting.

Hoisting capacity matches the SA and the SH. The derrick clearance often does not. Published working height is 21 feet 6 inches with a 120-inch bail, and weight is about 30,000 pounds. A mast that cleared an SA can be short once this bail and this drive are in it. The pipe handler is still a PH-75. Casing-running-tool readiness is listed as optional, so ask if that package is on the unit.

The SA is 800 horsepower and 37,100 ft-lb. The SH is the middle torque rating at 54,600 ft-lb. The HD is 1,200 horsepower and 58,800 ft-lb. An SA that has been through a 1,200 or 1,400 horsepower upgrade kit can look like an HD and is not one. The kit and the serial number are the difference.

Measure the bail and the working height against the mast you will hang it in. Confirm both motors are 600 horsepower induction motors and that makeup and breakout are the 62,500 and 75,000 ft-lb the brochure lists for this model. The rig’s drives have to be sized for 1,200 horsepower, not for the original 800.