TDS-11SA and TDS-11HP Top Drive Systems

Objective

To advise customers of an available upgrade for the TDS-11SA and TDS-11HP Top Drives to convert from 800 HP to 1200 HP by adding 600 HP drilling motors, in addition to upgrading the gear box, power service loops, and variable frequency drive (VFD).

Description

NOV has developed an upgrade kit to convert existing TDS-11SA and TDS-11HP 800 HP units to 1200 HP rated units. The kit includes important upgrades to the gearbox, motors, and the cooling system to safely accommodate the increased performance. Critical items including bearings, bearing housings, gears, and the gearbox cover, will be upgraded to ensure the top drive design integrity is maintained for the additional loading through the increase in horsepower. Once implemented, the top drive will be fully rated to the motor performance curves shown in Figure 1.

Solution

This upgrade kit includes bearings, gears, main body cover, motors, blowers, oil cooler, encoder, and all applicable hoses, cables, and bracketry. Upgrading the inverters in the VFD house and the power service loops ensures the tool will consistently run at the higher continuous rated torque with no power loss. NOV will not support VFD modifications by third parties, as outlined in Product Bulletin 1000033750-PIB. Service loops and VFD configurations will be reviewed at the time of request due to the variety of configurations deployed in the field.

With a 5-year interval overhaul schedule, this fully engineered upgrade will maintain the same 20 year expected service life, under normal operating conditions, as a brand-new TDS-11SA or TDS-11HP Top Drive. Due to the complexity of the motor housing modifications, this upgrade must be performed at an NOV Rig Systems Service Center. Once upgraded, the 1200 HP top drive will be fitted with a new nameplate with the upgraded model name: TDS 11SAE.Initially the upgrade will be available for API 500 / 505 Class 1 Div 2 or Zone II applications, with the ATEX, IECEX versions following.

Caution: Upgrading the TDS-11SA with larger motors only and not performing the gear box, service loop, or VFD upgrades is not recommended by NOV as this could lead to premature bearing and gear failure due to the deflections, fatigue, and heat induced by running at higher speeds and torque than designed for. This type of unapproved modification to the top drive system could not only reduce tool life but will void warranty.