Top drives have been adopted as standard equipment in the oil patch. While there are many well known providers for this important component, most drillers can count them on one hand. One small service company, Global Drilling Support (GDS) International, has taken lessons learned and developed a new high-performance top drive that can be customized per the specific needs of each application.

Keith Holliday, president and CEO, and Paul Nicholson, vice president, are top drive veterans, with more than 35 combined years of experience in manufacturing, servicing, rebuilding, and operating top drives. Holliday and Nicholson originally founded GDS as a service company in 2008 focused on repairing and rebuilding top drives and providing parts service for all major brands. In 2009, the company’s focus took a different direction as its owners began to consider the development of a new top drive design.

Having had years of experience dealing with a number of chronic problems while either servicing or operating top drives, Holliday and Nicholson set out to build a tema that could produce a top drive that would effectively address many of the issues that often plague existing designs. The result of their efforts was the company’s Global Drilling Machine (GDM) line of top drives. This line of top drives represents an evolutionary upgrade to existing designs formulated to deliver a combination of high torque, reliability, and maintainability. To meet a wide range of market applications, the GDM line includes a range of top drives from 500 tons to 800 tons.

Design concept

The GDM top drive

The GDM top drive was conceived to provide ready access to all common maintenance areas, adding to the speed and ease of service and repair operations. (Images courtesy of GDS International)

The design of the GDM line of top drives was directed by a core set of objectives – providing a rugged mechanical design with a minimum number of failure points that was also capable of producing both high-torque and high-rpm output. In addition, the GDM top drive was conceived to provide ready access to all common maintenance areas, adding to the speed and ease of service and repair operations. Personnel safety also was factored into the GDM envelope, with built-in work platforms supplied as standard for the top drives. Manufactured under an API 8C License (Cert. No. 8C_0161), GDM top drives offer a number of key features. Both the 500- and 800-ton models use industry-standard GE drive motors, with a unique self-aligning cou- pling, which adds significantly to motor life. These top drives also incorporate a solid drive pinion supported from both the top and the bottom for increased reliability. Another key element in the GDM design is its use of a robust helical gear assembly, which contributes to the units’ higher torque capabilities, longer life, and quieter operation. An optional torque multiplier also is available. Forced-spray lubrication was included to ensure consistent lubrication of all key parts of these top drives. Similarly, all GDM top drives use submerged thrust bearings to extend their operational life and reliability.

GDM top drives also benefit from the manufacturer’s advanced control system. This system incorporates a comprehensive operational and maintenance module, which provides for a proactive approach to preventative maintenance and service and adds to the reliability and long life of the top drive. Another key element of the control system, an adjustable pipe handling module, allows for automatic positioning with the racking board and derrick man.

Proprietary remote IBOP actuator

Another key feature of all GDM top drives is GDS’ advanced remote internal blowout preventer (IBOP) actuator. Already proven as an aftermarket component on a wide range of top drive models, this remote actuator offers a number of features not found on conventional IBOP actuators. To begin, this unit is based on a design philosophy that emphasizes a simple, compact structure with fewer moving parts. The compact footprint of this actuator provides ample room for elevator links to pass, and its three-cylinder design allows uniform actuation.

The IBOP actuator

The IBOP actuator is based on a design philosophy that emphasizes a simple, compact structure with fewer moving parts. The compact footprint of this actuator provides ample room for elevator links to pass, and its three-cylinder design provides uniform actuation.

From an operational perspective, this GDS actuator allows for opening and closing actuation while in rotation, eliminating the mess often associated with having to stop rotation before opening and closing. This proven unit also provides manual operation through actuation cams, eliminating the need for rotating seals.

The 850 and beyond

The GDM 850 is designed to operate at 1,570 continuous horsepower from 120 to 240 rpm (maximum). Built to deliver the torque required by today’s demanding deepwater and horizontal drilling applications, the GDM 850 will deliver 64,000 ft-lbs of continuous torque at 0 to 116 rpm. This top drive also is designed to provide up to 88,000 lbs of intermittent torque at 0 to 188 rpm.

The GDM 850’s static brake capacity is rated at 57,000 lbs, while pipehandling capacity is at 110,000 ft-lbs. This 850 is designed to deliver 7,500 psi mud flow through a 4-in. passage. Applicable to land, barge, and offshore use, the GDM 850 weighs less than 35,000 lbs and is 7 m (23 ft) tall with 120-in. elevator links.

The first of the GDM 850s was sold to Lafayette, La.-based Megadrill Services Ltd. for installation on the company’s new Majestic in-land barge rig. The Majestic, a newly built 3000HP rig, is under contract with a major operating company to drill in Nigeria.