Article

Connection Performance without Compromise

50% fewer turns necessary from stab to makeup

Steam curls around series of Grant Prideco pipes as they are cooled during manufacturing

Rising well costs and expensive connection repair rates drove a conversation between NOV and its customers on how to combat these persistent issues. The result: a stronger, more cost-effective drill-pipe connection that doesn’t compromise on performance.

The Delta™ rotary-shouldered drill-pipe connection addresses the needs of a diverse, shifting market by balancing performance and reliability while maintaining cost effectiveness. The connection delivers torque slightly above that of the industry’s reference, the XT™ connection. The Delta connection also improves hydraulic performance using streamlined, 130-ksi tool joints. Enhanced fatigue resistance allows a simpler threading process, which reduces connection maintenance cost and contributes to lowering the cost of ownership. The Delta connection’s balanced thread form design engages more threads at stab-in, minimizing stab damage and evenly distributing stress. In addition, the connection doesn’t require the use of a stabbing guide, making it much easier to handle on the rig.

A macro shot of a Grant Prideco connector

The Delta connection is a stronger, more cost-effective drill-pipe connection that still achieves high levels of performance.

The modified geometry of the Delta connection reduces the number of turns necessary to make up the connection, increasing efficiency and reducing wear on the threads. Compared to similar products, the Delta connection requires 50% fewer turns from stab to makeup. Time-wise, the connection can be spun in as little as 4 seconds, while XT connections typically require 8 seconds. This decrease in connection time translates to increased cost effectiveness and ease of use on the rig floor. Ease of use is further improved by a reduction in the minimum required tong-gripping distance from the box face.

Wider field inspection tolerances reduce the need for frequent repairs without compromising the connection's performance. A reduction in material loss of 30% for face-and-chase repair operations allows for more recuts, while the total refacing amount has been increased by 50%, allowing for additional refaces to take place before recut is needed. The reduction in tong-gripping distance results in increased room for recuts without changing the length of the tool joint. NOV has also developed best practices in the shop environment for recuts, which will result in less than a 1-in. loss on pin or box for a full face-and-chase recut.

A Grant Prideco technician inspects a pallet of connectors during manufacturing

The Delta connection has undergone extensive testing at NOV's research and development technology center.

The Delta connection has undergone extensive testing at NOV's research and technology development center, with early results conclusively proving that the new connection made up twice as fast as its predecessor. Damage was minimal and was primarily related to handling; generally, only refacing was required. For a final alignment on cost reductions, the Delta connection has the lowest royalty on repair services across all of NOV's double-shoulder connections. The Tuboscope business unit further supports the connection with lower charges to pipe owners and the inclusion of the TracID™ RFID-based tagging and inventory management system.

NOV is prepared to address the changing drilling landscape as an upturn in land factory drilling projects drives the need for efficient, high-performance products and technologies. The Delta connection is potentially the most balanced connection ever put to market, and its proprietary features reduce customers’ total cost of ownership. In engineering, a "delta" indicates the degree of difference—for drill-pipe connections, Delta is the difference.

Authors

Andrei Muradov

Director of Research and Development

NOV Employee Andrei Muradov

Andrei Muradov has worked at NOV for 22 years, most recently as director of research and development for Grant Prideco. He holds a bachelor’s degree with honors in petroleum engineering from Gubkin University of Oil and Gas, and he completed the NOV Ventures program at McCombs School of Business. During his oilfield tenure, Andrei has focused on tubular integrity and design. He holds four patents.

Dan Morgan

Director of Field Service Claims

NOV Employee Dan Morgan

Dan draws from his 35 years of experience with NOV to serve the global drill pipe customer base. Dan earned his knowledge and skills from the shop floor up, holding positions of increasing responsibility in quality, metrology, and product engineering, which led to his current position dealing directly with customers at every level. Dan attended training for ASM metallurgy, quality methods, management, leadership, steel mill processes, and well drilling. He has co-authored SPE papers, advised on industry standards, and received recognition awards. Having received multiple commendations from customers and management, Dan is passionate about safely providing quality products and building customer satisfaction and loyalty.

Guillaume Plessis

Director of Global Marketing

NOV Employee Guillaume Plessis

Guillaume Plessis joined NOV with the legacy Grant Prideco team in 2008. A graduate of Arts et Métiers Paris-Tech, Guillaume has dedicated almost 20 years to drilling tubulars, first as a product engineer and progressing toward marketing and product management. Guillaume has published numerous papers and is an active player in the industry’s technical committees.