DRILCO Rotary Substitutes (Subs) | Schlumberger

DRILCO Rotary Substitutes (Subs)

Variety of subs for cross over or disposable connections

Rotary substitutes (subs) have two primary applications. They can be used to cross over from one connection size to another, or as the disposable component used to extend the connection life of a more expensive drillstem member. Rotary subs are available with box × pin, box × box, or pin × pin connections.

The following DRILCO rotary subs are available:

  • Straight-OD sub—used to connect drillstem members that have a similar OD
  • Reduced-section sub—used to connect drillstem members that have different diameters that warrant the cross-sectional change necessary to accommodate different connections
  • Saver sub—used to extend the life of the rotary kelly by taking the connection wear each time it is made up to a drillstem component.
Rotary Subs straight-OD subs, reduced-section subs, and saver subs
Rotary Subs top drive sub and lift sub
Top drive sub (left) and lift sub (right).

Bit sub

DRILCO offers a complete line of bit subs. They are made from materials that are heat-treated to drill collar specifications. Size availability ranges from 3 1/8- to 11-in OD and 36- to 48-in length.

Lift sub

A lift sub enables the safe, efficient handling of straight OD tubulars—such as drill collars, shock tools, jars, directional equipment, and other tools—by using the drillpipe elevators.

Top drive sub

Top drive subs serve as the sacrificial element between the drillstring and the top drive, reducing repair and maintenance costs. These tools are manufactured from selected bars of alloy steel, heat-treated to provide the strength and toughness required to carry the entire weight of the drillstring. They exceed API specifications for drillpipe tool joint mechanical properties.

View All

Share This