DRILCO Machine Shop Services | Schlumberger

DRILCO Machine Shop Services

Tubular repairs, stub welding, tool joint buildup, hardbanding, and straightening

All machine shop services are provided by qualified DRILCO personnel. Highly trained and experienced machinists ensure that each job is done to API standards in your area for machine shop services.

Tubular repair services

Connection recuts are the most common type of tubular repair; we remove the minimum amount of material required to ensure a full repair. We are also licensed to recut proprietary connections from many other major manufacturers of tubular products. The most common cause of failure or damage of rotary-shouldered connections is insufficient torque applied during makeup. To reduce stress on the connection, an API stress-relief groove and bore back box can be machined, while fatigue life can be increased with cold-working. We also offer kemplating, the application of a phosphate coating that provides a barrier between the metallic surfaces of the pin and box.

Tool joint buildup is an industry-accepted procedure to extend the service life of drillpipe and Hevi-Wate transition drillpipe. Tool joints that meet minimum length and diameter criteria can be professionally restored to their original OD.

Stub-welding (stubbing) ends on drill collars and specialty tools

When drillstem members become too short through repeated reworking of connections, box-weak from OD wear, or pin-weak from ID wear, they can be put back into service by stub-welding new material to the ends of the worn tools and cost-effectively restoring the physical dimensions. This process is called stubbing.

Machine Services welding
Machine Services hardbanding

Rotary kelly repair

The following conditions can be repaired:

  • Connection damage—connections can be recut a number of times
  • Crookedness—in most cases, a bent kelly can be straightened using a hydraulic straightener
  • Rounded drive corners—these can be repaired by reversing the ends or remachining the drive flats to a smaller, non-API size.


The quality application of hardband provides OD wear protection on drill collars, drillpipe, heavy-wall drillpipe, and other tools used in drilling applications. Granular tungsten carbide or a selection of other casing-friendly hardband materials can be used.


Bent tubular products and drilling tools can cause premature wear and subsequent failure of BOP equipment, and drillstring and BHA members. Drillpipe, drill collars, Hevi-Wate transition drillpipe, and rotary kellys can be straightened.

Makeup and breakout

Makeup and breakout services help improve rig economics by allowing drillpipe to be shipped in preassembled double lengths, reducing rig time spent on making up or breaking connections. In addition, we can break in rotary-shouldered connections in a controlled environment, ensuring reliable onsite performance.
Machine Services Makeup and breakout
Machine Services Spiraling

Sub accessories

We are licensed to machine third party proprietary connections on various sub accessories.

Other services include

  • drill collar spiraling
  • turning drill collar OD
  • manufacturing and repairing crossover subs, pup joints, and saver subs
  • repairing downhole tools
  • redressing and repairing stabilizers
  • custom repairs.

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