Concentric String Reamer

The most efficient and cost-effective solution to hole opening where pass-through restrictions are not an issue


Our one-piece concentric string reamers have a proven track record of effectively enlarging the wellbore to the desired diameter at impressive penetration rates. The cutting structure is laid out to optimize cutting efficiency through the stress-relieved formations while generating a smooth torque response. The flexibility of the design enables it to be used successfully when drilling ahead or in a dedicate hole-opening assembly. The low-torque design means it is an excellent tool to use in conjunction with an underreamer when a larger hole size is required that could be achieved using a conventional underreamer.


  • Force-balanced cutting structure – Ensures tool stability even in demanding applications
  • CFD-enhanced hydraulics layout – Optimized nozzle placement and orientation ensure efficient cutter cleaning and cooling while eliminating recirculation
  • Large selection of premium PDC cutters – Cutter type and geometry can be optimized to suit the demands of each specific application
  • Integral one-piece design – Ensures tool is efficiently force balanced and minimizes risk in demanding applications
  • Non-aggressive gauge – Ensures the tool follows the pilot hole and does not deviate
  • BHA design flexibility – Can be used in tandem with underreamers for additional enlargement
  • DS-1 and NS-2 compliant – Enables unrestricted use in all challenging global applications
Rendered front view of Concentric String Reamer

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