Drilling Type Underreamer (DTU)

The work horse of our rental fleet, the DTU is used for a variety of well bore enlargement applications.

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The HOC DTU Underreamer has gone through several changes and modifications to adapt to the ever changing drilling applications and environments.

Features and Benefits:

  • Long proven history with over 2.5 million feet underreamed worldwide.
  • Expansion ratios 70% and larger than the OD of the body.
  • Hydraulically expandable with pump pressure.
  • Cutter arms move upward and out simultaneously in the body.
  • Fail safe cutter arm retraction.
  • Reverse actuating mechanism maintains that tool is open while drill string weight prohibits tool closure.
  • Unrestricted flow through ID.
  • Roller cone cutters are specifically designed for the HOC DTU underreamers and are consistent with down hole diameters.
  • Body machined from heat-treated steel bar, giving it exceptional strength.
  • Jet nozzles near the cutters allow for cutter washing and cooling.
  • Cutting Structures available include:
    1. Sealed Bearing Mill Tooth
    2. Sealed Bearing TCI
    3. PDC
    4. HOC’s ADD Cutter


DTU Specifications


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