OnGauge Sealed-Bearing Roller Reamer | Schlumberger


Torque-reduction sealed-bearing roller reamer

Torque reduction minimizes stick/slip and downhole vibration

Designed with a pressure compensated bullet seal and bearing assembly, the OnGauge torque-reduction sealed-bearing roller reamer reduces the downhole torque typically experienced using fixed-blade stabilizers. Torque reduction enables a more stable drilling environment, enabling extended runs in complex extended-reach wellbore geometries. Reducing downhole torque also improves weight transfer to the bit and minimizes stick/slip so that more energy is available at the bit to improve ROP and extend the operational life of the drill bit and MWD and LWD tools.

Torque reduction can be achieved using the OnGauge torque-reduction sealed-bearing roller reamer.
The OnGauge roller reamer has three cutter assemblies that rotate continuously, minimizing surface area and associated friction so that more torque transmits to the cutters to fracture and remove rock. Using a roller reamer will cause the BHA to have less parasitic torque, enabling more torque to go to the cutters, therefore fracturing and removing the rock more effectively.
Illustration of the OnGauge torque-reduction sealed-bearing roller reamer retention.
Reliable cutter retention is achieved through mechanical retention blocks. The tapered geometry forces the cutter block into the reamer body.

Cutter retention system provides assurance in harsh environments

A wedge-style cutter retention system prevents lost cutter incidents, and a durable sealed-bearing assembly ensures high loads, temperatures, and rotary speeds to extend bearing life.

Illustration of the OnGauge torque-reduction sealed-bearing roller reamer.

Hole size, in 8 1/2 8 3/4 12 1/4 17 1/2
Tool length, in 87 87 111 116
Max. body diameter, in 7 24/25 7 24/25 11 71/100 15 1/2
Fishing neck diameter, in 6 3/4 6 3/4 8 1/4 9 1/2
Fishing neck length, in  28 28 39 39
Bore diameter, in 2 1/4 2 1/4 3 3
Annular flow area, in2 9.9 13.29 22.26 82.5
 Max. recommended speed, rpm 150 150 125 125
Max. temperature, degF 300 300 300 300
Body weight, lbm 782 782 1,236 2,658
Recommended max. cutter revolutions, millions 10 10 10 10


  • Usable in extended-reach drilling (ERD) operations and complex well geometries
  • Torque reduction for severely packed hole assemblies
  • Effective in extremely abrasive drilling conditions


  • Reduces downhole torque caused by doglegs, wellbore spiraling, and the well profile
  • Maintains borehole quality and addresses ledging formations
  • Maintains hole gauge in abrasive conditions
  • Improves ROP and increases bit life due to reduced stick/slip
Maximum cutter revolutions: 10,000,000
Maximum rpm for 12.25 or larger: 125 rpm
Maximum rpm for 8.5 or smaller: 150 rpm
Maximum temperature: 300 degF
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