12 1/4 - 14 1/2 in QDR5213(311.15 - 368.3 mm)

ER 20055 IADC S243

Design Specifications

Total Cutters45
Cutter Size13mm (1/2 in), 16mm (5/8 in)
Face Cutters(43) 13mm, (2) 16mm
Gauge Cutters(43) 13mm, (2) 16mm
Drill Out Cutters(43) 13mm, (2) 16mm
Conditioning Cutters(43) 13mm, (2) 16mm
Blade Count7
Pilot Diameter8 1/2 in
Maximum Tool Diameter9 1/2 in
Nozzles4 Standard Series 60N
Junk Slot Area (sq in)87.92
Gauge Length1 1/2 in
Gauge ProtectionOptions Available
Upper Connection6-5/8" API Reg. Box
Lower Connection4-1/2" API Reg.
LengthMake-Up: 57 7/8 in Overall: 62 5/16 in
Fishing NeckDiameter: 8 1/8 in Length: 18 11/16 in

Operating Parameters

Rotary SpeedSuitable for Rotary & PDM
Weight-on-Bit6,000 To 36,000 (lbs)
2,727 To 16,362 (daN)
3 To 16 (Tonnes)
Flow Rate (GPM)500 To 1200
Hydraulic Horsepower (HSI)1 To 6
The operating parameters listed here are general parameters, please contact your local Schlumberger representative for precise recommendations for your individual well.


Pilot conditioning section improves tool stability & by stress relieving the formation with this intermediate stage, drilling the larger hole can be done at a more aggressive ROP

Drill collar connections allow flexible drillstring placement to optimize reamer and BHA performance.

Both the pilot hole section and the reamer cutting structure contain PDC inserts & carbide hardfacing on gauge to maintain hole integrity and extend tool life.

Short gauge length improves directional responsiveness without compromising hole integrity or tool stability.