With a distance of 652 m, the project team in Aalbach realized a particularly long HDD drilling underneath a main road. Despite drilling fluid losses in nearly all drilling phases, three HDPE product pipes (2 x 315 mm, 1 x 280 mm, SDR 9) were successfully pulled in through claystone, clay shale, and marl.
Technical Specifications
Distance: 652 m
Rig / Machine: PD 150/65+
High-Pressure Pump: 1600 l/min
Pilot Bore: 6 ¾” Mud Motor, 9 7/8″ TCI Bit
Tracking System: Paratrack II + PWD
Obstacle: Main road
Reaming: Rock Reamers 16″, 22″ TCI Cutters
Drilling Profile:
- Entry angle: 14 degrees
- Exit angle: 15 degrees
- Vertical radii: 350 m
- TVD: 17,3 m
Geology: Claystone, clay shale, marl
Product Pipes: 2 x HDPE 315 mm, SDR 9; HDPE 280 mm, SDR 9
Drilling Fluid: Bentonite-based
Final Pullback Force:
- 315 mm – 110 kN
- 315 mm – 107 kN
- 280 mm – 85 kN
Key Feature / Complexity: Fluid losses (circulation losses) in almost all drilling phases.
