Large-diameter boreholes are required in many water well, mining, geothermal and foundation projects.
Compared with smaller holes, selecting a large DTH drill bit requires greater attention to the complete drilling system.
Depending on the application, professional DTH bits can be available in diameters exceeding 200 mm, with larger options used for specialized drilling projects.
The correct size depends on the required finished borehole diameter.
As bit diameter increases:
More rock must be broken.
More cuttings must be removed.
The annular area changes.
Air demand may increase.
The compressor must provide sufficient pressure and airflow for the selected hammer and hole diameter.
Large bits generally require appropriately sized DTH hammers.
The shank must match the hammer exactly, while the hammer must provide sufficient impact energy for the drilling conditions.
The drilling rig should provide adequate:
Rotary torque
Feed control
Pullback force
Mast capacity
Tool handling capability
Large drilling tools can also increase the weight handled during rod changes.
Large DTH bits may use flat, concave, convex or other application-specific face configurations.
Selection should consider:
Rock hardness
Abrasiveness
Fracturing
Borehole stability
Required penetration
YKDRILL's DTH product range includes multiple hammer and bit sizes for different international drilling applications, including large-diameter options.
For correct selection, customers should provide target hole diameter, drilling depth, rock formation, rig model and compressor parameters.
The most efficient large-diameter bit is the one correctly matched to the entire drilling system.
