Air Rock Drilling

How it works

Compressed air carries cuttings to the surface. Direct rotary air and down-the-hole hammer systems are common approaches.

Where it fits

Suitable for consolidated or semi-consolidated formations. Loose overburden can require casing or another circulation method.

Planning considerations

Formation stability, compressor requirements and water inflow influence method selection.

Two common approaches

Direct rotary air

Compressed air travels down the drill string and carries cuttings back toward the surface. It helps clear the bit and expose changes in the formation.

Down-the-hole hammer

A pneumatic hammer breaks rock at the bottom of the bore while the string rotates. The contractor matches the tooling and air supply to the ground conditions.

Formation matters

Unstable overburden may need casing or fluid-supported drilling before the rig reaches suitable rock. Inflow, dust control, access and compressor capacity also influence the drilling plan.