What characteristics define air rotary drilling?

Air rotary drilling is characterized by the use of compressed air as the primary circulating medium during the drilling process. This method is particularly advantageous for drilling through soft to medium-density rock formations, as the compressed air effectively lifts cuttings out of the hole and cools the drill bit simultaneously. The use of air allows for a faster drilling speed, reduces the potential for collapse in unstable formations, and minimizes the risk of contamination in groundwater sources.

In contrast to other drilling methods that rely on mud or water, air rotary drilling does not require heavy mud fluids, nor does it utilize water for cooling. High-viscosity fluids are typically associated with other drilling techniques that need additional support to stabilize the borehole and carry cuttings away from the drill site. Therefore, the defining characteristic of air rotary drilling is its reliance on compressed air, setting it apart from other conventional drilling methods.