What is the purpose of stabilizers in air rotary drilling?

• A. To cool the drill bit
• B. To increase the air pressure
• C. To remove cuttings more quickly
• D. To guide the drill string and reduce deviation

Answer: (D)

Stabilizers in air rotary drilling are used to guide the drill string and reduce deviation. They have blades that lightly touch the borehole wall to center the bottom part of the string as it rotates. This centralization keeps the bit on the intended trajectory, minimizes wandering and doglegs, and helps maintain a consistent weight on bit. By keeping the assembly aligned, hole quality stays more uniform and wear on the drill string is reduced. They aren’t primarily for cooling, increasing air pressure, or speeding up cutting removal—that’s handled by other parts of the system and drilling process.