Which of the following is an advantage of air rotary drilling over mud rotary?

• A. Faster drilling
• B. Higher mud weight requirements
• C. More fluid handling
• D. Slower penetration

Answer: (A)

The main advantage comes from using air as the circulating medium instead of drilling mud. With air, there’s no mud to mix, pump, or manage, and the cuttings are carried to the surface quickly by the air stream. This reduces downtime for mud handling and allows the bit to advance more rapidly, so penetration can be faster than with mud rotary.

The other factors describe aspects tied to mud systems. Higher mud weight requirements are tied to mud rotary, not air rotary, so they aren’t advantages of using air. Fluid handling is more burdensome in mud systems, whereas air rotary minimizes that need. Slower penetration is simply not how air drilling behaves.