Which of the following is an advantage of high pressure air rotary drilling in unconsolidated formations?

• A. Faster drilling
• B. Higher equipment cost
• C. Increased formation collapse risk
• D. Longer bit life

Answer: (A)

High-pressure air drilling speeds things up in unconsolidated formations because the air stream continuously lifts and evacuates the cuttings, keeping the hole clean and reducing resistance at the bit. Without drilling mud to carry away debris, the bit can penetrate more quickly, leading to faster drilling overall. The other options describe costs or risks rather than a true advantage: higher equipment cost is a downside, increased formation collapse risk can be a concern with air drilling due to lack of hydrostatic support, and longer bit life is not a guaranteed or typical benefit.