Which of the following is listed as a precaution when sand seams are encountered during air rotary drilling in unconsolidated formations?

• A. Casing Advancement
• B. Reduce Air Pressure
• C. Monitor Cuttings
• D. Use of Foam or Polymers

Answer: (B)

When sand seams appear in unconsolidated formations during air rotary drilling, the immediate precaution is to reduce the circulating air pressure. Lowering the energy of the air column directly decreases the force pushing sand into the borehole, which helps prevent excessive sand influx, hole instability, and potential surface safety issues. This pause-and-limit approach gives you better control as you evaluate the seam and decide on the next steps. While monitoring cuttings or using stabilization aids like foam or polymers can aid overall drilling, reducing air pressure specifically addresses the immediate risk posed by the sand seam.