Page 71 - Air and Gas Drilling Manual

Chapter 2: Surface Equipment 2-21
2.4.6 Gas Detector
Gas detectors (gas sniffers) are used only in air drilling operations directed at the
recovery of oil and natural gas. Figure 2-14 shows the position of the gas detector
on the blooey line. This detector can detect very small quantities of hydrocarbons
that might enter the blooey line from the annulus. As the drill bit is advanced and
hydrocarbon producing formations are drilled, the hydrocarbons are entrained in the
return air flow to the surface with entrained rock cuttings. The detector alerts the
drilling rig crew that hydrocarbons are in the annulus. This alert allows rig
personnel to take safety precautions against subsurface and surface fires or
explosions.
2.4.7 Pilot Light
Figures 2-1 and 2-14 show a pilot light at the end of the blooey line. Pilot
lights are used only in air or gas drilling operations directed at the recovery of oil
and natural gas. The pilot light is a small open flame (propane or natural gas)
maintained at the end of the blooey line to ignite and burn any hydrocarbons that
might exit the line as the drilling operation progresses. Many new air and gas
drilling operations are equipped with electric igniters instead of open flame pilot
lights.
References

1. Mitchell, B. J., Personal communication, November 1982.
2. Moore, W. W., Fundamentals of Rotary Drilling, Energy Publications, 1981.

3. Hook, R. A., Cooper, L. W., and Payne, B. R., “Air, Mist and Foam Drilling:
A Look at Latest Techniques: Parts I and II,” World Oil, April and May 1977.
4. “Bulletin on Performance Properties of Casing, Tubing, and Drill Pipe,” API Bul
5C2, Twentieth Edition, May 31, 1987.
5. “API Specification for Line Pipe,” API Spec 5L, Thirty-Fourth Edition, May 31,
1984.

6. “API Recommended Practices for Blowout Prevention Equipment Systems for
Drilling Wells,” API RP 53, First Edtion, February 1976.

7. Bourgoyne, A. T., “Rotating Control Head Applications Increasing,” Oil and
Gas Journal, October 9, 1995.
8. Hannegan, D. M., “RCHs Lower Cost, Boost Productivity,” The American Oil
and Gas Reporter, April 1996.