AIR ROTARY DRILLING QUESTIONS & ANSWERS
1. What precautions must be 1. Reduce Air Pressure
used when sand seams 2. Use of Foam or Polymers
are encountered in air ro- 3. Monitor Cuttings
tary drilling in unconsoli- 4. Casing Advancement
dated formation? 5. Slow Drilling Rate
2. How are samples ob- Continuous Sampling of Cuttings:
tained in air rotary drilling Split-Spoon Sampling
in unconsolidated forma- Drilling Fluids/Polymers
tions?
3. Hole cleaning and pene- Air Pressure and Volume
tration rates will vary with Formation Type
air rotary. What factors af- Bit Type and Condition
fect cleaning and pene- Drilling Fluid/Injection
tration? Drill Pipe Size and
Depth Cutting Size and
Volume
4. Why is information con-
cerning the geology Permeability of the Formation
im- portant in proper Stability of the Formation
grout- Formation Pressure
ing of unconsolidated for- Groundwater Flow
mations? Formation Composition.
5. When would you gravel When the formation is unconsolidated, to prevent sand or
pack a well? fine mate- rial from entering the well, and to enhance water
flow by stabilizing the borehole
6. What formations are best clay, sand, or shale.
to use a soft tri-cone
bit?
,NGWA - STUDY GUIDE - AIR ROTARY COMPREHENSIVE
AIR ROTARY DRILLING QUESTIONS & ANSWERS
7.
,NGWA - STUDY GUIDE - AIR ROTARY COMPREHENSIVE
AIR ROTARY DRILLING QUESTIONS & ANSWERS
What functions must a drill
Transmit torque
pipe perform to drill circulate drilling fluid/air support
unconsolidated for- drill string weight maintain
mations? borehole integrity
8. When would you use to add weight on the bit, stabilize the drill string, and prevent buck-
heavy drill collars? ling in deep or hard formations.
9. Explain how chip catchers
help collect cuttings for accurate formation logging by preventing
can aid in formation log- loss of samples during drilling, ensuring representative
ging? data.
10. How does bit design vary
with geology? varies by formation hardness, with softer formations needing wider
teeth and harder formations requiring tougher, more
durable ma- terials.
11. Heavy steel casing would
best be used in what best used in the air rotary process for stabilizing unconsolidated or
ro- tary process? collapsing formations.
12. What air compressor
level
checks must be made dai- filters
ly? belts
air
pressure
leaks
13. What type of drill bit main- Cleaning
tenance can be done in the field?
14.
, NGWA - STUDY GUIDE - AIR ROTARY COMPREHENSIVE
AIR ROTARY DRILLING QUESTIONS & ANSWERS