NGWA - Study Guide - Air Rotary-
NGWA - STUDY GUIDE - AIR ROTARY
COMPREHENSIVE AIR ROTARY
DRILLING QUESTIONS & ANSWERS
What precautions must be used when sand seams are encountered in air rotary drilling
in unconsolidated formation? - answer1. Reduce Air Pressure
2. Use of Foam or Polymers
3. Monitor Cuttings
4. Casing Advancement
5. Slow Drilling Rate
How are samples obtained in air rotary drilling in unconsolidated formations? -
answerContinuous Sampling of Cuttings:
Split-Spoon Sampling
Drilling Fluids/Polymers
Hole cleaning and penetration rates will vary with air rotary. What factors affect cleaning
and penetration? - answerAir Pressure and Volume
Formation Type
Bit Type and Condition
Drilling Fluid/Injection
Drill Pipe Size and Depth
Cutting Size and Volume
Why is information concerning the geology important in proper grouting of
unconsolidated formations? - answerPermeability of the Formation
Stability of the Formation
Formation Pressure
Groundwater Flow
Formation Composition.
When would you gravel pack a well? - answerWhen the formation is unconsolidated, to
prevent sand or fine material from entering the well, and to enhance water flow by
stabilizing the borehole
What formations are best to use a soft tri-cone bit? - answerclay, sand, or shale.
What functions must a drill pipe perform to drill unconsolidated formations? -
answerTransmit torque
, circulate drilling fluid/air
support drill string weight
maintain borehole integrity
When would you use heavy drill collars? - answerto add weight on the bit, stabilize the
drill string, and prevent buckling in deep or hard formations.
Explain how chip catchers can aid in formation logging? - answerhelp collect cuttings for
accurate formation logging by preventing loss of samples during drilling, ensuring
representative data.
How does bit design vary with geology? - answervaries by formation hardness, with
softer formations needing wider teeth and harder formations requiring tougher, more
durable materials.
Heavy steel casing would best be used in what rotary process? - answerbest used in
the air rotary process for stabilizing unconsolidated or collapsing formations.
What air compressor checks must be made daily? - answerOil level
filters
belts
air pressure
leaks
What type of drill bit maintenance can be done in the field? - answerCleaning
inspecting for wear
sharpening teeth
replacing damaged parts
Differential sticking of drill pipe can be prevented by what methods? - answerUse higher
mud flow
reduce drill string contact
maintain proper mud weight.
What common fishing tool are used in rotary drilling? - answerOvershot
spear
fishing magnets
junk baskets
Regular maintenance of the rotary swivel consists of what? - answerLubrication,
checking for leaks, inspecting bearings, and replacing worn seals.
What methods are used to clean the hole of cuttings in air rotary drilling in
unconsolidated formations? - answerAirflow, foam injection, and polymer use.
NGWA - STUDY GUIDE - AIR ROTARY
COMPREHENSIVE AIR ROTARY
DRILLING QUESTIONS & ANSWERS
What precautions must be used when sand seams are encountered in air rotary drilling
in unconsolidated formation? - answer1. Reduce Air Pressure
2. Use of Foam or Polymers
3. Monitor Cuttings
4. Casing Advancement
5. Slow Drilling Rate
How are samples obtained in air rotary drilling in unconsolidated formations? -
answerContinuous Sampling of Cuttings:
Split-Spoon Sampling
Drilling Fluids/Polymers
Hole cleaning and penetration rates will vary with air rotary. What factors affect cleaning
and penetration? - answerAir Pressure and Volume
Formation Type
Bit Type and Condition
Drilling Fluid/Injection
Drill Pipe Size and Depth
Cutting Size and Volume
Why is information concerning the geology important in proper grouting of
unconsolidated formations? - answerPermeability of the Formation
Stability of the Formation
Formation Pressure
Groundwater Flow
Formation Composition.
When would you gravel pack a well? - answerWhen the formation is unconsolidated, to
prevent sand or fine material from entering the well, and to enhance water flow by
stabilizing the borehole
What formations are best to use a soft tri-cone bit? - answerclay, sand, or shale.
What functions must a drill pipe perform to drill unconsolidated formations? -
answerTransmit torque
, circulate drilling fluid/air
support drill string weight
maintain borehole integrity
When would you use heavy drill collars? - answerto add weight on the bit, stabilize the
drill string, and prevent buckling in deep or hard formations.
Explain how chip catchers can aid in formation logging? - answerhelp collect cuttings for
accurate formation logging by preventing loss of samples during drilling, ensuring
representative data.
How does bit design vary with geology? - answervaries by formation hardness, with
softer formations needing wider teeth and harder formations requiring tougher, more
durable materials.
Heavy steel casing would best be used in what rotary process? - answerbest used in
the air rotary process for stabilizing unconsolidated or collapsing formations.
What air compressor checks must be made daily? - answerOil level
filters
belts
air pressure
leaks
What type of drill bit maintenance can be done in the field? - answerCleaning
inspecting for wear
sharpening teeth
replacing damaged parts
Differential sticking of drill pipe can be prevented by what methods? - answerUse higher
mud flow
reduce drill string contact
maintain proper mud weight.
What common fishing tool are used in rotary drilling? - answerOvershot
spear
fishing magnets
junk baskets
Regular maintenance of the rotary swivel consists of what? - answerLubrication,
checking for leaks, inspecting bearings, and replacing worn seals.
What methods are used to clean the hole of cuttings in air rotary drilling in
unconsolidated formations? - answerAirflow, foam injection, and polymer use.
