Dry Air Drilling
Assessment Dry Air Drilling
1. What is the most common form of cuttings collected at the surface during underbalanced drilling?
A .Cobbles
B .Gravel
C .Sand
D .Dust ✔
2. Annular pressure drop always increases as a function of annular velocity.
A .True
B .False ✔
3. What relationship is used to estimate the cuttings slip velocity?
A .Reynolds’ number
B .Stokes’ law ✔
C .Newton’s law
D .Darcy’s law
4. Which of the following variables is NOT a part of the Reynolds’ number definition within the context of underbalanced drilling?
A .Fluid density
B .Fluid viscosity
C .Mean particle diameter
D .Annular pressure ✔
E .Particle slip velocity
5. An increase in the mass of air and cuttings in the annulus causes
A .an increase in frictional pressure drop. ✔
B .a decrease in frictional pressure drop.
C .no change in frictional pressure drop.
6. The major disadvantage of Angel’s equation is that it requires some knowledge about the cutting size and shape, which is difficult to obtain.
A .True
B .False ✔
7. Which of these is NOT among the primary components of an air compression system?
A .Compressors
B .Boosters
C .Diverters ✔
D .Mist pumps
E .None of the above
8. What component of a typical air compression system is located farthest from the compressors?
A .Booster
B .Standpipe ✔
C .Air header
D .High-pressure bleed line
E .Mist pump
9. The main function of boosters are to protect the compression system from any back flow.
A .True
B .False ✔
10. What is the function of the upper float valve on a drill string used for underbalanced drilling?
A .To prevent cuttings from flowing back
B .To reduce cuttings velocity
C .To maintain the pressurized air during connections ✔
11. A rotating control head can be used to replace the existing BOP equipment.
A .True
B .False ✔
12. According to regulations, how far should the outlet a blooie be located from the drilling rig?
A .15 to 20 feet
B .25 to 40 feet
C .60 to 75 feet
D .100 to 150 feet ✔
13. In dry air drilling, compressors are typically turned off while making connections.
A .True
B .False ✔
14. Moistened cuttings in the wellbore have the tendency to build what?
A .Scale deposits
B .A mud cake
C .A mud ring ✔
D .None of the above
15. Which of the following is NOT a water influx control technique?
A .Resin and catalyst systems
B .Squeeze cementing
C .Carbon dioxide injection ✔
D .Water-based polymer solutions
16. The best remedial action to water inflow is to switch from dry air to mist or foam drilling.
A .True ✔
B .False
17. What is the concentration of natural gas that is combustible at atmospheric conditions?
A .2 to 5 percent
B .5 to 15 percent ✔
C .15 to 20 percent
D .25 to 40 percent
18. The typical consequence of a downhole fire is a melted drill string.
A .True ✔
B .False
19. Which of these is NOT one of the advantages of reverse circulation drilling over regular air drilling?
A .Less permeability damage to formation
B .Lower risk of bit plugging ✔
C .Less wellbore erosion
D .Less air volume requirement
