1. What is mud rotary drilling? A drilling method that uses a rotating drill bit
and circulating drilling fluid (mud) to cut through subsurface formations and
remove cuttings from the borehole.
2. What are the three main components of a rotary drilling system? The
rotation system, circulation system, and hoisting system.
3. What is the purpose of drilling mud? To cool and lubricate the drill bit,
transport cuttings to the surface, stabilize the borehole walls, and control
subsurface pressures.
4. What does NGWA stand for? National Ground Water Association.
5. What is the difference between direct and reverse rotary drilling? Direct
rotary pumps fluid down through the drill pipe and up the annulus, while
reverse rotary pumps fluid down the annulus and up through the drill pipe.
6. What is penetration rate? The speed at which the drill bit advances through
the formation, typically measured in feet or meters per hour.
7. What is a drill string? The assembly of drill pipe, drill collars, and drilling
tools that transmits rotational power and fluid to the drill bit.
8. What is the kelly in rotary drilling? A square or hexagonal steel pipe that
connects the drill string to the rotary table and transmits rotational force.
9. What is torque in drilling? The rotational force applied to turn the drill
string and bit, measured in foot-pounds or newton-meters.
10. What is the purpose of drill collars? To provide weight on the bit for
drilling and to keep the drill string in tension above the collars.
11. What is a tricone bit? A roller cone drill bit with three rotating cones
containing cutting elements such as teeth or inserts.
,12. What is weight on bit (WOB)? The amount of downward force applied to
the drill bit, typically measured in thousands of pounds.
13. What is RPM in drilling? Revolutions per minute - the rotational speed of
the drill string and bit.
14. What is the purpose of the mud pump? To circulate drilling fluid through
the system at the required pressure and flow rate.
15. What is a mud pit? An earthen or steel tank used to store and condition
drilling mud during operations.
16. What is the function of a desander? To remove sand-sized particles
(typically 45-74 microns) from the drilling fluid.
17. What is the purpose of a desilter? To remove silt-sized particles (typically
15-44 microns) from the drilling mud.
18. What is a shale shaker? The primary solids control device that removes
drill cuttings from the mud using vibrating screens.
19. What is drilling fluid viscosity? A measure of the fluid's resistance to flow,
which affects its carrying capacity and pressure losses.
20. What is gel strength? The ability of drilling mud to suspend solids when
circulation stops, measured at 10 seconds and 10 minutes.
21. What is the purpose of bentonite in drilling mud? To increase viscosity,
provide gel strength, stabilize borehole walls, and reduce fluid loss.
22. What is fluid loss in drilling? The rate at which drilling fluid filtrate
invades permeable formations, leaving behind filter cake.
23. What is a lost circulation zone? A highly permeable or fractured formation
where drilling fluid is lost rather than returning to surface.
24. What is differential sticking? When the drill string becomes stuck against
the borehole wall due to pressure differential across the filter cake.
25. What is hole deviation? The angular departure of a borehole from vertical,
measured in degrees.
26. What is formation pressure? The pressure exerted by fluids (water, oil,
gas) within the pore spaces of subsurface formations.
27. What is hydrostatic pressure? The pressure exerted by a column of fluid
due to its weight, calculated as fluid density times true vertical depth.
, 28. What is overbalanced drilling? Drilling with mud weight sufficient to
maintain wellbore pressure greater than formation pressure.
29. What is a blowout? An uncontrolled flow of formation fluids to the surface
due to insufficient well control.
30. What is the mud balance used for? To measure the density (weight) of
drilling fluid, typically in pounds per gallon or specific gravity.
Section 2: Drilling Equipment (Questions 31-60)
31. What is a rotary table? A mechanical device on the drill rig floor that
rotates the kelly and drill string.
32. What is a top drive system? A motor-driven rotating system suspended
from the rig's traveling block that eliminates the need for a kelly and rotary
table.
33. What is the purpose of the crown block? To support the drilling line and
provide mechanical advantage for the hoisting system.
34. What is the traveling block? A movable pulley system that supports the
hook, swivel, and drill string weight during operations.
35. What is the drawworks? The hoisting machinery including the drum,
brakes, and transmission used to raise and lower the drill string.
36. What is a swivel? A rotating connection that allows drilling fluid to enter
the drill string while it rotates.
37. What is a standpipe? A vertical pipe that conducts drilling mud from the
pump to the swivel and rotary hose.
38. What is the rotary hose (kelly hose)? A flexible, high-pressure hose
connecting the standpipe to the swivel.
39. What is the purpose of the derrick or mast? To provide vertical support
for raising and lowering the drill string and casing.
40. What are slips? Wedge-shaped devices that grip the drill pipe and support
the drill string weight in the rotary table.
41. What are elevators? Clamp-like devices that attach to the drill pipe to lift
or lower it during tripping operations.
42. What is a drill pipe sub? A short threaded connector used to join drill
string components with different thread types.
and circulating drilling fluid (mud) to cut through subsurface formations and
remove cuttings from the borehole.
2. What are the three main components of a rotary drilling system? The
rotation system, circulation system, and hoisting system.
3. What is the purpose of drilling mud? To cool and lubricate the drill bit,
transport cuttings to the surface, stabilize the borehole walls, and control
subsurface pressures.
4. What does NGWA stand for? National Ground Water Association.
5. What is the difference between direct and reverse rotary drilling? Direct
rotary pumps fluid down through the drill pipe and up the annulus, while
reverse rotary pumps fluid down the annulus and up through the drill pipe.
6. What is penetration rate? The speed at which the drill bit advances through
the formation, typically measured in feet or meters per hour.
7. What is a drill string? The assembly of drill pipe, drill collars, and drilling
tools that transmits rotational power and fluid to the drill bit.
8. What is the kelly in rotary drilling? A square or hexagonal steel pipe that
connects the drill string to the rotary table and transmits rotational force.
9. What is torque in drilling? The rotational force applied to turn the drill
string and bit, measured in foot-pounds or newton-meters.
10. What is the purpose of drill collars? To provide weight on the bit for
drilling and to keep the drill string in tension above the collars.
11. What is a tricone bit? A roller cone drill bit with three rotating cones
containing cutting elements such as teeth or inserts.
,12. What is weight on bit (WOB)? The amount of downward force applied to
the drill bit, typically measured in thousands of pounds.
13. What is RPM in drilling? Revolutions per minute - the rotational speed of
the drill string and bit.
14. What is the purpose of the mud pump? To circulate drilling fluid through
the system at the required pressure and flow rate.
15. What is a mud pit? An earthen or steel tank used to store and condition
drilling mud during operations.
16. What is the function of a desander? To remove sand-sized particles
(typically 45-74 microns) from the drilling fluid.
17. What is the purpose of a desilter? To remove silt-sized particles (typically
15-44 microns) from the drilling mud.
18. What is a shale shaker? The primary solids control device that removes
drill cuttings from the mud using vibrating screens.
19. What is drilling fluid viscosity? A measure of the fluid's resistance to flow,
which affects its carrying capacity and pressure losses.
20. What is gel strength? The ability of drilling mud to suspend solids when
circulation stops, measured at 10 seconds and 10 minutes.
21. What is the purpose of bentonite in drilling mud? To increase viscosity,
provide gel strength, stabilize borehole walls, and reduce fluid loss.
22. What is fluid loss in drilling? The rate at which drilling fluid filtrate
invades permeable formations, leaving behind filter cake.
23. What is a lost circulation zone? A highly permeable or fractured formation
where drilling fluid is lost rather than returning to surface.
24. What is differential sticking? When the drill string becomes stuck against
the borehole wall due to pressure differential across the filter cake.
25. What is hole deviation? The angular departure of a borehole from vertical,
measured in degrees.
26. What is formation pressure? The pressure exerted by fluids (water, oil,
gas) within the pore spaces of subsurface formations.
27. What is hydrostatic pressure? The pressure exerted by a column of fluid
due to its weight, calculated as fluid density times true vertical depth.
, 28. What is overbalanced drilling? Drilling with mud weight sufficient to
maintain wellbore pressure greater than formation pressure.
29. What is a blowout? An uncontrolled flow of formation fluids to the surface
due to insufficient well control.
30. What is the mud balance used for? To measure the density (weight) of
drilling fluid, typically in pounds per gallon or specific gravity.
Section 2: Drilling Equipment (Questions 31-60)
31. What is a rotary table? A mechanical device on the drill rig floor that
rotates the kelly and drill string.
32. What is a top drive system? A motor-driven rotating system suspended
from the rig's traveling block that eliminates the need for a kelly and rotary
table.
33. What is the purpose of the crown block? To support the drilling line and
provide mechanical advantage for the hoisting system.
34. What is the traveling block? A movable pulley system that supports the
hook, swivel, and drill string weight during operations.
35. What is the drawworks? The hoisting machinery including the drum,
brakes, and transmission used to raise and lower the drill string.
36. What is a swivel? A rotating connection that allows drilling fluid to enter
the drill string while it rotates.
37. What is a standpipe? A vertical pipe that conducts drilling mud from the
pump to the swivel and rotary hose.
38. What is the rotary hose (kelly hose)? A flexible, high-pressure hose
connecting the standpipe to the swivel.
39. What is the purpose of the derrick or mast? To provide vertical support
for raising and lowering the drill string and casing.
40. What are slips? Wedge-shaped devices that grip the drill pipe and support
the drill string weight in the rotary table.
41. What are elevators? Clamp-like devices that attach to the drill pipe to lift
or lower it during tripping operations.
42. What is a drill pipe sub? A short threaded connector used to join drill
string components with different thread types.
