Drill Off Test Procedure

  1. Maintain a constant RPM. Select a WOB (near maximum allowable).
  2. Record the time to drill off a weight increment, ie 5000 lbs.
  3. Record length of pipe drilled during step 2.
  4. From steps 2 and 3 the drill rate in feet per hours may be found.
  5. Repeat steps 2 and 3 at least four times. The last test should be at the same value as the first. This repeat test will determine if the formation has changed or not.
  6. Plot seconds to drill off versus bit weight.
  7. Plot penetration rate versus bit weight.
  8. Select the bit weight which produced the fasted ROP. Maintain this WOB constant and repeat the above but for varying RPM.
  9. Plot ROP versus RPM and select the RPM which resulted in the fastest ROP. This is the optimum rotary speed.
  10. These values for RPM and WOB obtained will result in optimum progress for the particular formation and bit type.

DRILL OFF TEST Example

Oil

BIT WT

TIME FOOTAGE

DRILL RATE

Ol

(lbs)

(sec) (feet)

(fph)

50,000

59 0.5

30.5

90

45.000

62 0.5

29.0

40,000

68 0.6

31.8

100

, 35 000

74 0.48

23.4

30

35 40

45

50

BIT WEIGHT

(KLBS)

30,000

78 0.45

20.8

50,000

60 0.5

30.0

30

/

s.

/

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  • leon
    What is a drill off test?
    9 years ago
  • pippin
    How to conduct drill off test?
    3 years ago
  • dina goodchild
    Where to check drill pipe date of manufacture?
    3 years ago

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