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Torque in 100 daN.m

NOTE 1

The maximum allowable torques and pulls have been calculated with maximum stress values limited to 85% of the minimum yield of the material in question

NOTE 2

Minimum unit torsional 1—300

yieldstrength in shear assumed at 57.7% of minimum unit yieldstrength in tension

3=4.5"-16.6 lbs/ft 4=3.5"-15.5 lbs/ft 5—3.5"-13.3 lbs/ft

ALLOWABLE TORQUE AND PULL ON API "PREMIUM" DRILLPIPE WITH .85 SAFETY FACTOR (S.I. UNITS)

NOTE 2

Minimum unit torsional |_ 300

yieldstrength in shear assumed at 57.7% of minimum unit yieldstrength in tension

TORQUE VERSUS NUMBER OF TURNS (PIPE BODY)

Outside

Inside

K-factor

K-factor

Diameter

Diameter

new-pipe

premium-pipe

inch | mm

inch ! mm

lbs/ft ! kg/m

field units

S.I. units

field units

S.I. units

3 h \ 88.9

2.764! 70.2

13.3 119.79

4599.73

19469.33

3411.07

14437.69

3 188.9

2.602166.1

15.5 123.07

5228.08

22119.07

3797.93

16069.14

4 1/2 ¡114.3

3.958(100.5

13.75i20.46

8258.98

35019.58

6347.46

26911.53

4 1/2 [114.3

3.826! 97.2

16.6 124.70

9820.87

41523.80

7464.74

31563.88

4 V2 jl14.3

3.640! 92.5

20.0 ! 29.76

11763.50

49710.46

8794.41

37169.52

5 127

4.408! 112

16.25124.18

12412.92

52424.28

9547.16

40325.41

5 ! 127

4.276106.6

19.5 ! 29.02

14581.51

61734.05

11104.53

47011.99

,5 I 127

4.000101.6

25.6 138.10

18509.75

78330.59

13786.58

58342.83

^ Premium Class = Minimum remaining wall thickness = 80% (Uniform wear)

Torque in N-m(ft.lbs) = Kx turns/100m (turns/1000 ft) in S.I. : K = 0.00051 (D4- d4)[D and d in mm] in Field : K = 50.16192167(D*- d4)[D and d in inch]

The K-factor calculation is based on a shear modulus of 8.2737 x 1010N/m2(11.71 x 106 psi) Example:

i27mm 29.02 kg/m new D.P. grade E stuck at 3672 m

Weight of free pipe in air is

111000 daN Allowable torque is 3300 daN-m

(graph page C-17)

5" 19.5 lbs/ft "new D.P" grade E stuck at' 11900 ft. Weight of free pipe in air is

11900 x 20.99 - 250000 lbs. Allowable torque is 24000 ft-lbs

(graph page C-14)

3300x10 61734.48

0.5346

Turns per 1000 ft =

24000 14581.51

Number of turns is 0.5346 x 36.72 = 19.6 turns

Note:

Remember that if the tooljoint make-up torque is less than the allowable pipe body torque then when applying lefthand torque the pipe may back off before the allowable pipe body torque has been reached. If this is not desired the lower torque limit is determined by the lowest actually used tooljoint make up torque.

Note:

The graphs C-14 and C-17 have a safety factor of 85%. In A.P.I. R.P.7G. no safety factor is applied.

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