บิต IADC 437 216 มม. สำหรับชั้นที่อ่อนนุ่ม

IADC

WOB(KN/mm Bit Dia.)

RPM(r/min)

Applicable Formations

435

515

0.20~0.70

200~80

 Soft with very low compressive strength such as shale ,clay, sandstone ,soft  limestone ,etc

535

0.35~0.80

200~80

Medium soft with low compressive strength and harder abrasive stringers ,such as hard shale ,hared gypsolyte, soft limestone, sandstone and dolomite with stringer ,etc

417

437

0.35~0.90

140~70

Very soft with low compressive strength and high drillability, such as shale, clay, sandstone and conglomerate ,etc.

517

527

 0.35~1.05

120~50

Soft with low compressive strength, such as shale, clay, sandstone, soft limestone, salt bed and hard gypsolyte, etc

537

547

0.35~1.05

110~40

Medium soft with low compressive strength and harder abrasive stringers, such as hard shale, hard gypsolyte, soft limestone, sandstone and dolomite with stringers ,etc

617

627

0.35~1.05

80~40

Medium hard with high compressive strength and thick &hard stringers, such as hard shale, limestone, sandstone and dolomite, etc

637

737

0.70~1.20

70~40

Medium hard with high compressive strength and high abrasiveness ,such as limestone ,dolomite, sandstone and chert ,etc

Note: The upper limits of WOB and RPM in above table should not be used simultaneously

NO.

Tricone bit size

Thread  

NO.

Tricone bit size

Thread 

Inch

mm

inch

mm

1

3-3/4

95.3

2-3/8 " REG Pin

28

9-5/8

244.5

6-5/8

2

3-7/8

98.4

29

9-7/8

250.8

6-5/8" REG Pin

3

4-1/8

104.8

30

10-1/2

266.7

4

4-1/4

108.0

31

10-5/8

269.9

5

4-1/2

114.3

32

11

279.4

6

4-5/8

117.5

2-7/8" REG Pin

33

11-5/8

6-5/8

7

4-3/4

120.7

34

12

304.8

8

4-7/8

123.8

35

12-1/4

311.2

9

5-1/2

139.7

3-1/2" REG Pin

36

12-5/16

6-5/8

10

5-5/8

142.9

37

12-3/8

314.3

11

5-2/3

143.9

38

12-7/16

315.9

12

5-3/4

146.1

39

12-5/8

320.7

13

5-7/8

149.2

40

13-1/8

333.4

14

6

152.4

41

13-1/2

342.9

15

6-1/8

155.6

42

13-5/8

346.1

16

6-1/4

158.8

43

13-3/4

349.3

17

6-1/2

165.1

44

14-1/2

374.7

7-5/8" REG Pin

18

6-5/8

168.3

45

14-3/4

374.7

19

6-3/4

171.5

46

15-1/2

393.7

20

7-1/2

190.5

4-1/2" REG Pin

47

16

7-5/8

21

7-5/8

193.7

48

17-1/2

444.5

22

7-7/8

200.0

49

18-7/8

479.4

23

8-3/8

212.7

50

20

508.0

24

8-1/2

215.9

51

22

558.8

25

8-5/8

219.1

52

24

609.6

26

8-3/4

222.3

53

26

660.4

27

9-1/2

241.3

6 5/8 " REG Pin