Casing & Tubing

Grades of casing pipe:

• API 5CT H40
• API 5CT J55
• API 5CT K55
• API 5CT M65
• API 5CT N80 (1,Q)
• API 5CT L80 (9Cr,13Cr)
• API 5CT C90
• API 5CT T95
• API 5CT P110
• API 5CT Q125

Sizes of casing pipe:
Casing pipe diameter: from 4 1/2 inch  to 20 inch  （48.26mm - 508mm)
Casing pipe nominal weight: from 9.5 lb/ft  to 169 lb/ft, from 9.5 ppf  to 169 ppf
Casing pipe lenght: R1, R2, R3

Types of casing pipe:
Seamless casing pipe (small-diameter, medium-diameter)
ERW casing (medium-diameter)
Casing pup joint
Casing coupling

Applications of casing pipe: 

oil well extracting casing
borehole casing
borewell casing

Connections of casing pipe
API 5CT is applicable to following connections which complied with API SPEC 5B:
• SC: Short round thread casing
• LC: Long ound thread casing
• BC: Buttress thread casing
• NU: Non-upset tubing
• EU: External upset tubing
• IJ: Integral tubing connections


 
4 groups of grade
• Group 1: All casing and tubing in Grades with H, J, K, N and R
• Group 2: All casing and tubing in Grades with C, L, M and T
• Group 3: All casing and tubing in Grade P
• Group 4: All casing in Grade Q

Casing pipe finishing process

Chemical composition of API 5CT steel casing pipe and tubing pipes:

Chemical composition,mass fraction(%)

Group

Grade

Type

C

Mn

Mo

Cr

Ni

Cu

P

S

Si

Min.

Max.

Min.

Max.

Min.

Max.

Min.

Max.

Max.

Max.

Max.

Max.

Max.

1

H40

–

–

–

–

–

–

–

–

–

–

–

0.03

0.030

–

J55

–

–

–

–

–

–

–

–

–

–

–

0.03

0.030

–

K55

–

–

–

–

–

–

–

–

0.03

0.030

–

N80

1

–

–

–

–

–

–

–

–

–

–

0.03

0.030

–

N80

Q

–

–

–

–

–

–

–

–

–

–

0.03

0.030

–

R95

–

–

0.45

–

1.90

–

–

–

–

–

–

0.03

0.030

0.45

2

M65

–

–

–

–

–

–

–

–

–

–

–

0.03

0.030

–

L80

1

–

0.43

–

1.90

–

–

–

–

0.25

0.35

0.03

0.030

0.45

L80

9Cr

–

0.15

0.30

0.60

0.90

1.10

8.00

10.00

0.50

0.25

0.02

0.010

1.00

L80

13Cr

0.15

0.22

0.25

1.00

–

–

12.00

14.00

0.50

0.25

0.02

0.010

1.00

C90

1

–

0.35

–

1.20

0.25

0.85

–

1.50

0.99

–

0.02

0.010

–

T95

1

–

0.35

–

1.20

0.25

0.85

0.40

1.50

0.99

–

0.02

0.010

–

C110

–

–

0.35

–

1.20

0.25

1.00

0.40

1.50

0.99

–

0.02

0.005

–

3

P110

–

–

–

–

–

–

–

–

–

–

–

0.03

0.030

–

4

Q125

1

–

0.35

–

1.35

–

0.85

–

1.50

0.99

–

0.02

0.010

–

• a.The carbon content for L80 may be increased up to 0.50% maximum if the product is oil-quenched.
• b. The molybdenum content for Grade C90 Type 1 has no minimum tolerance if the WT is less than 17,78mm.
• c.The carbon content for R95 may be increased up to0.55% maximum if the product is oil-quenched.
• d.The molybdenum content for T95 Type 1 may be decreased to 0.15% minimum if the WT is less than 17,78mm.
• e. For EW Grade P110,the phosphorus content shall be 0.020% maximum and the sulfur content 0.010% maximum
• NL=no limit.Elements shown shall be reported in product analysis.

Mechanical properties of API 5CT steel casing pipe and tubing pipes:

Size table of casing pipe

Outside Diameter (Inches)	Available Poundage (Pounds Per Foot)
4-1/2	9.50 PPF to 15.10 PPF
5	11.50 PPF to 24.10 PPF
5-1/2	14.00 PPF to 43.10 PPF
6-5/8	20.00 PPF to 32.00 PPF
7	17.00 PPF to 57.10 PPF
7-5/8	24.00 PPF to 55.30 PPF
7-3/4	46.10 PPF
8-5/8	24.00 PPF to 49.00 PPF
9-5/8	32.30 PPF to 75.60 PPF
10-3/4	32.75 PPF to 85.30 PPF
11-3/4	42.00 PPF to 71.00 PPF
13-3/8	48.00 PPF to 72.00 PPF
16	65.00 PPF to 109.00 PPF
18-5/8	87.50 PPF
20	94.00 PPF to 133.00 PPF

Size table of tubing

Outside Diameter (Inches)	Corresponding Poundage (Pounds Per Foot)
1.050	1.14 PPF to 1.54 PPF
1.315	1.70 PPF to 2.24 PPF
1.660	2.09 PPF to 3.07 PPF
1.900	2.40 PPF to 5.15 PPF
2.063	3.24 PPF to 4.50 PPF
2-3/8	4.00 PPF to 7.45 PPF
2-7/8	6.40 PPF to 11.50 PPF
3-1/2	7.70 PPF to 17.00 PPF
4	9.50 PPF to 22.20 PPF
4-1/2	12.60 PPF to 26.10 PPF

Marking on casing pipe

Casing pipe are in a warehouse

Casing pipe are in operation at yard