OCTG
OCTG (Casing and Tubing)
OCTG, or oil country tubular goods, refers to a variety of steel products that are used in the drilling and extraction of oil and gas. The API 5CT standard covers a wide range of OCTG products, including tubing, casing, and couplings. OCTG products are essential for the safe and efficient operation of oil and gas wells. The API 5CT standard helps to ensure that OCTG products meet the highest standards of quality and safety. It includes requirements for material quality, dimensions, strength, threading, and testing. The API 5CT standard is an important part of the oil and gas industry, and it helps to ensure that OCTG products are safe for use in petroleum operations.
PRODUCT FEATURES
Types of OCTG (Tubing and Casing)
Casing and tubing are both used in the process of drilling for petroleum. Casing is placed before drilling begins and completely surrounds the wellbore. Its purpose is to protect the soil layers and groundwater from contamination by drilling mud and/or frac fluids. Additionally, casing stabilizes the wellbore. Drilling and casing operations alternate – the drill string is removed at predetermined intervals and the wellbore is lined and cemented with casing.
Tubing is used to carry petroleum from the well’s depths to the surface. This is the third phase of the wellbore process. Oil and gas occasionally self-elevate to the surface; however, pumps are typically required to bring the fluids to the surface. Besides the 4 1/2-inch diameter, tubing is normally smaller in diameter than casing. Consequently, tubing must be affixed to external support structures, such as a rig or platform, in order to prevent collapse due to pressure differentials.
Production Standards of OCTG
API 5CT is the American Petroleum Institute’s specification for oil and gaswell casing and tubing. The specification covers coupling, threading, dimensions and other mechanical properties for oil and gas industry products like casing and tubing. API 5CT is the most common standard used in oil and gas industry applications. The specification covers several grades of steel, including J55, K55, N80, L80 and P110. Coupling is a threaded connection used to join oil and gas well casing or tubing. Threading refers to the process of cuttinng threads into the end of a pipe or coupling. Dimensions vary depending on the type of casing or tubing being used. American Petroleum Institute standards are voluntary consensus standards that are not mandated by law. However, oil and gas companies often require that products used in their operations meet API standards.
Dimensions and Sizes of OCTG (Tubing and Casing)
- Specification & Size of Tubing
DN | O. D. | Weight | W. T. | End Processing | |||||||||
Non-upset coupling-thread | Upset coupling-thread | OCTG Steel Grade | |||||||||||
in | mm | lb./ft. | lb./ft. | in | mm | H40 | J55 | L80 | N80 | C90 | T95 | P110 | |
2-3/8 | 2.375 | 60.32 | 4.00 | – | 0.167 | 4.24 | PU | PN | PN | PN | PN | PN | – |
4.60 | 4.70 | 0.190 | 4.83 | PNU | PNU | PNU | PNU | PNU | PNU | PNU | |||
5.80 | 5.95 | 0.254 | 6.45 | – | – | PNU | PNU | PNU | PNU | PNU | |||
6.60 | – | 0.295 | 7.49 | – | – | P | – | P | P | – | |||
7.35 | 7.45 | 0.336 | 8.53 | – | – | PU | – | PU | PU | – | |||
2-7/8 | 2.875 | 73.02 | 6.40 | 6.50 | 0.217 | 5.51 | PNU | PNU | – | – | – | – | – |
7.80 | 7.90 | 0.276 | 7.01 | – | – | – | – | – | – | – | |||
8.60 | 8.70 | 0.308 | 7.82 | – | – | PLB | PLB | PLBE | – | PLB | |||
9.35 | 9.45 | 0.340 | 8.64 | – | – | PLB | PLB | PLBE | – | PLB | |||
10.50 | – | 0.392 | 9.96 | – | – | PLB | PLB | PLB | – | PLB | |||
11.50 | – | 0.440 | 11.18 | – | – | – | – | PLB | – | ||||
3-1/2 | 3.500 | 88.90 | 7.70 | – | 0.216 | 5.49 | PN | PN | PN | PN | PN | PN | – |
9.20 | 9.30 | 0.254 | 6.45 | PNU | PNU | PNU | PNU | PNU | PNU | PNU | |||
10.20 | – | 0.289 | 7.34 | PN | PN | PN | PN | PN | PN | – | |||
12.70 | 12.95 | 0.375 | 9.52 | – | – | PNU | PNU | PNU | PNU | PNU | |||
14.30 | – | 0.430 | 10.92 | – | – | P | – | P | P | – | |||
15.50 | – | 0.476 | 12.09 | – | – | P | – | P | P | – | |||
17.00 | – | 0.530 | 13.46 | – | – | P | – | P | P | – | |||
4 | 4.000 | 101.60 | 9.50 | – | 0.226 | 5.74 | PN | PN | PN | PN | PN | PN | – |
– | 11.00 | 0.262 | 6.65 | PU | PU | PU | PU | PU | PU | – | |||
13.20 | – | 0.330 | 8.38 | – | – | P | – | P | P | – | |||
16.10 | – | 0.415 | 10.54 | – | – | P | – | P | P | – | |||
18.90 | – | 0.500 | 12.70 | – | – | P | – | P | P | – | |||
22.20 | – | 0.610 | 15.49 | – | – | P | – | P | P | – | |||
4-1/2 | 4.500 | 114.30 | 12.60 | 12.75 | 0.271 | 6.88 | PNU | PNU | PNU | PNU | PNU | PNU | – |
15.20 | – | 0.337 | 8.56 | – | – | P | – | P | P | – | |||
17.00 | – | 0.380 | 9.65 | – | – | P | – | P | P | – | |||
18.90 | – | 0.430 | 10.92 | – | – | P | – | P | P | PLB | |||
21.50 | – | 0.500 | 12.70 | – | – | P | – | P | P | PLB | |||
23.70 | – | 0.560 | 14.22 | – | – | P | – | P | P | PLB | |||
26.10 | – | 0.630 | 16.00 | – | – | P | – | P | P | PLB | |||
P——Plain；N—— Non-upset coupling-thread；U—— Upset coupling-thread； L——Integral | |||||||||||||
- Specification & Size of Casing Pipe
DN | O. D. | Weight | W. T. | End Machining Form | ||||||||
OCTG Steel Grade | ||||||||||||
in | mm | lb/ft | kg/m | in | mm | H40 | J55 | L80 | N80 | C90 | P110 | |
K55 | T95 | |||||||||||
4-1/2 | 4.500 | 114.3 | 9.50 | 14.14 | 0.205 | 5.21 | PS | PS | – | – | – | – |
10.50 | 15.63 | 0.224 | 5.69 | – | PSB | – | – | – | – | |||
11.60 | 17.26 | 0.250 | 6.35 | – | PSLB | PLB | PLB | PLB | PLB | |||
13.50 | 20.09 | 0.290 | 7.37 | – | – | PLB | PLB | PLB | PLB | |||
15.10 | 22.47 | 0.337 | 9.56 | – | – | – | – | – | PLB | |||
5 | 5.000 | 127 | 11.50 | 17.11 | 0.220 | 5.59 | – | PS | – | – | – | – |
13.00 | 19.35 | 0.253 | 6.43 | – | PSLB | – | – | – | – | |||
15.00 | 22.32 | 0.296 | 7.52 | – | PSLB | PLB | PLB | PLBE | PLB | |||
18.00 | 26.79 | 0.362 | 9.19 | – | – | PLB | PLB | PLBE | PLB | |||
21.40 | 31.85 | 0.437 | 11.10 | – | – | PLB | PLB | PLB | PLB | |||
23.20 | 34.53 | 0.478 | 12.14 | – | – | – | – | PLB | – | |||
24.10 | 35.86 | 0.500 | 12.70 | – | – | – | – | PLB | – | |||
5-1/2 | 5.500 | 139.7 | 14.00 | 20.83 | 0.244 | 6.20 | PS | PS | – | – | – | – |
15.50 | 23.07 | 0.275 | 6.98 | – | PSLB | – | – | – | – | |||
17.00 | 25.30 | 0.304 | 7.72 | – | PSLB | PLB | PLB | PLBE | PLB | |||
20.00 | 29.76 | 0.361 | 9.17 | – | – | PLB | PLB | PLBE | PLB | |||
23.00 | 34.23 | 0.415 | 10.54 | – | – | PLB | PLB | PLBE | PLB | |||
26.80 | 39.88 | 0.500 | 12.70 | – | – | – | – | – | – | |||
29.70 | 44.20 | 0.562 | 14.27 | – | – | – | – | – | – | |||
32.60 | 48.51 | 0.625 | 15.88 | – | – | – | – | – | – | |||
35.30 | 52.53 | 0.687 | 17.45 | – | – | – | – | – | – | |||
38.00 | 56.55 | 0.750 | 19.05 | – | – | – | – | – | – | |||
40.50 | 60.27 | 0.812 | 20.62 | – | – | – | – | – | – | |||
43.10 | 64.14 | 0.875 | 22.22 | – | – | – | – | – | – | |||
6-5/8 | 6.625 | 168.28 | 20.00 | 29.76 | 0.288 | 7.32 | PS | PSLB | – | – | – | – |
24.00 | 35.72 | 0.352 | 8.94 | – | PSLB | PLB | PLB | PLBE | PLB | |||
28.00 | 41.67 | 0.417 | 10.59 | – | – | PLB | PLB | PLBE | PLB | |||
32.00 | 47.62 | 0.475 | 12.06 | – | – | PLB | PLB | PLBE | PLB | |||
7 | 7.000 | 177.8 | 17.00 | 25.30 | 0.231 | 5.87 | PS | – | – | – | – | – |
20.00 | 29.76 | 0.272 | 6.91 | PS | PS | – | – | – | – | |||
23.00 | 34.23 | 0.317 | 8.05 | – | PSLB | PLB | PLB | PLBE | – | |||
26.00 | 38.69 | 0.362 | 9.19 | – | PSLB | PLB | PLB | PLBE | PLB | |||
29.00 | 43.16 | 0.408 | 10.36 | – | – | PLB | PLB | PLBE | PLB | |||
32.00 | 47.62 | 0.453 | 11.51 | – | – | PLB | PLB | PLBE | PLB | |||
35.00 | 52.09 | 0.498 | 12.65 | – | – | PLB | PLB | PLBE | PLB | |||
38.00 | 56.55 | 0.540 | 13.72 | – | – | PLB | PLB | PLBE | PLB | |||
42.70 | 63.54 | 0.625 | 15.88 | – | – | – | – | – | – | |||
46.40 | 69.05 | 0.687 | 17.45 | – | – | – | – | – | – | |||
50.10 | 74.56 | 0.750 | 19.05 | – | – | – | – | – | – | |||
53.60 | 79.77 | 0.812 | 20.62 | – | – | – | – | – | – | |||
57.10 | 84.97 | 0.875 | 22.22 | – | – | – | – | – | – | |||
7-5/8 | 7.625 | 193.68 | 24.00 | 35.72 | 0.300 | 7.62 | PS | – | – | – | – | – |
26.40 | 39.29 | 0.328 | 8.33 | – | PSLB | PLB | PLB | PLBE | PLB | |||
29.70 | 44.20 | 0.375 | 9.52 | – | – | PLB | PLB | PLBE | PLB | |||
33.70 | 50.15 | 0.430 | 10.92 | – | – | PLB | PLB | PLBE | PLB | |||
39.00 | 58.05 | 0.500 | 12.70 | – | – | PLB | PLB | PLBE | PLB | |||
42.80 | 63.69 | 0.562 | 14.27 | – | – | PLB | PLB | PLB | PLB | |||
45.30 | 67.41 | 0.595 | 15.11 | – | – | PLB | PLB | PLB | PLB | |||
47.10 | 70.09 | 0.625 | 15.88 | – | – | PLB | PLB | PLB | PLB | |||
51.20 | 76.19 | 0.687 | 17.45 | – | – | – | – | – | – | |||
55.30 | 80.30 | 0.750 | 19.05 | – | – | – | – | – | – | |||
8-5/8 | 8.625 | 219.08 | 24.00 | 35.72 | 0.264 | 6.71 | – | PS | – | – | – | – |
28.00 | 41.62 | 0.304 | 7.72 | PS | – | – | – | – | – | |||
32.00 | 47.62 | 0.352 | 8.94 | PS | PSLB | – | – | – | – | |||
36.00 | 53.57 | 0.400 | 10.16 | – | PSLB | PLB | PLB | PLBE | PLB | |||
40.00 | 59.53 | 0.450 | 11.43 | – | – | PLB | PLB | PLBE | PLB | |||
44.00 | 65.48 | 0.500 | 12.70 | – | – | PLB | PLB | PLBE | PLB | |||
49.00 | 72.92 | 0.557 | 14.15 | – | – | PLB | PLB | PLBE | PLB | |||
9-5/8 | 9.625 | 244.48 | 32.30 | 48.07 | 0.312 | 7.92 | PS | – | – | – | – | – |
36.00 | 53.57 | 0.352 | 8.94 | PS | PSLB | – | – | – | – | |||
40.00 | 59.53 | 0.395 | 10.03 | – | PSLB | PLB | PLB | PLBE | – | |||
43.50 | 64.73 | 0.435 | 11.05 | – | – | PLB | PLB | PLBE | PLB | |||
47.00 | 69.94 | 0.472 | 11.99 | – | – | PLB | PLB | PLBE | PLB | |||
53.50 | 79.62 | 0.545 | 13.84 | – | – | PLB | PLB | PLBE | PLB | |||
58.40 | 86.91 | 0.595 | 15.11 | – | – | PLB | PLB | PLB | PLB | |||
59.40 | 88.40 | 0.609 | 15.47 | – | – | – | – | – | – | |||
64.90 | 96.58 | 0.672 | 17.07 | – | – | – | – | – | – | |||
70.30 | 104.62 | 0.734 | 18.64 | – | – | – | – | – | – | |||
75.60 | 112.50 | 0.797 | 20.24 | – | – | – | – | – | – | |||
10-3/4 | 10.750 | 273.05 | 32.75 | 48.74 | 0.279 | 7.09 | PS | – | – | – | – | – |
40.50 | 60.27 | 0.350 | 8.89 | PS | PSB | – | – | – | – | |||
15.50 | 67.71 | 0.400 | 10.16 | – | PSB | – | – | – | – | |||
51.00 | 75.90 | 0.450 | 11.43 | – | PSB | PSB | PSB | PSBE | PSB | |||
55.50 | 82.59 | 0.495 | 12.57 | – | – | PSB | PSB | PSBE | PSB | |||
60.70 | 90.33 | 0.545 | 13.84 | – | – | – | – | PSBE | PSB | |||
65.70 | 97.77 | 0.595 | 15.11 | – | – | – | – | PSB | PSB | |||
73.20 | 108.93 | 0.672 | 17.07 | – | – | – | – | – | – | |||
79.20 | 117.86 | 0.734 | 18.64 | – | – | – | – | – | – | |||
85.30 | 126.94 | 0.797 | 20.24 | – | – | – | – | – | – | |||
11-3/4 | 11.750 | 42.00 | 62.50 | 0.333 | 8.46 | PS | – | – | – | – | – | |
47.00 | 69.94 | 0.375 | 20.24 | – | – | – | – | – | – | |||
54.00 | 80.36 | 0.435 | 8.46 | – | – | – | – | – | – | |||
60.00 | 89.29 | 0.489 | 9.53 | – | – | – | – | – | – | |||
65.00 | 96.73 | 0.534 | 11.05 | – | – | – | – | – | – | |||
71.00 | 105.66 | 0.582 | 14.42 | – | – | – | – | – | – | |||
13-3/8 | 13.375 | 339.73 | 48.00 | 71.43 | 0.330 | 8.38 | PS | – | – | – | – | – |
54.50 | 81.10 | 0.380 | 9.65 | – | PSB | – | – | – | – | |||
61.00 | 90.78 | 0.430 | 10.92 | – | PSB | – | – | – | – | |||
68.00 | 101.19 | 0.480 | 12.19 | – | PSB | PSB | PSB | PSB | PSB | |||
72.00 | 107.15 | 0.514 | 13.06 | – | – | PSB | PSB | PSB | PSB | |||
16 | 16.000 | 406.4 | 65.00 | 96.73 | 0.375 | 9.53 | PS | – | – | – | – | – |
75.00 | 111.61 | 0.438 | 11.13 | – | PSB | – | – | – | – | |||
84.00 | 125.01 | 0.495 | 12.57 | – | PSB | – | – | – | – | |||
109.00 | 162.21 | 0.656 | 16.66 | – | P | P | P | – | P | |||
18-5/8 | 18.625 | 473.08 | 87.50 | 130.21 | 0.435 | 11.05 | PS | PSB | – | – | – | – |
20 | 20.000 | 508 | 94.00 | 139.89 | 0.438 | 11.13 | PSL | PSLB | – | – | – | – |
106.50 | 158.49 | 0.500 | 12.70 | – | PSLB | – | – | – | – | |||
133.00 | 197.93 | 0.635 | 16.13 | – | PSLB | – | – | – | – | |||
P——Plain；S——Short-thread；L——Long-thread；B——Buttress thread；E——Extreme thread | ||||||||||||
Chemical Composition of OCTG (Tubing and Casing)
Group | OCTG Steel Grade | Type | C | Mn | Mo | Cr | Ni | Cu | P | S | Si | ||||
min. | max. | min. | max. | min. | max. | min. | max. | min. | max. | max. | max. | max. | |||
1 | H40 | – | – | – | – | – | – | – | – | – | – | – | 0.03 | 0.03 | – |
J55 | – | – | – | – | – | – | – | – | – | – | – | 0.03 | 0.03 | – | |
K55 | – | – | – | – | – | – | – | – | – | – | – | 0.03 | 0.03 | – | |
N80 | 1 | – | – | – | – | – | – | – | – | – | – | 0.03 | 0.03 | – | |
Q | – | – | – | – | – | – | – | – | – | – | 0.03 | 0.03 | – | ||
2 | M65 | – | – | – | – | – | – | – | – | – | – | – | 0.03 | 0.03 | – |
L80 | 1 | – | 0.43 | – | 1.9 | – | – | – | – | 0.25 | 0.35 | 0.03 | 0.03 | 0.5 | |
9Cr | – | 0.15 | 0.3 | 0.6 | 0.9 | 1.1 | 8 | 10 | 0.5 | 0.25 | 0.02 | 0.01 | 1.0 | ||
13Cr | 0.15 | 0.22 | 0.25 | 1 | – | – | 12 | 14 | 0.5 | 0.25 | 0.02 | 0.01 | 1.0 | ||
C90 | 1 | – | 0.35 | – | 1.2 | 0.25 | 0.85 | – | 1.5 | 0.99 | – | 0.02 | 0.01 | – | |
2 | – | 0.5 | – | 1.9 | – | NL | – | NL | 0.99 | – | 0.03 | 0.01 | – | ||
C95 | – | – | 0.45 | – | 1.9 | – | – | – | – | – | – | 0.03 | 0.03 | 0.5 | |
T95 | 1 | – | 0.35 | – | 1.2 | 0.25 | 0.85 | 0.4 | 1.5 | 0.99 | – | 0.02 | 0.01 | – | |
2 | – | 0.5 | – | 1.9 | – | – | – | – | 0.99 | – | 0.03 | 0.01 | – | ||
3 | P110 | – | – | – | – | – | – | – | – | – | – | – | 0.03 | 0.03 | – |
4 | Q125 | 1 | – | 0.35 | – | 1.35 | – | 0.85 | – | 1.5 | 0.99 | – | 0.02 | 0.01 | – |
2 | – | 0.35 | – | 1 | – | NL | – | NL | 0.99 | – | 0.02 | 0.02 | – | ||
3 | – | 0.5 | – | 1.9 | – | NL | – | NL | 0.99 | – | 0.03 | 0.01 | – | ||
4 | – | 0.5 | – | 1.9 | – | NL | – | NL | 0.99 | – | 0.03 | 0.02 | – | ||
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, 78 mm. c. The carbon content for R95 may be increased up to 0, 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, 78 mm. 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 OCTG (Tubing and Casing)
Group | OCTG Steel Grade | Type | Total | Yield Strength | Tensile | Hardness | W. T. | Changes in Hardness | ||
min. | max. | min. | HRC | HBW | ||||||
1 | H40 | – | 0.5 | 276 | 552 | 414 | – | – | – | – |
J55 | – | 379 | 552 | 517 | – | – | – | – | ||
K55 | – | 379 | 552 | 655 | – | – | – | – | ||
N80 | 1 | 552 | 758 | 689 | – | – | – | – | ||
Q | 552 | 758 | 689 | – | – | – | – | |||
2 | M65 | – | 0.5 | 448 | 586 | 586 | 22 | 235 | – | – |
L80 | 1 | 552 | 655 | 655 | 23 | 241 | – | – | ||
9Cr | 552 | 655 | 655 | 23 | 241 | – | – | |||
13Cr | 552 | 655 | 655 | 23 | 241 | – | – | |||
C90 | 1、2 | 621 | 724 | 689 | 25.4 | 255 | ≤ 12.70 | 3.0 | ||
621 | 724 | 689 | 25.4 | 255 | 12.71 ~ 19.04 | 4.0 | ||||
621 | 724 | 689 | 25.4 | 255 | 19.05 ~ 25.39 | 5.0 | ||||
621 | 724 | 689 | 25.4 | 255 | ≥25.40 | 6.0 | ||||
C95 | – | 655 | 758 | 724 | – | – | – | – | ||
T95 | 1、2 | 655 | 758 | 724 | 25.4 | 255 | ≤ 12.70 | 3.0 | ||
655 | 758 | 724 | 25.4 | 255 | 12.71 ~ 19.04 | 4.0 | ||||
655 | 758 | 724 | 25.4 | 255 | 19.05 ~ 25.39 | 5.0 | ||||
655 | 758 | 724 | 25.4 | 255 | ≥25.40 | 6.0 | ||||
3 | P110 | – | 0.6 | 758 | 965 | 862 | – | – | – | – |
4 | Q125 | all | 0.65 | 862 | 1034 | 931 | – | – | ≤ 12.70 | 3.0 |
862 | 1034 | 931 | – | – | 12.71 ~ 19.04 | 4.0 | ||||
862 | 1034 | 931 | – | – | ≥19.05 | 5.0 | ||||
OCTG for Sand Control - Slotted Liner
Slotted liner is a well screening device that is used for sand control and fluid retention in petroleum wells. It consists of a series of slotted holes that are drilled into the well screen to allow fluid to flow through while retaining sand and other particulate matter. Slotted liner is an effective way to improve well productivity and prevent formation damage. It is also a cost-effective alternative to traditional well screens. Slotted liner can be used in both new and existing wells, and it is available in a variety of materials and configurations.
