OCTG

TUSPIPE-TUBING-CASING-OCTG-API-5CT-N80

OCTG

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.

Why Choose TUSPIPE?

pipe-icon

Since 1998, Tianjin United Steel Pipe Co., Ltd (TUSPIPE) has been committed to supplying high-quality line pipes.

With over 500,000 tons annual production capacity, the company serves various fields and industries, such as oil & gas exploitation and transmission, ship & auto-building, water & electricity, environmental protection, mechanical engineering, infrastructure construction and etc.

TUSPIPE places a premium on product quality and rigorous product quality control. In order to maintain good product quality,  the company has established a Test & Inspection Center since 2004. With a series of state-of-the-art tests and inspection equipment, the test & inspection center is able to perform the tensile tests, hydro tests, impact tests, DWTT, etc.

Play Video about Tianjin United Steel Pipe Co., Ltd office building

Types of OCTG (Drill Pipe, Casing and Tubing)

OCTG stands for oil country tubular goods. It is a family of rolled metal products that are utilized in oil and gas drilling and production operations. The term OCTG encompasses a wide range of products, including drill pipe, casing, and tubing. These products are used to connect the wellhead to the downhole equipment, allowing oil and gas to be extracted from the ground. OCTG is a critical component of the oil and gas industry, and its products are essential for safe and efficient drilling operations.

Drill Pipe

Drill Pipe is a type of pipe that is used in oil and gas wells. It is made up of several different parts, including the kelly, the bit, the drill string, and the casing. The kelly is the part of the drill pipe that is attached to the rig, and it helps to rotate the drill string. The bit is the part of the drill pipe that drills into the rock, and it is usually made of steel or tungsten. The drill string is the part of the drill pipe that extends from the kelly to the bit, and it helps to provide support for the bit as it drills. The casing is the final part of the drill pipe, and it helps to protect the wellbore from collapse. All of these parts work together to help oil and gas wells function properly.

Casing Pipe

Casing and tubing are both used in the process of drilling for petroleum. The casing is placed before drilling begins and surrounds the wellbore. Its purpose is to protect the soil layers and groundwater from contamination by drilling mud and/or frac fluids. Additionally, the 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

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 the casing. Consequently, the tubing must be affixed to external support structures, such as a rig or platform, to prevent collapse due to pressure differentials.

Types of OCTG Connections

Oil Country Tubular Goods (OCTG) are pipes used in the oil and gas industry to transport crude oil, natural gas, and other fluids. They come in different sizes and grades, and each length of pipe has a specific use. OCTG connections are what join these pieces of pipe together to form a network that can transport oil and gas from one location to another. 

API connections are the most commonly used type of connection in the oil and gas industry. They meet or exceed all American Petroleum Institute (API) specifications. API proposes two types of coupling: Non-Upset coupling (NU) and External Upset coupling (EU). NU connections are used for joining two pipes of the same diameter, while EU connections are used for joining two pipes of different diameters.

Premium connections are proprietary connections that offer premium features not available on API connections. Most premium connections offer a metal-to-metal seal for improved high-pressure seal integrity. Premium connections exist with features such as flush connections, recess-free bores, and special clearance. This type of connection is preferred for gas wells, high-pressure wells, as well as for wells producing corrosive effluents.

In addition, OCTG threading is a process that creates grooves on the body and end of casing pipes. These grooves form a seal when the pipe is connected to another piece of equipment or piping. The threads are typically Leak–proof, strong, and durable enough to withstand the distribution network for oil and gas. There are three different types of OCTG threading, each with specific benefits: Short round thread casing (STC), long round thread casing (LTC), and buttress thread casing (BTC).

STC is a good choice for shorter-length casing applications that do not involve high axial loads or bending. LTC is well suited for situations where some axial load is encountered but overall well conditions do not include extremes of temperature or pressure. BTC is an excellent connection for use in well situations involving higher axial loads and moderate internal pressures and temperatures. STC and LTC both feature a non–runout design of round threads, each with eight round crested threads per inch. BTC has a square thread with a flat root and crest, a runout design, and five buttress threads per inch.

Each type of OCTG threading has benefits that make it ideal for certain applications. When selecting the best type of threading for your project, be sure to consider the well conditions and the type of equipment that will be used.

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.

API 5CT tubing and casing steel pipe manufacture certificate

Dimensions and Sizes of OCTG (Tubing and Casing)

- Specification & Size of Tubing

DN O. D. Weight W. T. End Processing
Non-upset Upset Steel Grade
coupling-thread coupling-thread
Inch mm lb./ft. lb./ft. Inch mm H40 J55 L80 N80 C90 T95 P110
2002/3/8 2.375 60.32 4 0.167 4.24 PU PN PN PN PN PN
4.6 4.7 0.19 4.83 PNU PNU PNU PNU PNU PNU PNU
5.8 5.95 0.254 6.45 PNU PNU PNU PNU PNU
6.6 0.295 7.49 P P P
7.35 7.45 0.336 8.53 PU PU PU
2002/7/8 2.875 73.02 6.4 6.5 0.217 5.51 PNU PNU
7.8 7.9 0.276 7.01
8.6 8.7 0.308 7.82 PLB PLB PLBE PLB
9.35 9.45 0.34 8.64 PLB PLB PLBE PLB
10.5 0.392 9.96 PLB PLB PLB PLB
11.5 0.44 11.18 PLB
2003/1/2 3.5 88.9 7.7 0.216 5.49 PN PN PN PN PN PN
9.2 9.3 0.254 6.45 PNU PNU PNU PNU PNU PNU PNU
10.2 0.289 7.34 PN PN PN PN PN PN
12.7 12.95 0.375 9.52 PNU PNU PNU PNU PNU
14.3 0.43 10.92 P P P
15.5 0.476 12.09 P P P
17 0.53 13.46 P P P
4 4 101.6 9.5 0.226 5.74 PN PN PN PN PN PN
11 0.262 6.65 PU PU PU PU PU PU
13.2 0.33 8.38 P P P
16.1 0.415 10.54 P P P
18.9 0.5 12.7 P P P
22.2 0.61 15.49 P P P
2004/1/2 4.5 114.3 12.6 12.75 0.271 6.88 PNU PNU PNU PNU PNU PNU
15.2 0.337 8.56 P P P
17 0.38 9.65 P P P
18.9 0.43 10.92 P P P PLB
21.5 0.5 12.7 P P P PLB
23.7 0.56 14.22 P P P PLB
26.1 0.63 16 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
Steel Grade
Inch mm lb/ft kg/m Inch mm H40 J55 L80 N80 C90 P110
K55 T95
2004/1/2 4.5 114.3 9.5 14.14 0.205 5.21 PS PS
10.5 15.63 0.224 5.69 PSB
11.6 17.26 0.25 6.35 PSLB PLB PLB PLB PLB
13.5 20.09 0.29 7.37 PLB PLB PLB PLB
15.1 22.47 0.337 9.56 PLB
5 5 127 11.5 17.11 0.22 5.59 PS
13 19.35 0.253 6.43 PSLB
15 22.32 0.296 7.52 PSLB PLB PLB PLBE PLB
18 26.79 0.362 9.19 PLB PLB PLBE PLB
21.4 31.85 0.437 11.1 PLB PLB PLB PLB
23.2 34.53 0.478 12.14 PLB
24.1 35.86 0.5 12.7 PLB
2005/1/2 5.5 139.7 14 20.83 0.244 6.2 PS PS
15.5 23.07 0.275 6.98 PSLB
17 25.3 0.304 7.72 PSLB PLB PLB PLBE PLB
20 29.76 0.361 9.17 PLB PLB PLBE PLB
23 34.23 0.415 10.54 PLB PLB PLBE PLB
26.8 39.88 0.5 12.7
29.7 44.2 0.562 14.27
32.6 48.51 0.625 15.88
35.3 52.53 0.687 17.45
38 56.55 0.75 19.05
40.5 60.27 0.812 20.62
43.1 64.14 0.875 22.22
2006/5/8 6.625 168.28 20 29.76 0.288 7.32 PS PSLB
24 35.72 0.352 8.94 PSLB PLB PLB PLBE PLB
28 41.67 0.417 10.59 PLB PLB PLBE PLB
32 47.62 0.475 12.06 PLB PLB PLBE PLB
7 7 177.8 17 25.3 0.231 5.87 PS
20 29.76 0.272 6.91 PS PS
23 34.23 0.317 8.05 PSLB PLB PLB PLBE
26 38.69 0.362 9.19 PSLB PLB PLB PLBE PLB
29 43.16 0.408 10.36 PLB PLB PLBE PLB
32 47.62 0.453 11.51 PLB PLB PLBE PLB
35 52.09 0.498 12.65 PLB PLB PLBE PLB
38 56.55 0.54 13.72 PLB PLB PLBE PLB
42.7 63.54 0.625 15.88
46.4 69.05 0.687 17.45
50.1 74.56 0.75 19.05
53.6 79.77 0.812 20.62
57.1 84.97 0.875 22.22
2007/5/8 7.625 193.68 24 35.72 0.3 7.62 PS
26.4 39.29 0.328 8.33 PSLB PLB PLB PLBE PLB
29.7 44.2 0.375 9.52 PLB PLB PLBE PLB
33.7 50.15 0.43 10.92 PLB PLB PLBE PLB
39 58.05 0.5 12.7 PLB PLB PLBE PLB
42.8 63.69 0.562 14.27 PLB PLB PLB PLB
45.3 67.41 0.595 15.11 PLB PLB PLB PLB
47.1 70.09 0.625 15.88 PLB PLB PLB PLB
51.2 76.19 0.687 17.45
55.3 80.3 0.75 19.05
2008/5/8 8.625 219.08 24 35.72 0.264 6.71 PS
28 41.62 0.304 7.72 PS
32 47.62 0.352 8.94 PS PSLB
36 53.57 0.4 10.16 PSLB PLB PLB PLBE PLB
40 59.53 0.45 11.43 PLB PLB PLBE PLB
44 65.48 0.5 12.7 PLB PLB PLBE PLB
49 72.92 0.557 14.15 PLB PLB PLBE PLB
2009/5/8 9.625 244.48 32.3 48.07 0.312 7.92 PS
36 53.57 0.352 8.94 PS PSLB
40 59.53 0.395 10.03 PSLB PLB PLB PLBE
43.5 64.73 0.435 11.05 PLB PLB PLBE PLB
47 69.94 0.472 11.99 PLB PLB PLBE PLB
53.5 79.62 0.545 13.84 PLB PLB PLBE PLB
58.4 86.91 0.595 15.11 PLB PLB PLB PLB
59.4 88.4 0.609 15.47
64.9 96.58 0.672 17.07
70.3 104.62 0.734 18.64
75.6 112.5 0.797 20.24
2010/3/4 10.75 273.05 32.75 48.74 0.279 7.09 PS
40.5 60.27 0.35 8.89 PS PSB
15.5 67.71 0.4 10.16 PSB
51 75.9 0.45 11.43 PSB PSB PSB PSBE PSB
55.5 82.59 0.495 12.57 PSB PSB PSBE PSB
60.7 90.33 0.545 13.84 PSBE PSB
65.7 97.77 0.595 15.11 PSB PSB
73.2 108.93 0.672 17.07
79.2 117.86 0.734 18.64
85.3 126.94 0.797 20.24
2011/3/4 11.75 42 62.5 0.333 8.46 PS
47 69.94 0.375 20.24
54 80.36 0.435 8.46
60 89.29 0.489 9.53
65 96.73 0.534 11.05
71 105.66 0.582 14.42
2013/3/8 13.375 339.73 48 71.43 0.33 8.38 PS
54.5 81.1 0.38 9.65 PSB
61 90.78 0.43 10.92 PSB
68 101.19 0.48 12.19 PSB PSB PSB PSB PSB
72 107.15 0.514 13.06 PSB PSB PSB PSB
16 16 406.4 65 96.73 0.375 9.53 PS
75 111.61 0.438 11.13 PSB
84 125.01 0.495 12.57 PSB
109 162.21 0.656 16.66 P P P P
2018/5/8 18.625 473.08 87.5 130.21 0.435 11.05 PS PSB
20 20 508 94 139.89 0.438 11.13 PSL PSLB
106.5 158.49 0.5 12.7 PSLB
133 197.93 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 Steel Type C Mn Mo Cr Ni Cu P S Si
Grade 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
13Cr 0.15 0.22 0.25 1 12 14 0.5 0.25 0.02 0.01 1
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)

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.

Line-Pipe
Line Pipe
Slotted-Liner
Slotted Liner
Pipe-Fabrication-Spooling
Steel Fabrication
pipe-fittings
Pipe Fittings
Scroll to Top

Get A Quote Now

Fill in the form below and our team will be happy to assist you