Casing

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Casing

Casing
Casing
Casing
Casing
Casing

Pipe Type: Seamless casing pipe, ERW casing pipe,API Spec 5CT J55 K55 N80 L80 Casing Pipe;Seamless Steel Oil Well Casing Pipe，J55 casing pipe, K55 casing, N80 casing, L80 casing, P110 casing, T95 casing, Q125 casing, Sour service casing

Outer diamater(OD): 114.30mm-508mm

Wall thickness(WT): 5.21mm-16.13mm

Length: R1; R2; R3

Grade: J55;K55;N80-Q;L80-1;L80-9Cr;L80-13Cr,C95,P10

Standard: API 5CT PSL1/PSL2  J55,K55,N80-1,N80-Q, API 5CT PSL1/PSL2  L80-1, L80-9Cr,L80-13Cr,C90, C95, P110, Q125

Thread types: STC;LTC;BTC;VAM TOP equivalent;New VAM equivalent;CS equivalent;HSC equivalent;NUE;EUE;LTC;XC

Thread: NUE, EUE, VAM, STC, LTC, BTC, XC, VAM TOP, NEW VAM,HYDRILL CS

Application: Casing Pipe is widely used for fastening oil and gas well wall or borehold, with bigger diameter than tubing, including surface casings, technical casings andproduction casings.

  • Description
  • Specification
  • Standard
  • Process
  • Packing

API 5CT Steel Casing (OCTG)

Our API 5CT casing pipes are engineered to serve as the structural retainer for the walls of oil and gas wells. Designed to withstand external collapse pressure and internal yield strength, these pipes ensure the integrity of the wellbore during drilling and production phases.


1. Technical Specifications

Outside Diameter (OD):4-1/2" to 20" (114.3mm – 508mm)

Wall Thickness (WT):5.21mm – 16.13mm

Length Range:R1 (4.88m-7.62m), R2 (7.62m-10.36m),R3 (10.36m-14.63m)

Manufacturing Process:Seamless (SMLS) or Electric Resistance Welded (ERW)


2. API 5CT Steel Grades

We provide a full spectrum of grades categorized by strength and environmental resistance:

Group 1:J55, K55, N80-1, N80-Q

Group 2 (Restricted Yield):L80-1, L80-9Cr, L80-13Cr, C90, T95

Group 3 (High Strength):P110

Group 4:Q125


3. Connection & Threading Types

To ensure leak-proof performance under high pressure, we offer standard and premium connections:

STC(Short Round Thread Casing)

LTC(Long Round Thread Casing)

BTC(Buttress Thread Casing)

Premium Connections:Gas-tight threads for extreme high-pressure or sour service (H2S) environments.


4. Key Application Areas

Surface Casing:Protects freshwater zones and supports the blowout preventer.

Intermediate Casing:Isolates high-pressure zones and unstable formations.

Production Casing:The final conduit for oil and gas production, ensuring long-term well stability.


5. Quality Assurance & Protection

Compliance:Full adherence to API Spec 5CT latest edition; supplied withMTC (EN 10204 3.1).

Testing:100% NDT (Ultrasonic & Magnetic Particle), Hydrostatic testing, and Drift testing.

Surface Treatment:External black painting/vanish, color coding as per API standards.

Packaging:Steel strapped bundles with thread protectors (plastic or composite) for secure maritime transit.

Mechanical properties of Tubing

Group Grade Type Total Yield Strength (Mpa) Tensile Hardness max
% min. max. MPa HRC HBW
1 H40 — 0.5 276 552 414 — —
J55 — 0.5 379 552 517 — —
K55 — 0.5 379 552 655 — —
N80 1 0.5 552 758 689 — —
N80 Q 0.5 552 758 689 — —
R95 — 0.5 655 758 724 — —
2 M65 — 0.5 445 586 586 22 235
L80 1 0.5 552 655 655 23 241
L80 9Cr 0.5 552 655 655 23 241
L81 13Cr 0.5 552 655 655 23 241
C90 1 0.5 621 724 689 25.4 255
T95 1 0.5 655 758 724 25.4 255
C110 — 0.7 758 828 793 30 286
3 P110 — 0.6 758 965 862 — —
4 Q125 1 0.65 862 1034 931 — —
a. In case of dispute, laboratory Rockwell C hardness testing shall be used as the referee method.
b. No hardness limits, but the maximum variation is controlled by manufacturer acc API 5CT.


Chemical components for Casings

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 0.03 —
J55 — — — — — — — — — — — 0.03 0.03 —
K55 — — — — — — — — — — — 0.03 0.03 —
N80 1 — — — — — — — — — — 0.03 0.03 —
N80 Q — — — — — — — — — — 0.03 0.03 —
R95 — — 0.45 — 1.9 — — — — — — 0.03 0.03 0.45
2 M65 — — — — — — — — — — — 0.03 0.03 —
L80 1 — 0.43 — 1.9 — — — — 0.25 0.35 0.03 0.03 0.45
L80 9Cr — 0.15 0.3 0.6 0.9 1.1 8 10 0.5 0.25 0.02 0.01 1
L81 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 —
T95 1 — 0.35 — 1.2 0.25 0.85 0.4 1.5 0.99 — 0.02 0.01 —
C110 — — 0.35 — 1.2 0.25 1 0.4 1.5 0.99 — 0.02 0.005 —
3 P110 — — — — — — — — — — — 0.03 0.03 —
4 Q125 1 — 0.35 — 1.35 — 0.85 — 1.5 0.99 — 0.02 0.01 —
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.


Api 5ct Tubing Casing Deviation

Items Allowable Deviation
Out Diameter D ≤ 101.60mm ± 0.79mm
D ≥ 114.30mm + 1.0%, -0.5%
Wall Thickness -12.50%
Mass (Single Lengths) +6.5%, -3.5%

API Casing Table--Specification & Size

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
4 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 –
5 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 – – – – – –
6 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 – – – – – –
7 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 – – – – – –
8 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
9 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 – – – – – –
10 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 – – – – – –
11 3/4 11.75 298.45 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 – – – – – –
13 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
18 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

Oil Casing &Tubing (Octg) Production Process

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