· Keywords: API 5CT Casing, Well Casing, Seamless (SMLS), Electric Resistance Welded (ERW), Casing, Oil Pipe
· Size: OD: 4 1/2’’ ~ 20’’ (114.3mm ~ 508mm)；WT: 0.205’’ ~ 0.635’’ (5.21mm ~ 16.13mm)；LENGTH: R1, R2, R3
· Standard & Grade: API 5CT J 55/K55/N80/C75/L80/C90/T95/Q125
· Ends: Beveled, Square Cut, With LTC/STC/BTC/VAM Connection
· Packing: Protection Caps in Both Ends, Waterproof Paper Wrapped, Two Tags
· Usage: Used as the Structural Retainer for the Walls of Oil, Gas Wells
· Thread types: STC, LTC, BTC, Special Clearance, Premium Connection
· Application: Oil Well Casing Serves As Well Sidewall
Casing is a large-diameter pipe that serves as the structural retainer for the walls of oil and gas wells, or well bore.It is inserted into a well bore and cemented in place to protect both subsurface formations and the well bore from collapsing and to allow drilling fluid to circulate and extraction to take place. Steel Casing Pipes have smooth wall & minimum yield strength of 35,000 psi.
Well Casing serves as well sidewall. Standards and Technical Conditions for Supply:API Spec 5CT ISO13680 Grade: J55, K55, N80-1,N80-Q, L80-1, L80-9Cr,L80-13Cr,C95, P110. Tread types: NUE, EUE, VAM, STC, LTC, BTC, special clearance, XC,VAM TOP,NEW VAM.
Oil Casing Pipe: Casings are used for fixing the well wall or down hole, which have wide diameters, can be divided into conductor casings, technical casings and Oil casings.
Uses: Well Casing serves as well sidewall.
Standards and Technical Conditions for Supply: API Spec 5CT
Grade of pipe casing: J55, K55, N80-1,N80-Q, L80-1, L80-9Cr,L80-13Cr,C95, P110.
Tread types of pipe casing : STC, LTC, BTC, special clearance, XC,VAM TOP,NEW VAM.
Dimension: OD: 114.3-508mm WT: 5.21-16.13mm
What is API 5CT casing ?
API SPEC 5CT well casing is utilized in fixing the well wall or down hole, which has wider diameters. API SPEC 5CT can be divided into conductor casing, technical casing and oil casing.
API 5CT is standard technical specifications for steel casing pipes used for oil wells in petroleum and natural gas industries.
Common Grades
• J55/K55
• N80/N80Q/L80
• C90
• R95/T95
• P110/C110
• Q125
Lengths:
| Oil Casing | Range 1 | Range 2 | Range 3 |
| 4.88~7.62 | 7.62~10.36 | 10.36~14.63 |
Dimension:
| Labels | Outside diameter D | Nominal linear mass T&C | Wall thickness t | J55 | N80 | L80 | C90 | P110 | Q125 |
| mm | kg/m | mm | K55 | 1/Q? | T95 |
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 |
| 4 1/2 | 9.5 | 114.3 | 14.14 | 5.21 | PS | - | - | - | - | - |
| 4 1/2 | 10.5 | 114.3 | 15.63 | 5.69 | PSB | - | - | - | - | - |
| 4 1/2 | 11.6 | 114.3 | 17.26 | 6.35 | PSLB | PLB | PLB | PLB | PLB | - |
| 4 1/2 | 13.5 | 114.3 | 20.09 | 7.37 | - | PLB | PLB | PLB | PLB | - |
| 4 1/2 | 15.1 | 114.3 | 22.47 | 8.56 | - | - | - | - | PLB | PLB |
| 5 | 11.5 | 127 | 17.11 | 5.59 | PS | - | - | - | - | - |
| 5 | 13 | 127 | 19.35 | 6.43 | PSLB | - | - | - | - | - |
| 5 | 15 | 127 | 22.32 | 7.52 | PSLBE | PLBE | PLBE | PLBE | PLBE | - |
| 5 | 18 | 127 | 26.79 | 9.19 | - | PLBE | PLBE | PLBE | PLBE | PLBE |
| 5 | 21.4 | 127 | 31.85 | 11.1 | - | PLB | PLB | PLB | PLB | PLB |
| 5 | 23.2 | 127 | 34.53 | 12.14 | - | PLB | PLB | PLB | PLB | PLB |
| 5 | 24.1 | 127 | 35.86 | 12.7 | - | PLB | PLB | PLB | PLB | PLB |
| 5 1/2 | 14 | 139.7 | 20.83 | 6.2 | PS | - | - | - | - | - |
| 5 1/2 | 15.5 | 139.7 | 23.07 | 6.98 | PSLBE | - | - | - | - | - |
| 5 1/2 | 17 | 139.7 | 25.3 | 7.72 | PSLBE | PLBE | PLBE | PLBE | PLBE | - |
| 5 1/2 | 20 | 139.7 | 29.76 | 9.17 | - | PLBE | PLBE | PLBE | PLBE | - |
| 5 1/2 | 23 | 139.7 | 34.23 | 10.54 | - | PLBE | PLBE | PLBE | PLBE | PLBE |
| 5 1/2 | 26.8 | 139.7 | 39.88 | 12.7 | - | - | - | P | - | - |
| 5 1/2 | 29.7 | 139.7 | 44.2 | 14.27 | - | - | - | P | - | - |
| 5 1/2 | 32.6 | 139.7 | 48.51 | 15.88 | - | - | - | P | - | - |
| 5 1/2 | 35.3 | 139.7 | 52.53 | 17.45 | - | - | - | P | - | - |
| 5 1/2 | 38 | 139.7 | 56.55 | 19.05 | - | - | - | P | - | - |
| 5 1/2 | 40.5 | 139.7 | 60.27 | 20.62 | - | - | - | P | - | - |
| 5 1/2 | 43.1 | 139.7 | 64.14 | 22.22 | - | - | - | P | - | - |
| 6 5/8 | 20 | 168.28 | 29.76 | 7.32 | PSLB | - | - | - | - | - |
| 6 5/8 | 24 | 168.28 | 35.72 | 8.94 | PSLBE | PLBE | PLBE | PLBE | PLBE | - |
| 6 5/8 | 28 | 168.28 | 41.67 | 10.59 | - | PLBE | PLBE | PLBE | PLBE | - |
| 6 5/8 | 32 | 168.28 | 47.62 | 12.06 | - | PLBE | PLBE | PLBE | PLBE | PLBE |
| 7 | 17 | 177.8 | 25.3 | 5.87 | - | - | - | - | - | - |
| 7 | 20 | 177.8 | 29.76 | 6.91 | PS | - | - | - | - | - |
| 7 | 23 | 177.8 | 34.23 | 8.05 | PSLBE | PLBE | PLBE | PLBE | - | - |
| 7 | 26 | 177.8 | 38.69 | 9.19 | PSLBE | PLBE | PLBE | PLBE | PLBE | - |
| 7 | 29 | 177.8 | 43.16 | 10.36 | - | PLBE | PLBE | PLBE | PLBE | - |
| 7 | 32 | 177.8 | 47.62 | 11.51 | - | PLBE | PLBE | PLBE | PLBE | - |
| 7 | 35 | 177.8 | 52.09 | 12.65 | - | PLBE | PLBE | PLBE | PLBE | PLBE |
| 7 | 38 | 177.8 | 56.55 | 13.72 | - | PLBE | PLBE | PLBE | PLBE | PLBE |
| 7 | 42.7 | 177.8 | 63.54 | 15.88 | - | - | - | P | - | - |
| 7 | 46.4 | 177.8 | 69.05 | 17.45 | - | - | - | P | - | - |
| 7 | 50 | 177.8 | 74.56 | 19.05 | - | - | - | P | - | - |
| 7 | 53.6 | 177.8 | 79.77 | 20.62 | - | - | - | P | - | - |
| 7 | 57.1 | 177.8 | 84.97 | 22.22 | - | - | - | P | - | - |
| 7 5/8 | 24 | 193.68 | 35.72 | 7.62 | - | - | - | - | - | - |
| 7 5/8 | 26.4 | 193.68 | 39.29 | 8.33 | PSLBE | PLBE | PLBE | PLBE | - | - |
| 7 5/8 | 29.7 | 193.68 | 44.2 | 9.52 | - | PLBE | PLBE | PLBE | PLBE | - |
| 7 5/8 | 33.7 | 193.68 | 50.15 | 10.92 | - | PLBE | PLBE | PLBE | PLBE | - |
| 7 5/8 | 39 | 193.68 | 58.04 | 12.7 | - | PLBE | PLBE | PLBE | PLBE | PLBE |
| 7 5/8 | 42.8 | 193.68 | 63.69 | 14.27 | - | PLB | PLB | PLB | PLB | PLB |
| 7 5/8 | 45.3 | 193.68 | 67.41 | 15.11 | - | PLB | PLB | PLB | PLB | PLB |
| 7 5/8 | 47.1 | 193.68 | 70.09 | 15.88 | - | PLB | PLB | PLB | PLB | PLB |
| 7 5/8 | 51 | 193.68 | 76.19 | 17.45 | - | - | - | P | - | - |
| 7 5/8 | 55.3 | 193.68 | 82.3 | 19.05 | - | - | - | P | - | - |
| 8 5/8 | 24 | 219.08 | 35.72 | 6.71 | PS | - | - | - | - | - |
| 8 5/8 | 28 | 219.08 | 41.67 | 7.72 | - | - | - | - | - | - |
| 8 5/8 | 32 | 219.08 | 47.62 | 8.94 | PSLBE | - | - | - | - | - |
| 8 5/8 | 36 | 219.08 | 53.57 | 10.16 | PSLBE | PLBE | PLBE | PLBE | - | - |
| 8 5/8 | 40 | 219.08 | 59.53 | 11.43 | - | PLBE | PLBE | PLBE | PLBE | - |
| 8 5/8 | 44 | 219.08 | 65.48 | 12.7 | - | PLBE | PLBE | PLBE | PLBE |
|
| 8 5/8 | 49 | 219.08 | 72.92 | 14.15 | - | PLBE | PLBE | PLBE | PLBE | PLBE |
| 9 5/8 | 32 | 244.48 | 48.07 | 7.92 | - | - | - | - | - | - |
| 9 5/8 | 36 | 244.48 | 53.57 | 8.94 | PSLB | - | - | - | - | - |
| 9 5/8 | 40 | 244.48 | 59.53 | 10.03 | PSLBE | PLBE | PLBE | PLBE | - | - |
| 9 5/8 | 43.5 | 244.48 | 64.73 | 11.05 | - | PLBE | PLBE | PLBE | PLBE | - |
| 9 5/8 | 47 | 244.48 | 69.94 | 11.99 | - | PLBE | PLBE | PLBE | PLBE | PLBE |
| 9 5/8 | 53.5 | 244.48 | 79.62 | 13.84 | - | PLBE | PLBE | PLBE | PLBE | PLBE |
| 9 5/8 | 58.4 | 244.48 | 86.91 | 15.11 | - | PLB | PLB | PLB | PLB | PLB |
| 9 5/8 | 59 | 244.48 | 88.4 | 15.47 | - | - | - | P | - | - |
| 9 5/8 | 64.9 | 244.48 | 96.58 | 17.07 | - | - | - | P | - | - |
| 9 5/8 | 70.3 | 244.48 | 104.62 | 18.64 | - | - | - | P | - | - |
| 9 5/8 | 75.6 | 244.48 | 112.5 | 20.24 | - | - | - | P | - | - |
| 10 3/4 | 32.75 | 273.05 | 48.74 | 7.09 | - | - | - | - | - | - |
| 10 3/4 | 40.5 | 273.05 | 60.27 | 8.89 | PSB | - | - | - | - | - |
| 10 3/4 | 45.5 | 273.05 | 67.71 | 10.16 | PSBE | - | - | - | - | - |
| 10 3/4 | 51 | 273.05 | 75.9 | 11.43 | PSBE | PSBE | PSBE | PSBE | PSBE | - |
| 10 3/4 | 55 | 273.05 | 82.59 | 12.57 | - | PSBE | PSBE | PSBE | PSBE | - |
| 10 3/4 | 60.7 | 273.05 | 90.33 | 13.84 | - | - | - | PSBE | PSBE | PSBE |
| 10 3/4 | 65.7 | 273.05 | 97.77 | 15.11 | - | - | - | PSB | PSB | PSB |
| 10 3/4 | 73.2 | 273.05 | 108.93 | 17.07 | - | - | - | P | - | - |
| 10 3/4 | 79.2 | 273.05 | 117.86 | 18.64 | - | - | - | P | - | - |
| 10 3/4 | 85.3 | 273.05 | 126.94 | 20.24 |
|
|
| P |
|
|
| 11 3/4 | 42 | 298.45 | 62.5 | 8.46 | - | - | - | - | - | - |
| 11 3/4 | 47 | 298.45 | 69.94 | 9.53 | PSB | - | - | - | - | - |
| 11 3/4 | 54 | 298.45 | 80.36 | 11.05 | PSB | - | - | - | - | - |
| 11 3/4 | 60 | 298.45 | 89.29 | 12.42 | PSB | PSB | PSB | PSB | PSB | PSB |
| 11 3/4 | 65 | 298.45 | 96.73 | 13.56 | - | P | P | P | P | P |
| 11 3/4 | 71 | 298.45 | 105.66 | 14.78 | - | P | P | P | P | P |
| 13 3/8 | 48 | 339.72 | 71.43 | 8.38 | - | - | - | - | - | - |
| 13 3/8 | 54.5 | 339.72 | 81.1 | 9.65 | PSB | - | - | - | - | - |
| 13 3/8 | 61 | 339.72 | 90.78 | 10.92 | PSB | - | - | - | - | - |
| 13 3/8 | 68 | 339.72 | 101.19 | 12.19 | PSB | PSB | PSB | PSB | PSB | - |
| 13 3/8 | 72 | 339.72 | 107.15 | 13.06 | - | PSB | PSB | PSB | PSB | PSB |
| 16 | 65 | 406.4 | 96.73 | 9.53 | - | - | - | - | - | - |
| 16 | 75 | 406.4 | 111.61 | 11.13 | PSB | - | - | - | - | - |
| 16 | 84 | 406.4 | 125.01 | 12.57 | PSB | - | - | - | - | - |
| 16 | 109 | 406.4 | 162.21 | 16.66 | P | P | P | - | P | P |
| 18 5/8 | 87.5 | 473.08 | 130.21 | 11.05 | PSB | - | - | - | - | - |
| 20 | 94 | 508 | 139.89 | 11.13 | PSLB | - | - | - | - | - |
| 20 | 106.5 | 508 | 158.49 | 12.7 | PSLB | - | - | - | - | - |
| 20 | 133 | 508 | 197.93 | 16.13 | PSLB | - | - | - | - | - |
| P——Plain end; S——Short round thread;L——Long round thread;B——Buttress thread;E——Extreme line. |
Mechanical Properties:
| Group | Grade | Type | Total elongation under load % | Yield strength Mpa | Tensile strength min MPa | Hardness max |
| min | max | HRC | HBW |
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |
| 1 | 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 | - | - |
| 2 | L80 | 1 | 0.5 | 552 | 655 | 655 | 23 | 241 |
| L80 | 9Cr | 0.5 | 552 | 655 | 655 | 23 | 241 |
| L80 | 13Cr | 0.5 | 552 | 655 | 655 | 23 | 241 |
| C90 | 1?2 | 0.5 | 621 | 724 | 689 | 25.4 | 255 |
| C95 | - | 0.5 | 655 | 758 | 724 | - | - |
| T95 | 1?2 | 0.5 | 655 | 758 | 724 | 25.4 | 255 |
| 3 | P110 | - | 0.6 | 758 | 965 | 862 | - | - |
| 4 | Q125 | All | 0.65 | 862 | 1034 | 931 | - | - |
Tolerance
| Types of steel tubes | Outer Diameter | Wall Thickness |
| Cold-rolled tubes | Tube sizes(mm) | Tolerances(mm) | Tolerances(mm) |
| ＜114.3 | ±0.79 | －12.5% |
|
|
Chemical Composition
| Standard | Grade | Chemical compositions（％） |
| API SPEC 5CT | J55 | C | Si | Mn | P | S | Cr | Ni | Cu | Mo | V |
| K55 | 0.34～0.39 | 0.20～0.35 | 1.25～1.50 | ≤0.020 | ≤0.015 | ≤0.15 | ≤0.20 | ≤0.20 | / | / |
| N80 | 0.34～0.38 | 0.20～0.35 | 1.45～1.70 | ≤0.020 | ≤0.015 | ≤0.15 | / | / | / | 0.11～0.16 |
| L80 | 0.15～0.22 | ≤1.00 | 0.25～1.00 | ≤0.020 | ≤0.010 | 12.0～14.0 | ≤0.20 | ≤0.20 | / | / |
| P110 | 0.26～0.395 | 0.17～0.37 | 0.40～0.70 | ≤0.020 | ≤0.010 | 0.80～1.10 | ≤0.20 | ≤0.20 | 0.15～0.25 | ≤0.08 |
Mechanical Properties
| Grade | Type | Total elongation under load (%) | Yield strength (min) | Yield strength (max) | Tensile strength min Mpa | Hardness Max (HRC) | Hardness Max(HBW) |
| 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 | - | - |
| L80 | 1 | 0.5 | 552 | 655 | 655 | 23 | 241 |
| L80 | 9Cr | 0.5 | 552 | 655 | 655 | 23 | 241 |
| L80 | 13Cr | 0.5 | 552 | 655 | 655 | 23 | 241 |
| C90 | - | 0.5 | 621 | 724 | 689 | 25.4 | 255 |
| C95 | - | 0.5 | 655 | 758 | 724 | - | - |
| T95 | - | 0.5 | 655 | 758 | 724 | 25.4 | 255 |
| P110 | - | 0.6 | 758 | 965 | 862 | - | - |
| Q125 | All | 0.65 | 862 | 1034 | 931 | - | - |