pipes with various sizes, materials and specification.
Welkin supply different sizes and grades coils&plate for oil& gas , shipbuilding, infrastructure.etc
Valves with different application, even customized
Welkin provide costomized services for our clients for specific project requirements.
API Casing& Tubing
Casing is the major structural component of a well. Casing is needed to:
· Maintain borehole stability
· Prevent contamination of water sands
· Isolate water from producing formations
· Control well pressures during drilling, production, and workover operations
Casing provides locations for the installation of:
· Blowout preventers
· Wellhead equipment
· Production packers
· Production tubing
The cost of casing is a major part of the overall well cost, so selection of casing size, grade, connectors, and setting depth is a primary engineering and economic consideration.
Casing strings
There are six basic types of casing strings:
· Conductor Casing
· Surface Casing
· Intermediate Casing
· Production Casing
· Liner
· Liner tieback casing
| Labels | Nominal Linear masses | Wall Thickness(in) | Type of End-finish | ||||||||||||
| 1 | 2 | O.D.(in) | Ext-upset T&C(Ib/ft) | Non-upset T&C(Ib/ft) | Integ.joint(Ib/ft) | ||||||||||
| NU T&C | EU T&C | IJ | H40 | J55 | L80/R95 | N80 Type1.Q | C90 | T95 | P110 | ||||||
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 |
| 2 3/8" | 4 | 2.375 | 4 | 0.167 | PN | PN | PN | PN | PN | PN | |||||
| 4.6 | 4.7 | 2.375 | 4.6 | 4.7 | 0.19 | PNU | PNU | PNU | PNU | PNU | PNU | PNU | |||
| 5.8 | 5.95 | 2.375 | 5.8 | 5.95 | 0.254 | PNU | PNU | PNU | PNU | PNU | |||||
| 6.6 | 2.375 | 6.6 | 0.295 | P | P | P | |||||||||
| 7.35 | 7.45 | 2.375 | 7.36 | 7.45 | 0.336 | PU | PU | PU | |||||||
| 2 7/8" | 6.4 | 6.5 | 2.875 | 6.4 | 6.5 | 0.217 | PNU | PNU | PNU | PNU | PNU | PNU | PNU | ||
| 7.8 | 7.9 | 2.875 | 7.8 | 7.9 | 0.276 | PNU | PNU | PNU | PNU | PNU | |||||
| 8.6 | 8.7 | 2.875 | 8.6 | 8.7 | 0.308 | PNU | PNU | PNU | PNU | PNU | |||||
| 9.35 | 9.45 | 2.875 | 9.35 | 9.45 | 0.34 | PU | PU | PU | |||||||
| 10.5 | 2.875 | 10.5 | 0.392 | P | P | P | |||||||||
| 11.5 | 2.875 | 11.5 | 0.44 | P | P | P | |||||||||
| 3 1/2" | 7.7 | 3.5 | 7.7 | 0.216 | PN | PN | PN | PN | PN | PN | |||||
| 9.2 | 9.3 | 3.5 | 9.2 | 9.3 | 0.254 | PNU | PNU | PNU | PNU | PNU | PNU | PNU | |||
| 10.2 | 3.5 | 10.2 | 0.289 | PN | PN | PN | PN | PN | PN | ||||||
| 12.7 | 12.95 | 3.5 | 12.7 | 12.9 | 0.375 | PNU | PNU | PNU | PNU | PNU | |||||
| 14.3 | 3.5 | 14.3 | 0.43 | P | P | P | |||||||||
| 15.5 | 3.5 | 15.5 | 0.476 | P | P | P | |||||||||
| 17 | 3.5 | 17 | 0.53 | P | P | P | |||||||||
| 4" | 9.5 | 4 | 9.5 | 0.226 | PN | PN | PN | PN | PN | PN | |||||
| 10.7 | 11 | 4 | 11 | 0.262 | PU | PU | PU | PU | PU | PU | |||||
| 13.2 | 4 | 13.2 | 0.33 | P | P | P | |||||||||
| 16.1 | 4 | 16.1 | 0.415 | P | P | P | |||||||||
| 18.9 | 4 | 18.9 | 0.5 | P | P | PP | |||||||||
| 22.2 | 4 | 22.2 | 0.61 | P | P | ||||||||||
| 4 1/2" | 12.6 | 12.75 | 4.5 | 12.6 | 12.75 | 0.271 | PNU | PNU | PNU | PNU | PNU | PNU | |||
| 15.2 | 4.5 | 15.2 | 0.337 | P | P | P | |||||||||
| 17 | 4.5 | 17 | 0.38 | P | P | P | |||||||||
| 18.9 | 4.5 | 18.9 | 0.43 | P | P | P | |||||||||
| 21.5 | 4.5 | 21.5 | 0.5 | P | P | P | |||||||||
| 23.7 | 4.5 | 23.7 | 0.56 | P | P | P | |||||||||
| 26.1 | 4.5 | 26.1 | 0.63 | P | P | P | |||||||||
| Size | Weight | Outside | Wall | Type of end finish | |||||||||
| Designation | Designation | Diameter | Thickness | Grade | |||||||||
| In | Mm | In | Mm | J55/K55 | L80-1 | N80 | C90 | C95 | T95 | P110 | M65 | ||
| 4 1/2" | 9.5 | 4.5 | 114.3 | 0.21 | 5.21 | PS | - | - | - | - | - | - | - |
| 10.5 | 4.5 | 114.3 | 0.22 | 5.69 | PSB | - | - | - | - | - | - | - | |
| 11.6 | 4.5 | 114.3 | 0.25 | 6.35 | PSLB | PLB | PLB | PLB | PLB | PLB | PLB | PLB | |
| 13.5 | 4.5 | 114.3 | 0.29 | 7.37 | - | - | PLB | PLB | PLB | PLB | PLB | PLB | |
| 15.1 | 4.5 | 114.3 | 0.34 | 8.56 | - | - | - | - | - | - | PLB | - | |
| 5 | 11.5 | 5 | 127 | 0.22 | 5.59 | PS | - | - | - | - | - | - | - |
| 13 | 5 | 127 | 0.25 | 6.43 | PSLB | - | - | - | - | - | - | - | |
| 15 | 5 | 127 | 0.3 | 7.52 | PSLB | PLB | PLB | PLB | PLB | PLB | PLB | PLB | |
| 18 | 5 | 127 | 0.36 | 9.19 | - | PLB | PLB | PLB | PLB | PLB | PLB | PLB | |
| 5 | 21.4 | 5 | 127 | 0.44 | 11.1 | - | PLB | PLB | PLB | PLB | PLB | PLB | PLB |
| 23.2 | 5 | 127 | 0.48 | 12.14 | - | PLB | PLB | PLB | PLB | PLB | PLB | PLB | |
| 24.1 | 5 | 127 | 0.5 | 12.7 | - | PLB | PLB | PLB | PLB | PLB | PLB | PLB | |
| 5 /2" | 14 | 5.5 | 139.7 | 0.24 | 6.2 | PS | - | - | - | - | - | - | - |
| 15.5 | 5.5 | 139.7 | 0.28 | 6.99 | PSLB | - | - | - | - | - | - | - | |
| 17 | 5.5 | 139.7 | 0.3 | 7.72 | PSLB | PLB | PLB | PLB | PLB | PLB | PLB | PLB | |
| 20 | 5.5 | 139.7 | 0.36 | 9.17 | - | PLB | PLB | PLB | PLB | PLB | PLB | PLB | |
| 23 | 5.5 | 139.7 | 0.42 | 10.54 | - | PLB | PLB | PLB | PLB | PLB | PLB | PLB | |
| 26.8 | 5.5 | 139.7 | 0.5 | 12.7 | - | - | - | P | - | P | - | - | |
| 29.7 | 5.5 | 139.7 | 0.56 | 14.27 | - | - | - | P | - | P | - | - | |
| 32.6 | 5.5 | 139.7 | 0.63 | 15.88 | - | - | - | P | - | P | - | - | |
| 35.3 | 5.5 | 139.7 | 0.69 | 17.45 | - | - | - | P | - | P | - | - | |
| 38 | 5.5 | 139.7 | 0.75 | 19.05 | - | - | - | P | - | P | - | - | |
| 40.5 | 5.5 | 139.7 | 0.81 | 20.62 | - | - | - | P | - | P | - | - | |
| 43.1 | 5.5 | 139.7 | 0.88 | 22.22 | - | - | - | P | - | P | - | - | |
| 6 5/8" | 20 | 6.63 | 168.28 | 0.29 | 7.32 | PSLB | - | - | - | - | - | - | - |
| 24 | 6.63 | 168.28 | 0.35 | 8.94 | PSLB | PLB | PLB | PLB | PLB | PLB | PLB | PLB | |
| 26 | 6.63 | 168.28 | 0.42 | 10.59 | - | PLB | PLB | PLB | PLB | PLB | PLB | PLB | |
| 32 | 6.63 | 168.28 | 0.48 | 12.06 | - | PLB | PLB | PLB | PLB | PLB | PLB | PLB | |
| 7" | 20 | 7 | 177.8 | 0.27 | 6.91 | PS | - | - | - | - | - | - | PS |
| 23 | 7 | 177.8 | 0.32 | 8.05 | PSLB | PLB | PLB | PLB | PLB | - | - | PLB | |
| 26 | 7 | 177.8 | 0.36 | 9.19 | PSLB | PLB | PLB | PLB | PLB | PLB | PLB | PLB | |
| 29 | 7 | 177.8 | 0.41 | 10.36 | - | PLB | PLB | PLB | PLB | PLB | PLB | PLB | |
| 32 | 7 | 177.8 | 0.45 | 11.51 | - | PLB | PLB | PLB | PLB | PLB | PLB | PLB | |
| 35 | 7 | 177.8 | 0.5 | 12.65 | - | PLB | PLB | PLB | PLB | PLB | PLB | PLB | |
| 38 | 7 | 177.8 | 0.54 | 13.72 | - | PLB | PLB | PLB | PLB | PLB | PLB | PLB | |
| 7 5/8" | 26.4 | 7.63 | 193.68 | 0.33 | 8.33 | PSLB | PLB | PLB | PLB | PLB | PLB | PLB | PLB |
| 29.7 | 7.63 | 193.68 | 0.38 | 9.52 | - | PLB | PLB | PLB | PLB | PLB | PLB | PLB | |
| 33.7 | 7.63 | 193.68 | 0.43 | 10.92 | - | PLB | PLB | PLB | PLB | PLB | PLB | PLB | |
| 39 | 7.63 | 193.68 | 0.5 | 12.7 | - | PLB | PLB | PLB | PLB | PLB | PLB | PLB | |
| 42.8 | 7.63 | 193.68 | 0.56 | 14.27 | - | PLB | PLB | PLB | PLB | PLB | PLB | PLB | |
| 45.3 | 7.63 | 193.68 | 0.6 | 15.11 | - | PLB | PLB | PLB | PLB | PLB | PLB | PLB | |
| 47.1 | 7.63 | 193.68 | 0.63 | 15.68 | - | PLB | PLB | PLB | PLB | PLB | PLB | PLB | |
| 8 5/8" | 24 | 8.63 | 219.08 | 0.26 | 6.71 | PS | - | - | - | - | - | - | - |
| 28 | 8.63 | 219.08 | 0.3 | 7.72 | - | - | - | - | - | - | - | - | |
| 32 | 8.63 | 219.08 | 0.35 | 8.94 | PSLB | - | - | - | - | - | - | - | |
| 36 | 8.63 | 219.08 | 0.4 | 10.16 | PSLB | PLB | PLB | PLB | PLB | PLB | PLB | ||
| 40 | 8.63 | 219.08 | 0.45 | 11.43 | - | PLB | PLB | PLB | PLB | PLB | PLB | PLB | |
| 44 | 8.63 | 219.08 | 0.5 | 12.7 | - | PLB | PLB | PLB | PLB | PLB | PLB | PLB | |
| 49 | 8.63 | 219.08 | 0.56 | 14.15 | - | PLB | PLB | PLB | PLB | PLB | PLB | PLB | |
| 9 5/8" | 32.3 | 9.63 | 244.48 | 0.31 | 7.92 | - | - | - | - | - | - | - | - |
| 36 | 9.63 | 244.48 | 0.35 | 8.94 | PSLB | - | - | - | - | - | - | PSLB | |
| 40 | 9.63 | 244.48 | 0.4 | 10.03 | PSLB | PLB | PLB | PLB | PLB | PLB | PSLB | ||
| 43.5 | 9.63 | 244.48 | 0.44 | 11.05 | - | PLB | PLB | PLB | PLB | PLB | PLB | PLB | |
| 47 | 9.63 | 244.48 | 0.47 | 11.99 | - | PLB | PLB | PLB | PLB | PLB | PLB | PLB | |
| 53.5 | 9.63 | 244.48 | 0.55 | 13.84 | - | PLB | PLB | PLB | PLB | PLB | PLB | - | |
| 58.4 | 9.63 | 244.48 | 0.6 | 15.11 | - | PLB | PLB | PLB | PLB | PLB | PLB | - | |
| 59.4 | 9.63 | 244.48 | 0.61 | 15.47 | - | - | - | P | - | P | - | - | |
| 64.9 | 9.63 | 244.48 | 0.67 | 17.07 | - | - | - | P | - | P | - | - | |
| 70.3 | 9.63 | 244.48 | 0.73 | 18.64 | - | - | - | P | - | P | - | - | |
| 75.6 | 9.63 | 244.48 | 0.8 | 20.24 | - | - | - | P | - | P | - | - | |
| 10 3/4" | 32.75 | 10.75 | 273.05 | 0.28 | 7.09 | - | - | - | - | - | - | - | - |
| 40.5 | 10.75 | 273.05 | 0.35 | 8.89 | PSB | - | - | - | - | - | - | PSB | |
| 10 3/4" | 45.5 | 10.75 | 273.05 | 0.4 | 10.16 | PSB | - | - | - | - | - | - | PSB |
| 51 | 10.75 | 273.05 | 0.45 | 11.43 | PSB | PSB | PSB | PSB | PSB | PSB | PSB | PSB | |
| 55.5 | 10.75 | 273.05 | 0.5 | 12.57 | - | PSB | PSB | PSB | PSB | PSB | PSB | PSB | |
| 60.7 | 10.75 | 273.05 | 0.55 | 13.84 | - | - | - | PSB | - | PSB | PSB | - | |
| 65.7 | 10.75 | 273.05 | 0.96 | 15.11 | - | - | - | PSB | - | PSB | PSB | - | |
| 73.2 | 10.75 | 273.05 | 0.67 | 17.07 | - | - | - | P | - | P | - | - | |
| 79.2 | 10.75 | 273.05 | 0.73 | 18.64 | - | - | - | P | - | P | - | - | |
| 85.3 | 10.75 | 273.05 | 0.8 | 20.24 | - | - | - | P | - | P | - | - | |
| 11 3/4" | 42 | 11.75 | 298.45 | 0.33 | 8.46 | - | - | - | - | - | - | - | - |
| 47 | 11.75 | 298.45 | 0.38 | 9.53 | PSB | - | - | - | - | - | - | PSB | |
| 54 | 11.75 | 298.45 | 0.44 | 11.05 | PSB | - | - | - | - | - | - | PSB | |
| 60 | 11.75 | 298.45 | 0.49 | 12.42 | PSB | PSB | PSB | PSB | PSB | PSB | PSB | PSB | |
| 65 | 11.75 | 298.45 | 0.53 | 13.56 | - | P | P | P | P | P | P | - | |
| 71 | 11.75 | 298.45 | 0.58 | 14.78 | - | P | P | P | P | P | P | - | |
| 13 3/8" | 48 | 13.38 | 339.72 | 0.33 | 8.38 | - | - | - | - | - | - | - | - |
| 54.5 | 13.38 | 339.72 | 0.38 | 9.65 | PSB | - | - | - | - | - | - | PSB | |
| 61 | 13.38 | 339.72 | 0.43 | 10.92 | PSB | - | - | - | - | - | - | PSB | |
| 68 | 13.38 | 339.72 | 0.48 | 12.19 | PSB | PSB | PSB | PSB | PSB | PSB | PSB | PSB | |
| 72 | 13.38 | 339.72 | 0.54 | 13.06 | - | PSB | PSB | PSB | PSB | PSB | PSB | - | |
| 16" | 65 | 16 | 406.4 | 0.38 | 9.53 | - | - | - | - | - | - | - | - |
| 75 | 16 | 407.4 | 0.44 | 11.13 | PSB | - | - | - | - | - | - | PSB | |
| 84 | 16 | 408.4 | 0.5 | 12.57 | PSB | - | - | - | - | - | - | - | |
| 109 | 16 | 409.4 | 0.66 | 16.66 | PSB | P | P | - | - | - | P | - | |
| 18 5/8" | 87.5 | 18.63 | 437.08 | 0.44 | 11.05 | PSB | - | - | - | - | - | - | PSB |
| 20" | 94 | 20 | 508 | 0.44 | 11.13 | PSB | - | - | - | - | - | - | PSB |
| 106.5 | 20 | 508 | 0.5 | 12.7 | PSB | - | - | - | - | - | - | PSB | |
| 133 | 20 | 508 | 0.64 | 16.13 | PSB | - | - | - | - | - | P | - | |
Chemical Composition(%)
Grade | Chemical Composition% | ||||||||||||
C | Mn | Mo | Cr | Nl | Cu | P | S | Si | |||||
min | max | min | max | min | max | min | max | max | max | max | max | Max | |
J55 | - | - | - | - | - | - | - | - | - | - | 0.030 | 0.030 | - |
K55 | - | - | - | - | - | - | - | - | - | - | 0.030 | 0.030 | - |
N80-1 | - | - | - | - | - | - | - | - | - | - | 0.030 | 0.030 | - |
N80Q | - | - | - | - | - | - | - | - | - | - | 0.030 | 0.030 | - |
M65 | - | 0.43 | - | 1.90 | - | - | - | - | 0.25 | 0.35 | 0.030 | 0.030 | 0.45 |
L80-1 | - | 0.35 | - | 1.00 | 0.25 | 0.75 | - | 1.2 | 0.99 | - | 0.020 | 0.010 | - |
C90-1 | - | 0.50 | - | 1.90 | - | NL | - | NL | 0.99 | - | 0.030 | 0.010 | - |
C90-2 | - | 0.45 | - | 1.90 | - | - | - | - | - | - | 0.030 | 0.030 | 0.45 |
C95 | - | 0.35 | - | 1.20 | 0.25 | 0.85 | 0.40 | 1.50 | 0.99 | - | 0.020 | 0.010 | - |
T95-1 | - | 0.50 | - | 1.90 | - | - | - | - | 0.99 | - | 0.030 | 0.010 | - |
T95-2 | - | - | - | - | - | - | - | - | - | - | - | 0.030 | 0.45 |
P110 | - | - | - | - | - | - | - | - | - | - | - | 0.030 | 0.45 |
Mechanical Properties:
Group |
Grade | Yield Strength | Tensile Strength | Hardness | Allowable Hardness Variation | |||||
min | max | min | max | |||||||
Psi | Mpa | Psi | Mpa | Psi | Mpa | HRC | BHN | HRC | ||
1 | J55 | 55,000 | 379 | 80,000 | 552 | 75,000 | 517 | - | - | - |
K55 | 55,000 | 379 | 80,000 | 552 | 95,000 | 655 | - | - | - | |
N80-1 | 80,000 | 552 | 80,000 | 758 | 100,000 | 689 | - | - | - | |
N80Q | 80,000 | 552 | 80,000 | 758 | 100,000 | 689 | - | |||
2 | M65 | 65,000 | 448 | 85,000 | 586 | 85,000 | 586 | 22 | 235 | - |
L80-1 | 80,000 | 552 | 95,000 | 655 | 95,000 | 655 | 23 | 241 | - | |
C90-1 | 90,000 | 621 | 105,000 | 724 | 100,000 | 689 | 25.4 | 255 | 3.0 | |
C90-2 | 90,000 | 621 | 105,000 | 724 | 100,000 | 689 | 25.4 | 255 | 3.0 | |
C95 | 95,000 | 655 | 110,000 | 758 | 105,000 | 724 | - | - | - | |
T95-1 | 95,000 | 655 | 110,000 | 758 | 105,000 | 724 | 25.4 | 255 | 3.0 | |
T95-2 | 95,000 | 655 | 110,000 | 758 | 105,000 | 724 | 25.4 | 255 | 3.0 | |
3 | P110 | 110,000 | 758 | 140,000 | 965 | 125,000 | 862 | - | - | - |
Length
Range 1 | Range 2 | Range 3 | |
Tubing | 6.1-7.32m | 8.53-9.75m | 11.58-12.8m |
Casing | 4.88-7.62m | 7.62-10.36m | 10.36-14.63m |
Pup joint | 0.5m-6m(2feet-20feet) | ||
Manufacturing Procedure

Manufacturing Facilities