Alcance de la norma API 5CT
La norma API 5CT define las condiciones técnicas de entrega para los siguientes productos:
Tuberías de revestimiento (de superficie, intermedias y de producción)
Tuberías de producción
Conectores de tubería (segmentos cortos de tubería)
Piezas de acoplamiento y materiales de acoplamiento
Materiales accesorios asociados
La norma API 5CT establece tres Niveles de Especificación de Producto (NPE):
NPE-1: Requisitos básicos (norma predeterminada)
NPE-2: Requisitos técnicos y de prueba adicionales
NPE-3: Niveles de rendimiento más altos para aplicaciones críticas
La NPE-1 sirve como requisito base, mientras que la NPE-2 y la NPE-3 introducen controles más estrictos sobre propiedades como la composición química, las pruebas mecánicas y la inspección no destructiva. Estos niveles avanzados se aplican a la mayoría de los grados de acero, excepto H40, L80 9Cr y C110, que siguen sus disposiciones específicas.
Si el comprador y el fabricante lo acuerdan mutuamente, la norma API 5CT también puede aplicarse a tuberías de extremo liso con espesores de pared o dimensiones superiores al rango estándar.
Grados de acero API 5CT
La norma API 5CT abarca diversos grados de acero para diferentes condiciones de pozo:
Grade | Typical Application | Yield Strength (psi) |
H40 | Mild depth wells | 40,000 |
J55 | Shallow to medium wells | 55,000 |
K55 | Similar to J55 but higher strength | 55,000 |
N80 | Sour service, moderate strength | 80,000 |
L80 | Deep wells and sour gas applications | 80,000 |
C90 | High collapse resistance | 90,000 |
T95 | Sour service with corrosion resistance | 95,000 |
P110 | Ultra-deep and high-pressure wells | 110,000 |
Q125 | Ultra-high-pressure applications | 125,000 |
Thread Type | Description |
STC | Short round thread coupling |
LTC | Long round thread coupling |
BTC | Buttress thread coupling |
NU | Non-upset tubing connection |
EU | External upset tubing connection |
IJ | Integral joint tubing (no separate coupling) |
Prueba e inspección de tuberías de producción y revestimiento API 5CT
- Prueba hidrostática
Esta prueba verifica la capacidad de la tubería para soportar la presión interna. Se bombea agua a la tubería a un nivel de presión específico para detectar fugas. Las tuberías que fallan se reparan y se vuelven a probar, lo que garantiza un transporte seguro de fluidos bajo presión.
- Prueba de flexión
Se dobla una muestra para verificar la integridad de la soldadura. Si aparecen grietas, la tubería se rechaza. Esta prueba garantiza la resistencia de la soldadura y la calidad general del producto.
- Prueba de aplanamiento
Esta prueba evalúa la resistencia de la tubería a la deformación y al agrietamiento. Se comprime una muestra a lo largo y luego se inspecciona para detectar defectos, lo que confirma la integridad estructural de la tubería.
- Prueba de impacto Charpy (CVN)
Utilizada para evaluar la tenacidad, esta prueba mide la cantidad de energía que absorbe el material al ser golpeado. Las áreas clave que se prueban incluyen el cuerpo de la tubería, la costura de soldadura y la zona afectada por el calor, lo que garantiza la durabilidad en condiciones adversas.
¿Qué es API 5CT OCTG? API 5CT OCTG se refiere a una norma específica del Instituto Americano del Petróleo (API) que rige los Productos Tubulares para Campos Petrolíferos (OCTG), una categoría de productos de tubería de acero de alta resistencia ampliamente utilizados en la perforación, terminación y producción de pozos de petróleo y gas natural.
Los OCTG incluyen tubería de revestimiento, tubería de producción y tubería de perforación. API 5CT define específicamente los estándares de fabricación, propiedades mecánicas, pruebas e inspección para tuberías de revestimiento y tubería de producción. Estos componentes son vitales para la integridad de un pozo, ya que proporcionan soporte estructural y permiten el transporte seguro de fluidos en condiciones extremas de fondo de pozo.
Tabla de OCTG API 5CT: Grados y aplicaciones comunes
Steel Grade | Application | PSL Available | H₂S Resistance | Tensile Strength (min) |
J55 | Standard shallow wells | PSL-1, PSL-2 | No | 517 MPa |
N80 | Medium-depth wells | PSL-1, PSL-2 | Limited | 689 MPa |
L80 | Sour service environments | PSL-1, PSL-2 | Yes | 655 MPa |
P110 | Deep, high-pressure wells | PSL-1, PSL-2 | No | 758 MPa |
DN | O. D. | Weight | W. T. | End Processing | |||||||||
Non-upset coupling-thread | Upset coupling-thread | Steel Grade | |||||||||||
in | mm | lb./ft. | lb./ft. | in | mm | H40 | J55 | L80 | N80 | C90 | T95 | P110 | |
2 3/8 | 2.38 | 60.3 | 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 | – | |||
2 7/8 | 2.88 | 73 | 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 | – | ||||
3 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 | 102 | 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 | – | |||
4 1/2 | 4.5 | 114 | 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 |
DN | O. D. | Weight | W. T. | End Machining Form | ||||||||
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 | 9.5 | 14.14 | 0.205 | 5.21 | PS | PS | – | – | – | – |
10.5 | 15.63 | 0.224 | 5.69 | – | PSB | – | – | – | – | |||
11.6 | 17.26 | 0.250 | 6.35 | – | PSLB | PLB | PLB | PLB | PLB | |||
13.5 | 20.09 | 0.290 | 7.37 | – | – | PLB | PLB | PLB | PLB | |||
15.1 | 22.47 | 0.337 | 9.56 | – | – | – | – | – | PLB | |||
5 | 5.000 | 127 | 11.5 | 17.11 | 0.220 | 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 | 0.500 | 12.7 | – | – | – | – | PLB | – | |||
5 1/2 | 5.500 | 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 | 0.500 | 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 | 0.750 | 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 | 7.000 | 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 | 0.540 | 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 | 0.750 | 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 | 0.300 | 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 | 0.430 | 10.92 | – | – | PLB | PLB | PLBE | PLB | |||
39 | 58.05 | 0.500 | 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 | 0.750 | 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 | 0.400 | 10.16 | – | PSLB | PLB | PLB | PLBE | PLB | |||
40 | 59.53 | 0.450 | 11.43 | – | – | PLB | PLB | PLBE | PLB | |||
44 | 65.48 | 0.500 | 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 | 10.750 | 273.05 | 32.75 | 48.74 | 0.279 | 7.09 | PS | – | – | – | – | – |
40.5 | 60.27 | 0.350 | 8.89 | PS | PSB | – | – | – | – | |||
15.5 | 67.71 | 0.400 | 10.16 | – | PSB | – | – | – | – | |||
51 | 75.9 | 0.450 | 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 | 11.750 | 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 | 0.330 | 8.38 | PS | – | – | – | – | – |
54.5 | 81.1 | 0.380 | 9.65 | – | PSB | – | – | – | – | |||
61 | 90.78 | 0.430 | 10.92 | – | PSB | – | – | – | – | |||
68 | 101.19 | 0.480 | 12.19 | – | PSB | PSB | PSB | PSB | PSB | |||
72 | 107.15 | 0.514 | 13.06 | – | – | PSB | PSB | PSB | PSB | |||
16 | 16.000 | 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 | 20.000 | 508 | 94 | 139.89 | 0.438 | 11.13 | PSL | PSLB | – | – | – | – |
106.5 | 158.49 | 0.500 | 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 |