What are OCTG pipes? Oil country tubular goods are pipes used for onshore and offshore oil & gas upstream operations (extract oil and gas from the wellbore). OCTG pipes may be classified into three main families: drill pipes (to perforate the soil and reach the reserve), casing pipes (to consolidate the well and prepare it for the actual extraction), and tubing pipes (to extract the product from the ground to the surface). API 5CT is the reference specification for OCTG pipes.
TYPES OF OCTG PIPE
First, OCTG is the acronym of “Oil Country Tubular Goods” – i.e. pipes for oil (and gas) extraction from the soil. The three main OCTG pipe types are:
- Casing pipes are used to stabilize the wellbore. A casing pipe is subject to axial tensions and to internal pressures generated by the pumped oil or gas, by their heavyweight and the external pressures coming from the surrounding rocks
- Tubing pipes are tubular goods through which the oil or gas is transported from the wellbore to the surface. Tubing segments are generally around 30′ long with a threaded connection on each end (standard or premium connections are available)
- Drill pipes are heavyweight seamless tubular that rotate the drill bit and circulates the drilling fluid. Pipe segments of 30′ are coupled with tool joints. Drill pipe is subject to high torque by drilling, axial tension by their weight, and internal pressure due to the purging of the drilling fluid. Additionally, alternating bending loads due to non-vertical or deflected drilling may be superimposed on these basic loading patterns
The API 5CT specification covers seamless and welded casing and tubing pipes for upstream operations (pipes that belong to the OCTG family, as illustrated above).
Let’s review each type of OCTG pipe more in detail.
OCTG “CASING” PIPES
Function
OCTG casing pipes are a key structural component for an oil & gas well and have the following scope:
- Keep the borehole stability in the well
- Prevent the bore contamination from water sands
- Prevent water from producing formations
- Exercise a tight control of the wellbore pressures during the drilling, production, and repair operations
Casing pipes are used to install:
- Blowout Preventers (BOP)
- Other wellhead equipment necessary to extract hydrocarbons
- Production tubing and packers
Casing pipes are also one major individual component of the overall cost of the well, therefore the correct selection of the casing size, materials, connectors, and depth shall be at the top of design engineers (for cost and efficiency reasons).
The six basic types of casing strings are:
- Conductor Casing
- Surface Casing
- Intermediate Casing
- Production Casing
- Liner
- Liner tieback casing
Oilfield casing pipes are positioned into the wellbore and cemented in place to secure both subsurface formations and the wellbore from collapsing, also to enable drilling mud to circulate and extraction to take place.
The strict quality requirement for steel is due to the harsh working conditions of the casing.
The steel product should be produced and checked in accordance with special standards or specifications. ISO 11960 and API Spec 5CT have specified the steel product standards of the casing.
Dimensions and Materials
Casing pipes are available in a diameter range 4 1/2 to 20 inches, and in the following materials: H-40, J-55, K-55, N-80, L-80/C, 90/T, 95, P110, Q-125 – as discussed in more detail below.
End Connection Types
The main types of connections for casing pipes are STC (short threads), LTC (long threads), BTC (buttress threads) and premium gas-tight connections.
OCTG “TUBING” PIPES
Function
Tubing pipes are used to bring oil and gas from the underground reserves up to the field for further processing.
Tubing pipes need resistance to mechanical stress as they are subject to very high loads and deformations during the production operations.
In addition, tubing pipes sizes should be properly calculated to support the expected oil and gas flow from the ground to the surface (a too-small diameter would decrease the production rate and the return on investment on the wellbore licenses, whereas too large tubing would generate non-recoverable costs due to the greater amount of steel used for the bore construction vs. the actual requirement (steel for the casing and tubing pipes).
Sizes and Materials
Tubing pipes are manufactured in seamless and welded execution, in the size range of 1.050 to 5 1/2 inches (consult this article to see the AP5CT tubing pipes sizes) and in the following material grades: H-40, J-55, K-55, N-80, L-80, C-90, T-95, P-110, Q-125 (more details about API 5CT tubing materials are in this article).
End Connections
The main types of connections for tubing pipes are NUE (non-upset), EUE (external upset) and premium. Corrosion resistance under sour service conditions is a very important OCTG characteristic, especially for casing and tubing.
OCTG PIPE MANUFACTURING PROCESS
The manufacturing processes of casing and tubing pipes include:
- Continuous mandrel-rolling process and the push bench process for sizes between 21 and 178 mm OD.
- Plug mill rolling for sizes between 140 and 406 mm OD.
- Cross-roll piercing and Pilger rolling for sizes between 250 and 660 mm OD.
These processes typically do not allow the thermo-mechanical processing customary for the strip and plate products used for welded pipes.
Therefore, the high-strength seamless pipe must be produced by increasing the alloying content in combination with a suitable heat treatment such as quench & tempering.
Meeting the fundamental requirement of a fully martensitic microstructure even at large pipe wall thickness requires good hardenability. Chrome (Cr) and Manganese (Mn) are the main alloying elements used to produce good hardenability in conventional heat-treatable steel.
However, the requirement for good sulfide stress cracking (SSC) resistance limits their use. Mn tends to segregate during continuous casting and can form large MnS inclusions that reduce hydrogen-induced cracking (HIC) resistance. Higher levels of Cr can lead to the formation of Cr7C3 precipitates with coarse plate-shaped morphology, which acts as hydrogen collectors and cracks initiators.
Alloying with Molybdenum can overcome the limitations of Mn and Cr alloying. Mo is a much stronger hardener than Mn and Cr, so it can easily recover the effect of a reduced amount of these elements.
Traditionally, OCTG grades were carbon-manganese steels (up to the 55-KSI strength level) or Mo-containing grades up to 0.4% Mo. In recent years, deep well-drilling and reservoirs containing contaminants that cause corrosive attacks have created a strong demand for higher-strength materials resistant to hydrogen embrittlement and SCC.
Highly tempered martensite is the structure most resistant to SSC at higher strength levels, and 0.75% is the Mo concentration that produces the optimum combination of yield strength and to SSC resistance.
OCTG PIPE SUPPLIERS
The top OTCG pipes suppliers are:
Tenaris (Argentina)
Tenaris is based in Argentina and manufactures a wide range of mechanical, structural, process and OCTG pipes. In the OCTG area, Tenaris supplies drilling, casing and tubing pipes with standard and premium connections, and other tubular equipment for upstream operations (as sucker rods and coil tubes). Tenaris produces OCTG pipes in most major API grades (as listed below), including carbon, alloy, and higher grades. Besides being a mill, Tenaris is also involved in contracting and consulting in upstream, midstream and downstream oil & gas.
US Steel Tubular Products (USA)
US Steel is a multinational steel company covering a wide range of industries, from food to oil and gas. The company has a key role in the OCTG industry, as it produces drill, casing, and tubing pipes API 5CT in most sizes and API material grades with different types of commercial and proprietary connections.
Nippon Steel and Sumitomo (Japan)
Nippon Steel is an accredited supplier of OCTG pipes, used throughout the world and recognized for their exceptional quality. The company has been very active in developing stronger materials and innovative connections. Further, the company has a well-established distribution business, able to support exploration and upstream activities in real-time.
Arcelor Mittal (India)
Arcelor Mittal, a giant Indian/French steel conglomerate, is involved in the production and distribution of OCTG pipes for exploration and extraction operations. The Arcelor Mittal pipe and tubes division represents a small fraction of the whole company turnover (definitely less than 5%) but can be still be considered one of the major players in the oil exploration and upstream industries.
TMK (Russia)
TMK is one of the top five pipe manufacturers in the world. Besides process pipes, TMK manufactures and distributes also seamless and welded OCTG pipes in various material grades through a consolidated network of regional offices.
Vallourec (France)
Despite its troubled situation in the last few years, Vall0urec is a major player in the OCTG industry. The company manufactures and distributes drill, casing and tubing pipes with premium connections.
OCTG PIPE DIMENSIONS
CASING PIPE
Note: P = plain end, S = short round thread, L = long round thread, B = buttress thread. Sizes per API 5CT specification
Source: API – American Petroleum Institute
| OCTG Pipe Sizes (Casing) API5CT |
Weight Lbs/ft |
Outside Diameter | Wall Thickness | Type End Finish | |||||||||
| Grade | |||||||||||||
| ln. | mm | ln. | mm | H-40 | J-55 K-55 | M-65 | L-80C-95 | N-80 | C-90T-95 | P-110 | Q-125 | ||
| 7 5/8” | 24.00 | 7.625 | 193.68 | 0.300 | 7.62 | PS | — | — | — | — | — | — | — |
| 26.40 | 7.625 | 193.68 | 0.328 | 8.33 | — | PSLB | PSLB | PLB | PLB | PLB | PLB | — | |
| 29.70 | 7.625 | 193.68 | 0.375 | 9.53 | — | — | PLB | PLB | PLB | PLB | PLB | — | |
| 33.70 | 7.625 | 193.68 | 0.430 | 10.92 | — | — | PLB | PLB | PLB | PLB | PLB | — | |
| 39.00 | 7.625 | 193.68 | 0.500 | 12.70 | — | — | — | PLB | PLB | PLB | PLB | PLB | |
| 42.80 | 7.625 | 193.68 | 0.562 | 14.27 | — | — | — | PLB | PLB | PLB | PLB | PLB | |
| 45.30 | 7.625 | 193.68 | 0.595 | 15.11 | — | — | — | PLB | PLB | PLB | PLB | PLB | |
| 47.10 | 7.625 | 193.68 | 0.625 | 15.88 | — | — | — | PLB | PLB | PLB | PLB | PLB | |
| 51.20 | 7.625 | 193.68 | 0.687 | 17.45 | — | — | — | — | — | P | — | — | |
| 55.30 | 7.75 | 193.68 | 196.85 | 19.05 | — | — | — | — | — | P | — | — | |
| 7 3/4” | 46.10 | 8.625 | 219.08 | 0.595 | 15.11 | — | — | — | P | P | P | P | P |
| 8 5/8” | 24.00 | 8.625 | 219.08 | 0.264 | 6.71 | — | PS | PS | — | — | — | — | — |
| 28.00 | 8.625 | 219.08 | 0.304 | 7.72 | PS | — | PS | — | — | — | — | — | |
| 32.00 | 8.625 | 219.08 | 0.352 | 8.94 | PS | PSLB | PSLB | — | — | — | — | — | |
| 36.00 | 8.625 | 219.08 | 0.400 | 10.16 | — | PSLB | PSLB | PLB | PLB | PLB | PSLB | — | |
| 40.00 | 8.625 | 219.08 | 0.450 | 11.43 | — | — | PLB | PLB | PLB | PLB | PLB | — | |
| 44.00 | 8.625 | 219.08 | 0.500 | 12.70 | — | — | PLB | PLB | PLB | PLB | PLB | — | |
| 49.00 | 9.625 | 244.48 | 0.557 | 14.15 | — | — | — | PLB | PLB | PLB | PLB | PLB | |
| 9 5/8” | 32.30 | 9.625 | 244.48 | 0.312 | 7.92 | PS | — | — | — | — | — | — | — |
| 36.00 | 9.625 | 244.48 | 0.352 | 8.94 | PS | PSLB | PSLB | — | — | — | — | — | |
| 40.00 | 9.625 | 244.48 | 0.395 | 10.03 | — | PSLB | PSLB | PLB | PLB | PLB | — | — | |
| 43.50 | 9.625 | 244.48 | 0.435 | 11.05 | — | — | PLB | PLB | PLB | PLB | PLB | — | |
| 47.00 | 9.625 | 244.48 | 0.472 | 11.99 | — | — | PLB | PLB | PLB | PLB | PLB | PLB | |
| 53.50 | 9.625 | 244.48 | 0.545 | 13.84 | — | — | — | PLB | PLB | PLB | PLB | PLB | |
| 58.40 | 9.625 | 244.48 | 0.595 | 15.11 | — | — | — | PLB | PLB | PLB | PLB | PLB | |
| 59.40 | 9.625 | 244.48 | 0.609 | 15.47 | — | — | — | — | — | P | — | — | |
| 64.90 | 9.625 | 244.48 | 0.672 | 17.07 | — | — | — | — | — | P | — | — | |
| 70.30 | 9.625 | 244.48 | 0.734 | 18.64 | — | — | — | — | — | P | — | — | |
| 75.60 | 9.625 | 244.48 | 0.797 | 20.24 | — | — | — | — | — | P | — | — | |
| OCTG Casing Pipe Size API5CT |
Weight Lb/ft | Outside Diameter | Wall Thickness | Type End Finish | |||||||||
| Grade | |||||||||||||
| ln. | mm | ln. | mm | H-40 | J-55 K-55 |
M-65 | L-80 C-95 |
N-80 | C-90T-95 | P-110 | Q-125 | ||
| 10 3/4” | 32.75 | 10.75 | 273.05 | 0.279 | 7.09 | PS | — | — | — | — | — | — | — |
| 40.50 | 10.75 | 273.05 | 0.350 | 8.89 | PS | PSB | PSB | — | — | — | — | — | |
| 45.50 | 10.75 | 273.05 | 0.400 | 10.16 | — | PSB | PSB | — | — | — | — | — | |
| 51.00 | 10.75 | 273.05 | 0.450 | 11.43 | — | PSB | PSB | PSB | PSB | PSB | PSB | — | |
| 55.50 | 10.75 | 273.05 | 0.495 | 12.57 | — | — | PSB | PSB | PSB | PSB | PSB | — | |
| 60.70 | 10.75 | 273.05 | 0.545 | 13.84 | — | — | — | — | — | PSB | PSB | PSB | |
| 65.70 | 10.75 | 273.05 | 0.595 | 15.11 | — | — | — | — | — | PSB | PSB | PSB | |
| 73.20 | 10.75 | 273.05 | 0.672 | 17.07 | — | — | — | — | — | P | — | — | |
| 79.20 | 10.75 | 273.05 | 0.734 | 18.64 | — | — | — | — | — | P | — | — | |
| 85.30 | 10.75 | 273.05 | 0.797 | 20.24 | — | — | — | — | — | P | — | — | |
| 11 3/4” | 42.00 | 11.75 | 298.45 | 0.333 | 8.46 | PS | — | — | — | — | — | — | — |
| 47.00 | 11.75 | 298.45 | 0.375 | 9.53 | — | PSB | PSB | — | — | — | — | — | |
| 54.00 | 11.75 | 298.45 | 0.435 | 11.05 | — | PSB | PSB | — | — | — | — | — | |
| 60.00 | 11.75 | 298.45 | 0.489 | 12.42 | — | PSB | PSB | PSB | PSB | PSB | PSB | PSB | |
| 65.00 | 11.75 | 298.45 | 0.534 | 13.56 | — | — | — | P | P | P | P | P | |
| 71.00 | 11.75 | 298.45 | 0.582 | 14.78 | — | — | — | P | P | P | P | P | |
| 13 3/8” | 48.00 | 13.375 | 339.73 | 0.330 | 8.38 | PS | — | — | — | — | — | — | — |
| 54.50 | 13.375 | 339.73 | 0.380 | 9.65 | — | PSB | PSB | — | — | — | — | — | |
| 61.00 | 13.375 | 339.73 | 0.430 | 10.92 | — | PSB | PSB | — | — | — | — | — | |
| 68.00 | 13.375 | 339.73 | 0.480 | 12.19 | — | PSB | PSB | PSB | PSB | PSB | PSB | — | |
| 72.00 | 13.375 | 339.73 | 0.514 | 13.06 | — | — | — | PSB | PSB | PSB | PSB | PSB | |
| P-plain end；S-short round thread；L-long round thread；B-buttress thread | |||||||||||||
TUBING PIPE
Note: P = plain end, N = Non-upset thread and coupling, U = upset thread and coupling. Sizes per API 5CT specification
Source: API – American Petroleum Institute
| OCTG Pipe Sizes (Tubing) API5CT |
Weight Lb/ft | Outside Diameter | Wall Thickness | Nominal Weight | Type End Finish | |||||||
| Grade | ||||||||||||
| Nonupset | Ex-upset | mm | mm | Nonupset | Ex-upset | J-55 | L-80 | N-80 | C-90 | T-95 | P-110 | |
| T & C | T & C | T & C | T & C | |||||||||
| 2 3/8” | 4 | — | 60.32 | 4.24 | 5.95 | — | PN | PN | PN | PN | PN | — |
| 4.6 | 4.7 | 60.32 | 4.83 | 6.85 | 6.99 | PNU | PNU | PNU | PNU | PNU | PNU | |
| 5.8 | 5.95 | 60.32 | 6.45 | 8.63 | 8.85 | — | PNU | PNU | PNU | PNU | PNU | |
| 6.6 | — | 60.32 | 7.49 | 9.82 | — | — | P | — | P | P | — | |
| 7.35 | 7.45 | 60.32 | 8.53 | 10.94 | 11.09 | — | PU | — | PU | PU | — | |
| 2 7/8” | 6.4 | 6.5 | 73.02 | 5.51 | 9.52 | 9.67 | PUN | PNU | PNU | PNU | PNU | PNU |
| 7.8 | 7.9 | 73.02 | 7.01 | 11.61 | 11.76 | — | PNU | PNU | PNU | PNU | PNU | |
| 8.6 | 8.7 | 73.02 | 7.82 | 12.8 | 12.95 | — | PNU | PNU | PNU | PNU | PNU | |
| 9.35 | 9.45 | 73.02 | 8.64 | 13.91 | 14.06 | — | PU | — | PU | PU | — | |
| 10.5 | — | 73.02 | 9.96 | 15.63 | — | — | P | — | P | P | — | |
| 11.5 | — | 73.02 | 11.18 | 17.11 | — | — | P | — | P | P | — | |
| 3 1/2” | 7.7 | — | 88.9 | 5.49 | 11.46 | — | PN | PN | PN | PN | PN | — |
| 9.2 | 9.3 | 88.9 | 6.45 | 13.69 | 13.84 | PNU | PNU | PNU | PNU | PNU | PNU | |
| 10.2 | — | 88.9 | 7.34 | 15.18 | — | PN | PN | PN | PN | PN | — | |
| 12.7 | 12.95 | 88.9 | 9.52 | 18.9 | 19.27 | — | PNU | PNU | PNU | PNU | PNU | |
| 14.3 | — | 88.9 | 10.92 | 21.28 | — | — | P | — | P | P | — | |
| 15.5 | — | 88.9 | 12.09 | 23.07 | — | — | P | — | P | P | — | |
| 17 | — | 88.9 | 13.46 | 25.3 | — | — | P | — | P | P | — | |
| 4” | 9.5 | — | 101.6 | 5.74 | 14.14 | — | PN | PN | PN | PN | PN | PN |
| 10.7 | 11 | 101.6 | 6.65 | — | 16.37 | PU | PU | PU | PU | PU | PU | |
| 13.2 | — | 101.6 | 8.38 | 19.64 | — | — | P | — | P | P | — | |
| 16.1 | — | 101.6 | 10.54 | 23.96 | — | — | P | — | P | P | — | |
| 18.9 | — | 101.6 | 12.7 | 28.13 | — | — | P | — | P | P | — | |
| 22.2 | — | 101.6 | 15.49 | 33.04 | — | — | P | — | P | P | — | |
| 4 1/2” | 12.6 | 12.75 | 114.3 | 6.88 | 18.75 | 18.97 | PUN | PNU | PNU | PNU | PNU | PNU |
| 15.2 | — | 114.3 | 8.56 | 22.62 | — | — | P | — | P | P | — | |
| 17 | — | 114.3 | 9.65 | 25.3 | — | — | P | — | P | P | — | |
| 18.9 | — | 114.3 | 10.92 | 28.13 | — | — | P | — | P | P | — | |
| 21.5 | — | 114.3 | 12.7 | 32 | — | — | P | — | P | P | — | |
| 23.7 | — | 114.3 | 14.22 | 35.27 | — | — | P | — | P | P | — | |
| 26.1 | — | 114.3 | 16 | 38.84 | — | — | P | — | P | P | — | |
API 5CT TOLERANCES
| Execution | Outer Diameter | Wall Thickness |
| Cold rolled | Tube sizes(mm) | Tolerances(mm) |
| ＜114.3 | ±0.79 | －12.5％ |
| ≥114.3 | －0.5％，＋1％ |
OCTG PIPE MATERIALS
The most common materials for OCTG pipes are API H40, J55, K55, L80, N80, P110, and Q125 (casing and tubing pipes). These API grades feature increasing mechanical properties (tensile and yield strength).
OCTG casing and tubing pipes are available in the following material grades:
API H40
API H40 grade is for general purpose OCTG pipe material with the following mechanical properties:
Chemical Composition
| C | Mn | Mo | Cr | Ni | Cu | Ti | P | S | Si | V | Al | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Min | – | – | – | – | – | – | – | – | – | – | – | – |
| Max | – | – | – | – | – | – | – | 0.030 | 0.030 | – | – | – |
Mechanical Properties
| Min Tensile Strength | 414 MPa | 60,000 psi min |
| Min Yield Strength | 276 MPa | 552 MPa max |
| 40,000 psi | 80,000 psi max | |
| Total Elongation Under Load | 0.500 % | – |
API J55
The J55 API-5CT casing pipe is a comparatively low steel grade in oil drilling. It is widely applied to shallow oil and gas extraction. Because of its low cost among other grades of steel, it enjoys wider applications, can be generally used in shallow wells, geothermal wells, and water wells.
Chemical Composition
| C | Mn | Mo | Cr | Ni | Cu | Ti | P | S | Si | V | Al | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Min | – | – | – | – | – | – | – | – | – | – | – | – |
| Max | – | – | – | – | – | – | – | 0.030 | 0.030 | – | – | – |
Mechanical Properties
| Min Tensile Strength | 517 MPa | 75,000 psi min |
| Min Yield Strength | 379 MPa | 552 MPa max |
| 55,000 psi | 80,000 psi max | |
| Total Elongation Under Load | 0.500 % | – |
API L80
L80 belongs to steel grades group of the corrosion-resistant casing. L80 API oilfield casing pipe includes L80-1, L80-9Cr, and L80-13Cr. L80-1 is used in the H2S environment, while L80-9Cr and L80-13Cr are used in the CO2 environment. In the corrosive environment in which carbon dioxide predominates, Super 13Cr has a higher corrosion resistance than L80-13Cr. With a relatively high price, the product applies to more complicated geological conditions and runs down deeper into the well. In the exploitation of oil and gas, the use of L80 is less frequent than J55, N80, and other materials.
Chemical Composition
| C | Mn | Mo | Cr | Ni | Cu | Ti | P | S | Si | V | Al | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Min | – | – | – | – | – | – | – | – | – | – | – | – |
| Max | 0.430 | 1.900 | – | – | 0.250 | 0.350 | – | 0.030 | 0.030 | 0.450 | – | – |
Mechanical Properties
| Min Tensile Strength | 655 MPa | 95,000 psi min |
| Min Yield Strength | 552 MPa | 655 MPa max |
| 80,000 psi | 95,000 psi max | |
| Total Elongation Under Load | 0.500 % | – |
| Hardness | 23 Max HRC | 241 Max HBW |
9Cr-L80 Chemical Composition
| C | Mn | Mo | Cr | Ni | Cu | Ti | P | S | Si | V | Al | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Min | – | 0.300 | 0.900 | 8.000 | – | – | – | – | – | – | – | – |
| Max | 0.150 | 0.600 | 1.100 | 10.000 | 0.500 | 0.250 | – | 0.020 | 0.010 | 1.000 | – | – |
9Cr-L80 Mechanical Properties
| Min Tensile Strength | 655 MPa | 95,000 psi min |
| Min Yield Strength | 552 MPa | 655 MPa max |
| 80,000 psi | 95,000 psi max | |
| Total Elongation Under Load | 0.500 % | – |
| Hardness | 23 Max HRC | 241 Max HBW |
API N80
API-5CT N80 oilfield casing pipe contains N80-1 and N80-Q types. Those two materials are absolutely consistent regarding the chemical composition and mechanical attributes, they are just variations in the heat treatment.
During the heat treatment, N80-1 steel is treated by normalizing and tempering, while N80Q steel is treated by quenching and tempering. Therefore, the collapsing strength and internal pressure strength of N80Q are higher than that of N80-1. N80-1 or N80Q should be clearly shown by the designer when N80 casing is selected.
Due to the high capability of the N80 material, those API-5CT casing pipes are broadly applied in natural gas as well as coal bed methane extraction, and geothermal wells.
Chemical Composition
| C | Mn | Mo | Cr | Ni | Cu | Ti | P | S | Si | V | Al | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Min | – | – | – | – | – | – | – | – | – | – | – | – |
| Max | – | – | – | – | – | – | – | 0.030 | 0.030 | – | – | – |
Mechanical Properties
| Min Tensile Strength | 689 MPa | 100,000 psi min |
| Min Yield Strength | 552 MPa | 758 MPa max |
| 80,000 psi | 110,000 psi max | |
| Total Elongation Under Load | 0.500 % | – |
| Hardness | – | – |
API P110
The P110 API-5CT steel casing pipe is the high grade amongst other grades of steel. The white band is marked on the finished casing to point out the materials. During petroleum drilling and producing, this pipe is generally used in a variety of complicated territory due to its higher tensile strength and higher yield. It goes down the deepest into the well among other types.
However, the price is comparatively high, as well as the quantity of usage is comparatively few. P110 casing pipe is mainly used in a particular surrounding and when the drilling depth extends to a particular level.
API Q125
This API grade is generally used for deep wellbore service and not in sour condensate wells. The hardness testing (quadrant) is required without any specified limits other than the variation between readings.
API5CT MATERIALS CHEMICAL COMPOSITION
| Group | OCTG pipe materials | Type | C | Mn | Mo | Cr | Ni max. | Cu max. | P max. | S max. | Si max. | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| min. | max. | min. | max. | min. | max. | min. | max. | ||||||||
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 |
| 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 c | – | 1.9 | – | – | – | – | – | – | 0.03 | 0.03 | 0.45 | |
| 2 | M65 | – | – | – | – | – | – | – | – | – | – | – | 0.03 | 0.03 | – |
| L80 | 1 | – | 0.43 a | – | 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 | |
| L80 | 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 b | 0.85 | – | 1.5 | 0.99 | – | 0.02 | 0.01 | – | |
| T95 | 1 | – | 0.35 | – | 1.2 | 0.25 d | 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 | e | – | – | – | – | – | – | – | – | – | – | 0.030 e | 0.030 e | – |
| 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 wall thickness 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 wall thickness 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.
OCTG PIPE MATERIALS – MECHANICAL PROPERTIES
| Group | OCTG pipe materials | Type | Total elongation under load % | Yield strength MPa | Tensile strength min. MPa | Hardness a max. | Specified wall thickness mm | Allowable hardness variation b HRC | ||
|---|---|---|---|---|---|---|---|---|---|---|
| min. | max . | HRC | HBW | |||||||
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 |
| 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
|
448
|
586
|
586
|
22
|
235
|
–
|
–
|
|
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
|
0.5
|
621
|
724
|
689
|
25.4
|
255
|
≤ 12.70 12.71 to 19.04 19.05 to 25.39 ≥ 25.40
|
3.0 4.0 5.0 6.0
|
|
|
T95
|
1
|
0.5
|
655
|
758
|
724
|
25.4
|
255
|
≤ 12.70 12.71 to 19.04 19.05 to 25.39 ≥ 25.40
|
3.0 4.0 5.0 6.0
|
|
|
C110
|
–
|
0.7
|
758
|
828
|
793
|
30
|
286
|
≤ 12.70 12.71 to 19.04 19.05 to 25.39. ≥ 25.40
|
3.0 4.0 5.0 6.0
|
|
| 3 |
P110
|
–
|
0.6
|
758
|
965
|
862
|
–
|
–
|
–
|
–
|
| 4 |
Q125
|
1
|
0.65
|
862
|
1034
|
931
|
b
|
–
|
≤ 12.70 12.71 to 19.04 ≥ 19.05
|
3.0 4.0 5.0
|
| a In case of dispute, laboratory Rockwell C hardness testing shall be used as the referee method. b No hardness limits are specified, but the maximum variation is restricted as a manufacturing control in accordance with 7.8 and 7.9 of API Spec. 5CT. |
||||||||||
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6 Responses
It is good article for me.
We are drilling and cementing tools supplier.
Thank you for your appreciated comment. Should you need further information on some specific topics, kindly send us an email to [email protected]. To submit an RFQ for piping materials, please visit this page: https://projectmaterials.com/submit-rfq-mto. Best regards, Projectmaterials
The J55 API -5CT casing pipe is a comparatively low steel grade in oil drilling. It is widely applied to shallow oil and gas extraction. Because of its low cost among other grades of steel, it enjoys wider applications, can be generally used in shallow wells, geothermal wells, and water wells.
Thank you for your appreciated comment. Should you need further information on some specific topics, kindly send us an email to [email protected]. To submit an RFQ for piping materials, please visit this page: https://projectmaterials.com/submit-rfq-mto. Best regards, Projectmaterials
Do you have tubing pipes of the sizes 4′ 4 5/8′, and 5′ for sale. It must be buttress threaded and with a threaded coupling joints with the following specs:
L: around 32″
Conditions : tested and galvanized, used , new
thickness: above 0.23 mm
quantity : open
Hello. I would like to know which of these casings would be best suited to be used in a percussion application where the casings would be driven from ground level using a high speed air hammer.
Also we have had problems when threading casing with chrome. When screwing casing together these joints will then not unscrew. Can you explain.
Please advise
Bobby