API 5CT Standard OCTG Pipe - Eastern Steel

API 5CT standard

The API 5CT standard is an important standard used in the oil and gas industry to regulate octg pipe. 

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Here are some key points and requirements of the API 5CT standard:

1.Outer diameter

The API 5CT standard has clear provisions for the allowable deviation of the outer diameter of the pipe. For example, for pipes with an outer diameter less than 114.3mm, the outer diameter deviation is ±0.79mm; while for pipes with an outer diameter greater than or equal to 114.3mm, the outer diameter deviation is -0.5%D to +1.0%D.

2.Wall thickness

The allowable deviation of wall thickness is -12.5%.

3.Allowable deviation of weight

The weight deviation of a single pipe is -3.5% to +6.5%, while the weight deviation is -3.5% for orders with a vehicle load less than 18.144 tons; the weight deviation is -1.75% for orders with a vehicle load greater than or equal to 18.144 tons.

4.Length 

The length deviation of casing and liner is clearly specified. For example, the first-level length is 4.88 to 7.62 meters, and the minimum allowable length is 1.83 meters.

5.Straightness

The straightness requirement of the pipe is that the deviation from the straight line or the chord height should not exceed the specified value. For example, for pipes with an outer diameter greater than or equal to 114.3mm, the total curvature should be less than or equal to 0.2%L.

6.Through rod

The API 5CT standard also has clear provisions for the requirements of through rods. For example, for casing pipe and liner with an outer diameter less than 244.5mm, the minimum diameter of the standard through rod is 152mm, and the calculated inner diameter d-3.18mm.

7.Chemical composition

The API 5CT standard has detailed provisions for the different chemical compositions of steel grades. For example, the H40 steel grade does not specify the carbon content, while the J55 and K55 steel grades do not specify the carbon content.

8.Mechanical properties

The API 5CT standard has clear provisions for the yield strength and tensile strength of different steel grades. For example, the yield strength of the J55 steel grade is 379 to 552 MPa, and the tensile strength is greater than or equal to 517 MPa.

9.Hardness

API 5CT standard also stipulates the hardness of different steel grades. For example, the maximum hardness of C90 steel grade is HRC 25.4, and the maximum hardness of Q125 steel grade is also HRC 25.4.

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10.Impact requirements

API 5CT standard also clearly stipulates the requirements for impact test. For example, the Charpy V-notch (CVN) absorption energy requirement for J55 and K55 steel grades is that the full-size transverse Cv is greater than or equal to 20J, and the full-size longitudinal Cv is greater than or equal to 27J.

11.Surface quality

API 5CT standard requires that all inner and outer edges of all pipe ends should not have burrs, and all pipes should not have defects such as quenching cracks, surface cracking defects, etc.

12.Hydrostatic test

API 5CT standard requires that steel pipes should be subjected to hydrostatic test one by one, and at least reach the specified hydrostatic test pressure without leakage, and the pressure stabilization time should be no less than 5 seconds.

Why choose API 5CT standard octg pipe

API 5CT standard octg pipe

API 5CT standard octg pipe plays an important role in preventing oil wells from being damaged by shallow oil layers and supporting oil and gas transportation. In addition, the casing pipe can support the weight of the wellhead layer to prevent collapse. API 5CT casing pipe ensures the smooth progress of the entire drilling process, and then transports oil and gas from the well to the ground.

API 5CT octg pipe is the lifeblood of the oil well, so it should have higher quality requirements. Because under special circumstances, poor quality pipes are easily damaged. It is easy to cause accidents and even cause the oil well to be directly scrapped. Therefore, there are many requirements for the selection of API 5CT octg pipe, such as selecting and purchasing according to the bottom hole pressure. When you buy casing pipe, we recommend that you choose a regular enterprise that provides casing and tubing that can always maintain good performance even under harsh conditions.

Provide the best API 5CT standard casing and common problems

High quality and competitive price API 5CT casing is your best choice. We are a professional supplier and enterprise for the production of API 5CT oil casing. We will provide the best service, and we will also answer your questions sincerely. For example, here are two questions raised by customers.

1.How to reduce the erosion of sand control joints?

----Use high-precision punching technology and side slots.

2.How to ensure the reliability of sand control?

----Let the oil casing be locally squeezed by external force, and let the gap of the compressed part be reduced under the action of external force. If the joint of the oil casing is along the axis of the pipe body, straight seam welding can be used.

Oil casing pipe is a high-end product produced by steel pipes. There are many types of casings. There are 15 categories of casing diameter specifications, and the outer diameter range is 114.3-508mm; the steel grades are mainly divided into J55, K55, N80, L-80, P-110, C-90, C-95, T-95, etc. There are 11 types of casing pipe end buckle types and requirements. The buckle types that can be processed include STC, LC, BC, VAM and other buckle types.

The production and installation process of oil casing involves a lot of testing, mainly as follows:

1. Ultrasonic testing
When ultrasonic waves propagate in the material being tested, changes in the material's acoustic properties and internal organization have a certain impact on the propagation of ultrasonic waves. By detecting the degree and condition of the impact of ultrasonic waves, we can understand the changes in material properties and structure.

2. Radiographic detection

Radiographic testing uses the difference in the amount of radiation transmitted through normal parts and defective parts to cause the difference in blackness on the film.

3. Penetration testing
Penetrant testing uses the capillary action of liquid to penetrate the penetrant into the open defects on the surface of solid materials, and then uses the developer to suck the penetrant out to the surface to reveal the existence of defects.

Penetration testing is suitable for various metal and ceramic workpieces, and the time from penetration operation to defect display is relatively short, generally about half an hour. It can detect surface fatigue, stress corrosion and welding cracks, and can directly measure the size of cracks.

4. Magnetic particle testing
Magnetic particle testing uses magnetic flux leakage at defects to absorb magnetic particles and form magnetic marks to provide defect display. It can detect surface and sub-surface defects. The nature of defects is easy to identify. Paint and electroplated surfaces do not affect detection sensitivity.

5. Eddy current testing
Eddy current testing mainly uses the eddy currents induced by ferromagnetic coils in the workpiece to analyze the internal quality of the workpiece. It can detect surface and near-surface defects of various conductive materials. Usually, it is difficult to control the parameters and the test results are difficult to interpret, and it requires detection objects. It must be a conductive crack and the length of the defect can be measured indirectly.

6. Magnetic flux leakage detection
Magnetic flux leakage detection of oil casing is based on the high magnetic permeability characteristics of ferromagnetic materials. It detects the quality of in-service oil casings by measuring changes in magnetic permeability caused by defects in ferromagnetic materials.

7. Magnetic memory detection
Magnetic memory detection is derived from the relationship between the physical nature of magnetic phenomena in metals and the dislocation process. It has many advantages such as high efficiency, low cost, and no need for polishing. It has important and wide application prospects in industry.

Among several detection methods, there is currently no special standard for product magnetic memory detection and has yet to be developed. The remaining six types have their own detection standards and are relatively mature.

The company is the world’s best api 5ct pipe supplier. We are your one-stop shop for all needs. Our staff are highly-specialized and will help you find the product you need.