Oil Casing Pipe – API 5CT Grades P110, N80, L80, K55 (Carbon Steel Seamless)

Material

This product is a seamless oil casing pipe made from carbon steel, conforming to API 5CT (Oil Country Tubular Goods – Casing & Tubing) grades P110, N80, L80, K55. These grades denote progressively higher strength and toughness, for use in petroleum and petrochemical wells. Seamless construction gives high structural integrity and resistance to internal and external pressure.

Specification

• Standard: API Spec 5CT

• Grades: P110, N80, L80, K55

• Type: Seamless carbon steel tube / pipe

• Wall finish: Typically black (for casing), machined threads as per ASTM/API connection types (BTC, LTC, STC, premium threads)

• Sizes: Outer diameters typically from ~4½″ up to ~20″ for casing, with wall thicknesses to suit pressure classes.

• Heat treatment: For grades like P110 and N80-Q, quenched & tempered; for some others normalized or normalized + tempered depending on grade.

Chemical Composition

Mechanical Properties

Key Features

• High strength and toughness: higher grades (P110, N80) provide high yield and ultimate strength, required in deep wells and high pressure.

• Seamless construction: avoids weld seams, which are potential weak points under internal/external pressures.

• Variety of grades: allows selection based on depth, pressure, corrosion environment (presence of H₂S, CO₂), economic trade-offs.

• Threaded connections compatible with API 5CT requirements.

• Corrosion resistance: Cr-variants (e.g. L80-9Cr, L80-13Cr) used in sour service or CO₂ environments.

Execution

• Primary Standard: API Spec 5CT – specification for casing and tubing materials, dimensions, mechanical and chemical properties.

• Related Standards: ISO 11960 (international equivalent or close for many regions) for casing and tubing steels.

• Heat Treatment Requirements: For certain grades (e.g. P110, N80-Q), quenching and tempering as per API 5CT. Normalizing or normalized + tempering for other grades or PSL2 variants.

Applications

General Application Field: Oil and gas wells – both drilling / completion / production phases; includes petroleum extraction, natural gas wells, petrochemical feedstock wells; also wells involving corrosive environments and high pressures.

Specific Uses by Grade / Environment:

• J55, K55: Shallow wells; surface casing; less intense pressure; non-sour environments; cost-sensitive projects.

• N80: Intermediate to deeper wells; higher pressures; zones requiring better collapse resistance; in some cases moderate sour service if spec’ed appropriately (e.g. N80-Q).

• L80 & its Cr-variants: Service in CO₂ or H₂S containing fluids; sour or corrosive environments; deeper or offshore wells with need for corrosion resistance plus mechanical strength.

• P110: Deep wells, high pressure; high collapse, internal and external pressures; production casing / tubing where strength is critical; zones with extreme mechanical stresses.

Q: Are you trading company or manufacturer ?

A: manufacturer,also can do trading.

Q: How long is your delivery time?

A: Generally speaking,it is 10-15 days if the goods are in stock,or it is 30-40 days if the goods are not in stock,

it is according to quantity.

Q: Do you provide samples? is it free or extra ?

A: Yes, we could offer the sample for free charge but need pay the cost of freight.

Q: What is your terms of payment ?

A: Payment<=2000USD, 100% in advance. Payment>=2000USD, 30% T/T in advance ,balance before shippment.

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