API 5CT OCTG Oil Well Casing

API 5CT casing Product Description

GNEE API 5CT Oil Well Casing includes a complete line of OCTG steel grades for global oilfield and underground engineering.All casings are manufactured in full compliance with API 5CT standards, adopting high-quality seamless carbon steel, precise hot rolling technology, uniform wall thickness and stable mechanical properties.

Fitted with standard STC, LTC and BTC API thread connections, our casing delivers fast installation, tight sealing and strong downhole pressure resistance.Each batch is strictly inspected by hydrostatic testing and ultrasonic NDT, with complete material test reports and certifications to ensure reliable performance in complex working conditions.

Each steel grade features standard color marking for easy identification and correct grade selection.Widely used for oil and gas well surface casing, intermediate casing, water wells, geothermal projects and coalbed methane development.

GNEE offers abundant inventory, customized processing, anti-corrosion treatment and seaworthy packaging, providing stable supply and one-stop procurement solutions for global customers and long-term project cooperation.

Not only K55 grade, but also full series OCTG casing J55,N80,L80,P110 for harsh working conditions. Gain one-stop oilfield piping solutions and stable long-term supply by sending your inquiry. Contact our team to get more information.

OCTG Oil Casing Core Features

Strict API 5CT Compliance & Quality Assurance

Fully certified to API SPEC 5CT (PSL-1/PSL-2), with full material test reports (MTR) and third-party inspection (UT/MT/HT) to guarantee consistency and reliability.

K55 Grade Identification: Green full-color coupling + two bright green paint bands on the pipe body (600mm from pipe end) for instant grade recognition, avoiding misapplication.

Superior Mechanical Performance

Minimum Yield Strength: 55,000 psi (379 MPa); Minimum Tensile Strength: 95,000 psi (655 MPa) – delivers excellent resistance to burst, collapse, and axial tension under downhole pressure.

Seamless hot-rolled manufacturing process ensures uniform wall thickness, no weld defects, and enhanced structural integrity.

Versatile Threaded Connections

Standard API 5B threaded ends: STC (Short Round Thread), LTC (Long Round Thread), BTC (Buttress Thread) – compatible with standard API couplings, easy to install and connect on-site.

Optional premium connections available for high-pressure, high-temperature (HPHT) or complex well conditions.

Wide Application & Environmental Adaptability

Suitable for sweet (non-sour) environments, moderate temperature (-20°C to 175°C), and medium-pressure wellbores.

Available with external coating (FBE, epoxy) for additional corrosion protection in aggressive formations.

Seamless Well Casing Pipe Specifications

Casing Size / Weight / Dimension Table (Inch + MM)

More casing pipes and their colors

Our Advantages

• Cooperate with top Chinese API 5CT manufacturers, strictly controlling the whole production process from raw materials to packaging.

Supply high-quality, stable-performance OCTG casing at competitive factory prices, covering full common steel grades (J55, K55, N80-1, N80Q, L80, P110).

• Provide premium connection casing and customized heavy-duty solutions for harsh downhole conditions (high pressure, high temperature, complex formations).
• Manufactured to API 5CT & API 5B standards, with seamless structure, uniform wall thickness and excellent mechanical properties; each batch passes strict inspections with complete MTR and certifications.
• Offer reliable wellbore protection solutions, adaptable to various projects (shallow/medium/deep wells, water wells, geothermal, oil & gas exploitation).
• Support customized services (size, thread, anti-corrosion) and fast global delivery, helping customers reduce procurement costs and improve efficiency.

Inspection Equipment (API 5CT Standard)

Production Scenarios 

Applications

• Primary casing, intermediate casing, and surface casing for oil & gas exploration wells
• Geothermal wells, water well drilling, and coalbed methane extraction
• Shallow to medium-depth wells (up to 3,000m) with moderate pressure and temperature
• Wellbore stabilization, formation isolation, and fluid containment

Packaging & Shipping

Protected with steel bundle packing + plastic pipe end caps.

Moisture-proof and seaworthy package for long-distance sea and land transportation.

Certificate

FAQ

Q: What steel grades of API 5CT casing are available?

A: We provide full common steel grades, including J55, K55, N80-1, N80Q, L80 and P110, meeting different project needs.

Q: What is the wall thickness range of the API 5CT casing, and can it be customized?
A: The standard wall thickness of the casing is 3-12mm (adjustable according to needs). We support custom wall thickness, and can also customize the size according to your project requirements.

Q: How to ensure the quality of the casing, and is there any test report?
A: Every batch of casing undergoes strict ultrasonic inspection and hydrostatic pressure test. We provide complete test reports and certification documents to ensure that the product meets API 5CT standards.

Q:What steel grades are available for Buttress Thread Casing, and what are the applicable working conditions?
A: We provide full-series API 5CT steel grades, including J55, K55, N80-1, N80Q, L80 and P110, which can be selected according to the downhole pressure, temperature and corrosion conditions. It is mainly suitable for deep wells, ultra-deep wells, high-pressure gas wells and complex formation wells that need to bear large axial loads and internal pressure, and can also be used in geothermal wells and coalbed methane development projects with harsh working conditions.

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