API 5CT N80 Oil Casing | Specs, Types & Applications

API 5CT N80 Oil Casing Introduction

API 5CT N80 seamless steel casing for oil well drilling

1. What Is API 5CT N80 Casing?

API 5CT defines standards for petroleum tubular products. N80 casing owns a minimum yield strength of 80 ksi (552 MPa), widely used to stabilize borehole formations.

Two main subtypes:

  • N80‑1: Normalized & tempered, cost option for medium-depth wells
  • N80‑Q: Quenched & tempered, higher toughness for deeper drilling

2. Key Mechanical Properties

  • Minimum yield strength: 552 MPa
  • Minimum tensile strength: 689 MPa
  • Elongation: ≥13%

It features better collapse resistance compared with J55 casing.

3. Available Sizes & Threads

Common OD: 4‑1/2”, 5‑1/2”, 7”, 9‑5/8”, 13‑3/8”

Available connections: STC, LTC, BTC. Custom wall thicknesses are supported.

4. Typical Applications

Suitable for 1000–3500 m conventional oil/gas wells, geothermal wells and mine gas drainage.

Not recommended for wells with severe H₂S or CO₂ corrosion.

5. Baoyang Steel Quality Assurance

All N80 casing strictly follows API 5CT requirements:

  • Full-length ultrasonic inspection
  • Mandatory hydrostatic pressure test
  • Precise dimension & thread checking
  • Complete MTC material certificates
  • Anti-rust coating & plastic thread protectors for shipment

6. Summary

API 5CT N80 is a highly versatile casing grade with balanced strength and competitive cost.

Baoyang Steel supplies certified N80‑1 and N80‑Q seamless casing with customizable sizes and threads for your drilling projects.