Key points of seamless stainless steel pipes for oil and gas

Seamless stainless steel pipes are mainly used in the oil and gas industry:

1. Oil and gas transportation: corrosion resistance, high pressure resistance
2. Downhole pipes: high temperature resistance, corrosion resistance
3. Refining equipment: acid and alkali resistance, sulfide corrosion resistance

4. LNG (liquefied natural gas) transportation: maintain toughness under low temperature environment

Depending on the working conditions, the following stainless steel materials are mainly used:

Austenitic stainless steel (such as 304, 316, 316L): strong corrosion resistance, suitable for general corrosive environments.
Duplex stainless steel (such as 2205, 2507): has both high strength and corrosion resistance, suitable for high Cl⁻ (chloride ion) and H₂S (hydrogen sulfide) environments.
Super austenitic stainless steel (such as 904L, 254SMO): resistant to strong acid and seawater corrosion, used in harsh working conditions.
Martensitic stainless steel (such as 13Cr, super 13Cr): resistant to CO₂ corrosion, suitable for CO₂-containing oil and gas wells

Key performance requirements:
Corrosion resistance: Resistant to corrosive media such as H₂S, CO₂, Cl⁻.
High strength: Meet the needs of high-pressure transportation and downhole operations.
Low-temperature toughness (LNG application): Maintain good impact toughness at -196°C.
Welding performance: Convenient for on-site welding construction.
Dimensional accuracy: Ensure sealing and connection reliability.

Main standards and specifications:
API 5LC (Corrosion-resistant alloy pipeline standard)
ASTM A312 (Austenitic stainless steel seamless steel pipe)
ASTM A790 (Duplex stainless steel seamless steel pipe)
NACE MR0175/ISO 15156 (Material standard for hydrogen sulfide corrosion resistance)

Production process:
Hot rolling/cold rolling: Ensure high dimensional accuracy and surface quality.
Bright annealing (BA): Improve corrosion resistance and keep the surface smooth.
Non-destructive testing (UT/ET): Ensure no defects and meet the requirements of high-pressure pipelines.

Industry trends:
Deep-sea oil and gas development: Use high-grade duplex stainless steel (such as 2507).
Shale gas/unconventional oil and gas: Super 13Cr martensitic stainless steel is increasingly used.

Environmental protection requirements: The demand for low-emission and long-life stainless steel pipes is rising.

Conclusion:

Seamless stainless steel pipes for oil and gas must meet the requirements of high strength, corrosion resistance, and high pressure resistance. Different materials (such as 316L, 2205, super 13Cr) are selected for different working conditions, and must comply with API, ASTM, NACE and other standards to ensure safety and reliability.

Read more: Stainless Steel ERW vs Seamless Pipe