Alloy pipes are critical in the oil and gas industry due to their strength, corrosion resistance, and ability to withstand extreme temperatures and pressures. Here are the key applications, categorized by function and environment:
1. Upstream Applications (Exploration & Production)
A. Downhole Tubing & Casing
- Material Grades: API 5CT (L80, 13Cr, Super Duplex), Inconel 625
- Functions:
- Transport oil/gas from reservoirs to surface.
- Protect wells from collapse and corrosion.
- Challenges:
- High-pressure, high-temperature (HPHT) wells.
- Sour service (H₂S/CO₂ corrosion).
B. Subsea Pipelines & Risers
- Material Grades: Duplex 2205, Super Duplex 2507, API 5L X65/X70 with Cr-Mo
- Functions:
- Transport hydrocarbons from seabed to platforms.
- Resist seawater corrosion and high pressure.
2. Midstream Applications (Transportation & Storage)
A. Transmission Pipelines
- Material Grades: API 5L X52-X80 (with micro-alloying additions like Nb, V)
- Functions:
- Long-distance transport of crude oil/gas.
- Handle high-pressure flow (up to 2,500 psi).
B. LNG (Liquefied Natural Gas) Systems
- Material Grades: 304L/316L stainless steel, 9% Ni steel
- Functions:
- Cryogenic piping for LNG storage (-162°C).
- Prevent brittle fracture at low temps.
3. Downstream Applications (Refining & Processing)
A. Refinery Piping
- Material Grades: ASTM A335 P5/P9/P11, 321H, 347H
- Functions:
- Transfer crude oil and intermediates between units.
- Resist sulfidation (sulfur compounds) and carburization.
B. Hydroprocessing Units
- Material Grades: 321H, 347H, Alloy 800H
- Functions:
- Handle high-temperature hydrogen (up to 500°C).
- Prevent hydrogen embrittlement.
C. Catalytic Cracking (FCC) Units
- Material Grades: 304H, 316H, Inconel 625
- Functions:
- Transport hot hydrocarbons and catalysts.
- Resist erosion-corrosion from catalyst particles.
