High-pressure oil pipelines are high-pressure tubular infrastructure used for transporting crude oil, refined oil products, natural gas or oil-gas mixtures. The design pressure is usually 10-120 mpa and they are mainly used for:

Oil and gas field development: High-pressure gathering and transportation from oil Wells to processing stations (such as the transportation of fracturing flowback fluid, with a pressure of ≥70MPa).

Long-distance transportation: Cross-border/cross-regional crude oil and natural gas trunk pipelines (such as the China-Russia Eastern Gas Pipeline with a design pressure of 10MPa).

Inside the refining and chemical plant: High-pressure process pipelines (such as hydrocracking units, with a pressure of 20-35 mpa).

Its core requirements include:

◆ High strength: Resistant to internal high pressure and external loads (such as soil stress, seismic loads).

◆ Corrosion resistance: Resistant to corrosive media such as H₂S, CO₂, and Cl⁻ in oil and gas (for example, sulfur-containing crude oil pipelines need to resist SSC stress corrosion).

◆ Sealing performance: Prevent leakage from causing safety accidents (the leakage rate should be ≤1×10⁻⁹ Pa · m³/s).

Key components and materials

Pipe body Material:

High-strength steel: X70, X80 pipeline steel (yield strength 485-55mpa), used for long-distance pipelines.

Alloy steel pipes: 13Cr, 22Cr stainless steel or duplex steel (such as 2507), used in high-sulfur oil and gas fields.

Specification:

Long-distance pipelines: Outer diameter 323-1422mm, wall thickness 7-40mm (for example, the China-Russia Eastern Pipeline uses φ1422×21.4mm X80 steel pipes).

Gathering and transportation pipeline: Outer diameter 60-610mm, wall thickness 9-30mm (such as φ323×25mm X70 steel pipe in shale gas fields).

Anti-corrosion system

Internal anti-corrosion: Epoxy resin coating (thickness ≥300μm) or inner lining of stainless steel to reduce corrosion caused by oil flow erosion.

External anti-corrosion: 3 layers of PE anti-corrosion coating (epoxy powder at the bottom, adhesive in the middle, and PE at the bottom), with a service life of over 50 years.

Ancillary equipment:

Valve: High-pressure ball valve/gate valve (pressure Class 900#-Class 2500#), equipped with remote actuator.

Pigging device: Intelligent pigging device for detection (such as magnetic flux leakage detection, capable of identifying defects with a wall thickness of ≥2%).