Objective Drainage steel pipes frequently fail due to corrosion in shale gas field station, especially in drainage condition,where they are exposed to high-mineral water, bacteria and CO₂, seriously affecting safety production. Non-metal pipes offer benefits like corrosion resistance and lower costs, but their applicability for anti-corrosion purposes requires further clarification.

Methods Accelerated aging tests were conducted on fiber-reinforced composite pipes and steel skeleton composite pipes under conditions of simulated gas field drainage corrosion at 90 ℃ for varying durations. The study investigated corrosion resistance and performance damage characteristics through macro and micromorphology of specimens, Shore hardness of surfaces, infrared spectroscopy, oxidative induction, and circumferential tensile mechanical testing. Subsequently, a lifespan prediction model based on strength performance and the time-temperature equivalence principle was constructed to assess their long-term operational performance.

Results Under simulated drainage corrosion conditions, no defects were observed in the macro and micro morphology of specimens. Surface hardness showed no significant changes. Analysis of infrared spectroscopy and oxidative induction revealed damage to the material's molecular chain cross-linking structure and the introduction of new functional groups such as hydroxyl and carbonyl. With prolonged aging time, a noticeable reduction in strength occurred, with steel skeleton composite pipes exhibiting more pronounced effects. The predicted service life of fiber-reinforced composite pipes reached 28 years, while that of steel skeleton composite pipes was 23 years.

Conclusions Non-metal pipes have good corrosion resistance to the media under the drainage conditions. However, as service time increases, the pipes become more susceptible to aging, reflected in the gradual degradation of their molecular structures, reduced antioxidant capability, and declined mechanical strength. Fiber-reinforced composite pipes are more suitable for shale gas field drainage conditions.