Aging Characterization and Life Prediction of HDPE Inner Liner in Glass Fiber-Reinforced Composite Pipes for Produced-Water Applications

As oil and gas field development enters mid and late stages, steel pipeline corrosion becomes more severe, driving the adoption of non-metallic pipes. This study tested non-metallic composite pipe HDPE inner-layer materials in simulated produced water at 60 °C and 70 °C, analyzing surface structure, mechanical properties, and chemical composition via systematic analytical methods. The findings indicate that the surface roughness Ra of the sample remains stable following immersion, with no voids observed; the tensile strength of the material decreases by 8.94% and 15.36% at temperatures of 60 °C and 70 °C. Infrared research indicated that the material’s structure remained stable at both temperatures, with no occurrence of oxidation or chain scission. The environmentally corrected lifetime (24.3 years) provides a practical framework for operators in analogous Sichuan Basin conditions, bridging the gap between idealized laboratory predictions and field performance.