Polyamide (PA) material is a polymer with amide groups (-CO-NH-) in the repeating units of its macromolecular backbone. It features high strength, good resilience, fatigue resistance, corrosion resistance, low moisture absorption, excellent wear resistance, non-polar molecular structure, low surface free energy, strong anti-scaling properties, and smooth surface. These characteristics help reduce friction coefficients and improve the wear resistance of oil pipes.

Polyamide materials have a Vicat softening temperature above 200°C, and their long-term use temperature can reach 125°C. In addition to all the advantages of ultra-high molecular weight polyethylene (UHMWPE) lined pipes, polyamide lined pipes offer significantly improved temperature resistance, making them suitable for ultra-deep wells, high-temperature wells, and wells with higher mineralization.

Table 1: Temperature Resistance Grade

Table 2: Geometric Dimensional Requirements for Liner

Table 3: Performance Requirements for Liner