Effect of high‐temperature, high‐pressure, and acidic conditions on the structure and properties of high‐performance fibers

High‐performance fibers such as carbon, aramid, and glass fiber generally have excellent mechanical, thermal, and chemical resistance and they have potential applications in oil and gas exploitation where high‐temperature and high‐pressure (HTHP) H2S/CO2 corrosive environments usually exist. To investigate the corrosion behavior of these fibers under such environments, two corrosion environments (HTHP water, HTHP H2S/CO2) were simulated in a high‐temperature high‐pressure reactor. Scanning electron microscope, X‐ray diffraction, density measurements, and single fiber tensile test were performed to study the surface morphology, crystal structure, and mechanical properties before and after corrosion. After exposure to the second corrosion environment, the carbon aramid fibers had no obvious mass loss and tensile strength retention of 70.28% and 49.66%, respectively. The surface of the aramid fiber and carbon fibers was significantly damaged which led to an increase in surface defects and a decrease in crystallinity. The glass fiber had clear weight loss due to a large number of defects being formed in the structure and the retention of tensile fracture strength was 48.18%. Corrosion under HTHP H2S/CO2 conditions caused more serious damage to the high‐performance fiber structures.