Damage evaluation of carbon fiber reinforced composites under corrosion condition of sour gas well

The paper focuses on the excellent chemical inertness characteristics of nonmetallic materials and evaluates the performance of three types of new carbon fiber-reinforced resin-based composites under various simulated corrosion conditions in wellbores. Through comprehensive analysis of macro and micromorphology, moisture absorption performance, strength performance, and molecular structure, the damage characteristics and applicability of carbon fiber composites in oil and gas wellbore conditions were clarified. T700/epoxy and T300/epoxy composites experienced damage dominated by physical effects such as moisture absorption and wet thermal stress, manifested as swelling, deformation, and cracking at the macro level, and pore formation and delamination cracking at the micro level. After continuous corrosion tests, the tensile strength of T700/bismaleimide composite (913 MPa) was higher than that of T700/epoxy composite (814 MPa) and T300/epoxy composite (636 MPa), with reductions of 12.4%, 14.3%, and 19.5% respectively. The research results showed T700 carbon fiber/bismaleimide resin composites had the best mechanical and chemical stability.