油气田用热塑性塑料管材环境应力开裂研究进展

In response to the growing corrosive environment of oil and gas fields, the increase of CO₂ and H₂S content especially, thermoplastics were broadly employed in transporting the oil and gas due to their good corrosion resistance. However, the failure accidents often occurred due to environmental stress cracking (ESC) in the process of use, which brought a hidden danger for safety of pipelines and environment. In this paper, the research progress about ESC of thermoplastic plastic pipes used in oil and gas fields was investigated firstly. ESC evaluation method, the interaction of different polymer/solvent system, the influence of environmental factors on the ESC behavior, and impact of material modification on ESCR performance were reviewed. Then, the mechanism of ESC was analyzed by plasticizing theory, the influence of the surface energy, and molecular chain rupture mechanism. The deficiencies of the present study were pointed out: (1) the method for rapid analysis with ESC behavior of thermoplastic plastic pipe has not been established; (2) the influence of thermoplastic structure on ESC fails to consider fully; (3) no research about ESC mechanism of thermoplastic under mixed medium. Suggestions for the future research direction were provided.