In the CO2 capture,utilization,storage and enhanced oil recovery(CCUS-EOR)environment,rubber packer failure in injection wells is a serious problem.The performance and applicability of nitrile rubber(NBR)in CO2 environments within CCUS-EOR systems were in-vestigated,and the suitability range of NBR was established to provide guidance on the selection and application of rubber seals for CO2 sys-tems.Corrosion and aging tests of NBR in CO2 environments were conducted following the standard GB/T 34903.1-2017.Before and after CO2 environment corrosion aging test,changes in sample appearance were observed,and mass variation was recorded.Additionally,hardness,ten-sile strength,elongation at break and Vicat softening temperature tests were performed.Infrared analysis was conducted on samples both before corrosion test and after exposure to gaseous conditions at 100℃ and 30 MPa.Results showed that after CO2 corrosion testing,the mass of NBR increased,hardness decreased,tensile strength decreased,and Vicat transition temperature declined.The influence of temperature and pres-sure on the properties of NBR materials after CO2 environmental testing was as follows:as pressure increased,the Shore hardness and tensile strength of NBR decreased,while density increased;as temperature increased,Shore hardness increased,tensile strength decreased,and den-sity decreased.The functional groups and chemical bonds of NBR exhibited minimal changes after the CO2 tests,indicating no significant aging.However,NBR was found to face risks of corrosion and cracking in high-temperature and high-pressure CO2 environments,attributed to rapid gas decompression(RGD)damage of NBR under high pressure.NBR was deemed suitable for use in low-to-moderate temperature and low-pressure CO2 environments.
万方数据