Experimental Study on the Impact of Corrosion on the Rubber in Packers in a CO2 Injection Well

As the core part of the packer,packer rubber has direct relationship with the sealing function of packer.CO2 corrosion on the rubber material can cause sealing failures and induce sustained casing pressure,thus affecting the safety of production of a CO2 injection well.Corrosion experiments were conducted on NBR and HNBR under simulated environment in high temperature high pressure autoclave.Comparisons were made on the mechanic performances and shape of the rubber materials through corrosion of gas and liquid phase.Results showed that the tensile properties of nitrile rubber and HNBR decreased significantly and the hardness was also reduced after corrosion.The corrosion in the liquid phase environment was much more severe than that in the gaseous phase environment.Effects of actual conditions on the mechanic performances of rubber materials,instead of the mechanical performance under its initial state,should be considered in making engineering design.The research results can provide references for the selection of rubber material in CO2 injection well.