oa Development of Sealing Materials for CCUS Packers Resistant to Supercritical CO2 and Analysis of Corrosion Mechanisms

This paper aims to investigate the corrosion resistance of different sealing rubber materials in a supercritical CO2 environment. Ten base rubber materials commonly used in the oil and gas industry, including fluoro rubber, nitrile rubber, hydrogenated nitrile rubber, ethylene propylene diene monomer (EPDM) rubber, and perfluoro elastomer (FFKM), were studied. The materials’ mechanical properties and mass/volume change rates before and after corrosion were tested. Through comprehensive comparative analysis, the best-performing base rubber material was selected. Different vulcanization systems and reinforcing materials were compared and optimized. The final rubber composite material was subjected to gas permeability and gas burst resistance tests, achieving the rubber material’s gas diffusion coefficient-temperature curve and verifying its gas burst resistance. The corrosion mechanism of supercritical CO2 on rubber was analyzed through molecular structure characterization. Based on the final formulation, CCUS packer rubber was manufactured, and its sealing performance was tested under simulated CCUS downhole conditions. This research contributes to addressing the current shortcomings in the gas sealing performance of CO2 injection packers, offering significant economic and social benefits.