CO2 Gas Channel Identification in the CCUS-EOR Process Based on the Fuzzy Comprehensive Evaluation Method

In CO2 flooding, variations in mobility and formation heterogeneity may cause gas to traverse high-permeability or interconnected channels, leading to ineffective gas circulation. This limits recovery rates, ultimately leading to reduced financial benefits. Consequently, the identification of CO2 gas channeling becomes crucial for developing targeted management strategies and improving the efficacy of CCUS-EOR operations. This paper applies an established AHP–fuzzy comprehensive evaluation framework to the screening and prioritization of gas-channeling risk in an ultra-low-permeability CO2-EOR reservoir. This approach combines six static geological parameters and three dynamic production parameters as indicators, enabling a comprehensive analysis of potential gas channeling in the A block of the Haian Oilfield. This method was applied to the production data from the A block, showing strong consistency with the observed production response. The results offer significant technical assistance and theoretical understanding for the scientific identification, risk evaluation, and subsequent management of CO2 gas channeling in oilfields.