Research on Safety Evaluation of CO2 Enhanced Oil and Gas Recovery (CO2-EOR) Project: A Case Study of Dagang Oilfield

Carbon Capture, Utilization, and Storage (CCUS) technology plays a crucial role in China's journey toward achieving "carbon neutrality". To ensure the optimal efficiency and risk mitigation of CO2-EOR projects, it is imperative to enhance the safety system. This study develops a comprehensive safety evaluation system for the CO2-EOR project at Dagang Oilfield, employing a combination of the Analytic Hierarchy Process (AHP) and expert scoring. The AHP method is used to analyze the relative importance of various safety factors, while expert scoring is employed to determine the weight of each factor. The system establishes four primary evaluation indexes and 17 secondary evaluation indexes. This score indicates the relative safety of the blocks, with a lower score reflecting higher safety. A safety assessment is conducted on the Ye 21 and Ye 22 blocks using this system, which results in an assessment score of 1.2721 (less risky), indicating a relatively low overall risk. The study aims to provide a practical framework for the safety evaluation of CO2-EOR projects, and the proposed method can be applied to other CCUS projects globally to enhance safety and risk management.