Research and Prospect of CCUS-EOR Technology and Carbon Emission Reduction Accounting Evaluation

Abstract

As a potential carbon emission reduction measure, carbon capture, utilization and storage technology is of great significance to achieve the goals of “carbon peak” and “carbon neutrality.” The implementation of carbon capture, utilization, and storage-enhanced oil recovery (CCUS-EOR) in the oil and gas industry serves the dual purpose of utilizing greenhouse gases as resources and enhancing oil recovery. This approach is a key strategy for achieving carbon emission reductions. In this study, the key problems of source-sink matching, injection mode, oil displacement storage, and leakage were analyzed in conjunction with CCUS-EOR technology used in both domestic and foreign oil fields. Additionally, the carbon emission reduction accounting methods of different oil fields were compared. Carbon source, carbon dioxide concentration, capture, and transportation mode are important influencing factors of carbon source selection. The project should follow the principle of proximity and select high-concentration gas source as the development object in the early stage; the main methods of carbon dioxide injection are continuous carbon dioxide injection, alternating water and gas injection, and CO₂ huff and puff among which injection speed and injection pressure are the key parameters; the underground occurrence state and storage capacity of carbon dioxide gas are dynamic changes in the process of oil displacement and storage; the three parts of surface leakage, injection wellbore leakage, and production well production are the key points of CCUS-EOR project leakage. The corresponding monitoring methods are analyzed for different leakage modes; the CCUS-EOR carbon emission reduction accounting method is comprehensively analyzed, and the application of carbon emission reduction accounting methods in major oilfields is compared. The accounting method of “life cycle assessment (LCA) + emission factor method + actual measurement method” is proposed. The research holds significant importance for enhancing the entire CCUS-EOR technology chain and refining the CCUS-EOR emission reduction accounting methodology. It also facilitates the integration of CCUS-EOR projects into the carbon trading market, thereby enabling the efficient development of carbon assets in carbon dioxide flooding projects within oil and gas fields.