CO2 Oil Displacement and Geological Storage Status and Prospects

Abstract

CCUS-enhanced oil recovery (EOR) technology relies on the unique properties of CO₂ gas in the process of efficient oil displacement while achieving effective storage, which has become one of the most economical and effective measures for reducing greenhouse gas emissions in today's society and is important for helping to realize the global strategic goal of carbon neutrality. Based on previous research results, this review presents the oil displacement and geological storage mechanisms of CO₂ in micropores in the oil and gas fields, and summarizes their respective influencing factors. At the same time, it also summarizes the current research status of CO₂-EOR and geological storage from the perspectives of laboratory experiments and numerical simulations. Moreover, it provides a detailed overview of four key technologies namely, miscibility improvement, swept volume expansion, storage potential assessment and storage safety monitoring, and their field applications. On this basis, this review compares the development status of field applications in Developed Countries and China, analyzes the problems of CCUS-EOR technology in theoretical research, technology research and development and project industrialization, and points out the future development directions. Results are presented that research on CO₂-EOR and geological storage in Developed Countries such as the United States started early and developed rapidly. A relatively complete industrial chain system has been formed, and the scale and number of CCUS-EOR projects are far ahead those in China. In China, relevant research started relatively late and developed slowly at the early stage. In recent years, due to the notable attention given to climate change and carbon storage, development efforts in China have gradually intensified. At present, there are more than 20 large-scale CCUS-EOR demonstration projects in operation, which are preliminarily ready for industrial promotion. Notably, the world has continued to increase its attention to CCUS-EOR projects based on national conditions, further improving policy guidance mechanisms, strengthening research and development efforts, promoting the construction of the full-process industry chain, achieving large-scale and refined development, and providing theoretical guidance and technical support for realizing the strategic goal of carbon neutrality.