Carbon Storage Potential of Shale Reservoirs Based on CO2 Fracturing Technology

Abstract

The development of shale reservoirs is important in ensuring China’s national energy security by achieving energy independence. Among the key technologies for shale oil production, CO₂ fracturing is an effective method that can not only enhance oil recovery but also promote large amounts of CO₂ storage, thereby supporting China’s goals of achieving a carbon peak and carbon neutrality. This research paper aims to study the impacts and prospective applications of CO₂ fracturing in shale reservoirs, using real exploitation parameters from the Gulong shale reservoir well 1 (GYYP1) well in the Songliao Basin. By utilizing numerical simulation, the dynamics of CO₂ production are analyzed. Adsorption and diffusion are identified as pivotal mechanisms for CO₂ storage in shale reservoirs. After the analysis of the fracturing process, approximately 22.13% of CO₂ is found to be adsorbed, which decreases to 11.06% after ten years due to pressure decline. Diffusion increases the volume of CO₂ interacting with a greater extent of shale, thereby enhancing the adsorption mechanism. Over time, the diffusion process results in a remarkable increase of 26.02% in CO₂ adsorption, ensuring the long-term and stable storage of CO₂ within the shale reservoir. This investigation delves into the contribution of these two crucial mechanisms of CO₂ storage in shale reservoirs, ultimately predicting that, by 2030, approximately two million tons of CO₂ can be effectively stored in the Daqing Oilfield through CO₂ fracturing in shale oil reservoirs. Such an achievement will undoubtedly contribute to the sustainable development of the energy sector and foster the transformation and upgrading of China’s energy structure.