Accurately characterizing \(\hbox {CO}_2\) sequestration and migration post-injection is crucial to the success of carbon capture and storage (CCS) projects. Time-lapse seismic monitoring technique is an effective tool; however, it can only reveal changes in elastic properties such as compressional wave velocity ( \(V_{\text {p}}\) ) and quality factor ( \(Q_{\text {p}}\) ). In contrast, reservoir simulation enables detailed tracking of fluid movement within the reservoir, allowing for precise simulation of \(\hbox {CO}_2\) saturation. Thus, to enable a more accurate characterization of \(\hbox {CO}_2\) migration, we develop an integrated workflow that closes the loop between reservoir saturation data and time-lapse seismic data, which operate at different resolution scales. First, we build a realistic geological model for \(\hbox {CO}_2\) storage based on the field information from typical saline aquifers in the Pearl River Mouth Basin (PRMB). Then, using rock physics theory, we establish relationships between \(\hbox {CO}_2\) saturation and seismic properties ( \(V_{\text {p}}\) and \(Q_{\text {p}}\) ) to construct seismic models. Subsequently, we employ time-lapse seismic techniques to analyze the effects of \(\hbox {CO}_2\) saturation changes on seismic data and quantitatively estimate these effects using the spectral-ratio method. Finally, the workflow developed in this study efficiently addresses challenges associated with varying observational scales and interdisciplinary research. It offers a valuable approach for predicting and detecting early \(\hbox {CO}_2\) leakage based on known reservoir properties. This dataset will be available as an open-access resource, providing a valuable tool for testing and advancing research in the CCS field.
