A Feasibility Evaluation Method for Seismic Monitoring of CO₂Geological Storage Based on Reservoir Simulation and PrestackPre-stackTime-Lapse AVO Inversion

Deep saline reservoirs play a crucial role and have broad application potential in CO₂ geological storage. To assess their storage capacity and monitor the migration process of CO₂ plumes, this paper takes the Utsira sandstone reservoir in the Sleipner area as the research object, constructs a numerical simulation model for CO₂ geological storage, and simulates the CO₂ saturation distribution and the evolution characteristics of reservoir physical parameters after CO₂ injection. Based on this, considering the elastic parameter response caused by changes in reservoir fluid properties, the time-varying characteristics of parameters such as P-wave velocity, S-wave velocity, and density are predicted using the fluid substitution theory of a rock physics model. Combined with AVO (or AVA, amplitude varying with incident angle) analysis and pre-stack time-lapse AVO inversion, the response capability of time-lapse seismic monitoring technology to the CO₂ storage process is systematically evaluated, and the feasibility of the pre-stack seismic inversion method in CO₂ geological storage monitoring is verified. This paper constructs an integrated feasibility evaluation process for CO₂ geological seismic monitoring, which includes reservoir simulation, rock physics, forward modeling, and pre-stack seismic inversion. This process achieves a systematic connection from reservoir simulation to seismic inversion, providing reliable methodological support for the dynamic monitoring and effect evaluation of CO₂ seismic storage in deep saline aquifers.