CO2地质封存在咸水层中的时延重力监测和封存质量评估OA

The substantial emission of greenhouse gases dominated by CO2 has brought severe climatic challenges.Carbon capture and storage(CCS)is widely regarded as one of the most promising solutions to achieve carbon neutrality and address the ongoing climate crisis.To ensure the reliability and long-term integrity of CO2 geological storage projects,it is imperative to design precise site characterization and monitoring protocols during both CO2 injection and post-injection phases.This study focused on the CO2 storage site in saline aquifers of the Johansen Formation in Norway,proposing an innovative time-lapse gravity monitoring methodology to elucidate CO2 migration patterns and mass estimation during CO2 injection and post-injection stages.A three-dimensional geological model was constructed using numerical simulation software to analyze CO2 migration characteristics and surface gravity responses under varying injection rates(20,40,and 60 kg/s).Key findings reveal that CO2 injection rates critically influence gravity anomaly magnitudes,with the maximum response reaching-15 μGal at 60 kg/s.Higher injection rates accelerate the attainment of instrument detection thresholds(e.g.,6 years at 60 kg/s).Post-injection gravity field variations effectively delineate CO2 plume migration toward shallower strata and dynamic brine saturation redistribution.Furthermore,the implementation of a depth-based extreme point(DEXP)multi-scale analysis method enables efficient estimation of stored CO2 mass with less than 2%error without requiring prior data,demonstrating superior accuracy compared to conventional Gaussian flux methods.This research validates the technical feasibility of time-lapse gravity monitoring for dynamic CO2 storage tracking while introducing a computationally efficient mass estimation approach with enhanced noise immunity.The proposed methodology provides critical technical support for long-term safety monitoring and quantitative evaluation of CCS projects.