Advances in monitoring technologies for offshore CO₂ geological storage

This study systematically reviews the application status of monitoring technologies in offshore carbon storage projects worldwide. The analysis is structured according to the spatial progression framework: “deep reservoirs—shallow formations and seabed interfaces—water columns”. The review identifies limitations in existing monitoring technologies, including signals of subtle reservoir changes being easily masked by noise, a lack of monitoring capability for intermittent dynamic leakage, acoustic monitoring being significantly disturbed by complex terrain defocusing and high ocean current background noise, sensors exhibiting poor stability under high-pressure and low-visibility conditions, and traditional sampling technologies having limitations in terms of timeliness and spatial coverage. To address the aforementioned limitations, this study proposes targeted research directions, such as developing broadband monitoring equipment and combining machine learning algorithms to enhance anti-noise capability and the accuracy of low-magnitude signal identification, optimizing the dynamic response model of electromagnetic monitoring and improving the efficiency of deep signal capture through acoustic-electrical-gravitational multi-physical field coupling technology, and breaking through deep-sea pressure-resistant and anti-corrosion packaging technology while integrating laser spectroscopy to enhance monitoring stability in extreme environments. Ultimately, an integrated monitoring network covering the entire migration path of CO₂ is formed, which provides academic support and technical reference for the full-life-cycle safety management and control of China’s offshore million-ton-level geological CO₂ storage projects.