Advances in Geochemical Monitoring Technologies for CO 2 Geological Storage.

CO₂ geological storage, as a large-scale, low-cost, carbon reduction technology, has garnered widespread attention due to its safety. Monitoring potential leaks is critical to ensuring the safety of the carbon storage system. Geochemical monitoring employs methods such as gas monitoring, groundwater monitoring, tracer monitoring, and isotope monitoring to analyze the reservoir's storage state and secondary changes after a CO₂ injection. This paper summarizes the recent applications and limitations of geochemical monitoring technologies in CO₂ geological storage. In gas monitoring, the combined monitoring of multiple surface gasses can analyze potential gas sources in the storage area. In water monitoring, pH and conductivity measurements are the most direct, while ion composition monitoring methods are emerging. In tracer monitoring, although artificial tracers are effective, the environmental compatibility of natural tracers provides them with greater development potential. In isotope monitoring, C and O isotopes can effectively reveal gas sources. Future CO₂ geological storage project monitoring should integrate various monitoring methods to comprehensively assess the risk and sources of CO₂ leakage. The incorporation of artificial intelligence, machine learning technologies, and IoT monitoring will significantly enhance the accuracy and intelligence of numerical simulations and baseline monitoring, ensuring the long-term safety and sustainability of CO₂ geological storage projects. [ABSTRACT FROM AUTHOR]