Research status and prospects of CO2 geological sequestration technology from onshore to offshore: A review

Abstract

CO₂ geological storage is a critical component of carbon capture, utilization and storage (CCUS) technology, and a key technical path towards achieving carbon neutrality. This study offers a comprehensive review of the theoretical and technical methods of onshore geological CO₂ storage, and highlights that current CO₂ terrestrial storage demonstration projects primarily focus on the traditional oil and gas reservoir collaborative flooding technology. Simultaneously, global CO₂ geological storage projects have begun to accelerate the development of deep saline aquifers storage and large-scale clustering in the direction of tens of millions of tons. In comparison to land-based sites, marine carbon sequestration sites possess greater storage potential, and are gradually emerging as the primary battlefield for carbon sequestration in the future due to their distance from aquifers and associated low risk. Storage in deep saline aquifers at marine area is the primary research focus in carbon sequestration, while the storage of submarine basalt mineralization holds great potential. The storage of CO₂ in the form of solid hydrate within appropriate seabed sediment environments or the formation of artificial CO₂ hydrate cap layer is conducive to the safe and efficient development of natural gas hydrate resources, and has emerged as a new hot research topic. In the future, the focus of CO₂ geological storage should be on the fine assessment and regional optimization of carbon storage potential, the implementation of demonstration projects of the entire marine geological carbon storage process encompassing capture, transportation, injection and geophysical monitoring, and the establishment of an intelligent, real-time, and professional database integrating geological, engineering and environmental aspects of carbon storage. This study holds significant relevance in accurately identifying the future technical research direction of CO₂ geological carbon sequestration, fostering technological advancements and innovations in carbon sequestration, and propelling the leapfrog development of CO₂ carbon sequestration in the submarine areas.