[H-SC06] CCUS (Carbon Dioxide Capture, Utilization, and Storage) for Climate Mitigation

[HSC06-12] Seal Function Caused by CO₂ Hydrate Assuming CO₂ Storage in Subseabed

Yuichi Magara¹, Taku Nishimura¹, *Yoshihiro Konno¹, Yusuke Jin², Takaomi Tobase³ (1.Graduate School of Frontier Sciences, The University of Tokyo, 2.National Institute of Advanced Industrial Science and Technology (AIST), 3.Electric Power Development Co.,Ltd.)

Keywords:Carbon dioxide storage, CO2 hydrate, Self-sealing

In order to expand the suitable area for CO₂ storage, CO₂ storage in subseabed using hydrate has been proposed. In this method, CO₂ hydrate is expected to form in the sediment and become a seal layer by itself.
In this study, we injected liquid CO₂ into an artificial sediment core of approximately 730 mm in height and 50 mm in diameter sealed in a core holder. The experiment was conducted under pressure and temperature conditions assuming a water depth of 600 m and 150 m below the seafloor. We observed the formation behavior of hydrate and the development of sealing functions in the flow field. The result showed that the sealing function did not immediately appear as a result of CO₂ hydrate formation. However, it was suggested that a strong sealing function could be ensured by repeatedly injecting liquid CO₂ to stimulate hydrate growth during the static period.