Experimental simulation of self-trapping mechanism of CO2 hydrates in marine sediments

Abstract

CO2 hydrate-bearing sediments imply that the formation of CO2 hydrates in unconsolidated sediments decreases permeability and increases the stiffness of the sediment system significantly. Therefore, CO2 hydrate-bearing sediments act as cap-rocks which prevent the CO2 leakage from CO2-stored layer. In this study, an experimental simulation of CO2 geological storage into marine unconsolidated sediments was performed. CO2 hydrates were formed during CO2 liquid injection process, resulting in prevention of CO2 upward flow. Temperature, pressure, P-wave velocity, and electrical resistance were measured during the experiment, and their measurement results verify the occurrence of self-trapping effect induced by CO2 hydrate formation.