Possibility of CO_2 Hydrate Sequestration in Sub-seabed Sediments in Japan

Abstract

There exist low temperature and high pressure in deep sub-seabed sediments, where many natural gas hydrate fields and free gas reservoirs trapped by them have been discovered. Following these discoveries, CO_2 hydrate sequestration in sub-seabed sediments has been proposed as a novel option for greenhouse gas control, where CO_2 is injected in seated sediments, reacts with pore water and forms hydrates. The hydrate-filled sediments are expected to serve as artificial cap rock, enabling a large volume liquid CO_2 to be stored in the underlying sediments. As a preliminary step toward the development of this technology, attempt is made to show the possible areas for the application of the technology according to the phase behavior, geographic and geologic conditions of the sea areas surrounding Japanese island. The results show that there exist a wide such area in Japan Sea and surrounding Hokkaido.