EXTRACTING GAS HYDRATES FROM MARINE SEDIMENTS

摘要

A process for extracting hydrocarbon gases from marine sediment hydrates. In one embodiment, the process includes drilling from a sea floor into a hydrate rich subsea sediment to form at least one opening therein. Electrical heaters are inserted into the opening or openings. The hydrate rich subsea sediment is heated with the electrical heaters in order to release hydrocarbon gas therefrom. The released hydrocarbon gas is collected in an overhead receiver. The hydrocarbon gas forms hydrates again when moving through the cold seawater and inside the overhead receiver. The overhead receiver is raised to a sea depth where pressure and temperature permit the hydrates to dissociate and to release the hydrocarbon gas. The hydrocarbon gas is then gathered from the top of the overhead receiver. In another embodiment, the process includes partitioning subsea marine sediments and loading the sediments into a container covered with an overhead receiver. The container loaded with hydrate rich sediments is lifted to a shallower sea depth where pressure and temperature permit hydrocarbon gas to be released. The hydrocarbon gas is then collected from the top of the overhead receiver. When the depleted sediment is returned to the sea floor, it can be used as a counterweight to lift a new load.