METHOD FOR CONVERTING HYDRATES BURIED IN THE WATERBOTTOM INTO A MARKETABLE HYDROCARBON COMPOSITION

摘要

A method for converting hydrates buried in the water bottom into a marketable hydrocarbon composition comprises: -excavating a hydrate containing slurry from the water bottom (14) by an underwater excavator (1); -inducing a slurry lifting assembly comprising a slurry pump (2) actuated by the tailings stream (8), to lift the slurry through a riser conduit (3) to a floating topsides vessel (7); -separating the slurry in a slurry separation assembly (4) at or near the topsides vessel (7) in to a transportable methane (CH 4 )containing intermediate product and a tailings stream; and -transporting the transportable methane containing intermediate product to a facility in which the intermediate product is converted into a marketable hydrocarbon composition. The use of a hydrate slurry pump (2) actuated by the tailings stream (8) allows to lift the slurry to the topsides vessel (7) in an economic and reliable matter since at least part of the energy and pressure required to lift the hydrate slurry to the water surface (13) is recycled back into the tailings stream (8) returning to the water bottom (14).