Chinese Academy of Sciences

Kefeng Yan

Gang Li

Yu Zhang

Yi Wang

Xiaosen Li

Zhaoyang Chen

Xuke Ruan

Jiayuan Zhou

Jinming Zhang

Qiunan Lv

A system and method for exploiting a marine natural gas hydrate resource including a vertical well, comprising a sleeve configured to penetrate through a marine layer and a hydrate reservoir covering layer, and penetrate downwards into a natural gas hydrate reservoir; a section of the sleeve in the natural gas hydrate reservoir is provided with a perforating channel; a horizontal well, connected to a bottom end of the sleeve; a production string, disposed in the sleeve and extending downwards into the horizontal well, wherein a bottom of the production string is provided with a gas/water collection inlet; a hot water injection pipe, disposed in the production string; and a bottom of the hot water injection pipe is provided with a hot water injection opening; and a gas bladder, disposed in the horizontal well and connected to the hot water injection opening in the hot water injection pipe.

System and method for exploiting marine natural gas hydrate resource

A system for exploiting natural gas hydrate with downhole gas-liquid synergic depressurization includes a casing configured to form an exploitation well. An upper end of the exploitation well is connected to a produced gas collection pipeline, and the produced gas collection pipeline is configured to be connected to a produced gas recovery system. A perforated channel is distributed in a section of the casing located in a natural gas hydrate reservoir. A tubular string component assembly is mounted in the exploitation well, and includes an outer string, a production tubular string and an auxiliary riser. A first check valve is mounted at the bottom of the outer string, a gas supply pipeline is connected into an upper portion of the outer string, and a flow controller is mounted in the gas supply pipeline. The production tubular string is mounted in the outer string.

System and method for exploiting natural gas hydrate with downhole gas-liquid synergic depressurization

A method for recovering gas in natural gas hydrate exploitation is disclosed, in which a gas-water mixture at a bottom of a exploitation well is delivered to an ocean surface platform through a marine riser, by adopting the gas-lift effect of methane gas derived from the dissociation of natural gas hydrate, so as to achieve a controllable flowing production of marine natural gas hydrate. In the startup stage, the pressure in the bottom of the well is decreased by the gas-lift effect of the injected gas to allow dissociation of the hydrate. In the flowing production stage, the flowing production is achieved by the gas-lift effect of the gas derived from the dissociation of the natural gas hydrate, wherein a seafloor gas tank is employed to control the flowing rate and replenish the consumed gas.

Method and system for recovering gas in natural gas hydrate exploitation

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Guangzhou, China

Kefeng Yan