Abstract: The present invention relates to disturbance on hydrate reservoirs with different buried depths, in particularly to a disturbance and stability analysis method for hydrate reservoirs with different buried depths. Preparing a series of stable hydrate systems parallel to a hydrate phase equilibrium curve, wherein both of the porosities and the hydrate saturations of various hydrate systems are consistent, but the buried depths are different; disturbing the series of hydrate systems prepared in the first step, conducting disturbance under different conditions aiming to the hydrate systems with different buried depths; analyzing the stability of the hydrate reservoirs.

Abstract: A system and method for exploiting deepwater shallow low-abundance unconventional natural gas by artificial enrichment is provided. The system includes a metallogenic system, a transport system and a collection system. The metallogenic system is used for clustering and enriching the deepwater shallow low-abundance nonconventional natural gas to form a natural gas hydrate reservoir. The metallogenic system includes an artificial foundation pit and a dome cap covering the top of the artificial foundation pit. The transport system is used for transporting low-abundance natural gas in a deepwater shallow low-abundance nonconventional natural gas stratum to the metallogenic system to provide a gas source for synthesizing the natural gas hydrate reservoir for the metallogenic system. The transport system includes oriented communication wells connecting the artificial foundation pit and the deepwater shallow low-abundance nonconventional natural gas stratum and filled with gravel particles.

Abstract: A system and method for exploiting deepwater shallow low-abundance unconventional natural gas by artificial enrichment is provided. The system includes a metallogenic system, a transport system and a collection system. The metallogenic system is used for clustering and enriching the deepwater shallow low-abundance nonconventional natural gas to form a natural gas hydrate reservoir. The metallogenic system includes an artificial foundation pit and a dome cap covering the top of the artificial foundation pit. The transport system is used for transporting low-abundance natural gas in a deepwater shallow low-abundance nonconventional natural gas stratum to the metallogenic system to provide a gas source for synthesizing the natural gas hydrate reservoir for the metallogenic system. The transport system includes oriented communication wells connecting the artificial foundation pit and the deepwater shallow low-abundance nonconventional natural gas stratum and filled with gravel particles.

Abstract: The present invention discloses a silty marine natural gas hydrate gravel stimulation mining method and a mining device. The mining method appropriately relaxes the sand retention accuracy of a wellbore, so that the fine sand and muddy components of the stratum can flow into the wellbore, and after a certain period of production, the coarse gravels are injected into the extra-pipe stratum of the production well to fill the deficit caused by the production of the fine components of the stratum and the hydrates, and then the well is opened for production. The method achieves the triple objectives of improving the productivity of the silty reservoir, preventing the large-area deficit in the stratum and extending the effective period of the sand retention of the wellbore, by way of the alternation of the rounds of the gravel injection and the hydrate reservoir fluid extraction.

Abstract: A submarine shallow hydrate exploitation device, including an exploitation unit and a collection unit. The exploitation unit includes: a submarine ship working on a seabed; a drain chamber arranged on the submarine ship, wherein a pressure valve is arranged at a top of the drain chamber, one-way drain holes are formed in a bottom of the drain chamber, and water from massive hydrates is controlled to be discharged out of the drain chamber; a high-speed spiral bit configured to mine and convey sediments; a rotary ring arranged at an inlet end of the drain chamber and configured to connect the drain chamber with the high-speed spiral bit to provide rotation power for the high-speed spiral bit; a steering arm arranged on the submarine ship and configured to realize a rotation of the high-speed spiral bit; a crusher arranged on the submarine ship and configured to crush dried massive hydrates.

Abstract: A submarine shallow hydrate exploitation device, including an exploitation unit and a collection unit. The exploitation unit includes: a submarine ship working on a seabed; a drain chamber arranged on the submarine ship, wherein a pressure valve is arranged at a top of the drain chamber, one-way drain holes are formed in a bottom of the drain chamber, and water from massive hydrates is controlled to be discharged out of the drain chamber; a high-speed spiral bit configured to mine and convey sediments; a rotary ring arranged at an inlet end of the drain chamber and configured to connect the drain chamber with the high-speed spiral bit to provide rotation power for the high-speed spiral bit; a steering arm arranged on the submarine ship and configured to realize a rotation of the high-speed spiral bit; a crusher arranged on the submarine ship and configured to crush dried massive hydrates.

Abstract: The present invention discloses a silty marine natural gas hydrate gravel stimulation mining method and a mining device. The mining method appropriately relaxes the sand retention accuracy of a wellbore, so that the fine sand and muddy components of the stratum can flow into the wellbore, and after a certain period of production, the coarse gravels are injected into the extra-pipe stratum of the production well to fill the deficit caused by the production of the fine components of the stratum and the hydrates, and then the well is opened for production. The method achieves the triple objectives of improving the productivity of the silty reservoir, preventing the large-area deficit in the stratum and extending the effective period of the sand retention of the wellbore, by way of the alternation of the rounds of the gravel injection and the hydrate reservoir fluid extraction.