Exploitation method for sea bed gas hydrate

Abstract

The invention relates to an exploitation method for sea bed gas hydrate, which comprises a depressurization decomposition stage and an ocean surface-layer warm water injection stage, wherein in the depressurization decomposition stage, the bottom parts of two exploitation wells can be drilled into the gas hydrate layer, the two exploitation wells can be used for sucking the fluid in the gas hydrate layer by a down-hole pump, the bottom-hole producing pressure can be controlled by controlling the delivery of the down-hole pump, and high-permeable areas are formed around wellbores at the bottomparts of the two exploitation wells; after the depressurization decomposition stage achieves the preset depressurization production time, the ocean surface-layer warm water injection stage is carriedout; in the ocean surface-layer warm water injection stage, a water injection pump is started for injecting ocean surface-layer warm water into the first exploitation well, the gas hydrate is decomposed, and the decomposed gas is output from the second exploitation well with lower pressure under the driving of pressure. The method can be widely used for exploiting the sea bed gas hydrate and particularly for exploiting the gas hydrate in the tropical sea area, the subtropical zone sea area, temperate zone sea area and other sea areas with ocean surface-layer warm water.

Description

technical field [0001] The invention relates to a seabed new energy mining method, in particular to a seabed natural gas hydrate mining method. Background technique [0002] Natural gas hydrate is considered as a promising potential energy because of its huge reserves, wide distribution and cleanness. Natural gas hydrate is an ice-like solid substance formed by natural gas and water under low temperature and high pressure conditions. Because natural gas hydrate contains a large amount of hydrocarbon gases such as methane, it is extremely flammable and is called "combustible ice". It is conservatively estimated that the carbon content of global natural gas hydrates is twice that of the total carbon content of fossil energy sources such as coal, oil, and natural gas. Hydrate has a high energy storage density, hardly produces any residue or waste after combustion, and has much less pollution than fuels such as coal, oil, and natural gas. [0003] The extraction methods of na...

AI Technical Summary

Problems solved by technology

However, heating hot water and steam on the production platform or on the ground requires a lot of energy, which leads to high cost and complicated equipment for the heat injection method, which makes natural gas hydrate production costly and economical.

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