Method for exploiting of submarine natural gas hydrate through solid replacement and pressure maintaining

Abstract

The invention discloses a method for exploiting of submarine natural gas hydrate through solid replacement and pressure maintaining, and belongs to the field of energy and environments. The method comprises the steps that by arranging a stope at a hydrate layer, the stope temperature and pressure are monitored by using a temperature and pressure sensor and fed back to an offshore platform, existing conditions of the hydrate are maintained by adopting a sealing device according to a hydrate temperature and pressure curve, the hydrate is made to be not disintegrated, the solid form of the hydrate is maintained, solid-state mechanization mining, solid-liquid slurry conveying, gas separation and liquefaction transport are further conducted on the hydrate, a separated hydrate skeleton is brokenagain, and a cavity is filled after a rapid solidification material is added, thus destroy of submarine landslide, tsunami and a submarine ecological environment can be effectively prevented, and thepurpose of green exploiting is achieved. According to the method for exploiting of the submarine natural gas hydrate through solid replacement and pressure maintaining, the system is simple, and themethod is suitable for a hydrate pressure bearing layer with an upper impermeable cover layer and a lower impermeable cover layer, and has a good application prospect.

Description

technical field [0001] The invention relates to the technical field of exploiting seabed natural gas hydrate, in particular to a method for exploiting seabed natural gas hydrate by solid replacement and pressure maintenance. Background technique [0002] Natural gas hydrate is a white crystalline substance formed by gas molecules and water under low temperature and high pressure conditions. It is mainly produced in seabed sediments and land permafrost, and the global resources are estimated to reach 2.1×10 16 m 3 , is twice the total amount of coal, oil and natural gas resources, and has huge potential for energy development. [0003] The current natural gas hydrate exploitation methods mainly include heat injection exploitation, depressurization exploitation, chemical reagent injection exploitation, CO 2 Displacement mining and solid-state fluidization mining (deep-sea shallow layer), etc., but these methods have certain shortcomings, such as serious heat loss in heat inj...

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Problems solved by technology

[0003] The current natural gas hydrate exploitation methods mainly include heat injection exploitation, depressurization exploitation, chemical reagent injection exploitation, CO 2 Displacement mining and solid-state fluidization mining (deep-sea shallow layer), etc., but these methods have certain shortcomings, such as serious heat loss in heat injection mining, expensive chemical reagents, etc., and these methods are easy to cause deformation of the seabed, causing seabed Landslides, tsunamis, marine ecological environment damage and other disasters

Therefore, there are certain hidden dangers in large-scale commercial mining using the above methods at present.

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