A method and device for mining seabed combustible ice

Abstract

Combustible ice, also called as Natural Gas Hydrate (NGH), is formed at the high pressure and low temperature, and much of the combustible ice is reserved in the seabed and tundra layer and is the third energy source human found. The invention provides a method and a device for exploiting combustible ice in the seabed by seabed firing. The method includes injecting combustion-supporting gas into a natural gas layer of the seabed combustible ice, strictly controlling flow velocity and flow of the combustion-supporting gas, firing through an electromagnetic ignitor, providing head for decomposition of NGH by burning a small part of natural gas, and accelerating decomposition of the combustible ice so as to improve gas production efficiency. Due to burning, the temperature of the natural gas is slightly higher than the balance temperature of the combustible ice, high pressure of gas reservoir of the combustible ice can be kept, and no hydrate of the integral seabed gas collection area is generated.

Description

technical field [0001] The invention relates to a method for mining combustible ice, in particular to a method for mining seabed combustible ice by igniting the seabed combustible ice, and belongs to the technical field of energy development. Background technique [0002] Combustible ice is a new type of clean resource discovered by humans under the seabed and permafrost. Crystalline hydrates formed by small molecule hydrocarbons and liquid water at lower temperatures and higher pressures, molecular formula M nH 2 O, M are gas molecules, mainly CH 4 , containing a small amount of C 2 h 6 、C 3 h 8 and other hydrocarbons. 1m 3 Combustible ice can decompose and release 164m 3 (Standard) natural gas, the global estimated total volume of combustible ice is about 1.8×10 16 ~2.1×10 16 m 3 , which is equivalent to twice the total amount of proven conventional fossil fuels in the world. [0003] According to data, my country's permafrost area ranks third in the world, mai...

AI Technical Summary

Problems solved by technology

Due to the high amount of chemical agents required by the chemical injection mining method and the threat of pollution to groundwater quality, the mining efficiency of the decomposition and decompression mining method is low, and there is a "self-protection reaction" in the conventional decomposition of combustible ice. In the process of transporting the heat medium from the sea level to the seabed, there is a large amount of energy loss, so people urgently need new mining methods

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