Method and system for exploiting seabed flammable ice

Abstract

The invention provides a method and system for exploiting seabed flammable ice. The method comprises the steps that two shafts are drilled through a drilling platform and reach a seabed flammable ice layer, the depths of the two shafts are different, the distance between the two shafts is small, two cavities are formed in the bottom of the shafts through explosives in an exploded mode, the two cavities are communicated, high-temperature sea water is constantly poured into the bottom of the deeper shaft, so that methane is changed into the gaseous state from the solid state, gaseous methane is jetted from the other shaft, moistures are eliminated through pressurization and cooling, the temperature is lowered to minus 162 DEG C in a refrigerating mode through a nitrogen compressor, so that liquid methane is formed, or the methane is made into flammable ice again to be stored, and part of methane is used as fuel for heating sea water. The method and system for exploiting the seabed flammable ice has the advantages that as long as pouring of the high-temperature sea water is stopped, the flammable ice can stop decomposition, insulation measures are applied to pipes and containing tanks, and therefore waste of heat energy cannot be generated; power is supplied by a diesel generator, the manufacturing cost is low, and operation is reliable; the method for exploiting the seabed flammable ice belongs to the gap permeation substitution method, and seabed collapse cannot be caused; emission only comprises carbon dioxide, and other waste is used for seabed backfilling and recycled.

Description

(1) Technical field [0001] The present invention relates to a mining method and system for seabed combustible ice (scientific name "natural gas hydrate"), especially a marine oil and gas resource mining method with simple structure, reliable operation, low cost, energy saving, environmental protection, safety, controllability and no pollutant discharge and system. (2) Background technology [0002] Submarine combustible ice is a crystal formed by the combination of methane gas and water molecules in a low-temperature and high-pressure environment. The main gas component produced after heating and decompression is high-purity methane. The methane molecule has only one carbon atom, and the emission of carbon dioxide after combustion is small. And no sulfide is produced, it is an ideal clean energy. At present, there is no mature seabed combustible ice mining method and system in the world that has been put into commercial operation. The reason is that the existing mining meth...

AI Technical Summary

Problems solved by technology

At present, there is no mature seabed combustible ice mining method and system put into commercial operation in the world. The reason is that the existing mining methods are relatively complicated, costly, and lack of controllability and operability, which may easily cause natural gas Leakage, causing environmental pollution and atmospheric greenhouse effect, is still in the stage of laboratory exploration and cannot be put into commercial operation

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