Method for exploiting methane hydrate by using stored carbon dioxide

Abstract

The invention provides a method for exploiting methane hydrate by using stored carbon dioxide. The method comprises the following steps: selecting a methane hydrate soil layer at proper depth in a seabed, according to geological information, setting up a carbon dioxide injection well communicating from an ocean platform to the methane hydrate soil layer; injecting liquid state carbon dioxide into the carbon dioxide injection well, after the liquid state carbon dioxide diffuses and permeates into the methane hydrate soil layer, the liquid state carbon dioxide replaces with the methane hydrate, to generate methane gas; according to displacement efficiency of the carbon dioxide and the methane hydrate, determining exploitation time, and setting up a methane exploited well in the replacement range of the carbon dioxide injection well, the methane exploited well communicating with the methane hydrate soil layer, so as to realize exploitation of methane gas. After the carbon dioxide is injected and stored, the carbon dioxide would replace the methane hydrate in the regions in a permeating and flowing process, mechanical property variation of the stratum in the process is little, and geological disasters caused by air exhaust exploitation of the methane hydrate are prevented, and greenhouse gases are reduced.

Description

technical field [0001] The invention relates to the field of deep-sea resource exploitation, in particular to a method for replacing recoverable methane gas by storing carbon dioxide in seabed methane hydrate soil layers. Background technique [0002] At present, the oil and gas well depressurization mining method and heating mining method for exploiting methane gas in the subsea methane hydrate soil layer have been proved by the international methane hydrate experimental mining in the United States, Japan and Canada, and their efficiency can neither meet the needs of commercial exploitation nor meet the needs of commercial exploitation. It will cause geological and environmental effects that are unfavorable to humans. Therefore, it is necessary to propose a new economical and safe mining technology for methane hydrate, so as to provide technical reserves for the commercial utilization of methane hydrate. Contents of the invention [0003] The purpose of the present inven...

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Problems solved by technology

[0002] At present, the oil and gas well depressurization mining method and heating mining method for exploiting methane gas in the subsea methane hydrate soil layer have been proved by the international methane hydrate experimental mining in the United States, Japan and Canada, and their efficiency can neither meet the needs of commercial exploitation nor meet the needs of commercial exploitation. Will cause geological and environmental effects that are unfavorable to humans

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