Method for green mining of natural gas hydrate of shallow non-diagenesis stratum of deep seabed

Abstract

The invention discloses a method for green mining of natural gas hydrate and provides a method for mining of the natural gas hydrate of a shallow non-diagenesis stratum of a deep seabed. The method for green mining of the natural gas hydrate comprises the steps that the stored natural gas hydrate is mined in a solid mode in a storage zone of the natural gas hydrate at the pressure and the temperature of a natural environment; solid matter containing the natural gas hydrate is collected and smashed into particle matter and sea water and the particle matter are mixed through injection so that a gas-liquid-solid multi-phase mixed flow can be obtained; the gas-liquid-solid multi-phase mixed flow is lifted above the sea through a closed pipeline provided with a pressurization system; the gas-liquid-solid multi-phase mixture lifted above the sea through the closed pipeline is separated and treated, so that natural gas is obtained. According to the method, safe and green mining of the natural gas hydrate is achieved and potential risks at various aspects are avoided.

Description

technical field [0001] The invention relates to the technical field of development of unconventional oil and gas resources, in particular to a green mining method for mining natural gas hydrate in shallow non-diagenetic formations on the deep seabed. Background technique [0002] With the sustained and rapid development of my country's national economy, the contradiction between energy supply and demand has become increasingly prominent. In 2012, my country imported 207 million tons of crude oil, becoming the world's second largest importer of crude oil, and its dependence on foreign countries reached 56.7%, approaching or exceeding the internationally recognized energy security. Wire. Therefore, while intensifying the exploration and development of new fields in new oil and gas areas, searching for new alternative energy sources has become an important strategic measure to ensure national energy security and national security. [0003] The exploration, development and utili...

AI Technical Summary

Problems solved by technology

[0008] 1) The disorderly decomposition of weakly cemented gas hydrate in shallow non-diagenetic formations on the deep seabed may bring about potential submarine landslides and other geological disasters. The reservoir has no obvious structural boundaries and tight cap rocks. With the large-scale development of gas hydrates, the stratigraphic structure will begin to become evacuated, which may lead to instability of the seabed strata;

[0009] 2) The natural gas hydrate in the shallow non-diagenetic formation of the deep seabed is mainly decomposed into natural gas and water, and a large amount of natural gas will cause the greenhouse gas effect and cause damage to the atmospheric environment;

[0010] 3) Due to the decomposition of natural gas hydrate, a large amount of natural gas is released in an orderly manner, and the free expansion and rise of a large amount of gas may cause disasters to ships on the sea and air vehicles

[0011] In the existing natural gas hydrate mining technology, the natural gas hydrate deposits with certain reservoir caprocks in the deep sea are usually converted into gas and water underground by decompression\heat injection\injection agent, etc., the converted gas is collected, and then Produced through underwater production facilities or floating production facilities, this method can only be adapted to the development of deep-water diagenetic gas hydrates, and the current production efficiency cannot meet the threshold for industrial development, and this method cannot realize deep-water shallow formations. Development and Utilization of Cemented Natural Gas Hydrate

[0012] In summary, no matter whether it is natural gas hydrate in well-cemented deep seabed shallow diagenetic formations or poorly cemented deep seabed shallow non-diagenetic formations, in the prior art, the above three problems None of them were effectively addressed during the development process

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