Green production system of natural gas hydrate in shallow non-diagenetic formations of deep seabed

Abstract

The invention discloses a green mining system of natural gas hydrate. The green mining system is used for mining natural gas hydrate from non-lithified stratums of deep-sea seabed superficial layers. The green mining system comprises a seabed tunneling-fluidifying-lifting pry, a closed fluidifying gathering pipeline and a sea surface separating and processing system, wherein the seabed tunneling-fluidifying-lifting pry is used for excavating a natural gas hydrate reservoir in a solid state in a storage region of the natural gas hydrate by virtue of the temperature and pressure in a natural environment, collecting solid matter of the natural gas hydrate, and crushing the solid matters of the natural gas hydrate into particulate matters, and seawater and the particulate matters are mixed through injection to form gas-liquid-solid multiphase mixture flow; the closed fluidifying gathering pipeline comprises a closed pipeline which is connected with the seabed tunneling-fluidifying-lifting pry so as to lift the gas-liquid-solid multiphase mixture flow to the sea surface; the sea surface separating and processing system is arranged at a sea surface support system and comprises a separating device and a processing device, the separating device is used for separating a gas-liquid-solid multiphase mixture lifted to the sea surface through the closed pipeline, and the processing device is used for processing separated matters. According to the green mining system, the safe and green mining of the deep-sea natural gas hydrate is realized, and potential hazards in multiple 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 natural gas hydrate green exploitation system used for the development of natural gas hydrate in shallow non-diagenetic strata in deep sea. 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 ex...

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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 deep-sea shallow non-diagenetic formation is mainly decomposed into natural gas and water, and a large amount of natural gas will cause 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 disorderly, and the free expansion and rise of a large amount of gas may cause disasters to both sea surface ships 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 of industrial development. Development and Utilization of Cemented Natural Gas Hydrate

[0012] To sum up, whether it is natural gas hydrate in well-cemented diagenetic formations or natural gas hydrate in poorly cemented non-diagenetic formations, in the mining methods and mining equipment technologies studied at home and abroad, the above three problems are have not been effectively resolved during the development process

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