A kind of air extraction equipment for shallow soil in permafrost region

Abstract

The invention provides gas collecting equipment applicable to the collection of free-state natural gas existing in shallow-layer soil in a frozen soil area. Gas sample mixing can be avoided, the natural gas can be quickly collected, the requirements of regional natural gas hydrate sample research are met, and the gas collecting equipment comprises a pore forming device and a gas collecting device;the pore forming device comprises a drilling bit and a drilling rod, the tail end of the drilling head is provided with an attachment joint, and the attachment joint is of a hollow structure; an airinlet is formed in the side wall of the pore forming device and communicated with an inner cavity of the attachment joint; the drilling rod is of a cylinder structure, and the extending end of the attachment joint is inserted in the drilling rod and sleeved with the drilling rod; the gas collecting device comprises a gas collecting cylinder and a vacuumizing cylinder, the air inlet end of the gascollecting cylinder extends into the drilling rod and is communicated with the attachment joint, and the air outlet end of the gas collecting cylinder is communicated with the vacuumizing cylinder.

Description

technical field [0001] The present invention relates to the field of equipment for natural gas hydrate collection, in particular to a device for collecting the free gas produced by the decomposition of natural gas hydrate in the deep layer of the permafrost region after entering the shallow soil, which can effectively avoid in-situ The mixture of gas and outside air. Background technique [0002] Gas hydrate (Gas Hydrate for short) is an ice-like crystalline substance distributed in deep sea sediments or permafrost in land areas, formed by natural gas and water under high pressure and low temperature conditions. Because its appearance is like ice and it can burn when exposed to fire, it is also called "combustible ice" or "solid gas" and "gas ice". They are much smaller and have abundant reserves. The global reserves are enough for human beings to use for 1,000 years, so they are regarded by various countries as an alternative energy source for future oil and gas. [0003]...

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Problems solved by technology

[0004] For this reason, relevant sampling methods and equipment research have been carried out at home and abroad. The in-situ gas extraction equipment currently studied is a spiral drill structure with a hollow structure in the middle. During the gas extraction process, due to the impact of the helical structure and The gap between the surrounding medium walls is large, and it is easy to introduce outside air into the natural gas hydrate layer, resulting in sample mixing and affecting the analysis and test results

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