Pressure chamber for in-situ generation and triaxial test of marine gas hydrate and using method thereof

Abstract

The invention discloses a pressure chamber for in-situ generation and triaxial test of marine gas hydrates and a using method thereof. The pressure chamber is composed of a base, a sleeve and a pistonrod. The sleeve is sequentially provided with a pressure bearing cavity, a refrigerant circulation cavity with rib edges and a heat preservation layer from inside to outside, and a refrigerant circulation pipeline is arranged on the sleeve. A pore pressure applying pipeline, a confining pressure applying pipeline and an air pressure applying pipeline are arranged on the base, and an insulating heat preservation layer is arranged on the surface of the lower bottom of the base. The using method comprises the following steps of: sequentially installing upper and lower main cushion blocks, upperand lower connection blocks, copper wire meshes, latex films, latex sleeves and hollow cylinder specimens on the base; and sequentially applying pore water pressure, inner and outer confining pressureand the pore air pressure to the hollow specimens until the hydrates are formed inside the specimens. The pressure chamber can provide platform support for the in-situ generation and the triaxial test of the marine gas hydrates under the conditions of gas horizontal migration.

Description

technical field [0001] The invention relates to a triaxial experimental pressure chamber and a using method thereof, in particular to a triaxial experimental pressure chamber suitable for the in-situ generation of hydrates in sea areas under the condition of gas horizontal migration and the using method thereof. Background technique [0002] Natural gas hydrate, also known as combustible ice, is an ice-state crystalline clathrate compound formed by water and natural gas in a high-pressure and low-temperature environment. Natural gas hydrate is a huge efficient and clean energy, and its reserves are about 2×10 16 m 3 , and its carbon content is about twice the total carbon content of the earth's fossil energy (oil, natural gas and coal). Gas hydrates mainly occur in the sediments of deep-sea continental slopes, continental uplifts and basins. [0003] Existing mining methods are mostly based on destroying reservoir phase equilibrium conditions: reducing pressure and increa...

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Problems solved by technology

[0005] The existing in-situ hydrate formation and triaxial experimental devices are mainly aimed at solid samples, which are ventilated in the vertical direction, the hydrate synthesis time is long, and the synthesized hydrates are unevenly distributed in the height direction of the sample

Application No. 201410112371.9 discloses "A Hollow Frozen Soil Test Device and Its Application Method". The hollow cylindrical sample can realize the temperature gradient in the horizontal direction, but it cannot achieve horizontal gas penetration, and the device is mainly aimed at frozen soil, which is difficult to achieve. Suitable for in situ formation and triaxial experiments of hydrates

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