Method and device for testing formation and decomposition of gas hydrate

Abstract

The invention relates to a method and device for testing formation and decomposition of gas hydrate. The method comprises: 1) filling a one-dimensional sand-filling resistivity model tube with sand, closing an end cover, checking leak tightness and putting the model tube into a thermostat; 2) injecting water and methane gas into the model tube, maintaining constant temperature state to gradually generate hydrate, detecting change values of temperature, pressure and resistivity in the tube through a thermocouple, a pressure sensor and an electrode arranged on the wall of the model tube respectively and transmitting the change values to a data acquisition module; 3) reducing pressure after opening the model tube through a back pressure control module during decomposition so as to gradually decompose the hydrate, or injecting hot water into the model tube so as to gradually decompose the hydrate; and 4) passing water and methane gas produced after decomposition through a measurement module, transmitting data to the data acquisition module, detecting the change values of the pressure, the temperature and the resistivity in the tube through the thermocouple, the pressure sensor and the electrode at the same time, transmitting the change values into the data acquisition module, recording and storing the change values. The method and the device can be widely applied in the field of various detection of the formation and decomposition of gas hydrate.

Description

technical field [0001] The invention relates to a natural gas hydrate (Natural Gas Hydrates, NGH) test method, in particular to a test method and device for the formation and decomposition of natural gas hydrate in a one-dimensional sand filling model in the field of marine technology. Background technique [0002] Natural gas hydrate is an ice-like solid crystal composed of natural gas and water molecules. Natural gas is mainly composed of methane, so it is also called methane hydrate. Because it contains a large amount of methane gas, it has extremely strong combustion power and can be burned directly, so it is also commonly known as "combustible ice". The energy density of natural gas hydrate is very high, which can produce a large amount of methane gas, and the reserves of natural gas hydrate are very rich. The combustion of natural gas hydrate only produces carbon dioxide and water, and will not pollute the environment. It is a rare green and clean energy. As a potenti...

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Problems solved by technology

However, the resistance method cannot be used in the methane-pure water-sediment system, because the resistance method is based on the change of the ion content in the solution, which causes the change of the conductivity, and methane is difficult to ionize in the aqueous solution, and the ion change is too small, so it is difficult to measure

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