Method and device for simulating experiment of permafrost region natural gas hydrate mining through replacement of CO2/N2

Abstract

The invention discloses a method and device for simulating an experiment of permafrost region natural gas hydrate mining through replacement of CO2 / N2. The simulation method includes the steps of core treatment and installation, pipe connection and pressure testing, vacuumizing treatment, injection of distilled water and CH4 in a response model and synthesis of natural gas hydrate. CO2 gas is injected after the synthesis is ended, and CH4 is displaced; CO2 / N2 is injected in the response model to perform replacement mining; after replacement, gas is collected, and quantitative analysis is performed; and the experiment simulating device comprises a hydrate response model unit, a gas supply unit, a liquid supply unit, a confining pressure control unit, an environment control unit, a vacuum treatment unit, a gas detection unit, a gas-liquid separation unit, an information acquiring and processing unit and an auxiliary unit. The method and device for simulating the experiment of the permafrost region natural gas hydrate mining through the replacement of CO2 / N2 can simulate external environment of the natural gas hydrate really, perform the experiment of the permafrost region natural gas hydrate mining through the replacement of CO2 / N2, furthermore can also perform the mining experiment through a heat injection method and a pressure drop method, and provide guidance for mining of the natural gas hydrate.

Description

technical field [0001] The invention relates to an experimental equipment and an experimental simulation method, in particular to a CO 2 / N 2 Experimental simulation method and device for natural gas hydrate in permafrost regions by displacement mining. Background technique [0002] Natural gas hydrate refers to a cage-shaped crystal substance formed by natural gas and water at a specific temperature and pressure. It looks like ice and snow. Because it can be ignited, it is commonly called "combustible ice". At the beginning of the research, the main purpose was to suppress the formation of hydrates, but with the intensification of energy shortages, natural gas hydrates have gradually attracted the attention of scientists at home and abroad, and relevant exploration, mining and experimental research have been carried out. As a high-density energy, it has wide distribution, large reserves and shallow burial, making it an ideal alternative energy source in the 21st century. ...

AI Technical Summary

Problems solved by technology

At present, the production methods of natural gas hydrate mainly include depressurization method, thermal excitation, chemical reagent method and the comprehensive application of these three methods. Decomposition occurs, and then the natural gas is extracted to the ground, but these schemes may cause problems such as submarine landslides or subsidence; recently, the technology of carbon dioxide replacement and exploitation of natural gas hydrate based on the replacement principle has attracted more and more attention, and natural gas is hydrated by carbon dioxide Natural gas in the natural gas is replaced to obtain carbon dioxide hydrate and natural gas, which can not only realize the exploitation of natural gas hydrate, but also realize the underground storage of carbon dioxide and reduce the greenhouse effect

[0004] Due to the complexity of on-site experimental research on natural gas hydrate, the current experimental research on natural gas hydrate exploitation is mainly indoor experimental simulation, and most of them simulate hydrate in porous media in the ocean, mainly for professional simulation of experimental research on natural gas hydrate exploitation in permafrost regions There are currently fewer laboratories, and there are fewer laboratories that focus on carbon dioxide replacement experimental simulation research

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