Experimental device for permeability change after carbon dioxide injection reacts with minerals in coal

Abstract

The invention discloses an experimental device for permeability variation after reaction of injected carbon dioxide and coal minerals. The experimental device comprises a gas and reaction liquid injection system, a coal reservoir fracture and reaction control simulation system, a computer-controlled monitoring system and a waste liquid and waste gas treatment system, wherein the outlet of the gas and reaction liquid injection system is connected with the inlet of the coal reservoir fracture and reaction control simulation system; the outlet of the coal reservoir fracture and reaction control simulation system is connected with the inlet of the waste liquid and waste gas treatment system; the coal reservoir fracture and reaction control simulation system is connected with the computer-controlled monitoring system through a data line. By adopting the experimental device, coal reservoir fracture systems under the conditions of different reservoir temperatures, different pressures, different mineral combinations and different filling ways can be tested in a simulated manner. The permeability variation after reaction of injected carbon dioxide and coal minerals in a reservoir under different conditions can be tested. The experimental device is high in automation degree, is mainly controlled by using a computer, and is easy and convenient to operate.

Description

technical field [0001] The invention belongs to the technical field of coal mine safety production, and in particular relates to an experimental device for permeability change after carbon dioxide injection reacts with minerals in coal. Background technique [0002] A large number of studies have shown that under the same conditions, the adsorption capacity of coal to carbon dioxide gas is greater than that of CH 4 Therefore, it is proposed that by injecting carbon dioxide gas into the coal seam, on the one hand, it may replace methane gas through competitive adsorption to improve the recovery rate of coal bed methane wells; gas, to reduce greenhouse gas emissions. During the formation process and after the formation of the coal seam, due to the release of the flow and the action of external forces, in addition to the formation of the coal matrix, there may also be the formation and invasion of foreign substances such as clay minerals and silicate minerals. Finally, the coa...

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Problems solved by technology

[0005] The present invention solves the problems caused by the inability to know the types and contents of clay minerals in coal, the types and contents of silicate minerals, the arrangement and filling methods in coal, and the differences in coal reservoir temperature and fracture development in the prior art. After injecting carbon dioxide gas, it reacts with these substances in coal, which causes the change law of coal reservoir permeability to be unclear, and may mislead the reality of the production of coalbed methane wells. This provides an experiment of permeability change after carbon dioxide injection reacts with minerals in coal. device, which can test the change in coal reservoir conductivity caused by injecting carbon dioxide with different types of clay minerals, different types of silicate minerals, different temperatures, and different degrees of development of original reservoir fractures. Provide theoretical guidance for reservoir selection and pump injection parameters

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