Double-purpose vapor and electric-heating three-shaft desorption and permeation test device

Abstract

The invention belongs to gas content experiment equipment in a coal bed of a coal mine, and particularly relates to a double-purpose vapor and electric-heating three-shaft desorption and permeation test device. An upper pressing cap (7) is connected with the upper end of a sleeve (26) of a three-shaft pressure chamber (6) by threads; a lower pressing cap (10) is connected with the lower end of the sleeve (26) by threads; a coal sample (28) is mounted in the middle of the sleeve (26); an upper pressing head (27) is mounted above the coal sample (28); a lower pressing head (25) is mounted below the coal sample (28); a baffle (8) is mounted on the connection part of the sleeve (26) on the upper pressing head (27) and the upper pressing cap (7); a piston (5) is mounted at a step of the upper pressing head (27); a thermocouple sensor (9) is mounted in a lower pressing cap hole (10-1); an electric heater (30) is arranged on the upper pressing head (27) and the coal sample (28); a vapor channel (21) is arranged in the upper pressing head (27), the lower pressing head (25) and the coal sample (28); and an upper pressing head hole (27-1) is connected with a methane gas bottle (15) through a pipeline (18) and a pressure adjusting valve (13), so that the gas absorption amount is reduced, and the gas desorption amount and the gas permeation amount in the coal bed can be increased.

Description

technical field [0001] The invention belongs to experimental equipment for gas content in coal seams of coal mines, in particular to a dual-purpose triaxial desorption and permeation experimental device for steam and electric heating. Background technique [0002] Coal mine gas is a major threat to the safety of coal mine production, but if it is utilized, it is a high-quality and clean energy. If the extraction and utilization of coal bed methane are done well, it can turn harm into benefit and turn waste into wealth. [0003] my country's geological conditions are complex, and coalbed methane reservoirs are characterized by low pressure, low permeability, low saturation, and high gas content. Except for a few coalbed methane in high-permeability areas such as Qinshui Basin, Fuxin and Tiefa Mining Areas, coalbed methane enters In addition to commercial development, most coalbed methane wells in coal production areas fail to meet the requirements of industrial production gas ...

AI Technical Summary

Problems solved by technology

However, the application of the above technologies currently has certain limitations. For example, the hydraulic fracturing technology is only suitable for the exploitation of coalbed methane in relatively hard fractured reservoirs, and the hydraulicization effect is very limited for coal reservoirs with soft coal seams and complex pores and fractures. , and because the coal seam has strong water absorption, the coal seam becomes soft after absorbing water, the proppant is embedded in the coal seam, and the pressure fracture is likely to be reclosed after pressure relief; gas injection mining is achieved by injecting CO into the coal seam 2 The effect of increasing coalbed methane production by gas through the principle of competing adsorption is obvious, but CO 2 The gas source and economy make the scope of application very limited; the plume horizontal well is only a method of drilling through the coal reservoir, which reduces the resistance of coalbed gas entering the wellbore, but fundamentally does not change the low permeability of the coal reservoir

Through the artificial pressure relief technology, the free gas in the coal seam can seep out, which can increase the gas extraction to a certain extent; but the gas existing in the free state in the coal seam only accounts for 10%~20% of the gas volume in the entire coal seam , usually the amount of adsorbed gas accounts for 80% to 90%, and the amount of gas extracted by hydraulic fracturing technology is small. Most of the gas in the adsorbed state will be discharged into the atmosphere with the mining of coal seams, so that the gas resources cannot be well obtained. use of

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