Method for combined co-mining of deep coal bed gas and coal by using multi-mode microwave radiation

Abstract

The invention discloses a method for combined co-mining of deep coal bed gas and coal by using multi-mode microwave radiation. Firstly, a microwave control system is arranged on the ground of a coal-bed gas well, and then a radiating antenna is arranged at a target perforation layer; starting a microwave source, radiating the coal seam in a high-power and short-time mode to enable the coal seam to generate and extend cracks, and improving the permeability of the coal seam; then the microwave radiation mode is adjusted to be low-power and long-time, the temperature of the coal bed is increased to the coal bed gas desorption temperature through the microwave heating technology, a production well is opened, and coal bed gas is exploited; and finally, radiating the coal seam for a long time by adopting medium power to enable the temperature of the coal seam to rise to the coal pyrolysis temperature, and exploiting tar and pyrolysis gas generated by underground coal pyrolysis. According to the method, the mode of microwave radiation is adjusted, the three effects of rock breaking and permeation increasing, coal bed gas mining and coal pyrolysis are achieved in the same well, the purpose of co-mining of deep coal bed gas and coal is achieved, and a feasible thought is provided for green and efficient conversion of deep coal.

Description

technical field [0001] The invention relates to the technical field of coal-bed methane and underground coal mining, and more specifically relates to a method for combining and co-mining deep-bed methane and coal by using multi-mode microwave radiation. Background technique [0002] Coal bed methane is an important part of my country's clean energy, and coal is the main force of my country's energy consumption structure. How to achieve the joint mining of coal bed methane and coal is one of the research directions for advocating green mining in today's society. The mining of deep underground coalbed methane and coal resources faces the following problems: First, coal seams have low porosity and low permeability. Although hydraulic fracturing can improve the permeability of coal seams, the introduction of external fluids will increase the damage to the formation and reduce the mining efficiency; second, the desorption of coalbed methane usually adopts the method of drainage a...

AI Technical Summary

Problems solved by technology

Although hydraulic fracturing can improve the permeability of coal seams, the introduction of external fluids will increase the damage to the formation and reduce the mining efficiency; second, the desorption of coalbed methane usually adopts the method of drainage and pressure reduction, but weakly water-bearing coal seams cannot effectively reduce Formation pressure, coalbed methane is difficult to decompress and desorb

Third, the coal after deep coalbed methane mining is difficult to mine by mechanical excavation

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