A method for regional pressure relief mining of coalbed methane

Abstract

The invention discloses a regional pressure release coal bed gas mining method comprising the following steps: using expansion high pressure charging equipment to pre-charge expansion fracture holes; carrying out impact penetration on coal bed thin portions around the expansion fracture holes; using a high pressure water injection pump to pump high pressure pre-injection water into high pressure water injection holes; carrying out impact penetration on coal bed thin portions around the high pressure water injection holes. The various pressure release modes are combined; high pressure water injection, air bag expansion and explosive can mutually interfere so as to fast release pressure of the coal bed gas with high efficiency, thus improving coal bed pressure release effect, and providing very good pressure release effect even on the hard-release high difficulty coal bed; the method uses pre-expansion and pre-high pressure water injection to carry out stable pressure release preparation for the coal bed; thins portions are firstly removed; explosive, water injection and expansion modes are employed for thorough and simultaneous pressure release, thus fundamentally completing regional pressure release coal bed gas mining in multi-angle, and improving coal bed pressure release safety and stability.

Description

technical field [0001] The invention belongs to the technical field of coal seam mining, and in particular relates to a method for regional pressure relief mining of coal seam gas. Background technique [0002] The natural conditions of coal mines in my country are poor, the geological conditions of coal fields are complex, the gas content of coal seams is high, and the permeability is generally low, generally in the range of (0.1~1.0)×10 -6 μm 2 , this feature determines the difficulty of gas drainage from the original coal seam in my country's coal mines. High-gas coal seams account for 50% to 70%, while high-gas low-permeability coal seams account for about 70% of them. Gas drainage in the pre-mining area is the main measure to solve the safety of coal mine production, realize the joint mining of coal and gas, and reduce environmental pollution. In order to reduce economic losses, preventing and reducing the danger of rock burst is particularly important and urgent for...

AI Technical Summary

Problems solved by technology

[0003] However, the current regional pressure relief methods are generally relatively traditional and lack comprehensive pressure relief measures. In this way, for complex and difficult to relieve pressure coal seams, the pressure relief effect is still not ideal. Therefore, it is necessary to develop a method that can comprehensively utilize various coal seams. A pressure relief method for regional coalbed methane, in order to improve the pressure relief effect of coalbed methane, and improve the safety and stability of coal mining

Images