Low-level multi-step crossing hole gas extraction method for coal interbedding coal seams

Abstract

The invention relates to a low-level multi-step crossing hole gas extraction method for coal interbedding coal seams. The low-level multi-step crossing hole gas extraction method is characterized in that transporting crossheadings (or air return crossheadings) are dug in the mined coal seams (1), a 0.3-1 m of inclined dip (3) penetrating into bottommost rock strata (2) of all coal interbeddings isconstructed obliquely downwards along the left (right) side of a roadway, a low-level drilling field (4) is dug, wherein the product of the length, the width and the height of the low-level drillingfield (4) is equal to 3.0 m*2.5 m*2 m, a plurality of low-level multi-step crossing holes (5) penetrating through the multiple coal seams to a mined bed are constructed in the low-level drilling fieldin the roadway tunneling direction obliquely upwards, multi-step sleeves (6-1), (6-2) and (6-3) are inserted into the low-level multi-step crossing holes (5), the sleeve (6-1) is connected with a multi-way part through a phi 120 mm of rubber hose (11), and the sleeve (6-1) is connected with a gas extraction pipeline (12) in the roadway to converge for low-level multi-step crossing hole (5) networking gas extraction operation. Gas at coal seam bottom plates is effectively extracted, the safe and efficient effects are achieved, and the low-level multi-step crossing hole gas extraction method can be used for implementation of outburst prevention measures of a working surface.

Description

technical field [0001] The invention relates to a gas drainage method for low-level multi-stage perforated drilling holes in coal-rock interbedded coal seams. Background technique [0002] my country is a country where coal is the main energy source. At present and in the next 20 years, coal will still account for a large proportion of my country's primary energy structure. Coal and gas outburst is an extremely complex phenomenon of gas dynamic disaster, which is extremely sudden and destructive. According to statistics, in 2010, there were 2,197 high-gas mines in my country, accounting for 17% of the national coal mines, and 1,044 coal and gas outburst mines, accounting for 8.1% of the total coal mines in the country. Mine gas disasters have become the number one killer of coal mines. seriously affect the safety production of coal mines. my country is one of the countries with the worst disasters in the world. In-depth understanding of the law, characteristics and mechani...

AI Technical Summary

Problems solved by technology

[0005] In order to solve the characteristics of coal-rock interbedded coal seam roadway excavation and mining of the working face, the amount of abnormal gas emission at the bottom is large, and it is difficult to drill holes for gas drainage on the negative slope of the working face when the construction is inclined downward. Drill sticking, drill pinching, and hole collapse after the drilling exits, making it impossible to construct long-distance drilling, and it is difficult to eliminate the danger of coal and gas outburst during roadway excavation and working face mining. Through the implementation of low-level multi-level penetration Borehole gas drainage eliminates the risk of coal seam area (or local) outburst, improves the efficiency of fully mechanized roadway excavation, and solves the problem of coal seams with interbedded coal seams during roadway excavation and working face recovery. , the problem that gas is difficult to control, the present invention provides a coal-rock interbedded coal seam anti-outburst gas extraction method for low-level multi-stage through-bed drilling

Images