Permeability enhancement method for ultra-thin layer water jet mining in low permeability soft coal seam

Abstract

The invention discloses a low-permeability soft coal seam extra-thin layer water jetting exploiting permeability increasing method. The method includes the following steps that 1 extra-thin layer water jetting exploiting parameters are designed; 2 extra-thin layer water jetting exploiting devices are machined, tested and installed; 3 a water jetting exploiting radius and a corresponding water jetting parameter are measured; 4 slag discharge holes and middle exploiting holes are constructed; 5 water jetting coal mining is started on an extra-thin layer; 6 when the coal mining reaches a designed location, the extra-thin layer water jetting exploiting devices are closed; 7 jetting exploiting drill holes and the slag discharge holes are linked to pumping-releasing pipelines to pump and release; 8 the steps ranging from 5 to 7 are repeated, and next drilling construction and jetting exploiting are conducted; 9 detection is conducted on a extra-thin layer exploiting pressure relief effect. By means of the method, the flow of coal seam hectometer hole drilling gas is increased by times, the pumping and releasing time of the gas is greatly shortened, the pumping and releasing radius is increased by times, the well drilling construction quantity is reduced, the gas overrunning probability is greatly reduced in the tunneling period and stoping period, and valuable time and safety guarantee are provided for the coal mine safety-efficient stoping and tunneling.

Description

technical field [0001] The invention belongs to the technical field of coal mine safety production, and in particular relates to an anti-permeability method for ultra-thin layered water jet mining of low-permeability soft coal seams. Background technique [0002] On October 16, 2011, the State Administration of Work Safety, the National Development and Reform Commission, the National Energy Administration, and the State Coal Mine Safety Supervision Bureau issued the "Provisional Provisions on Coal Mine Gas Drainage Standards" with Ann Jian Zongmei [2011] No. 163 Mine with one of the following situations must conduct gas drainage and achieve drainage standards: (1) Mining dangerous coal seams with coal and gas outbursts; (2) The absolute gas emission of a coal mining face is greater than 5m / min or The absolute gas emission of a tunneling face is greater than 3m / min; (3) the absolute gas emission of a mine is greater than or equal to 40m / min; (4) the absolute gas emission of t...

AI Technical Summary

Problems solved by technology

The main problems: there are problems such as long punching time, large amount of water required for punching, uneven stress distribution and stress concentration that increase the risk of coal and gas outbursts, etc.

Existing problems: Since hydraulic cutting is mainly aimed at the enhancement of permeability and gas drainage of relatively hard high gas or outburst coal seams, the pressure of hydraulic cutting is high, the depth of cutting is shallow, the time of cutting is long, and the amount of coal produced Less, less efficient

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