A progressive shield type gas pressure relief and extraction method

Abstract

The invention provides a progressive shielding type gas depressurizing extraction method which is particularly suitable for depressurizing outburst elimination extraction of coal roadway strip gas in a soft high-outburst coal seam through seam-penetration drilling holes. The seam-penetration drilling holes are constructed in the portions, on the two sides of an upper coal roadway, of the coal seam from a base plate roadway. Since the high-gas-outburst coal seam has high outburst tendency, the depressurizing permeation increasing measure of direct drilling hole construction can cause severe disturbance to an original coal body to induce a hole jetting phenomenon, the coupling mode of common drilling holes and punching and cutting drilling holes under the condition of base plate seam penetration is built, and the drilling holes are divided into the partition holes, the shielding holes and the depressurizing holes. Through reasonable arrangement of the common seam-penetration drilling holes and the drilling, punching and cutting drilling coupled depressurizing drilling holes, the gas extraction effect of the area coal body is improved, the phenomena of an outburst elimination blanking zone and hole jetting are voided, the drilling construction speed in remarkably increased, and the gas extraction effect is remarkably improved, and the technology has good adaptability to all coal seams of different occurrence states.

Description

Technical field [0001] The invention relates to a progressive shield type gas pressure relief extraction method, which is especially suitable for coal seam areas where gas pressure reaches 2.0 MPa or dynamic phenomena occur during drilling, and belongs to the technical field of coal seam mining with high gas outburst. Background technique [0002] The coal seams with high gas outburst in my country have the characteristics of microporosity, low permeability, and high adsorption, which make pre-mining gas pre-drainage difficult and poor gas pre-drainage effect. Therefore, special measures must be taken to increase coal seam permeability and increase gas drainage rate. Hydraulic cutting, hydraulic punching and other hydraulic measures are currently the main pressure relief and permeability enhancement methods. By destroying the coal in the borehole, a pressure relief space is formed, which increases the permeability of the surrounding coal. However, due to the complex occurrence of...

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Problems solved by technology

[0003] Technical problem: The purpose of the present invention is to overcome the deficiencies in the prior art and provide a safe, efficient and economical solution that can effectively solve the problem of poor applicability of the existing drilling pressure relief and anti-reflection technology, combined with hydraulic punching With the technical advantages of hydraulic slotting, the coupling mode of ordinary drilling and "drilling-punching-cutting" drilling under the condition of floor penetration is established, and the drilling is divided into partition holes, cover holes and pressure relief holes. The sequence of hole construction and its spatial location increase the impact range and pressure relief effect of drilling through layers, thereby realizing efficient regional gas drainage

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