Gas extraction well location method based on overlying rock fracture shell

Abstract

The invention discloses a gas extraction well location method based on an overlying rock fracture shell. The gas extraction well location method based on the overlying rock fracture shell is characterized by comprising the step of drilling tilting holes with large diameters in multiple areas of a gob overlying rock from a gas tail lane (6) directly. The multiple areas of the gob overlying rock comprise a low post fracture shell (1), a middle post fracture shell (2) and a high post fracture shell (3) from bottom to top, wherein the low post fracture shell (1) is a gob fracture vertical destroying development zone, the high post fracture shell (3) is a gob separation layer fracture and micro fracture development zone, and the middle post fracture shell (2) is located between the high post fracture shell and the low post fracture shell. The construction of extracting and drilling is carried out directly by using the existing gas tail lane, and extraction drilling holes are respectively arranged in the multiple areas of the overlying rock. Not only can gas with high concentration be effectively extracted, but also a seepage field on a gob return air side zone is interfered. Extraction efficiency is high, the processes of digging, drilling and drainage lane are reduced, the link of process engineering is simplified, and cost is lowered.

Description

technical field [0001] The invention relates to the field of gas drainage in coal mines, in particular to a drilling arrangement method for gas drainage in overlying strata in goafs. Background technique [0002] At present, according to the theory of mine pressure strata control, the overlying strata of the goaf are generally divided into "three vertical zones" and "three horizontal zones" according to the characteristics of mining cracks in the overlying strata of the goaf. The "three vertical zones" can be divided into the curved subsidence zone, the roof fissure zone and the caving zone from top to bottom. Drainage is mainly aimed at the fractured zone development area. For example, the Chinese patent application No. 03113021.6 discloses a "Method of Gas Drainage from the Roof of the Mined Coal Seam", on the roof of the mined coal seam, for the desorbed gas that comes from the mining and pressure relief coal seam and collects in the "annular fracture circle" through the ...

AI Technical Summary

Problems solved by technology

Some drainage methods in mining fracture areas need to drill a separate roof drainage roadway, and use roof roadway drilling or roof roadway for pressure relief gas drainage. These methods increase the amount of gas control engineering and investment, and the drainage roadway It is itself a gas accumulation area with poor security

In addition, if the drainage is carried out in the "fracture zone" or "annular fracture circle", the drainage drilling is located at a lower level, and gradually becomes ineffective as the roof collapses and compacts. Drainage of high-concentration gas in the deep part of the goaf is not conducive to effectively reducing the gas gushing intensity in the goaf

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