Downward bedding Layer driLLing hydrauLic sLitting process method

Abstract

The invention discLoses a downward bedding Layer driLLing hydrauLic sLitting process method, and beLongs to the fieLd of coaL mine gas drainage. The method incLudes the steps of driLLing down the bedding Layer of a soft coaL Layer, using a system pressure wind and a spiraL driLL pipe for construction, stopping driLLing, cLosing the pressure wind, introducing the medium and high pressure water to perform the sLitting, and repeating after compLetion; for the downward bedding driLLing of a medium hard coaL Layer, using Low pressure water and the spiraL driLL pipe for construction, stopping driLLing, switching to the high pressure water for the sLitting operation, and repeating hydrauLic driLLing and sLitting work; adopting a forward driLLing and sLitting method in the soft and medium hard coaL Layer to form a Large area coaL body around the bedding driLLing for pressure reLief and permeabiLity enhancement. The method is suitabLe for pressure reLief and permeabiLity enhancement of the hydrauLic sLitting of the downward bedding driLLing of the high gas outburst coaL Layer in a coaL mine underground coaL road strip and a backstoping area, increases the exposed area of a coaL body, the effective infLuence range of the driLLing and the gas drainage rate, and reduces the number of hoLes driLLed. The method has the advantages of simpLe method, convenient operation, remarkabLe effect andwide popuLarization and appLication vaLue.

Description

technical field [0001] The invention belongs to the technical field of gas drainage in coal mines, and relates to a hydraulic slotting process method for down-bedding drilling. Background technique [0002] In coal mine excavation engineering, for the coal roadway driving face and mining face of a single outburst coal seam without protective layer protection, regional outburst prevention measures are often taken to prevent coal seam gas in the coal seam strip and coal seam gas in the back mining area. The following problems: for bedding drilling without pressure relief and antireflection measures, the diameter of the borehole is generally Φ113mm, the pressure relief range is small, the effective radius of gas pre-pumping is generally less than 2.5m, the drilling volume is large, and the efficiency is low, which affects the mine. Mining takes over. [0003] Hydraulic slotting is a series of slots formed under the cutting action of high-pressure water jets, which is equivalen...

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Problems solved by technology

[0005] In view of this, the object of the present invention is to provide a hydraulic slotting process for downward bedding drilling, which overcomes the disadvantages of low porosity rate and unsatisfactory drainage effect of downward bedding drilling in the prior art, and provides A down-bedding drilling hydraulic slotting process method that is simple, increases the gas permeability of coal, changes the gas storage state of coal, and improves the gas drainage effect

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