High-low-pressure subarea fracturing anatonosis type coal seam water injection method

Abstract

The invention discloses a high-low-pressure subarea fracturing anatonosis type coal seam water injection method. The method comprises the steps that drilling, hole sealing and water injecting are carried out on a coal face dynamic pressure area; drilling, hole sealing and water injecting are carried out on a coal face static pressure area; the coal face dynamic pressure area is a coal seam area distancing from the coal wall of a working face by 70-150 meters, and the coal face static pressure area is a coal seam area distancing from the coal wall of the working face by over 150 meters. The subarea coal seam drilling and water injecting mode is adopted, a twisted drill stem is selected as a drill stem adopted in the coal face dynamic pressure area, which is beneficial for discharging slag; moreover, a water powder swelling type hole sealing device and a high-molecular-material plugging structure are adopted for combined hole sealing, and then low-pressure water injecting is carried out; the coal face static pressure area is drilled multiple times by the adoption of a sectional type drilling implementation method, meanwhile, a three-ridge drill stem is selected, the contact area between the drill stem and the hole wall is reduced, and the phenomenon of tool sticking is prevented; high-pressure water injection is implemented to increase permeability of a coal seam, so that the coal seam water injection is optimal, and drilling and water injection efficiency are improved.

Description

technical field [0001] The invention relates to a water injection method for a mine, in particular to a high and low pressure partition-induced fracture-increasing seepage-increasing coal seam water injection method. Background technique [0002] In recent years, with the increase of energy demand and the continuous increase of mining intensity, shallow resources are decreasing day by day, and mines at home and abroad have entered the stage of deep resource exploitation one after another. The "three highs and one disturbance" problem is prominent in deep mining, which leads to a series of engineering disasters in deep mining, such as rock burst, severe mine pressure, and high dust concentration, compared with shallow engineering disasters, intensified in degree and frequency , the disaster mechanism is more complex. At the same time, the hazards of disasters such as ground temperature, coal spontaneous combustion, and coal and gas outbursts are also escalating, and disaster...

AI Technical Summary

Problems solved by technology

However, the current coal seam water injection technology is not mature, which is mainly reflected in the following aspects: There are mainly two problems in the drilling process: "drill sticking", "drill suction" and "slag discharge not smooth", which lead to difficulties in coal seam water injection drilling; Because the cement mortar is easy to dry and crack when sealing the hole, water leakage from the coal side will occur; the main problem of traditional water injection is that the water injection pressure is low, and the coal body cannot be fully wetted

In addition, since the current coal seam water injection technology mainly adopts the method of "drilling holes first, then injecting water", during the water injection process, the previously drilled water injection holes may "collapse" due to mining or other factors, resulting in water injection effects. bad

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