Drilling and punching automatic switching device for preventing and controlling gas outburst, and gas outburst prevention method

Abstract

The invention discloses a drilling and punching automatic switching technology and device for preventing and controlling gas outburst. The drilling and punching automatic switching device is mounted between a drill bit and a drilling rod with the same diameter as that of the drill bit and composed of a spring (with a fixing rod), a circular table cylinder, a conical plug, jet flow holes, a blocking plate, a connecting rod and the like. The conical plug is fixed inside the device, the specific spring connects the movable circular table cylinder with the fixing rod, and under the influence of the water pressure, the circular table cylinder moves to control water jet flow outlets and pressure. The problems that suitable drill bits are selected for different coal body hardness, and a punchingdrill bit needs to be replaced are solved, and hydraulic drilling under the low water pressure and hydraulic punching operation under the high water pressure can be achieved.

Description

technical field [0001] The invention relates to a hydraulic punching device, in particular to a drilling punch automatic switching device for preventing gas outburst and a method for preventing gas outburst. Background technique [0002] Coal and gas outburst is one of the major disasters that threaten the safe production of coal mines in my country. In order to effectively control outburst disasters, mines in my country generally adopt measures such as mining protective layers and large-scale pre-pumping. For a large number of single coal seams without protection seam mining conditions, gas pre-extraction must be carried out in this coal seam. However, outburst coal seams in my country are generally soft and low-permeability coal seams. Therefore, in order to achieve high-efficiency gas pre-extraction and prevent coal and gas outburst, hydraulic punching and other enhanced outburst prevention technologies are required. The hydraulic punching method is to rely on the impact...

AI Technical Summary

Problems solved by technology

[0003] However, in the current actual operation of hydraulic punching, some spaces need to withdraw the drill pipe after drilling, and replace the drilling bit with the punching bit. The replacement process is time-consuming and laborious; some mines use automatic switching bits, but the diameter of the jet hole Single, can not meet the needs of coal bodies with different hardness and different damage types, or cause a small amount of coal to be flushed out, and the punching speed is slow, or cause the coal flushing speed to be too fast, resulting in injection holes and hole blocking construction

The reason is that the hydraulic punching operation is carried out under complex geological conditions. The high-pressure water jet coal breaking process involves the mutual coupling of jet flow, coal, gas and other factors. The coal breaking process is extremely complicated. Moreover, coal bodies of different damage types and different hardness The coal body and the coal breaking conditions are very different, and the requirements for the water pressure of the punching hole and the punching parameters of the drill bit are relatively strict.

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