Borehole washing device for gas drainage drilling in coal mine

Abstract

The invention provides a hole flushing device for coal mine downhole gas extraction drill holes. The hole flushing device comprises a water tank, a high-pressure pump, a high-pressure hard pipe, a high-pressure hose, a self-propelled drill bit, a base, a winch, a pushing mechanism and the like. The winch and the pushing mechanism are fixed to the base. The device can correspond to the drill holes in different positions and at different angles by adjusting all parts of the base. The high-pressure hard pipe can penetrate through the pushing mechanism before being fed into the drill holes. The high-pressure hard pipe can be conveyed forwards along the drill holes through pushing force provided by the pushing mechanism. When high-pressure water passes through the high-pressure hose at the front end of the high-pressure hard pipe and the self-propelled drill bit, high-pressure water jet is generated to conduct rock breaking dredging on collapsed and blocked portions, and self-propelling force is generated. The device is simple in structure, small in overall size and convenient to adjust, and can be conveniently used in coal mine downhole narrow working space. A whole power pipeline can be conveyed in long distance under joint acting force of pulling in front and pushing behind, and the pipeline can be prevented from being clamped. The hole flushing speed is high, efficiency is high, cost can be greatly reduced, and the gas extraction effect is improved.

Description

technical field [0001] The invention belongs to the technical field of underground coalbed methane drainage in coal mines, and relates to a hole washing device for gas drainage boreholes, which are suitable for dredging collapsed and blocked gas drainage boreholes in soft coal seams. Background technique [0002] my country has a large number of high-gas mines, most of which have high gas content, high gas pressure, complex geological structure, and low coal seam permeability, which is 2 to 3 orders of magnitude lower than the average in the United States. As the depth of coal mining increases, the gas pressure and gas content will increase, and the permeability of coal seams will be lower, making coal mining and gas drainage more difficult, and gas disasters will be serious. Pre-pumping coal seam gas is an effective measure to prevent gas disasters and ensure safe production in coal mines, but coal seams in high-gas mines are generally soft; in Southwest China, 93.14% of mi...

AI Technical Summary

Problems solved by technology

However, the above-mentioned measures have the following problems: the improved drilling tools and drill bits are often more complex and heavy in structure; the manufacturing cost is higher; in addition, these measures still cannot completely solve the problem of collapse and blockage of boreholes, and the situation of borehole collapse and blockage still exist in large numbers

A mechanical drilling tool for clearing holes with a simple structure is designed in the "Drilling Tool for Clearing Holes" published by Chinese patent document CNI02312660A. Difficulty aligning holes, low drilling efficiency, a lot of time wasted when drilling back, and re-sealing after drilling, etc.

The operating machine has a compact structure, and can adjust the position and direction of the hole forming underground in the coal mine, and can perform multi-directional dredging, reaming, slitting, fracturing, etc. in the mine; but the operating machine is huge and difficult to adapt to the narrow underground working space ; At the same time, the used winding steel pipe has high hardness and is prone to fatigue damage, and in the process of drilling, pipe jamming and drilling deviation are prone to occur during forced propulsion

[0005] At present, there are not many methods and devices to solve the problem of drilling collapse and blockage in soft coal seams, and there are many problems

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