Anti-collapse method for long-distance horizontal drilling in soft coal seams in coal mines

Abstract

The invention relates to an anti-collapse method for long-distance horizontal hole drilling in a soft coal seam of an underground coal mine. The method comprises the following steps that: an extra-deep-hole dual-pipe drilling directional drilling machine is selected; an opening diameter and an opening depth of a drilling hole are selected; after one-opening drilling is completed, orifice casing pipe is put into the hole; after fixation of the orifice casing pipe, slip casting and well cementation are carried out, hole bottom cleaning and drilling are carried out after solidification completion, and then a pressure-resistant performance test is carried out; after the pressure-resistant performance test is done successfully, a hole bottom motor, a non-magnetic drilling rod, and a while-drilling guiding system are arranged to carry out dual-pipe directional drilling; and when drilling is carried out to a final hole position, an inner pipe is removed, sleeve pipes are connected and put into the hole one by one, a wire wrapping rubber pipe is put into the sleeve pipes after installation of the sleeve pipes, and then an outer pipe is removed to complete the whole process. With the method, a problem of difficult hole forming of the soft coal seam can be effectively solved; the drilling construction depth and the hole formation probability are improved; the high-efficiency pre pumping of gas is finally realized; the outburst danger of the coal and the gas is reduced; and safe and high-efficiency production of the coal can be realized.

Description

[0001] Technical field: [0002] The invention relates to the field of gas drainage in coal mines, in particular to an anti-collapse method for long-distance horizontal drilling in underground soft coal seams of coal mines. [0003] Background technique: [0004] More than 95% of high-gas and outburst mines in my country belong to low-permeability coal seams, with soft coal and high gas content. Various types of long-distance horizontal drilling underground for gas drainage play an important role in mine disaster prevention, gas resource development and utilization, and environmental protection. Reasonable and efficient gas drainage can greatly solve the problem of mine safety production and alleviate the tense situation of energy supply and demand . The pre-drainage of coal seam gas is based on the construction drainage borehole. The length and effective service life of the borehole determine the effect of gas extraction. In soft and outburst coal seams, high gas pressure, hi...

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Problems solved by technology

[0007] The purpose of the present invention is to provide an anti-collapse method for long-distance horizontal drilling in soft coal seams in coal mines, to solve the problem of easy collapse of holes in the drilling process of gas drainage in soft coal seam areas, and to improve the drilling depth , hole forming rate and prolong the effective life of drilling, realize efficient gas drainage, reduce the risk of coal and gas outburst, and realize safe and efficient production of coal mines

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