Soft outburst coal seam long drill hole forming system and method

Abstract

The invention provides a soft outburst coal seam long drill hole forming system and method. The system comprises a water jet generation system, a drill tool system, a supporting sleeve pipe, a pressure-retaining system and a gas-slag separator, wherein the drill tool system comprises a spiral drill bit, a drill rod and a drilling machine; the drilling machine clamps the tail end of the drill rod;the supporting sleeve pipe is arranged in the drill rod; the pressure-retaining system comprises a pressure-retaining pipe, a pressure display and a pressure-retaining sealing device; the front end ofthe pressure-retaining pipe stretches into the drill hole and the back end of the pressure-retaining pipe is placed outside the drill hole; and the drilling machine drives the drill rod to rotate anddrills into a coal rock seam. The hole forming method comprises the steps of placing the pressure-retaining pipe, drilling and crushing, pushing the supporting sleeve pipe out of the drill bit and the like. The system guarantees stable pressure in the drill hole and solves the problems of hole collapse, drill burying and the like occurring in long-distance drilling, thereby realizing efficient and smooth drilling operation, utilizing waste water maximally to perform circulating operation and significantly improving construction efficiency and economic benefit.

Description

technical field [0001] The invention relates to the technical field of coal seam gas drainage, in particular to a system and method for forming long holes in soft and outburst coal seams. Background technique [0002] The length of the borehole has an important impact on the gas drainage effect, and as the depth of coal mining increases, the high gas pressure and high ground stress in the coal seam will cause the borehole to collapse, resulting in problems such as injection holes, drill sticking, and buried drill. , can't guarantee the construction safety, has a strong impact on the efficiency of drilling construction, meanwhile, simply increasing the torque of the drilling rig and the strength of the drill pipe is still not enough to solve this type of drilling problem. [0003] Therefore, in the field of deep coal mining, there is an urgent need for a drilling system and method for high stress and high gas pressure, so as to ensure safe and efficient mining of deep coal re...

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Problems solved by technology

[0002] The length of the borehole has an important impact on the gas drainage effect, and as the depth of coal mining increases, the high gas pressure and high ground stress in the coal seam will cause the borehole to collapse, resulting in problems such as injection holes, drill sticking, and buried drill. , the construction safety cannot be guaranteed, which seriously affects the efficiency of drilling construction. At the same time, simply increasing the torque of the drilling rig and the strength of the drill pipe is still not enough to solve this type of drilling problem

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