A pre-fracture hydraulic fracturing roof cutting and pressure relief construction method and drilling equipment

Abstract

The invention discloses a prefabricated crack hydraulic fracturing, roof-cutting and pressure-relief construction method and a drilling machine. The prefabricated crack hydraulic fracturing, roof-cutting and pressure-relief construction method comprises the steps that drilled holes are constructed in a roof above coal pillars at regular intervals, and a special drill bit is adopted to construct grooves in the axial direction at regular intervals; packers and pre-opening rubber membranes are inserted, thus the grooves are located in a packing section, and openings of the rubber membranes and the grooves are aligned, then water is injected into the packing section, the packers are pressurized by a manual pump, and whether the pressure in the packing section is decreased or not or whether thewater flows out of the packing section or not is observed; and a high-pressure pump is connected for fracturing, and prefabricated crack directional hydraulic fracturing, roof-cutting and pressure-relief operation is completed. Through the implementation mode, stress of roadway surrounding rock can be effectively lowered, roadway deformation is controlled, the safety and efficiency of resource exploitation are improved, and the problems of underground secondary pollution, poor safety and high cost which are caused by a traditional blasting technology are solved.

Description

technical field [0001] The invention belongs to the technical field of coal mining, and in particular relates to a pre-fracturing hydraulic fracturing roof cutting and pressure relief construction method and a drilling tool. Background technique [0002] At present, my country's coal mining is mainly underground mining. Before the mining activities start, the coal stratum is in the original rock stress state. After large-scale underground mining, the weight of the rock formation above the gob will be transferred to the surrounding support area, forming a support pressure zone around the goaf, forming a mobile support pressure in front of the working face, and forming a support pressure in the upper and lower sides of the working face and behind the working face. Formation of residual bearing pressure. The overlying strata activities caused by the mining of the working face lead to large shrinkage of the roadway in the advanced section of the mining face and need to be repai...

AI Technical Summary

Problems solved by technology

With the advancement of coal mining technology, the technical requirements for manual intervention to change the roof structure of the mining face are getting higher and higher. The traditional blasting technology highlights many disadvantages: the management of pyrotechnics such as detonators in coal mines is complex and potentially dangerous; Blasting forced caving single-hole control range is small, blasting hole depth is limited, engineering quantity and explosive consumption are large; blasting causes secondary pollution such as air and vibration, and the toxic and harmful gases produced such as carbon monoxide pollute the underground working environment; large power disturbance, blasting The impact is easy to damage the support; the safety is poor, and the sparks of explosive blasting and the instantaneous generation of a large amount of harmful gases such as CO cause potential safety hazards, which are not suitable for high-gas mines; the cost of explosives and management costs are high

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