Segmental hydraulic fracturing coal seam pressure releasing device and method

Abstract

The invention relates to a segmental hydraulic fracturing coal seam pressure releasing device. A high pressure hydraulic pump station is connected to a segmental hydraulic fracturing hole packer through a high pressure hose and a steel push rod; and after the hole packer is fed into a fracturing hole by the push rod, water flows from the high pressure hydraulic pump station to the segmental hydraulic fracturing hole packer through the high pressure hose, flows through a pressure reducing mechanism and is injected into coal for hydraulic fracturing. Water flow also makes hole packing capsules on two sides of a water outlet swell to achieve a sealing effect, and a fracturing range is controlled between the two capsules. Due to the action of the pressure reducing mechanism, the pressure of the hole packing capsules is always greater than that of the water outlet to realize self sealing. During field implementation, a seam hole can be divided into a plurality of segments and is subjected to fracturing segment by segment; meanwhile, a control hole parallel to the fracturing hole is constructed to increase a free face and can drain, bring out coal dust and achieve a hydraulic loosening effect, and the coal between the hydraulic fracturing hole and the control hole is penetrated through pressure finally, so that the coal seam releases pressure fully, the pre-extraction time of the coal seam is shortened and the extraction rate is improved.

Description

technical field [0001] The invention relates to an underground coal seam hydraulic fracturing device and method, in particular to a staged hydraulic fracturing coal seam pressure relief device and a pressure relief method. Background technique [0002] Due to the difficulty of pre-pumping the gas in the high gas and low permeability coal seam, a large amount of gas gushes out during the mining operation of high gas and coal and gas outburst mines, which easily causes the gas in the working face to exceed the limit, and even coal and gas outburst occur ACCIDENT. With the development of high-efficiency and intensive coal production and the continuous increase of mining depth, this problem has increasingly restricted coal mine safety production. In coal and gas outburst mines that do not have protection layer mining conditions, pre-extraction of outburst coal seam gas has become an important regional outburst prevention measure. How to increase the effective range of drilling...

AI Technical Summary

Problems solved by technology

However, due to the complexity of the process, the fracturing equipment weighs tens to hundreds of tons, and cannot be used in the limited space underground.

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