Hydraulic pressing, flushing and pumping integrated hole sealing device and method

Abstract

The invention provides a hydraulic pressing, flushing and pumping integrated hole sealing device and method. The method comprises the following steps: tripping in a casing in one end of a drilling hole opening; injecting blocking cement plugs in the casing and drilling hole annular space; arranging an inner flange which is integrated with the casing on a portion, out of a drilling hole, of the casing; forming a round hole in the middle of an outer flange; welding a conical hollow ferrule on the periphery of the round hole; enabling a hydrofracture tube to penetrate in the ferrule and the round hole so as to enter the drilling hole; connecting the inner flange and the outer flange by a bolt; implementing hydrofracture after the ferrule and the hydrofracture tube are sealed; hermetically connecting an extraction pipeline and the ferrule when gas is extracted; and carrying out networking extraction after the inner flange is connected with the outer flange via the bolt. The hydraulic pressing, flushing and pumping integrated hole sealing device is simple in structure, convenient to mount and dismount, high in hole sealing speed and good in effect, and can be repeatedly used in a plurality of working procedures such as hydrofracture, punching and gas extraction, and the problems that during staged fracturing in the prior art, fracturing in each stage needs temporary hole sealing, and working procedures are complicated are solved.

Description

technical field [0001] The invention relates to a hole sealing technology for coal seam drilling, in particular to a hole sealing device and method integrating hydraulic pressure, punching and pumping in a coal mine. Background technique [0002] Gas disasters rank first among the five major disasters in my country's coal mines, including gas, water, fire, roof, and coal dust. loss. How to effectively prevent gas disasters has become an important problem that coal mine practitioners need to solve urgently. [0003] With the in-depth development of research on pressure relief and anti-permeability technology for high-gassy and low-permeability coal seams, hydraulic measures such as hydraulic fracturing, hydraulic punching, and hydraulic pressure punching have been gradually applied. Hydraulic fracturing uses high-pressure water as the medium, and injects high-pressure and large-displacement liquid into the coal seam at an injection rate greater than the filtration rate. The ...

AI Technical Summary

Problems solved by technology

The slurry type sealing is divided into two types: cement mortar sealing and polymer polyurethane foam sealing. The cement mortar has high compressive strength, but the sealing time is long. When deformed by ground stress, it is prone to air leakage; polyurethane organic foam materials have the advantages of high foaming ratio, light weight, and rapid hole sealing, but their compressive strength is low, and the sealing speed is difficult to control. In addition, the Such materials have problems such as excessive water expansion ratio, easy shrinkage after long-term storage, and separation from the wall of the drilled hole.

In addition, the slurry-type hole sealing is mostly suitable for permanent hole sealing, and is not suitable for staged fracturing that requires multiple sealings. Moreover, when hydraulic punching is performed after staged hydraulic fracturing is completed, the hole needs to be re-expanded for slag removal. cumbersome

The hole sealing process of the packer is simple and can be recycled and reused, but the hole sealing of the packer has high requirements on the drilling quality, especially when the coal is soft and the stress concentration around the hole is affected by mining, the hole is prone to If the wall is uneven, there will be a gap between the packer and the hole wall, and the seal is not tight, which will affect the sealing effect. Due to the limitation of construction technology, the drilling trajectory is prone to deviation, and it is difficult for the packer to be lowered accurately according to the requirements. default location

[0005] Hydraulic fracturing requires sealing the hole to suppress pressure, while punching requires opening the hole to discharge slag, and drainage requires the hole to be tightly sealed before being connected to the network for drainage. However, the existing sealing technology is too complicated and cumbersome, and the sealing effect is limited. It is not suitable for hydraulic pressure punching to quickly seal and unseal the requirements

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