A method of directional hydraulic blasting to improve the air permeability of coal seam

A technology of hydraulic blasting and air permeability, which is applied in earth-moving drilling, wellbore/well components, mining equipment, etc., can solve the problems such as the inability to meet the coal seam permeability, coal and gas outburst disasters, and the inability to meet the actual needs of production, etc.

Active Publication Date: 2015-08-19
CHONGQING UNIV
View PDF4 Cites 2 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although various conventional pressure relief and permeability enhancement measures have achieved certain effects, they are still unable to meet the actual needs of production. A single method can no longer meet the requirements of improving coal seam permeability and preventing coal and gas outburst disasters in deep coal mines.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • A method of directional hydraulic blasting to improve the air permeability of coal seam

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0016] Example 1: The average thickness of the coal seam 2 of a certain mine is 5m, the hardness of the coal seam 2 is f=3, it is a gently inclined coal seam 2, the overlying rock layer is hard sandstone 1, and its average thickness is 20m, in the coal mine underground transport stone gate , using a drilling rig to drill a hole 5 into the pre-mined coal and rock mass, the hole diameter is 75mm, and the depth of the hole 5 is 24m. Then carry out hydraulic cutting in the coal seam, and form a deep flat slot around the coal seam borehole 5 after cutting. Place a steel casing 8 with a diameter of 36 mm at the orifice, and use cement mortar 6 to fill the gap between the steel casing 8 and the drilled hole 5. When the cement mortar 6 is maintained for more than 48 hours and has sufficient strength, Fill the emulsion explosive 4 in a PVC pipe 7 with a diameter of 32mm, the charge amount is 100g, set a detonator 3 every 1 m in the emulsion explosive 4, send the PVC pipe 7 to the coal ...

Embodiment 2

[0017] Example 2: The average thickness of a coal seam 2 in a certain mine is 9m, and the hardness of the coal seam 2 is f=4, which is a gently inclined coal seam 2, and the overlying rock layer is hard sandstone 1, and its average thickness is 28m. , using a drilling rig to drill a hole 5 into the pre-mined coal and rock mass, the hole diameter is 94mm, and the depth of the hole 5 is 35m. Then carry out hydraulic cutting in the coal seam, and form a deep flat slot around the coal seam borehole 5 after cutting. Place a steel casing 8 with a diameter of 45 mm at the orifice, and use cement mortar 6 to fill the gap between the steel casing 8 and the drilled hole 5. When the cement mortar 6 is maintained for more than 48 hours and has sufficient strength, Fill the emulsion explosive 4 in a PVC pipe 7 with a diameter of 40 mm, the charge amount is 200 g, set a detonator 3 every 1 m in the emulsion explosive 4, send the PVC pipe 7 to the coal seam 2, and connect the lead wire 9 Le...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

A directional water pressure blasting method for improving coal bed gas permeability includes utilizing water pressure blasting splitting to change the structure of the coal and rock mass, firstly drilling holes inside a coal bed, performing high-pressure hydraulic cutting seam, and forming a deep flat slot around the drilling holes of the coal bed after cutting; and filling explosive into the drilling holes of the coal bed, then injecting water and sealing the hole, detonating the explosive to perform water pressure blasting, and enabling the periphery of the drilling holes of the coal bed to generate directional expanding fractures under the function of detonation pressures. Performing water pressure blasting in a high-gas low gas permeability coal bed can organically combine the waterpower and the explosive force of the explosive fully and reasonably, the water pressure blasting enables the cracks generated by hydraulic cutting seam to further expand and a directional expanding cross fracture net is formed on the periphery of the drilling holes of the coal bed, so that the gas permeability of the coal bed is greatly improved, the problem that the gas of the coal bed is hard to extract due to the small number of the cracks can be effectively solved, the concentrated stress of the coal bed is transferred to the deep of the coal mass, and the capacity of gas emission is improved. The directional water pressure blasting method for improving the coal bed gas permeability is simple in process, convenient to operate, safe, reliable, and good in controllability and effects.

Description

technical field [0001] The invention relates to a hydraulic blasting method, in particular to a method for improving the air permeability of a coal seam by directional hydraulic blasting. Background technique [0002] The air permeability of the coal seam is an important index to measure the gas pumpability of the coal seam. For the gas drainage of the low air permeability coal seam, special measures must be taken to increase the air permeability of the coal seam in order to effectively extract the gas. The methods tested at home and abroad include: coal seam water injection, hydraulic fracturing, high-pressure hydraulic slotting, deep hole blasting, etc. Coal seam water injection is to seep into the coal body through seepage and capillary force under the premise that the coal seam has a certain degree of air permeability. In the three-phase action of water, gas gas and coal body, water occupies the original gas position, and gas becomes In the free state, it escapes along ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Patents(China)
IPC IPC(8): E21F7/00E21B43/26E21B43/263
Inventor 夏彬伟付宏伟卢义玉宋晨鹏葛兆龙刘小川刘承伟赵彬钦
Owner CHONGQING UNIV
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap