CN104329113B - A kind of method of surface drilling standing seat earth release mash gas extraction - Google Patents

Abstract

The present invention provides a method for depressurizing and extracting gas from ground drilling, loosening and blasting the coal seam floor, comprising the following steps: drilling multiple ground wells on the ground surface of the working face along the advancing direction of the working face to the bottom of the coal seam working face for 2 ~3m; using the "L-shaped" drilling technology, a horizontal borehole is drilled at the bottom of the ground well along the advancing direction of the working face to connect two ground wells; explosives are filled in the horizontal borehole, and a detonating cord is used to penetrate Adjacent to the explosive, inject water into the ground drilling to seal the hole; detonate the explosive, and the explosive will loosen the coal seam and generate a large number of cracks, thereby achieving the purpose of pressure relief and permeability enhancement; the water in the ground drilling and horizontal drilling is pumped out, and the gas drainage pipe is connected Wells are drilled on the ground to extract the gas in the coal seam. The invention uses the ground to drill wells, blast the bottom plate rock layer of the working face, and extract the coal seam gas, and has the advantages of low cost, high safety, simplified gas extraction process, and the like.

Description

A method for pressure relief and drainage of coal seam floor by ground drilling and blasting

technical field

The invention relates to the technical field of coal mine blasting, in particular to a method for depressurizing and extracting gas from a coal seam floor by ground drilling and loosening blasting.

Background technique

The mining of high-gassy and low-permeability coal seams is often accompanied by the problem of a large amount of gas gushing out, which seriously affects and restricts the safe mining of coal mines. The root of solving this problem lies in the pre-extraction of coal seam gas. The method of pre-extraction of gas is mainly to drill holes for pre-extraction of gas from the coal seam of the working face through the underground gas extraction roadway. This method needs to be arranged in the coal seam floor of the working face For the gas drainage roadway, if necessary, another gas drainage roadway needs to be arranged in the coal seam roof strata of the working face. This method is not only expensive for roadway layout, but also time-consuming, labor-intensive and prone to accidents.

Contents of the invention

In order to solve the above-mentioned technical problems, the present invention provides a method for depressurizing and extracting gas from the coal seam floor by ground drilling, loosening and blasting, which can loosen and blast the coal seam of the working face by ground drilling, and depressurize and increase the pressure of the low-permeability coal seam. Permeate and extract coal seam gas.

To achieve the above object, the present invention adopts the following technical solutions:

A method for depressurizing and extracting gas by loosening and blasting a coal seam floor by ground drilling, comprising the following steps:

(a) Drill multiple ground wells on the overlying surface of the working face along the advancing direction of the working face to a place 2-3m below the floor of the coal seam working face;

(b) using "L-shaped" drilling technology, drilling horizontal boreholes along the advancing direction of the working face at the bottom of the ground wells described in step (a), and the horizontal boreholes are connected to adjacent ground wells;

(c) filling explosives in the horizontal borehole described in step (b), and penetrating the adjacent explosives with a detonating cord;

(d) injecting water into the surface drilling described in step (a) to seal the hole;

(e) detonating the explosive described in step (c), the explosive blasting loosens the coal seam and produces a large number of cracks;

(f) pump out the water in the ground well and the horizontal borehole, connect the gas extraction pipe to the ground well, and extract the gas in the coal seam.

The method for extracting gas by ground drilling loosening and blasting the coal seam floor according to the present invention, wherein the distance between the ground drilling holes in the step (a) is 200-300m.

The method for extracting gas by loosening and blasting coal seam floors by ground drilling according to the present invention, wherein the diameter of the ground drilling in the step (a) is 75-145 mm.

The method for extracting gas by ground drilling for loosening and blasting coal seam floors according to the present invention, wherein the diameter of the horizontal drilling in step (b) is the same as that of the ground drilling.

The method for pressure relief and drainage of coal seam floor by ground drilling and loosening blasting of coal seam floor according to the present invention, wherein the explosive in step (c) is water-gel explosive or emulsion explosive.

The method for extracting gas by ground drilling, loosening and blasting the coal seam floor for pressure relief and extraction according to the present invention, wherein the ground drilling described in step (d) is filled with water to seal the hole until it is flush with the ground or the vertical height of the water column exceeds 300m.

Compared with the existing pre-extraction method of gas, the present invention does not need to excavate the gas extraction roadway and reduces the arrangement of extraction boreholes, and has the advantages of low cost, short construction period, light labor, high efficiency and safety, and greatly simplifies The gas drainage process is completed; the ground drilling distance described in step (a) is 200-300m, which is conducive to taking into account the straightness of the horizontal hole and the number of ground drilling wells; the ground drilling water injection seal described in step (d) The hole should be level with the ground or the vertical height of the water column should exceed 300m, so that the pressure and gas of the explosion sealing hole will not leak out.

Description of drawings

Fig. 1 is the schematic diagram of the method for depressurizing and extracting gas from ground drilling and loosening blasting coal seam floor of the present invention;

Fig. 2 is a schematic diagram of the effect of the method for releasing pressure and extracting gas from the ground drilling and loosening the coal seam floor of the present invention.

1—ground drilling; 2—water column; 3—rock formation; 4—coal seam; 5—horizontal drilling; 6—detonator; 7—detonating cord; 8—water gel explosive; ground.

The method for depressurizing and extracting gas from the coal seam floor of the ground drilling loosening and blasting will be further described below in conjunction with specific embodiments and accompanying drawings.

detailed description

Example 1

In this embodiment, a method for depressurizing and extracting gas by loosening and blasting coal seam floors by drilling holes on the ground includes the following steps:

(a) On the overlying surface of the working face along the advancing direction of the working face, drill the ground drilling 1 with a diameter of 75mm every 200m to the place 2m below the floor of the working face of the coal seam 4;

(b) Utilize the "L-shaped" drilling technology to drill a horizontal borehole 5 with a diameter of 75mm along the advancing direction of the working face at the bottom of the ground well 1, and the horizontal borehole 5 is connected to the adjacent ground well 1;

(c) explosives 8 are filled in the horizontal borehole 5 described in step (b), and run through adjacent explosives 8 with detonating cord 7, and explosives 8 are water-gel explosives;

(d) Injecting water into the surface drilling 1 in step (b) to seal the hole until it is flush with the ground 11;

(e) Use the detonator 6 to detonate the explosive 8 in the step (c), and the explosive 8 explodes to loosen the coal seam 4 and produce a large number of cracks 10;

(f) The water in the ground well 1 and the horizontal borehole 5 is pumped out, the gas extraction pipe is connected to the ground well 1, and the gas in the coal seam 4 is extracted.

Example 2

In this embodiment, a method for depressurizing and extracting gas by loosening and blasting coal seam floors by drilling holes on the ground includes the following steps:

(a) On the overlying surface of the working face along the advancing direction of the working face, drill the ground drilling 1 with a diameter of 145mm every 300m to the place 3m below the floor of the working face of the coal seam 4;

(b) Utilize the "L-shaped" drilling technology to drill a horizontal borehole 5 with a diameter of 145mm along the advancing direction of the working face at the bottom of the ground well 1, and the horizontal borehole 5 is connected to the adjacent ground well 1;

(c) filling the explosive 8 in the horizontal borehole 5 described in the step (b), and passing through the adjacent explosive 8 with the detonating cord 7, and the explosive 8 is an emulsion explosive;

(d) Injecting water into the ground well 1 in step (b) to seal the hole until the vertical height of the water column 2 exceeds 300m;

(e) Use the detonator 6 to detonate the explosive 8 in the step (c), and the explosive 8 explodes to loosen the coal seam 4 and produce a large number of cracks 10;

(f) The water in the ground well 1 and the horizontal borehole 5 is pumped out, the gas extraction pipe is connected to the ground well 1, and the gas in the coal seam 4 is extracted.

During the blasting process, a safe distance of 30m between personnel and mechanical equipment should be kept from the ground drilling to prevent water and slag particles from damaging the equipment or injuring personnel during the blasting process.

The above-mentioned embodiments are only descriptions of preferred implementations of the present invention, and are not intended to limit the scope of the present invention. Variations and improvements should fall within the scope of protection defined by the claims of the present invention.

Claims (5)

1. A method for depressurizing and extracting gas from the coal seam floor by loosening and blasting the ground borehole, is characterized in that, comprises the following steps: (a) Drill multiple ground wells (1) on the overlying surface of the working face along the advancing direction of the working face to a place 2 to 3 m below the floor of the working face of the coal seam (4); (b) Utilize the "L-shaped" drilling technique, drill a horizontal borehole (5) at the bottom of the ground well (1) in step (a) along the advancing direction of the working face, and the horizontal borehole (5) Connecting adjacent said ground wells (1); (c) filling the explosive (8) in the horizontal borehole (5) described in step (b), and penetrating the adjacent explosive (8) with a detonating cord (7); (d) injecting water into the ground well (1) described in the step (a) to seal the hole; (e) detonating the explosive (8) described in the step (c), the explosive (8) blasting and loosening the coal seam (4), producing a large number of cracks (10); (f) extract the water in the ground well (1) and the horizontal borehole (5), connect the gas extraction pipe to the ground well (1), and extract the gas in the coal seam (4) ; The distance between the ground wells (1) described in the step (a) is 200-300m. 2. The method for extracting gas by ground drilling for loosening and blasting coal seam floors according to claim 1, characterized in that the diameter of the ground drilling (1) in step (a) is 75-145 mm. 3. The method for decompressing and extracting gas by ground drilling loosening and blasting coal seam floor according to claim 2, characterized in that: the diameter of the horizontal borehole (5) in step (b) is the same as the diameter of the ground drilling (1) same. 4. The method according to claim 3, wherein the method for extracting gas by loosening and blasting coal seam floors through ground drilling, is characterized in that: the explosive (8) in step (c) is a water-gel explosive or an emulsion explosive. 5. According to any one of claims 1-4, the method for extracting gas by ground drilling for loosening and blasting coal seam floor pressure relief, is characterized in that: the ground drilling (1) described in step (d) is injected with water to seal the hole The ground (11) is level or the vertical height of the water column (2) exceeds 300m.