CN111287787A - Method for efficiently pumping and discharging gas through top plate crack expansion - Google Patents

Abstract

The invention discloses a method for high-efficiency gas drainage by roof expansion cracking, and relates to the technical field of coal mine gas prevention and control. In the gas drainage roadway, the drainage hole drilling field is arranged on both sides of the drainage roadway, and the oblique drainage drilling hole is constructed in the drainage drilling field; Step 2: Coal seam roof cracking method, in the lower part of the drainage hole In the coal seam and within the range of 0-10m where the coal seam and the roof contact, the coal seam roof will be cracked, and the coal seam gas pressure will be relieved. The invention solves the problem of efficient drainage of coal seam gas before coal seam excavation construction, can expand the pressure relief space of coal seam gas pressure, improve the development degree of cracks in the roof of the coal mining face, is conducive to the release of coal seam gas, and further improves the coal seam working face edge Towards the drainage efficiency of the gas drainage alley, the on-site application is simple, the operation is convenient, the cost is low, and the success rate is high.

Description

A method for efficient gas drainage by roof expansion cracking

technical field

The invention relates to the technical field of coal mine gas prevention and control, relates to the drainage of coal seam gas used for underground coal mines, and in particular relates to a method for efficient gas drainage by roof expansion cracking.

Background technique

In the past ten years, a large number of fruitful researches have been carried out on coal seam gas drainage at home and abroad, especially in the gas pressure relief of high-traveling roadway and drilling medium fracturing. The trending high extraction roadway is mainly used for the prevention and control of gas drainage in the goaf during the mining period of the working face. ” so that it can be pumped to high concentrations of gas. Drilling medium fracturing gas pressure relief is mainly used for gas drainage in roadway drilling during roadway excavation or working face mining. The key parameters are the parameters of the fracturing medium and the parameters of the surrounding rock of the drilled hole.

The above-mentioned various coal seam gas drainage technologies have played a strong technical support for ensuring the safe production of coal mines, but the current various drainage technologies also have different defects and limitations in production practice, and the two technologies are not used in combination. Complement each other's advantages, so that the extraction effect has not been revolutionaryly improved.

SUMMARY OF THE INVENTION

In order to overcome the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a method for efficiently draining gas by roof expansion, which is simple in procedure, low in cost and easy to operate. The roof fracturing method can construct the gas drainage roadway along the strike on the coal seam roof before the coal seam mining disturbance, and construct the inclined fracturing drilling holes along the axial sides of the gas drainage roadway at intervals, so as to reduce the coal seam gas pressure. Pressure relief is carried out, and at the same time, the development of cracks in the roof of the coal seam is improved, the release of coal seam gas is promoted, and the efficient drainage of coal seam gas is realized.

In order to achieve the above object, the present invention adopts the following technical solutions, a method for efficiently draining gas by roof expansion cracking, comprising the following steps:

Step 1: At the position of distance H=0～100m from the normal line of the coal seam, the drainage roadway for gas drainage is arranged along the direction of the coal seam, and the drainage hole drilling field is arranged on both sides of the drainage roadway. The construction of the oblique pumping and drilling holes;

Step 2: The method for fracturing the roof of the coal seam, in the coal seam at the lower part of the extraction borehole and within the range of 0-10m where the coal seam and the roof are in contact, the roof of the coal seam is fractured, and the coal seam gas pressure is relieved.

Wherein, step 1 includes the following steps:

Step 1: Go to the location of the gas drainage lane, the width of the drainage lane is B=3.0～5.0m, and the height h=2.0～3.5m;

The second step: After the construction of the gas drainage roadway along the strike of the coal seam is completed, the drainage hole drilling field is arranged along the two sides of the high extraction roadway. Width b=3.0～5.0m, length l=0～5.0m;

Step 3: Arrange drainage drilling holes in the drainage hole drilling field on both sides of the drainage tunnel along the coal seam strike, the number of drilling holes is 1 to 10, and the vertical distance between the inner drilling hole and the inner side of the drainage hole drilling site is 0.5 ～5.0m, the vertical distance between the outer borehole and the side of the extraction lane is 0.5m;

Step 4: Construct the oblique drainage hole in the drainage hole drilling site, the diameter of the oblique drainage hole is φ=60~150mm, and the angle between the oblique drainage hole and the coal seam inclination layer is θ=5°~90 °, the distance H = 0~100m from the position of the opening in the construction of the oblique extraction drilling to the normal line of the coal seam.

Wherein, in the second step, the coal seam roof is fractured by using the blasting fracturing method, the carbon dioxide fracturing method, the hydraulic fracturing method and the high-energy pulse fracturing method.

As can be seen from the above content, the beneficial effects of the method for efficiently draining gas by roof expansion cracking of the present invention are:

The invention solves the problem of efficient drainage of coal seam gas before coal seam excavation construction, can expand the pressure relief space of coal seam gas pressure, improve the development degree of cracks in the roof of the coal mining face, is conducive to the release of coal seam gas, and further improves the coal seam working face edge The drainage efficiency of the gas drainage alley is of great significance to mine safety production and gas drainage. During the construction of drainage holes, the fracturing method is used to crack the coal seam and its roof, to relieve the pressure of coal seam gas, promote the release of coal seam gas, and realize efficient drainage of unexcavated and disturbed coal seam gas; the roof cracking can promote coal seam gas Analysis, improve the development rate of coal seam roof cracks, improve the gas drainage effect of gas drainage tunnel, and provide reliable guarantee for the safety production of coal mining; the method has simple on-site application, convenient operation, low cost and high success rate.

In addition to the objects, features and advantages described above, the present invention has other objects, features and advantages. The present invention will be described in further detail below with reference to the drawings.

Description of drawings

The accompanying drawings constituting a part of the present application are used to provide further understanding of the present invention, and the exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention.

Fig. 1 is the vertical sectional view along the strike arrangement of the gas drainage road and the drainage hole drilling field in the present invention;

FIG. 2 is a top plan view of the gas drainage lane along the strike in the present invention.

Fig. 3 is a vertical cross-sectional view of a drawing hole drilling field in the present invention.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention.

In the description of the present invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", The orientation or positional relationship indicated by "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying The device or element referred to must have a specific orientation, as well as a specific orientation configuration and operation, and therefore should not be construed as limiting the invention.

The terms "first" and "second" are only used for descriptive purposes, and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined with "first" and "second" may expressly or implicitly include one or more of the features; in the description of the present invention, unless otherwise specified, the meaning of "multiple" is two or more.

Example

As shown in Figure 1 to Figure 3, a method for efficiently draining gas by roof expansion is carried out according to the following steps:

Preparations before grouting, transport drilling equipment, fracturing medium materials (explosives, water, carbon dioxide or other high-energy materials), and vacuum suction pumps to the point where the measurement needs to be performed, and then install the equipment;

The location of the gas drainage roadway: at the distance H=0～100m from the normal line of the coal seam, the drainage roadway for gas drainage is arranged along the direction of the coal seam. The width of the gas drainage roadway is B=3.0～5.0m, and the height is h= 2.0～3.5m;

Drainage hole drilling field: After the construction of the gas drainage roadway along the strike of the coal seam is completed, the drainage hole drilling field is arranged along the two sides of the high extraction roadway, and the layout spacing is L=2.0～80.0m, and the drainage hole drilling field width is b= 3.0～5.0m, length l=0～5.0m;

Layout of drainage drilling holes: construct oblique drainage drilling holes in the drainage hole drilling site outside the two sides of the drainage road along the coal seam strike. The number of drilling holes is 1 to 10, and the inner drilling holes are within the The vertical distance of the gangway is 0.5-5.0m, and the vertical distance between the outer drilling and the road gangway of the drainage lane is 0.5m;

Drainage drilling: Construct a tilting drainage hole in the drainage hole drilling site, the diameter of the tilting drainage hole is φ=60~150mm, and the angle θ=5°~ 90°, the distance H=0~100m between the opening position and the normal line of the coal seam during the depression and oblique extraction drilling construction;

Coal seam roof fracturing method: in the coal seam at the lower part of the extraction hole and within the range of 0-10m at the contact point between the coal seam and the roof, blasting fracturing method, carbon dioxide fracturing method, hydraulic fracturing method and high-energy pulse fracturing method can be selected. ;

It also includes preparatory work: transport the materials and drilling equipment used for drilling the pitch-drilling hole to the selected measuring point location as required, and then drill the hole;

When drilling, the normal line length of the depression-inclined fractured hole from the coal seam is 0~100m, and the angle between the drilling axis and the inclined layer of the coal seam is θ=5°~90°. The pump cleans the pumice cuttings;

The physical and mechanical parameters of the roof strata of the coal seam are measured before the cracking is caused by the subduction-inclined drilling; by taking rock samples to carry out laboratory tests, and using the drilling instrument to carry out the drilling test, the occurrence of the strata of the coal seam roof and its bedding, The development of cracks, obtain the lithology of the working face roof and the corresponding physical and mechanical parameters, and obtain scientific and reliable data for subsequent cracking through the geomechanical test of the surrounding rock of the working face;

After completing the fracturing operation of the inclined drilling, the negative pressure ventilation discharges the gas generated after the fracturing operation of the drilling;

Specifically, when gas measurement is performed on soft and cracked coal, the three procedures of selecting the location of the gas drainage roadway along the strike, designing the roof drainage hole drilling site, and designing the parameters of the roof drainage hole are carried out one by one, and cannot be intersected. ; After the drilling construction is completed and the fracturing medium is filled, the fracturing is carried out. After the fracturing work is completed, the gas released by the fracturing hole is drained in a timely manner by negative pressure ventilation.

The invention solves the problem of efficient drainage of coal seam gas before coal seam excavation construction, can expand the pressure relief space of coal seam gas pressure, improve the development degree of cracks in the roof of the coal mining face, is conducive to the release of coal seam gas, and further improves the coal seam working face edge The drainage efficiency of the strike gas drainage roadway is of great significance to mine safety production and gas drainage; the present invention adopts the method of fracturing the roof inclining drainage hole, and the method includes the selection of the position of the gas drainage roadway along the strike, There are three procedures for the design of the roof drainage hole drilling site and the design of the roof drainage drilling parameters. The three procedures are carried out in sequence to ensure the effect of roof cracking and improve the gas drainage efficiency of the gas drainage tunnel along the strike face. The expansion method can expand the pressure relief range of coal seam gas pressure, improve the development degree of cracks in the roof of the coal mining face, which is conducive to the release of coal seam gas, thereby improving the drainage efficiency of gas drainage roadways along the strike of the coal seam working face, which is conducive to coal mining work. The safety production of the surface is guaranteed; the roof expansion method is simple in procedure, convenient in operation, low in cost and high in success rate.

The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection of the present invention. within the range.

Claims (3)

1. a method for efficiently draining gas by roof expansion cracking, is characterized in that, comprises the steps: Step 1: At the position of distance H=0～100m from the normal line of the coal seam, the drainage roadway for gas drainage is arranged along the direction of the coal seam, and the drainage hole drilling field is arranged on both sides of the drainage roadway. The construction of the oblique pumping and drilling holes; Step 2: The method for fracturing the roof of the coal seam, in the coal seam at the lower part of the drainage hole and within the range of 0-10m at the contact point between the coal seam and the roof, the roof of the coal seam is fractured, the pressure of the coal seam is relieved, and the coal seam gas pre-drainage is realized. 2. the method for efficiently draining gas by roof expansion cracking according to claim 1, is characterized in that, step 1 comprises the following steps: Step 1: Go to the location of the gas drainage lane, the width of the drainage lane is B=3.0～5.0m, and the height h=2.0～3.5m; The second step: After the construction of the gas drainage roadway along the strike of the coal seam is completed, the drainage hole drilling field is arranged along the two sides of the high extraction roadway. Width b=3.0～5.0m, length l=0～5.0m; Step 3: Arrange drainage drilling holes in the drainage hole drilling field on both sides of the drainage tunnel along the coal seam strike, the number of drilling holes is 1 to 10, and the vertical distance between the inner drilling hole and the inner side of the drainage hole drilling site is 0.5 ～5.0m, the vertical distance between the outer borehole and the side of the extraction lane is 0.5m; Step 4: Construct the oblique drainage hole in the drainage hole drilling site, the diameter of the oblique drainage hole is φ=60~150mm, and the angle between the oblique drainage hole and the coal seam inclination layer is θ=5°~90 °, the distance H = 0~100m from the position of the opening in the construction of the oblique extraction drilling to the normal line of the coal seam. 3. the method for efficiently draining gas by roof expansion cracking according to claim 1, is characterized in that, in step 2, adopts blasting fracturing method, carbon dioxide fracturing method, hydraulic fracturing method, high-energy pulse fracturing method to Its coal seam roof is cracked.

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