CN110725700B - Coal seam spraying reinforcement and graded glue injection cooperative hole sealing method - Google Patents

Abstract

The invention discloses a coal seam spraying reinforcement and graded glue injection synergistic sealing method, which relates to the technical field of coal seam synergistic sealing methods. The sealing method firstly sprays and reinforces the wall of the roadway, then constructs a gas drainage hole along the layer and injects glue to seal the hole, and finally injects colloid under pressure into the glue injection hole on both sides of the gas drainage hole through the glue injection pipe. Seal the fracture zone; with the progress of the extraction, when the gas concentration gradually decreases to a certain value, inject colloid into the injection hole again through the injection pipe to plug the secondary fractures. The invention discloses a coal seam spraying reinforcement and grading glue injection synergistic sealing method, which realizes the drilling hole plugging through the combination of roadway wall spraying reinforcement and drilling glue injection, and has the advantages of simple operation, low cost, high safety and good effect. At the same time, the two-stage glue injection method is used to better seal the secondary cracks caused by the shrinkage of the coal matrix due to the desorption flow of the coal seam gas, which further improves the effect and concentration of the gas drainage in the coal seam drilling holes.

Description

Coal seam spray reinforcement and graded glue injection synergistic sealing method

technical field

The invention relates to the technical field of a coal seam cooperative sealing method, in particular to a coal seam spraying reinforcement and graded glue injection cooperative sealing method.

Background technique

With the gradual exhaustion of shallow coal resources, the mining of deep coal resources will become the norm in the future. However, after entering the deep, the coal seam has high gas content and high pressure, which seriously threatens the safe production of the mine. CBM is a clean and efficient energy source and a strong greenhouse gas. According to statistics, the amount of CBM resources buried deeper than 2000m in China is about 36.81 trillion m ³ , ranking third in the world. Among them, the coalbed methane resources buried between 1000 and 2000m account for 61.2% of the total coalbed methane resources in the country, and have extremely high mining value. Therefore, realizing the efficient development of CBM is of great significance for ensuring mining safety, realizing resource utilization and environmental protection.

After the coal seam roadway is excavated, the stress balance state of the coal body is broken, which further leads to the fragmentation of the coal body around the roadway under the action of stress, forming a fissure zone. Moreover, after the gas drainage drilling and grouting drilling are completed, due to the disturbance of the drilling process and the pressure relief effect, more cracks are formed around the drilling hole on the basis of the original crack zone, which affects the gas drainage effect. Based on this problem, it is proposed to improve the effect and concentration of gas drainage in coal seam boreholes by grouting and sealing. However, the traditional grouting and sealing methods are mostly one-time grouting, and the sealing effect is poor, and the effect of improving gas drainage is not obvious.

Therefore, in order to improve the effect and concentration of gas drainage in coal seam drilling, it is urgent to find a new method of drilling and sealing for gas drainage, so as to meet the requirements of drilling and sealing of underground coal mines.

SUMMARY OF THE INVENTION

According to the purpose of the present invention, a coal seam spraying reinforcement and graded glue injection synergistic sealing method, comprising the following steps:

S1. After the coal seam roadway is excavated, a fissure zone is formed on the wall of the roadway and its surroundings. The slurry is sprayed on the wall of the roadway to reinforce the wall of the roadway, and an isolation barrier is formed to initially block the mining fissures of the roadway wall.

S2. According to the operation requirements, use the drilling device to construct the gas drainage hole and the glue injection hole in the direction of the roadway wall to the coal seam.

S3. Put a gas drainage pipe in the gas drainage hole and seal the hole with a hole sealing device.

S4. Put a third plug in the hole of the glue injection hole, put the glue injection pipe into the glue injection hole through the third plug, and inject colloid into the hole under pressure through the glue injection pipe to seal the mining fracture.

S5. Connect the gas extraction pipe to the extraction system for gas extraction.

S6. After a certain period of time, the coal matrix shrinks due to the desorption flow of coal seam gas, and the cracks increase, and the colloid is injected into the coal seam again through the rubber injection pipe to seal the secondary cracks.

S7. Continue gas extraction until the extraction work is completed.

Preferably, the depth of the gas drainage hole in S2 is 100-150m, the diameter is 113mm, and the distance between two adjacent gas drainage holes is 2-4m; the depth of the glue injection hole is 10-15m, and the diameter is 2-4m. 75mm; gas drainage holes and glue injection holes are alternately arranged, and the distance between two adjacent gas drainage holes and glue injection holes is 1-2m.

Preferably, the hole sealing device in S3 includes a hole sealing capsule, a water injection pipe, and a first plug and a second plug arranged at the front and rear; first, the first plug is fixedly installed on the drainage pipe and inserted into the gas drainage drill In the hole, then place the sealing capsule and the water injection pipe, and finally put the second plug through the water injection pipe and the extraction pipe into the gas drainage hole; the water injection pipe is connected to the water pump for water injection, the sealing capsule and the first plug The head and the second plug swell in contact with water to block the orifice to form a plugging section.

Preferably, the length of the sealing section in the gas drainage borehole in S3 is equal to the length of the glue injection borehole.

Preferably, the glue injection pressure in S3 is 1-3MPa.

Compared with the prior art, the advantages of the coal seam spraying reinforcement and grading glue injection synergistic sealing method disclosed in the present invention are:

(1) The combination of roadway wall spraying reinforcement and drilling glue injection to achieve drilling plugging can effectively seal the roadway wall and the cracks around the drilled hole, and at the same time, spraying reinforcement can effectively prevent wall air leakage and drilling deformation, and the operation is simple. , Low cost, high safety and good effect.

(2) The two-stage glue injection method can better seal the secondary cracks caused by the shrinkage of the coal matrix due to the desorption flow of the coal seam gas, which can significantly improve the gas drainage effect and the drainage concentration of the coal seam drilling holes, and save energy. The coal seam gas drainage is further improved, and the coal seam mining efficiency is further improved.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present invention or the prior art more clearly, the following briefly introduces the accompanying drawings used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only For some embodiments of the present invention, for those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative efforts.

FIG. 1 is a structural diagram of the implementation of the present invention.

The names of the parts represented by the numbers or letters in the figure are:

1-Drainage pipe; 2-Gas injection pipe; 3-Gas drainage hole; 4-Glue injection hole; 5-Second plug; 6-Third plug; 7-First plug; 8-Isolation Barrier; 9-colloid; 10-sealing capsule; 11-water injection pipe.

Detailed ways

The specific embodiments of the present invention will be briefly described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, those of ordinary skill in the art can obtain all other implementations without creative work. For example, all belong to the protection scope of the present invention.

FIG. 1 shows a preferred embodiment of the present invention, which is dissected in detail.

As shown in Figure 1, a coal seam spraying reinforcement and graded glue injection synergistic sealing method includes the following steps:

Step 1: After the coal seam roadway is excavated, a fissure zone is formed on and around the roadway wall, spraying slurry on the roadway wall to reinforce the roadway wall, and forming an isolation barrier 8 to initially block the roadway wall mining fissures and isolate the air.

Step 2: According to the operation requirements, use the drilling device to construct the gas drainage hole 3 and the glue injection hole 4 in the direction of the roadway wall toward the coal seam. Among them, the gas drainage hole 3 has a depth of 100-150m and a diameter of 113mm, and the distance between two adjacent gas drainage holes 3 is 2-4m; the glue injection hole 4 has a depth of 10-15m and a diameter of 75mm; Gas drainage holes 3 and glue injection holes 4 are alternately arranged, and the distance between two adjacent gas drainage holes 3 and glue injection holes 4 is 1-2m.

Step 3: Put the gas drainage pipe 1 in the gas drainage hole 3 and seal the hole with a hole sealing device. Specifically, the hole sealing device includes a hole sealing capsule 10, a water injection pipe 11, and a first plug 7 and a second plug 5 arranged in the front and rear; first, the first plug 7 is fixedly installed on the extraction pipe 1 and extended into the gas extraction pipe. In the mining hole 3, then place the sealing capsule 10 and the water injection pipe 11, and finally put the second plug 5 through the water injection pipe 11 and the extraction pipe 1 into the orifice of the gas extraction hole 3; the water injection pipe 11 is connected to the water pump After water injection, the sealing capsule 10 , the first plug 7 and the second plug 5 swell in contact with water to block the orifice to form a sealing section. The length of the sealing section in the gas drainage hole 3 is equal to the length of the glue injection hole 4 .

Step 4. Put the third plug 6 in the hole of the glue injection hole 4, put the glue injection pipe 2 into the glue injection hole 4 through the third plug 6, and pass the glue injection pipe 2 to the glue injection hole 4. The colloid 9 is injected by pressure to seal the mining fractures. Among them, the glue injection pressure is 1-3MPa. The glue injection time is comprehensively determined according to the actual glue injection hole 4 depth, glue injection rate and crack band width.

Step 5. Connect the gas extraction pipe 1 into the extraction system to perform gas extraction.

Step 6. After five hours of extraction, the coal matrix shrinks due to the desorption and flow of coal seam gas while the concentration of the extracted gas decreases, and the cracks increase, and the colloid 9 is injected into the coal seam again through the glue injection pipe 2 to seal the secondary cracks. Wherein, the extraction time can be determined according to the concentration of the extracted gas.

Step 7. Continue gas extraction until the extraction work is completed.

To sum up, the present invention discloses a method for coordinating hole sealing by spraying reinforcement of coal seams and grading glue injection, which realizes hole sealing through the combination of roadway wall spray reinforcement and drilling glue injection, which is simple in operation, low in cost and safe. High sex and good effect. At the same time, the two-stage glue injection method is adopted to better seal the secondary cracks caused by the shrinkage of the coal matrix due to the desorption flow of the coal seam gas, which further improves the effect and concentration of the gas drainage in the coal seam borehole.

The foregoing description of the disclosed embodiments enables those skilled in the art to make and use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be implemented in other embodiments without departing from the spirit and scope of the present invention. Thus, the present invention is not intended to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (4)

1. A coal seam spraying reinforcement and grading glue injection cooperative hole sealing method is characterized by comprising the following steps:

s1, forming a fracture zone on the wall surface and the periphery of a roadway after the coal seam roadway is excavated, spraying slurry on the wall of the roadway, reinforcing the wall of the roadway, and forming an isolation barrier (8) to primarily block the roadway wall mining-induced fracture;

s2, constructing a gas extraction borehole (3) and an injection borehole (4) in the direction from the wall of the roadway to the coal seam by using a drilling device according to the operation requirement;

s3, placing an extraction pipe (1) in the gas extraction drill hole (3) and plugging an orifice by using a hole sealing device; the hole sealing device comprises a hole sealing capsule (10), a water injection pipe (11), a first plug (7) and a second plug (5) which are arranged in front and back; firstly, a first plug (7) is fixedly arranged on an extraction pipe (1) and extends into a gas extraction drill hole (3), then a hole sealing capsule (10) and a water injection pipe (11) are placed, and finally a second plug (5) penetrates through the water injection pipe (11) and the extraction pipe (1) and is placed into an orifice of the gas extraction drill hole (3); the water injection pipe (11) is connected with a water pump for injecting water, the hole sealing capsule (10), the first plug (7) and the second plug (5) expand when meeting water, and the hole opening is sealed to form a hole sealing section;

s4, placing a third plug (6) into an orifice of the glue injection drill hole (4), placing the glue injection pipe (2) into the glue injection drill hole (4) through the third plug (6), and injecting a colloid (9) into the glue injection drill hole (4) through the glue injection pipe (2) in a pressing mode to plug the mining crack;

s5, connecting the gas extraction pipe (1) into an extraction system for gas extraction;

s6, after a certain period of time for extraction, because the coal matrix shrinks and cracks increase due to desorption flow of coal seam gas, injecting colloid (9) into the coal seam again through the glue injection pipe (2) to block secondary cracks;

and S7, continuing gas extraction until the extraction work is finished.

2. The method for the cooperative hole sealing of the coal seam by spraying, reinforcing and grading glue injection according to claim 1, characterized in that the depth of the gas extraction drill hole (3) in S2 is 100-150m, the diameter is 113mm, and the distance between two adjacent gas extraction drill holes (3) is 2-4 m; the depth of the glue injection drill hole (4) is 10-15m, and the diameter is 75 mm; the gas extraction drill holes (3) and the glue injection drill holes (4) are alternately arranged, and the distance between every two adjacent gas extraction drill holes (3) and every two adjacent glue injection drill holes (4) is 1-2 m.

3. The method for spraying, reinforcing and grading glue injection cooperative hole sealing of the coal seam according to claim 1, characterized in that the length of the hole sealing section in the gas extraction drill hole (3) in S3 is equal to the length of the glue injection drill hole (4).

4. The method for cooperatively sealing the hole of the coal seam by spraying, reinforcing and grading glue injection according to claim 1, wherein the glue injection pressure in S3 is 1-3 MPa.

Images