Double-injection and double-sealing type soundless cracking agent high-pressure rock breaking method

Abstract

The invention discloses a double-injection double-sealing type silent cracking agent high-pressure rock breaking method, and relates to the technical field of hard roof weakening and high-stress roadway surrounding rock pressure relief. Water injection and double-end hole sealing are conducted through a drilling hole packer; checking the sealing state of the debugging pipeline; high pressure of a soundless cracking agent is blended and injected; waiting for the soundless cracking agent to expand and break the rock; and releasing the pressure of the hole packer and carrying out the next circulation. The method can achieve the effect of presplitting the working face roof, guarantees smooth caving of the goaf roof, reduces the risk of goaf roof suspension, is suitable for a working face with hard crossheading roof rock strata and a goaf roof cantilever not prone to caving, and has wide application prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of weakening hard roof and unloading pressure of surrounding rock of high-stress tunnels, and specifically to a double-injection double-sealed silent breaker high-pressure rock breaking method, which is especially suitable for working faces with hard rock layers on the roof of the trench and cantilevered roof in the goaf, i.e., not easy to collapse. Background Art

[0002] With the high-intensity mining of coal resources in my country in recent decades, most shallow coal seams have been basically developed and recovered, and the focus of coal mine development is gradually shifting to the medium and deep coal seams in the central and western regions of my country. In particular, there are some hard roof working faces, which cause the problem of large-scale suspended roof after coal seam mining to be more prominent and difficult, increasing the difficulty of safe mining. Due to the lack of precedents and experience in safe mining of water-accumulated working faces on both sides, the commonly used methods for the problem of difficult roof collapse during the initial mining of the working face are mainly blasting forced roof caving method before and after mining, water injection weakening method, and hydraulic fracturing method. The blasting method is to form a three-dimensional crack system composed of several or more cracks in the target rock layer of the roof in advance, so that the strength of the roof is reduced along the crack direction, thereby weakening the overall strength of the hard roof and making it easy to collapse. The blasting method is simple to construct, but it is currently difficult to apply for approval of pyrotechnics, the project volume is large, the cost is high, and the risk factor is high; during the construction of the water injection weakening method, hard rocks such as sandstone and conglomerate are not easily soluble in water, and the effect and application scope of water injection weakening are very limited and difficult to control artificially. The directional long-hole drilling and conventional short-hole hydraulic fracturing technology are used to weaken the hard roof during the working face mining. In practical applications, hydraulic fracturing has many limitations, such as high requirements for rock permeability and serious water pollution. Therefore, finding a new, safe and efficient roof pre-cracking method has become a major problem that needs to be solved urgently. Summary of the invention

[0003] In view of the above-mentioned technical deficiencies, the purpose of the present invention is to provide a double-injection and double-sealed silent crushing agent high-pressure rock breaking method, which can weaken the roof, produce cracks in the rock layer of the chute roof, and cut off the roof cantilever under force during mining, so as to achieve the effect of pre-splitting the working face roof, ensure the smooth collapse of the goaf roof, reduce the risk of hanging roof in the goaf, and ensure safety during the advance pre-splitting period.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0005] The present invention provides a double-injection double-sealed silent breaker high-pressure rock breaking method, which is particularly suitable for working faces where the rock layer of the top plate of the trench is hard and the top plate of the goaf has a cantilever, that is, it is not easy to collapse. The method comprises the following steps:

[0006] 1) Arrangement of pre-splitting drilling holes: construct pre-splitting holes, determine the drilling azimuth, drilling slope and final hole depth, and the final hole faces the Laotang side;

[0007] 2) Double-end sealing of the borehole sealer by water injection; the sealer is arranged at the target fracturing layer, and water is injected to expand the sealer to seal the borehole;

[0008] 3) Check the sealing status of the debugging pipeline; check the grouting pump and pipelines required for grouting;

[0009] 4) Prepare the high pressure of the soundless crushing agent; mix the BC-high efficiency soundless crushing agent and water in a ratio of 3:1 and stir to obtain a fluid paste-like slurry;

[0010] 5) injecting a soundless cracking agent and waiting for it to expand and break the rock; injecting the paste-like slurry obtained in step 4) into the pre-splitting borehole and waiting for the soundless cracking agent to expand and break the rock;

[0011] 6) The sealer is depressurized and the next cycle is carried out. After the construction is completed, the sealer is drained and depressurized, and the discharged water flow stops flowing, that is, after the sealer is completely depressurized, the next layer is fracturing and the next cycle begins.

[0012] Preferably, in step 4), 25 kg of BC-high efficiency soundless crushing agent and 8.5 kg of water are poured into a stirring container and stirred evenly to obtain a fluid paste-like slurry.

[0013] Preferably, in step 5), water and the soundless breaker react after 30 minutes after being mixed, so the waiting time for the soundless breaker to react is greater than 30 minutes, and the grouting time requirement must be completed within 30 minutes.

[0014] Preferably, in step 5), when filling the silent crushing agent, it is required to fill in alternate holes, fill one borehole at a time, and do not operate simultaneously. After the borehole protection is filled, the next borehole can be constructed. If a punching hole occurs in a nearby borehole within 10m, the operation will be stopped immediately.

[0015] Preferably, within 5 hours after the soundless crushing agent is loaded into the pre-splitting borehole, protective facilities must be installed at the pre-splitting borehole, and people are not allowed to stay near the hole mouth or look up at the hole mouth to prevent the hole from breaking and injuring people.

[0016] The present invention provides a double-injection double-sealed silent breaker high-pressure rock breaking system, comprising a water tank 14 and a silent breaker mixing tank 15 respectively connected to a high-pressure water pump 16;

[0017] The outlets of the water tank 14 and the silent breaker mixing tank 15 are respectively connected to valve ② and valve ① of the four-way valve 11 through the high-pressure pipeline 13, and the valve ③ of the four-way valve 11 is connected to the long tube sealing device water injection pipe 2 of the sealing device 3 through the high-pressure pipeline, and the high-pressure pipeline is provided with a pressure gauge 9 and a flow meter 10;

[0018] The last valve of the four-way valve 11 is connected to one of the valves of the three-way valve 12. The other two valves of the three-way valve 12 are valve ④ and valve ⑤. Valve ④ is connected to the short tube hole sealer water injection pipe 4 of the hole sealer 3 through a high-pressure pipeline, and a pressure gauge 9 and a flow meter 10 are provided on the high-pressure pipeline. Valve ⑤ is connected to the drain pipe through a pipeline.

[0019] The present invention provides a method for using a double-injection double-sealing silent breaker high-pressure rock breaking system, the specific method is: during the sealing operation, the sealing device 3 is placed at a designated position of the rock formation through a high-pressure steel pipe, the main water source switch is turned on, valves ①, ③, and ⑤ are closed, valves ② and ④ are opened, and the pressure gauge 9 and the flow meter 10 are observed;

[0020] When the pressure increases to the specified pressure, first turn off the main water source switch, then close valve ④, so that the hole sealer 3 can seal the hole normally and complete the sealing operation;

[0021] During high-pressure rock breaking operation with the addition of silent crushing agent 15, it is necessary to open the main water source switch, open valves ① and ③, close valves ②, ④ and ⑤, and observe the pressure gauge 9. When the pressure increases and stabilizes, turn off the main water source switch, close valve ③, wait for the silent crushing agent 15 to act, and observe the effect;

[0022] After the above operation is completed, the water in the hole sealer 3 is released and the hole sealer 3 is withdrawn. During the withdrawal operation, valves ①, ② and ③ need to be closed, and valves ④ and ⑤ need to be opened. When no water flows out of the pipeline at valve ⑤, the hole sealer 3 is withdrawn and the next cycle is carried out.

[0023] The beneficial effects of the present invention are as follows: compared with the prior art, the present invention is particularly suitable for working faces with hard rock layers on the top of the drift and cantilevered top of the goaf, that is, those that are not prone to collapse. This method does not require the use of water and has ideal viscosity and sand-carrying performance; there is no water lock, no polymer residue, and no clay expansion. After the fracturing operation, only the proppant remains in the formation, causing minimal damage to the formation; it can greatly reduce the pumping pressure and produce longer cracks; after fracturing, no backflow is required and it can be put into production directly. It has huge advantages over the prior art in terms of construction and safety, and the crushing agent of the present invention does not belong to dangerous goods. The crushing agent can be mixed with water and poured into the hole through a hole sealer without the need for professional work. The present invention is non-toxic, odorless, silent, and vibration-free, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 A side view, a front view and a top view of the pre-splitting drilling arrangement of a mining face provided by an embodiment of the present invention;

[0026] Figure 2 Cross-sectional view of drilling and sealing holes for rail transport chute and belt transport chute;

[0027] Figure 3 A diagram of a double-injection and double-sealed silent breaker high-pressure rock breaking system provided in an embodiment of the present invention.

[0028] Description of reference numerals:

[0029] 1-silent crushing agent filling area; 2-long tube hole sealer injection pipe; 3-hole sealer; 4-short tube hole sealer water injection pipe; 5-transportation chute; 6-mining working face; 7-direct top; 8-basic top; 9-pressure gauge; 10-flow meter; 11-four-way valve; 12-three-way valve; 13-high-pressure pipeline; 14-water tank; 15-silent crushing agent mixing box; 16-high-pressure pump. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] This embodiment provides a double-injection double-sealed silent breaker high-pressure rock breaking method, comprising the following steps:

[0032] 1) Arrangement of pre-splitting drilling holes: construct a row of pre-splitting holes at a certain distance from the coal wall on the side of the protective coal pillar in the drift, name the drilling hole number S, determine the drilling azimuth and drilling slope according to the actual situation on site, determine the final hole depth according to the rock layer depth and the width of the roadway, and the final hole faces the Laotang side;

[0033] 2) Double-end sealing of the borehole sealer with water injection; before using the high-efficiency silent cracking agent, the borehole should be sealed in advance, and the sealer should be used. It can be placed in the target fracturing layer and then water can be injected to expand the sealer, thereby achieving the purpose of plugging the borehole;

[0034] 3) Check the sealing status of the debugging pipeline; turn on the grouting pump and inject clean water to check the sealing status of the debugging pipeline, and check to make sure that the grouting pump and grouting pipeline are sealed intact without leakage;

[0035] 4) Prepare the silent crushing agent; Divide into two groups, one group is responsible for preparing the proportion of BC-high-efficiency silent crushing agent, pour a whole bag of BC-high-efficiency silent crushing agent (25kg) into the mixing container, and quickly stir about 8.5kg of water (use a container on the ground to weigh 8.5kg of water, measure the water level of the container, and use the same container to measure the water of the same height underground.) and BC-high-efficiency silent crushing agent in a ratio of 1:3, and stir evenly into a fluid paste-like slurry; the other group is responsible for the perfect docking and debugging of the grouting pump; because BC-high-efficiency silent crushing agent is corrosive, construction workers must wear protective glasses and rubber gloves when operating;

[0036] 5) Inject the silent cracking agent and wait for it to expand and break the rock; inject the paste-like slurry obtained in step 4) into the pre-splitting borehole and wait for the silent cracking agent to expand and break the rock; the filling must be completed within 30 minutes, otherwise its fluidity and expansion effect will be significantly reduced. (Note: If the slurry is stored in the mixing container for too long after adding water for more than 30 minutes, it will spray).

[0037] 6) The sealer is depressurized and the next cycle is carried out. After the construction is completed, the sealer is drained and depressurized, and the discharged water flow stops flowing, that is, after the sealer is completely depressurized, the next layer is fracturing and the next cycle begins.

[0038] Preferably, 25 kg of BC-high efficiency soundless crushing agent and 8.5 kg of water are poured into a stirring container and stirred evenly to obtain a fluid paste-like slurry.

[0039] Reference Figure 1-Figure 2 , using the above method, combined with the mining face 6 of Henan Energy 110503 as an example, in order to ensure that the suspended roof of the goaf area of ​​the 110503 mining face does not exceed the regulations, it is necessary to construct pre-splitting drilling holes in the 110503 transport chute 5 (belt transport chute, rail transport chute), fill BC-high-efficiency silent crushing agent, weaken the roof, and create cracks in the rock layer of the roof of the transport chute. When the mining is advanced, the cantilever of the roof is cut off by force to achieve the effect of pre-splitting the roof of the working face and ensure that the roof of the goaf collapses smoothly.

[0040] In the pre-splitting drilling arrangement, the top plate pre-splitting holes are constructed using a ZYWL-1200 crawler drilling rig, the drill rod model is Φ42×800mm, and the drill bit is Φ50mm.

[0041] Pre-splitting holes in rail transport drift: A row of pre-splitting holes is constructed at the direct roof 7 position 1m (±0.2m) away from the coal wall on the side of the protective coal pillar in the rail transport drift. The first borehole (numbered S) has a borehole azimuth of 272°, a borehole slope of 80°, and a final hole depth of 19m. It must reach the basic roof 8, and the final hole faces the Laotang side. From the inside to the outside, a borehole is constructed every 500m, and the azimuth, slope, and final hole depth of each borehole are the same as those of the borehole (numbered S).

[0042] Pre-splitting holes in belt conveyor drift: A row of pre-splitting holes is constructed at the direct roof 7 position 1.5m (±0.2m) away from the coal wall on the side of the protective coal pillar in the belt conveyor drift. If the local protective coal pillar is irregular, the drilling holes are kept in a straight line. The first drilling hole (numbered X) has a drilling azimuth of 272°, a drilling slope of 80°, and a final hole depth of 19m. It must reach the basic roof 8, and the final hole faces the old pond side. From the inside to the outside, a drilling hole is constructed every 300mm-500mm, and the azimuth, slope, and final hole depth of each drilling hole are the same as the drilling hole (numbered X).

[0043] Carry out drilling plugging operation, use the plug to reach the target layer, inject water to expand the plug and plug the pre-cracked borehole. Before that, materials such as the soundless crushing agent need to be transported to the work site for mixing, pour a whole bag of BC-high-efficiency soundless crushing agent (25kg) into the mixing container, and quickly mix about 8.5kg of water (8.5kg of water is weighed in a container on the ground, and the water level of the container is measured. The same container is used to measure the water at the same height underground.) and BC-high-efficiency soundless crushing agent in a ratio of 1:3. After mixing evenly into a fluid paste-like slurry, there must be a person in charge on site to direct the operation, and the entire process from mixing the slurry to grouting must be supervised.

[0044] After the pre-splitting drill hole is injected with silent crushing agent, 12# iron wire is used to fix the four corners of the old belt on the top plate steel bar mesh at the pre-splitting drill hole of the top plate for auxiliary protection to prevent the hole from hurting people. The protection time shall not be less than 5 hours, and warning signs shall be hung on site to prohibit personnel from staying in this section. When filling the silent crushing agent, it is required to fill the holes one by one, and do not operate at the same time. After the drill hole protection is filled, the next drill hole can be constructed. If a punching hole occurs in the nearby drill hole within 10m, the operation shall be stopped immediately.

[0045] like Figure 3As shown, the present embodiment also provides a double-injection double-sealed silent breaker high-pressure rock breaking system, comprising a high-pressure water pump 16, a water tank 14, a silent breaker mixing box 15 and a hole sealer 3; the high-pressure water pump 16 is connected to the water tank 14 and the inlet of the silent breaker mixing box 15 through a high-pressure pipeline and a main three-way valve, respectively, and the outlets of the water tank 14 and the silent breaker mixing box 15 are connected to two valves (valve ② and valve ①) of the four-way valve 11 through a high-pressure pipeline 13, and the third valve of the four-way valve, namely valve ③, is connected to the long tube hole sealer water injection pipe 2 through a high-pressure pipeline, and a pressure gauge 9 and a flow meter 10 are provided on the high-pressure pipeline; the last valve of the four-way valve is connected to one of the valves of the three-way valve 12, and the other two valves of the three-way valve 12 are valve ④ and valve ⑤, and valve ④ is connected to the short tube hole sealer water injection pipe 4 through a high-pressure pipeline, and a pressure gauge 9 and a flow meter 10 are provided on the high-pressure pipeline, and valve ⑤ is connected to the drain pipe through a pipeline.

[0046] During the hole sealing operation, it is necessary to place the hole sealer 3 at the designated position of the rock formation through a high-pressure steel pipe, turn on the main water source switch, close valves ①, ③, and ⑤, open valves ② and ④, observe the pressure gauge 9 and the flow meter 10, and when the pressure increases to the specified pressure, first close the main water source switch, and then close valve ④, so that the hole sealer 3 can seal the hole normally and complete the hole sealing operation; during the high-pressure rock breaking operation with the silent crushing agent 15, it is necessary to open the main water pipe switch, open valves ① and ③, close valves ②, ④, and ⑤, and observe the pressure gauge 9. When the pressure increases steadily, close the main water pipe switch, close valve ③, wait for the silent crushing agent 15 to act for a certain time, and observe the effect in the silent crushing agent filling area 1; after the above operation is completed, it is necessary to release the water in the hole sealer 3 and withdraw the hole sealer 3. During the withdrawal operation, it is necessary to close valves ①, ②, and ③, and open valves ④ and ⑤. When it is observed that no water flows out of the pipeline at valve ⑤, the hole sealer 3 can be withdrawn for the next cycle.

[0047] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A double-injection double-sealed silent cracking agent high-pressure rock breaking method, characterized in that: The following steps are involved: 1) Pre-splitting drilling arrangement; Construct pre-splitting holes, determine the drilling azimuth, drilling slope and final hole depth, and the final hole should face the old pond side; 2) Double-end sealing of the borehole sealer by water injection; the sealer is arranged at the target fracturing layer, and water is injected to expand the sealer to seal the borehole; 3) Check the sealing status of the debugging pipeline; check the grouting pump and pipelines required for grouting; 4) Prepare the high pressure of the soundless crushing agent; mix the BC-high efficiency soundless crushing agent and water in a ratio of 3:1 and stir to obtain a fluid paste-like slurry; 5) injecting a soundless cracking agent and waiting for it to expand and break the rock; injecting the paste-like slurry obtained in step 4) into the pre-splitting borehole and waiting for the soundless cracking agent to expand and break the rock; 6) The sealer is depressurized and the next cycle is carried out. After the construction is completed, the sealer is drained and depressurized, and the discharged water flow stops flowing, that is, after the sealer is completely depressurized, the next layer is fracturing and the next cycle begins.

2. The method according to claim 1, characterized in that In step 4), 25 kg of BC-high efficiency soundless crushing agent and 8.5 kg of water are poured into a stirring container and stirred evenly to obtain a fluid paste-like slurry.

3. The method according to claim 2, characterized in that In step 5), water and the silent breaker react after 30 minutes after being mixed, so the waiting time for the silent breaker to react is more than 30 minutes, and the grouting time requirement must be filled within 30 minutes.

4. The method according to claim 3, characterized in that In step 5), when filling the silent crushing agent, it is required to fill in alternate holes, fill one borehole at a time, and do not operate at the same time. After the borehole protection is filled, the next borehole can be constructed. If a punching hole occurs in the nearby borehole within 10m, the operation will be stopped immediately.

5. A double-injection double-sealed silent cracking agent high-pressure rock breaking method as claimed in claim 4, characterized in that: Within 5 hours after the silent crushing agent is loaded into the pre-splitting drill hole, protective facilities must be set up at the pre-splitting drill hole. People are not allowed to stay near the hole mouth or look up at the hole mouth to prevent the hole from bursting and injuring people.

6. A double-injection double-sealed silent cracking agent high-pressure rock breaking system, characterized in that: It includes a water tank 14 and a soundless crushing agent mixing tank 15 respectively connected to a high-pressure water pump 16; The outlets of the water tank 14 and the silent breaker mixing tank 15 are respectively connected to valve ② and valve ① of the four-way valve 11 through the high-pressure pipeline 13, and the valve ③ of the four-way valve 11 is connected to the long tube sealing device water injection pipe 2 of the sealing device 3 through the high-pressure pipeline, and the high-pressure pipeline is provided with a pressure gauge 9 and a flow meter 10; The last valve of the four-way valve 11 is connected to one of the valves of the three-way valve 12. The other two valves of the three-way valve 12 are valve ④ and valve ⑤. Valve ④ is connected to the short tube hole sealer water injection pipe 4 of the hole sealer 3 through a high-pressure pipeline, and a pressure gauge 9 and a flow meter 10 are provided on the high-pressure pipeline. Valve ⑤ is connected to the drain pipe through a pipeline.

7. A method for using the double-injection double-sealed silent cracking agent high-pressure rock breaking system as described in claim 6, characterized in that: The specific method is as follows: during the sealing operation, the sealing device 3 is placed at the designated position of the rock formation through a high-pressure steel pipe, the main water source switch is turned on, valves ①, ③, and ⑤ are closed, valves ② and ④ are opened, and the pressure gauge 9 and the flow meter 10 are observed; When the pressure increases to the specified pressure, first turn off the main water source switch, then close valve ④, so that the hole sealer 3 can seal the hole normally and complete the sealing operation; During high-pressure rock breaking operation with the addition of silent crushing agent 15, it is necessary to open the main water source switch, open valves ① and ③, close valves ②, ④ and ⑤, and observe the pressure gauge 9. When the pressure increases and stabilizes, turn off the main water source switch, close valve ③, wait for the silent crushing agent 15 to act, and observe the effect; After the above operation is completed, the water in the hole sealer 3 is released and the hole sealer 3 is withdrawn. During the withdrawal operation, valves ①, ② and ③ need to be closed, and valves ④ and ⑤ need to be opened. When no water flows out of the pipeline at valve ⑤, the hole sealer 3 is withdrawn and the next cycle is carried out.

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