Hydrofracture top-cutting entry retaining method based on crushing agent

Abstract

The invention belongs to the technical field of safe mining of coal mines, and relates to a hydraulic fracturing roof-cutting entry retaining method based on a crushing agent, which comprises the following steps of: calculating to obtain a target fracturing horizon height h of roof-cutting entry retaining according to a working face height M and a residual crushing coefficient KZ of a roof; calculating the crack initiation pressure P of a target fractured position of the roof-cut entry retaining according to the rock stress P * and the tensile strength R of the rock at the fractured position of the roof-cut entry retaining; drilling is conducted according to the drilling position, the drilling length L and the drilling angle alpha; the prepared BC-efficient soundless cracking agent flowable pasty slurry is injected into a drill hole through a hydraulic fracturing system and is fractured at a target fractured layer, and after the BC-efficient soundless cracking agent flowable pasty slurry is subjected to standing reaction, the drill hole is fractured for multiple times in a single-hole retreating mode. The problems that a large amount of water resources are consumed, the rock permeability is possibly increased due to high-pressure water injection, and mine water disaster hidden dangers are caused are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of safe mining of coal mines, and in particular relates to a hydraulic fracturing, top cutting and lane retaining method based on a crusher. Background Art

[0002] In the process of coal mining, roof cutting and roadway retention technology is of great significance for improving coal resource recovery rate, reducing roadway excavation costs and ensuring safe production.

[0003] Traditional hydraulic fracturing technology for roof cutting and lane retention primarily relies on high-pressure water as the fracturing medium. By injecting high-pressure water into a borehole, cracks are formed in the coal seam roof rock, achieving the goals of roof cutting and lane retention. However, this technology has several limitations. On the one hand, the high consumption of water resources is a limiting factor in some water-scarce mining areas. On the other hand, high-pressure water injection can increase rock permeability, posing a potential risk of mine water hazards. Furthermore, the high operating and maintenance costs of high-pressure water equipment also affect mining efficiency and economic benefits. Therefore, finding a roof cutting and lane retention method that reduces water consumption and the increase in rock permeability caused by high-pressure water injection while maintaining low operating and maintenance costs has become a major challenge that needs to be addressed. Summary of the Invention

[0004] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a hydraulic fracturing and top cutting and lane retaining method based on crushing agents, which solves the problem of large-scale consumption of water resources and the problem that high-pressure water injection may cause increased rock permeability and trigger hidden dangers of mine water hazards under the premise of low operation and low maintenance costs.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions: The present invention provides a hydraulic fracturing top cutting and lane retaining method based on a breaker, comprising the following steps: According to the height of the working surface M and the residual expansion coefficient of the roof K Z Calculate the target fracturing layer height for cutting top and retaining lanes h ;Through rock stress P* and the tensile strength of the rock in the fracturing layer with top cutting and retaining R Calculate the target fracturing layer initiation pressure for cutting top and retaining lanes P , according to the target fracturing layer height h and the target fracture layer initiation pressure P Design the tunnel drilling plan; According to the tunnel drilling plan, the drilling position, drilling length L and drilling angle α are designed, and the drilling direction is always towards the goaf; Prepare BC-high-efficiency soundless crusher fluid paste slurry; The configured BC-high-efficiency soundless breaker fluid paste-like slurry is injected into the borehole through the hydraulic fracturing system, that is, grouting and fracturing are carried out at the target fracturing layer. After the BC-high-efficiency soundless breaker fluid paste-like slurry expands and breaks the rock and cuts the top, the borehole is fractured multiple times using a single-hole retreat method.

[0006] Preferably, the target fracturing layer height h The formula is: The working surface height M is obtained through on-site measurement, and the residual expansion coefficient K z The value is 1.1~1.5.

[0007] Preferably, the target fracture layer fracture pressure P The calculation formula is: P =1.3( P *+ R ),in P *Affected by depth, mining history of the coal seam and adjacent coal seams, and mining geological conditions. P * is the rock's deadweight stress, R is the tensile strength of the target layer rock mass.

[0008] Preferably, the vertical height of the borehole exceeds the immediate top of the lane retaining roadway and penetrates into the basic top to the overlying rock formation, and the target fracturing layer of the top cutting and lane retaining is located within the basic top.

[0009] Preferably, the drilling angle α and drilling length L Calculated according to the specific conditions of the working face; among them, the width of the laneway left in the working face b and drilling angle α Determination of the construction position of the drilling hole in the tunnel and the height of the target fracturing layer h and the horizontal distance to the lane boundary a Related, and the horizontal distance of the lane boundary a Should not be larger than the lane width b Two-thirds of the drilling length L The construction position along the drilling angle α The length of the line segment extending to the fracture layer.

[0010] Preferably, the drilling hole is located in the lane-retaining roadway and close to one side of the goaf, and the drilling direction is toward the goaf.

[0011] Preferably, the BC-high-efficiency soundless breaker fluid paste slurry is obtained by mixing and stirring the BC-high-efficiency soundless breaker and water in a mass ratio of 2.85:1 to 3.15:1. In actual applications, the mass ratio of the BC-high-efficiency soundless breaker to water may be adjusted according to the ambient temperature and the specific type of breaker.

[0012] Preferably, during the fracturing operation, the BC-high-efficiency silent breaker fluid paste slurry takes more than 30 minutes to fully react with water. In order to ensure the fracturing effect, the grouting operation needs to be completed within 30 minutes.

[0013] Preferably, the hydraulic fracturing system includes a mixing box, a high-pressure pump and a drilling rig, the BC-high-efficiency soundless breaker fluid paste-type slurry is arranged in the mixing box, the mixing box is connected to the high-pressure pump through a pipeline, the high-pressure pump is connected to the drilling rig through a pipeline, and the drilling rig transports the sealer to the designated target fracturing layer of the borehole.

[0014] Preferably, the sealer needs to be tested for air tightness before being transported to the designated target fracturing layer, and the sealer is used to fill the BC-high-efficiency soundless breaker fluid paste-like slurry to the target layer.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The hydraulic fracturing top cutting and lane retaining method based on breaker provided by the present invention solves the problem of reducing water resource consumption and increasing rock permeability caused by high-pressure water injection under the premise of low operation and low maintenance costs.

[0016] The hydraulic fracturing top cutting and lane retaining method based on breaker provided by the present invention first utilizes the target fracturing layer height. h and the target fracture layer initiation pressure P Design the tunnel drilling plan, the target fracturing layer height h and the target fracture layer initiation pressure P It is the prerequisite for the realization of cutting the top and leaving the lanes. Then, according to the lane-leaving drilling scheme, the position of the borehole, the length L of the borehole and the drilling angle α are designed, and the drilling direction is required to always face the goaf. This makes the lane-leaving drilling of the present invention different from the traditional hydraulic fracturing cutting the top and leaving the lanes drilling. Then, the BC-high-efficiency soundless breaker fluidity paste-type slurry is injected into the designed borehole through the hydraulic fracturing system, and the BC-high-efficiency soundless breaker fluidity paste-type slurry is fractured in the target fracturing layer, and the expansion effect of the breaker is used to assist in the formation of cracks. The micro-crack network formed by the BC-high-efficiency soundless breaker when it is sent into the target fracturing layer through the borehole is relatively stable, and will not be as easy to expand and connect as the cracks formed by direct injection of high-pressure water, thereby reducing the excessive increase in rock permeability. Although the breaker absorbs a certain amount of water during the reaction process, its water consumption is greatly reduced compared to the large amount of high-pressure water required for traditional hydraulic fracturing, thereby reducing water resource consumption.

[0017] The present invention is particularly suitable for water-scarce mining areas or working faces that need to leave lanes along the goaf. This method can improve the top cutting effect: the expansion pressure of the BC-high-efficiency soundless crushing agent can act on the rock formation more effectively, and compared with traditional hydraulic fracturing, it is not affected by the water absorption and permeability of the rock formation; it does not require a large amount of water supply equipment and pipeline systems, and at the same time avoids the drainage costs and flood safety hazards caused by water accumulation in the tunnel after traditional hydraulic fracturing; the present invention utilizes special BC-high-efficiency soundless crushing agents to greatly reduce the pumping pressure and can produce longer cracks. Compared with the existing technology, the construction process is simplified, and no professional workers are required. The operation can be carried out by simply mixing the crushing agent with water and pouring it into the hole through the sealer; in terms of safety, the crushing agent is not a dangerous item, and the whole process is non-toxic, odorless, silent, and vibration-free. The advantages are significant, and this method has broad application prospects.

[0018] In addition, the method provided by the present invention can also control the extension direction and length of the cracks by optimizing the fracturing parameters and construction technology, and avoid the cracks from connecting with the goaf of the mine or other potential water hazard channels, thereby effectively preventing the occurrence of mine water hazards.

[0019] The method of the present invention can also be combined with a downhole industrial water recycling system to recycle and reprocess the water used in the fracturing process, allowing it to be reused for fracturing or other downhole operations. This not only reduces dependence on fresh water resources but also improves water resource utilization efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of arrangement of boreholes in the coal seam roof in the present invention; Figure 2 This is a schematic diagram of the connection between the crushing agent filling and sealing device in the present invention.

[0021] Description of Reference Numerals 1. Direct roof; 2. Basic roof; 3. Overburden; 4. Drill hole; 5. Goaf; 6. Laneway; 7. Target fracturing layer; 8. Sealer; 9. Crusher mixing box; 10. High-pressure pump; 11. Drilling rig. DETAILED DESCRIPTION

[0022] The specific embodiments of the present invention are described in detail below, but it should be understood that the scope of protection of the present invention is not limited by the specific embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. The experimental methods described in the embodiments of the present invention are all conventional methods unless otherwise specified.

[0023] The inventors discovered that a large amount of water is required to form cracks during hydraulic fracturing. When high-pressure water is injected into the rock layer, cracks are formed, significantly increasing the permeability of the rock. This may cause the migration path of groundwater to change, increasing the risk of groundwater pollution. Most of the water used in the hydraulic fracturing process is injected into the ground and is difficult to recycle. Even if some water can be recovered, it is difficult to handle because it contains a large amount of chemical additives. In mine mining, high-pressure water injection may cause the permeability of the roof rock to increase, making it easier for groundwater to penetrate into the mine and increasing the risk of mine water disasters.

[0024] In light of this, the present invention proposes a hydraulic fracturing method for cutting and retaining tunnels using a breaker. This method reduces operating and maintenance costs while addressing the issues of high water consumption and the potential for high-pressure water injection to increase rock permeability and potentially cause mine water hazards. The principle is that a chemical reaction with water causes volume expansion, which in turn exerts pressure on the surrounding rock, causing it to fracture.

[0025] like Figure 1 As shown, the present invention provides a hydraulic fracturing top cutting and lane retaining method based on a breaker, comprising the following steps: According to the height of the working surface M and the residual expansion coefficient of the roof K Z Calculate the target fracturing layer height for cutting top and retaining lanes h ;Through rock stress P* and the tensile strength of the rock in the fracturing layer with top cutting and retaining R Calculate the target fracturing layer initiation pressure for cutting top and retaining lanes P By optimizing the fracturing parameters and construction technology, the extension direction and length of the cracks can be controlled to avoid the cracks from connecting with the goaf of the mine or other potential water hazard channels, thereby effectively preventing the occurrence of mine water hazards. First, by calculating the target fracturing layer height h, the appropriate fracturing layer height h can improve the stability of the cracks. If the fracturing layer is not selected properly, it may cause the cracks to be unstable or even closed. By accurately determining the fracturing layer height, it can be ensured that the cracks develop stably in the target rock formation, thereby improving the conductivity and stability of the cracks. By calculating the fracturing pressure P, excessive fracturing caused by excessive fracturing pressure can be avoided, thereby reducing damage to the roof structure. Reasonable fracturing pressure can ensure the fracturing effect while avoiding other problems caused by excessive fracturing pressure.

[0026] By limiting the drilling angle α, which can ensure that the cracks expand along the predetermined direction, thereby better controlling the direction and range of roof collapse. According to the structure and stress state of the roof rock strata, selecting the appropriate drilling angle can optimize the formation and expansion of cracks and improve the fracturing effect. A reasonable drilling angle can prevent cracks from connecting with groundwater channels and reduce the risk of mine water hazards. A reasonable drilling length can ensure uniform expansion of cracks during fracturing and improve fracturing efficiency. By controlling the drilling length, excessive expansion of cracks can be avoided and unnecessary damage to surrounding rock formations can be reduced; according to the location of the drill hole, the drilling length L and the drilling angle α Construction drilling 4; wherein the vertical height of the drilling 4 extends from the direct top 1 of the lane retaining roadway, through the basic top 2 and into the overlying rock stratum 3, and the target fracturing layer 7 of the lane retaining roadway is located within the basic top 2;

[0027] The configured BC-high-efficiency soundless breaker fluid paste-like slurry is injected into the borehole through the hydraulic fracturing system and fractured in the target layer. After the BC-high-efficiency soundless breaker fluid paste-like slurry is allowed to stand and react, the borehole is fractured multiple times using a single-hole backward method.

[0028] Specifically, the target fracturing layer height h The formula is: The working surface height M Obtained through on-site measurement, because the actual process of coal mining environment is complex, and there are significant differences in coal seam thickness, roof lithology, geological structure, etc. in different areas. On-site measured working face height M It can ensure the acquisition of accurate geological data, residual expansion coefficient K z The value range is 1.1~1.5, usually the residual expansion coefficient K z The value is 1.3, the precise target fracturing layer height h This ensures more effective fracture formation and expansion during the fracturing process, thereby improving the fracturing effect. By properly selecting the fracturing layer, it can ensure that the fracturing fluid can fully act on the target layer and form an effective fracture network.

[0029] Specifically, the target fracture layer fracture pressure P The calculation formula is: P =1.3( P *+ R ),in P *Affected by depth, mining history of the coal seam and adjacent coal seams, and mining geological conditions. P * is the rock's deadweight stress, R is the tensile strength of the target layer rock mass. By calculating the target layer fracture pressure P, which can avoid excessive fracturing caused by excessive fracturing pressure, thereby reducing damage to the roof structure. Reasonable fracturing pressure can ensure the fracturing effect while avoiding other problems caused by excessive fracturing pressure.

[0030] Specifically, the drilling angle α and drilling length L Calculated according to the specific conditions of the working surface; among them, , α is the angle between the drilling axis and the horizontal direction, h is the target fracturing layer height, l 1 It is the horizontal distance from the peak pressure in front of the working surface to the working surface. , l is the drilling length, k The range of the surplus index is 1.1-1.3. h is the target fracturing layer height, α The angle between the drilling axis and the horizontal direction. The width of the laneway left at the working face b and drilling angle α Determination of the construction position of the drilling hole in the tunnel and the height of the target fracturing layer h and the horizontal distance to the lane boundary a The horizontal distance a from the lane boundary should not be greater than the lane width. b Two-thirds of the drilling length L It is the length of the line segment formed by the construction position extending along the drilling angle α to the fracturing layer. α , which can ensure that the cracks expand along the predetermined direction, thereby better controlling the direction and range of roof collapse. According to the structure and stress state of the roof rock strata, selecting the appropriate drilling angle can optimize the formation and expansion of cracks and improve the fracturing effect. A reasonable drilling angle can avoid the cracks from being connected to the groundwater channel and reduce the risk of mine water hazards. A reasonable drilling length can ensure the uniform expansion of cracks during the fracturing process and improve the fracturing efficiency. By controlling the drilling length, excessive expansion of cracks can be avoided and unnecessary damage to the surrounding rock strata can be reduced.

[0031] Specifically, the vertical height of the borehole 4 exceeds the immediate roof 1 of the roadway 6 and penetrates into the basic roof 2 to the overlying rock layer 3 , and the target fracturing layer 7 of the top cutting and roadway retention is located within the basic roof 2 .

[0032] Specifically, the drilling position is in the reserved tunnel 6 and close to the side of the goaf, and the drilling direction is toward the goaf. A reasonable drilling direction can avoid the cracks from being connected to the groundwater channels, reducing the risk of mine water hazards. By limiting the direction of the drilling, it can be ensured that the cracks will not extend to potential water hazard channels. Limiting the layout of the drilling holes can ensure the effective expansion of the cracks, achieve pressure relief and collapse of the roof, and reduce the deformation of the tunnel surrounding rock.

[0033] Specifically, in actual applications, the ratio may be adjusted according to the ambient temperature and the specific type of crusher, and the range of the ratio is 2.85:1~3.15:1; usually, the flowable paste-like slurry of BC-high-efficiency soundless crusher is obtained by mixing BC-high-efficiency soundless crusher and water in a ratio of 3:1.

[0034] Specifically, during the fracturing operation, the BC-high-efficiency silent breaker fluid paste slurry takes more than 30 minutes to fully react with water. In order to ensure the fracturing effect, the grouting operation needs to be completed within 30 minutes.

[0035] Specifically, the hydraulic fracturing system includes a mixing box 9, a high-pressure pump 10 and a drilling rig 11. The BC-high-efficiency soundless breaker fluid paste-type slurry is arranged in the mixing box 9. The mixing box 9 is connected to the high-pressure pump 10 through a pipeline. The high-pressure pump 10 is connected to the drilling rig 11 through a pipeline. The drilling rig 11 transports the sealer 8 to the designated target fracturing layer 7 of the borehole 4.

[0036] Specifically, before the sealer 8 is transported to the designated target fracturing layer 7 , the air tightness of the sealer 8 needs to be tested, and the sealer 8 is used to fill the BC-high-efficiency soundless breaker fluid paste-like slurry to the target layer. Specific embodiments Reference Figure 1~Figure 2 , using the above method, combined with a coal mine 3A201 recovery working face as an example, with the continuous improvement of mine recovery efficiency, the traditional tunnel layout method can no longer meet the needs of mining and excavation succession. In order to improve the recovery rate and mining efficiency of coal resources, it is necessary to adopt the goaf-side tunnel retention technology in the first mining working face of the A2 coal seam in the newly developed three mining areas.

[0038] The A2 coal seam's roof and floor are generally flat, with few cracks. The roof is primarily composed of siltstone and fine sandstone, and exhibits good integrity. Because the mining depth of the coal seam does not exceed 300 meters and the seam is shallow, with a thickness of 1.61 to 2.30 meters (mining height 2 meters), the A2 coal seam is mined to retain lanes. Compared to other lane retention methods, the overall cost of retaining lanes is relatively low, offering significant cost advantages.

[0039] According to the working surface parameters, K ZThe residual expansion coefficient of the roof is taken as 1.3, and the vertical height of the drill hole is obtained h Taking 6.6m, in order to ensure the effect of hydraulic cutting top and retaining lanes, the scheme design arranges two rows of fracturing boreholes along the lower wall of the track lane, namely 1# borehole and 2# borehole. It should be noted that the vertical height of the borehole depth usually exceeds the direct roof 1 of the retained lane, and penetrates into the basic roof 2 and even the overlying rock layer, while the target fracturing layer 7 of the retained lane is roughly within the range of the basic roof 2.

[0040] Drill hole 1#: Drill hole 1# was drilled outward from the cut hole, starting at 4.9m from the south wall of the cut hole and 0.5m from the middle wall of the cut hole, in the roof. Holes were drilled 0.5m apart, 7.5m deep, with a plumb line angle of 20° and a horizontal angle of 70°, perpendicular to the trackway. Eleven holes were drilled. When the trackway was reached, the holes were drilled 0.1m from the lower wall of the trackway. All other parameters remained the same. The trackway was 1038m long, with a total of 2076 drill holes arranged, for a total drilling length of 15,660m.

[0041] The 2# borehole: The 2# borehole is also drilled outward from the cut eye, 5.4m away from the south wall of the cut eye and 0.5m away from the middle wall of the cut eye on the top plate, with a hole spacing of 2.5m, a hole depth of 14m, a plumb line angle of 60°, and drilled perpendicularly to the direction of the track tunnel, with 3 holes drilled; when the construction reaches the track tunnel, 5m away from the upper wall of the cut eye and 1m downward from the top plate, a hole is drilled in the lower wall, with a hole spacing of 5m, a hole depth of 15m, an angle of 30° to the horizontal and an angle of 45° to the direction of the track tunnel, and drilled in the direction of the goaf. The length of the track tunnel is 1038m, with a total of 208 boreholes arranged, and a total drilling length of 3162m.

[0042] BC-high-efficiency silent breaker and water are mixed and stirred in a ratio of 3:1 to obtain a fluid paste-like slurry. The obtained paste-like slurry is loaded into a breaker box 9 and injected into the pre-fractured borehole 4 through equipment such as a high-pressure pump 10 and a drilling rig 11. The target layer 7 is fractured using a sealer 8. After 30 minutes of waiting for the water and silent breaker to react after the mixture is proportioned, a single hole is fractured multiple times using a backward method, and the silent breaker is allowed to expand, break the rock and cut the top.

[0043] Borehole 1 was 7.5 meters deep, with two holes fractured simultaneously, separated by a 2-meter interval. Fracturing was performed in a backward motion from the bottom of the hole, for a total of five cycles. The sealer was 1 meter long, and the fracturing tubing was 0.7 meters long. The injection tubing was withdrawn one meter at a time, and each fracturing cycle lasted approximately 30 minutes.

[0044] Two holes were fractured simultaneously at borehole 2, with a distance of 10 meters between each fracturing. Fracturing was performed in a reverse motion from the bottom of the hole, for a total of five fracturing cycles. The sealer and fracturing tubing were 1 meter long, and two 1-meter injection pipes were withdrawn at a time. Each fracturing cycle lasted approximately 30 minutes.

[0045] After the silent cracking agent is injected into pre-split hole 4, use wire to secure the four corners of the old belt to the roof steel mesh at the pre-split hole 4 to provide additional protection and prevent the hole from injuring anyone. The protection period must be no less than 5 hours, and a warning sign should be posted on site prohibiting anyone from remaining in this section.

[0046] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims and their equivalents, the present invention is intended to include such modifications and variations.

Claims

1. A hydraulic fracturing method for cutting top and retaining lanes based on a crushing agent, characterized in that: The steps include: According to the height of the working surface M and the residual expansion coefficient of the roof K Z Calculate the target fracturing layer height for cutting top and retaining lanes h ;Through rock stress P* and the tensile strength of the rock in the fracturing layer with top cutting and retaining R Calculate the target fracturing layer initiation pressure for cutting top and retaining lanes P , according to the target fracturing layer height h and the target fracture layer initiation pressure P Design the tunnel drilling plan; According to the tunnel drilling plan, the position of the drilling hole, the drilling length L and the drilling angle α are designed, and the direction of the drilling hole (4) is always toward the goaf (5); Prepare BC-high-efficiency soundless crusher fluid paste slurry; The configured BC-high-efficiency soundless breaker fluid paste-like slurry is injected into the borehole through the hydraulic fracturing system, and it is fractured in the target fracturing layer. After the BC-high-efficiency soundless breaker fluid paste-like slurry expands and breaks the rock and cuts the top, the borehole is fractured multiple times using a single-hole retreat method.

2. A hydraulic fracturing method for cutting top and retaining lanes based on a breaker according to claim 1, characterized in that: The target fracturing layer height h The formula is: The working surface height M The residual expansion coefficient K is obtained through field measurement. z The value is 1.1~1.

5.

3. A hydraulic fracturing method for cutting top and retaining lanes based on a breaker according to claim 1, characterized in that: The target fracture layer initiation pressure P The calculation formula is: P =1.3( P *+ R ),in P *Affected by depth, mining history of the coal seam and adjacent coal seams, and mining geological conditions. P * is the rock self-weight stress, R is the tensile strength of the target layer rock mass.

4. A hydraulic fracturing method for cutting top and retaining lanes based on a breaker according to claim 1, characterized in that: The vertical height of the borehole (4) exceeds the immediate top (1) of the lane-retaining roadway (6), and penetrates into the basic top (2) to the overlying rock layer (3), and the target fracturing layer (7) of the top-cutting lane-retaining roadway is located within the basic top (2).

5. The hydraulic fracturing method for cutting top and retaining lanes based on a breaker according to claim 1, characterized in that: The drilling angle α and drilling length L are calculated based on the specific conditions of the working face; among them, the width of the laneway left in the working face is b and drilling angle α Determination of the construction position of the drilling hole in the tunnel and the height of the target fracturing layer h and the horizontal distance to the lane boundary a Related, and the horizontal distance of the lane boundary a Should not be larger than the lane width b Two-thirds of the drilling length L The construction position along the drilling angle α The length of the line segment extending to the fracture layer.

6. A hydraulic fracturing method for cutting top and retaining lanes based on a breaker according to claim 1, characterized in that: The drilling hole is located in the lane-retaining tunnel (6) and on one side close to the goaf (5), and the drilling direction is toward the goaf.

7. A hydraulic fracturing method for cutting top and retaining lanes based on a breaker according to claim 1, characterized in that: The BC-high-efficiency soundless breaker fluid paste slurry is obtained by mixing the BC-high-efficiency soundless breaker and water in a mass ratio of 2.85:1 to 3.15:

1.

8. A hydraulic fracturing method for cutting top and retaining lanes based on a breaker according to claim 7, characterized in that: During the fracturing operation, the BC-high-efficiency silent breaker fluid paste slurry takes more than 30 minutes to fully react with water. In order to ensure the fracturing effect, the grouting operation must be completed within 30 minutes.

9. The hydraulic fracturing method for cutting top and retaining lanes based on a breaker according to claim 1, characterized in that: The hydraulic fracturing system comprises a mixing box (9), a high-pressure pump (10) and a drilling rig (11), wherein the BC-high-efficiency soundless breaker fluid paste-type slurry is arranged in the mixing box (9), the mixing box (9) is connected to the high-pressure pump (10) through a pipeline, the high-pressure pump (10) is connected to the drilling rig (11) through a pipeline, and the drilling rig (11) transports the sealer (8) to the designated target fracturing layer (7) of the borehole (4).

10. A hydraulic fracturing method for cutting top and retaining lanes based on a breaker according to claim 7, characterized in that: Before the sealer (8) is transported to the designated target fracturing layer (7), the air tightness of the sealer (8) needs to be tested, and the sealer (8) is used to fill the BC-high-efficiency silent breaker fluid paste-like slurry to the target layer.

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