Downhole high pressure hydraulic fracturing actuator for inducing natural caving

Abstract

The underground high-pressure hydraulic fracturing actuator for inducing natural caving includes a drill rod, a spigot, an airbag ring, a first connecting pipe, a receiving net, a tray, a water pump, a second connecting pipe, a water tank, a top plate, a first piston rod, a first hydraulic cylinder, a support frame, a bracket, a suction pump, a third connecting pipe, a second hydraulic cylinder, a mounting frame, a liquid pipe, a liquid storage box, a second piston rod and a motor, which can effectively avoid sealing failure, ensure that high-pressure water can stably act on target rock stratum, avoid rock debris accumulation from hindering crack expansion, realize water resource filtration and recovery, reduce water resource waste, avoid the problem of underground roadway being blocked by silt, integrate drilling, sealing, water injection and slag cleaning functions, and have the advantages of no need for blasting in the natural caving process, no smoke dust pollution, controllable crack expansion direction and greatly reduced probability of ore dilution and loss.

Description

Technical Field

[0001] This invention relates to the field of underground metal mining technology, specifically to an underground high-pressure hydraulic fracturing actuator for inducing natural collapse. Background Technology

[0002] Natural caving is one of the core technologies for mining thick ore bodies in underground metal mines. Its principle is to weaken the boundary support structure of the ore and rock, utilizing geostress and the ore's own weight to achieve natural fracturing and caving of the ore body. In this process, the efficiency of induced caving engineering (such as side cutting and bottom pulling) directly determines the mine's production capacity and dilution rate.

[0003] Currently, the industry mainly uses the following technical methods for weakening and pre-fractured the boundaries of underground mining areas, but all of them have significant limitations, namely the limitations of traditional blasting pre-fracture methods:

[0004] Existing technologies mostly employ fan-shaped medium-deep hole blasting. Although the technology is mature, the violent vibrations generated by the blasting can easily disturb the stability of the surrounding rock and cause secondary geological disasters. At the same time, the blasting fumes and dust generated severely deteriorate the underground working environment and make it difficult to accurately control the direction of crack propagation, often leading to confusion of the ore-rock boundary and causing ore depletion or loss.

[0005] Others use conventional hydraulic fracturing technology, but the application of hydraulic fracturing technology has bottlenecks:

[0006] High-pressure hydraulic fracturing, as a non-explosive technology, can reduce vibration, but it faces the following three major challenges in practical applications:

[0007] (1) Poor sealing reliability: Traditional mechanical sealing devices or cement sealing are prone to "slipping" or sealing failure under high pressure water, resulting in pressure not being able to be transmitted to the target rock layer.

[0008] (2) Water waste and environmental protection issues: The large amount of backflow water generated by hydraulic fracturing carries rock debris and silt. If discharged directly, it will block the underground tunnels and cause water waste. There is a lack of effective on-site recycling and reuse mechanisms.

[0009] (3) Poor operational coordination: The existing drilling, sealing, water injection and slag removal are usually completed by multiple independent equipment in steps. The process conversion is time-consuming and laborious, and the equipment occupies a large amount of roadway space, making it difficult to arrange flexibly in the narrow mining area boundary.

[0010] There is a contradiction between the handling of rock cuttings and the fracturing effect in high-pressure hydraulic fracturing:

[0011] During hydraulic fracturing, high-pressure water flows out debris and fine sand from the borehole. Current technologies often focus only on "water injection and pressurization," neglecting the impact of "rock debris removal" on the fracturing effect. If the borehole opening lacks an effective receiving and filtering device, the accumulated rock debris will hinder the further expansion of the crack, resulting in a limited fracturing radius and an inability to effectively induce large-area collapse.

[0012] To address the aforementioned issues, several methods have been publicly disclosed: CN118327584A, "A combined deep-hole pre-fracturing and hydraulic fracturing method for naturally caving mining of steeply dipping thin ore bodies," employs a combination of downward deep-hole explosive pre-fracturing and directional hydraulic fracturing to induce natural caving. While applicable to steeply dipping thin ore bodies, it still relies on explosive blasting as a pre-fracturing method, but suffers from problems such as blasting vibration disturbing the surrounding rock and blasting dust. Its hydraulic fracturing is only used as an auxiliary method, lacking integrated borehole sealing / slag removal / water circulation functions, and the processes are fragmented; CN109162717B... A hydraulic tunneling method and equipment for mining and tunnel engineering is disclosed. It adopts a two-step method of "water jet crushing + high-pressure water splitting". The actuator head is a diamond drill bit, the middle is equipped with water jet spray, and the tail is equipped with a sealing element. It can be used for hydraulic tunneling. However, its expansion tube is wrapped with a metal slotted protective sleeve to control the splitting direction. The slotting direction of the metal protective sleeve on the expansion tube needs to be manually adjusted to control the splitting direction. It is highly dependent on construction experience and has no rock cuttings receiving and recycling structure. Rock cuttings are easy to accumulate at the borehole opening and hinder crack propagation. There is no special airbag structure for sealing the borehole. The sealing reliability is greatly affected by the roughness of the borehole wall.

[0013] Therefore, it is of great significance to develop a downhole high-pressure hydraulic fracturing actuator for inducing natural collapse. Summary of the Invention

[0014] The objective of this invention is to overcome the shortcomings of the prior art and provide a downhole high-pressure hydraulic fracturing actuator for inducing natural collapse. This actuator can both utilize natural collapse to achieve large-area collapse and induce natural collapse to solve the problem of hydraulic fracturing.

[0015] The objective of this invention is achieved through the following technical solution:

[0016] The downhole high-pressure hydraulic fracturing actuator for inducing spontaneous collapse includes drill pipe, tubing, airbag ring, first connecting pipe, collection mesh, tray, water pump, second connecting pipe, water tank, top plate, first piston rod, first hydraulic cylinder, support frame, bracket, suction pump, third connecting pipe, second hydraulic cylinder, mounting bracket, fluid passage pipe, fluid storage box, second piston rod, and motor. The tray with the collection mesh in the middle is integrated with the water tank. The support frame with a bracket at the bottom is mounted under the tray. Fluid storage boxes are symmetrically mounted on both sides under the support frame. A passage pipe is installed between the fluid storage boxes and the tray. The hydraulic system includes a mounting bracket on the left bottom side of the support frame, which houses a second hydraulic cylinder with a second piston rod on its upper side. A motor with a drill rod is mounted on the top of the second piston rod. A water pump with an outer gasket ring insert is mounted on the top of the water tank, and a first connecting pipe is connected to the gasket ring. A second connecting pipe connects the water pump to the water tank, and a suction pump is mounted at the bottom of the water tank. A third connecting pipe connects the suction pump to the water tank. Vertical plates are located on both sides of the middle section of the support frame. Inside each vertical plate is a first hydraulic cylinder with a first piston rod and a top plate at the end, enabling high-pressure hydraulic fracturing downhole.

[0017] Compared with the prior art, the innovative points and advantages or effects of this invention are as follows:

[0018] (1) The present invention facilitates the insertion of the subsequent tube into the hole by drilling the drill rod. Combined with the sealing of the airbag ring, it can effectively avoid the problem of sealing failure of the traditional sealing method and ensure that the high pressure water can act stably on the target rock layer.

[0019] (2) By combining the collection net, tray and suction pump, the fine sand, rock debris and water washed out can be collected in time. This not only avoids the accumulation of rock debris from hindering the expansion of cracks, but also achieves the filtration and recycling of water resources, reducing water waste and avoiding the problem of mud and sand clogging the underground tunnels.

[0020] (3) The drilling, sealing, water injection and slag removal functions are integrated into the same device, which reduces the process conversion time of multiple equipment in separate operations. The overall structure is compact and can adapt to the working space of narrow underground mining areas. By flushing the soil and fine sand in the cracks with high pressure water, the rock structure is gradually weakened and natural collapse is induced. The whole process will not produce violent blasting vibration, and also reduces the pollution of blasting smoke and dust. It can better control the direction of crack expansion and reduce the probability of ore dilution and loss.

[0021] In summary, this invention controls splitting through high-pressure hydraulics, which can further induce natural collapse and improve efficiency. Attached Figure Description

[0022] Figure 1 This is a diagram of a downhole high-pressure hydraulic fracturing actuator for inducing spontaneous collapse, based on the present invention.

[0023] Figure 2 for Figure 1 The diagram shows a side view of the tray and water tank of a downhole high-pressure hydraulic fracturing actuator used to induce natural collapse.

[0024] The symbols in the attached diagram represent:

[0025] 1. Drill rod 2. Insertion pipe 3. Airbag ring 4. First connecting pipe 5. Receiving mesh 6. Tray 7. Water pump 8. Second connecting pipe 9. Water tank 10. Top plate 11. First piston rod 12. First hydraulic cylinder 13. Support frame 14. Bracket 15. Suction pump 16. Third connecting pipe 17. Second hydraulic cylinder 18. Mounting bracket 19. Fluid inlet pipe 20. Liquid storage box 21. Second piston rod 22. Motor

[0026] The present invention will now be described in further detail with reference to the accompanying drawings. Detailed Implementation

[0027] like Figures 1-2 As shown, the downhole high-pressure hydraulic fracturing actuator for inducing spontaneous collapse includes a drill pipe 1, a tubing 2, an airbag ring 3, a first connecting pipe 4, a collection net 5, a tray 6, a water pump 7, a second connecting pipe 8, a water tank 9, a top plate 10, a first piston rod 11, a first hydraulic cylinder 12, a support frame 13, a bracket 14, a suction pump 15, a third connecting pipe 16, a second hydraulic cylinder 17, a mounting frame 18, a fluid inlet pipe 19, a fluid storage box 20, a second piston rod 21, and a motor 22. The tray 6, with the collection net 5 in the middle, is integrated with the water tank 9. The support frame 13, with the bracket 14 at the bottom, is mounted under the tray 6. Fluid storage boxes 20 are symmetrically mounted on both sides under the support frame 13. The fluid storage boxes 20 and the tray are connected. A fluid-conducting pipe 19 is installed between the 6 sections. A mounting bracket 18 is provided on the bottom left side of the support frame 13, which has a second hydraulic cylinder 17 with a second piston rod 21 on the upper side inside. A motor 22 with a drill rod 1 on the shaft is installed at the top of the second piston rod 21. A water pump 7 with an outer airbag ring 3 and an insert pipe 2 is installed at the top of the water tank 9. A first connecting pipe 4 is connected to the airbag ring 3. A second connecting pipe 8 is connected between the water pump 7 and the water tank 9. A suction pump 15 is installed at the bottom of the water tank 9. A third connecting pipe 16 is connected between the suction pump 15 and the water tank 9. Vertical plates are provided on both sides of the middle part of the support frame 13. A first hydraulic cylinder 12 with a first piston rod 11 with a top plate 10 on the end is installed inside the vertical plate, which can perform downhole high-pressure hydraulic fracturing.

[0028] The method of the present invention can be further described as follows:

[0029] The diameter of the drill rod 1 is slightly larger than that of the hollow insertion tube 2 that is connected to the water pump 7.

[0030] The airbag ring 3 is a hollow ring made of rubber material and is connected to the first connecting pipe 4. The side of the water tank 9 is equipped with an air pump connected to the first connecting pipe 4.

[0031] The receiving net 5 has a mesh structure and is connected to the hollow tray 6. The outlet pipe of the suction pump 15 is connected to the liquid storage box 20.

[0032] The outer side of the top plate 10 is fixedly covered with an anti-slip and wear-resistant pad layer made of high wear-resistant rubber or polyurethane material, and its surface is provided with a mesh pattern or conical protrusions to increase friction.

[0033] The mounting bracket 18 is a tripod, which is fixed to the second hydraulic cylinder 17 with fastening screws.

[0034] The assembly steps of the mechanism are as follows:

[0035] S1. Fix the device to the top of the well that needs to be split, and by controlling the first hydraulic cylinder 12, make the top plate 10 support the two side walls to achieve the positioning of the device;

[0036] S2. Control the second hydraulic cylinder 17 and the motor 22. The motor 22 drives the drill rod 1. Through the cooperation of the second hydraulic cylinder 17 and the motor 22, the drill rod 1 drills while the second hydraulic cylinder 17 controls the extension and withdrawal of the drill rod 1 to realize the drilling operation.

[0037] S3. After drilling is completed, insert the cannula 2 into the drilled hole, start the air pump corresponding to the airbag ring 3 to inflate the airbag ring 3, so that the airbag ring 3 seals at the junction of the cannula 2 and the drilled hole.

[0038] S4. Perform water filling operation. High-pressure water filling is performed by turning on the switch of water pump 7 and spraying water into the drilled hole through the insertion pipe 2. Because there are gaps in the well wall containing fine sand or soil, the high-pressure water washes over the gaps while the suction pump 15 generates suction on the top of the well through the tray 6, which accelerates the water and fine sand in the gaps to fall downwards. Then, through the tray 6 and the liquid pipe 19, the water flows to the liquid storage box 20, while most of the water continues to flow to the water tank 9. The repeated washing with water will increase the gaps in the well wall, gradually washing away the fine sand and soil in the gaps, and then loosening the split well wall until it collapses.

[0039] Example 1

[0040] The downhole high-pressure hydraulic fracturing actuator for inducing spontaneous collapse includes a tray 6, a water tank 9, and a support frame 13. The tray 6 and water tank 9 are an integral structure. A collection net 5 is provided in the middle of the tray 6. The support frame 13 is fixedly installed at the bottom of the tray 6. A bracket 14 is fixedly installed at the bottom of the support frame 13. Fluid storage boxes 20 are symmetrically installed on both sides of the bottom of the support frame 13. A fluid passage pipe 19 is installed between the fluid storage box 20 and the tray 6. A mounting frame 18 is fixedly installed on the left side of the bottom surface of the support frame 13. A second hydraulic cylinder 17 is installed inside the mounting frame 18. A second piston rod 21 is installed on the upper side of the second hydraulic cylinder 17. A top part of the second piston rod 21 is fixedly installed. A drill rod 1 is fixedly mounted on the motor shaft of the motor 22. A water pump 7 is fixedly mounted on the surface of the water tank 9. A pipe 2 is installed at the top of the water pump 7. An air bladder ring 3 is sleeved on the pipe 2. A first connecting pipe 4 is connected to the air bladder ring 3. A second connecting pipe 8 is connected between the water pump 7 and the water tank 9. A suction pump 15 is fixedly mounted at the bottom of the water tank 9. A third connecting pipe 16 is connected between the suction pump 15 and the water tank 9. Vertical plates are set on both sides of the middle part of the support frame 13. A first hydraulic cylinder 12 is fixedly mounted inside the vertical plates. A first piston rod 11 is mounted on the outside of the first hydraulic cylinder 12. A top plate 10 is fixedly mounted at the end of the first piston rod 11.

[0041] The outer side of the top plate 10 is fixedly covered with an anti-slip and wear-resistant pad layer. The anti-slip and wear-resistant pad layer is made of high wear-resistant rubber or polyurethane material, and its surface is provided with a mesh pattern or conical protrusion to increase friction.

[0042] The airbag ring 3 is made of rubber material and has a hollow ring structure. The airbag ring 3 is connected to the first connecting pipe 4. An air pump is provided on the side of the water tank 9 so that the air pump is connected to the first connecting pipe 4.

[0043] The diameter of the drill rod 1 is slightly larger than that of the insertion tube 2, which is a hollow tube and is connected to the water pump 7.

[0044] The receiving net 5 has a mesh structure and is connected to the tray 6, which is a hollow tray. The outlet of the suction pump 15 is connected to the liquid storage box 20 through a pipe.

[0045] The mounting bracket 18 is a tripod, and fastening screws are installed between the mounting bracket 18 and the second hydraulic cylinder 17.

[0046] Operating steps:

[0047] S1. Fix the device at the top of the well that needs to be split. By controlling the first hydraulic cylinder 12, the top plate 10 can be supported on both side walls to achieve the positioning of the device.

[0048] S2. Control the second hydraulic cylinder 17 and the motor 22. The motor 22 drives the drill rod 1. Through the cooperation of the second hydraulic cylinder 17 and the motor 22, while the drill rod 1 is drilling, the second hydraulic cylinder 17 can control the extension and withdrawal of the drill rod 1 to realize the drilling operation.

[0049] S3. After drilling is completed, insert the cannula 2 into the drilled hole. This process requires adjusting the installation position of the device first. After inserting the cannula 2 into the hole, start the air pump corresponding to the airbag ring 3 to inflate the airbag ring 3 so that the airbag ring 3 seals at the junction of the cannula 2 and the drilled hole.

[0050] S4. At this time, the water filling operation is carried out under high pressure. The switch of water pump 7 is turned on, and water will be sprayed into the drilled hole through the insertion pipe 2. There will be some gaps in the well wall, and fine sand or soil will be trapped in the gaps. The water will flush the gaps. At the same time, the suction pump 15 increases the suction, which will generate suction on the top of the well through the tray 6, accelerating the water and fine sand in the gaps to fall downwards. Through the tray 6 and the liquid pipe 19, the water flows to the liquid storage box 20, while most of the water continues to flow into the water tank 9. The repeated flushing of water will increase the gaps in the well wall, gradually washing away the fine sand and soil in the gaps, which will loosen them and eventually cause them to collapse.

[0051] No blasting is required; the collapse is induced by high-pressure hydraulics, and there is no smoke or dust. The drilling (second hydraulic cylinder 17 + motor 22 + drill rod 1), sealing (airbag ring 3 + first connecting pipe 4), water injection (water pump 7 + insertion pipe 2), and debris removal (collection net 5 + suction pump 15 + liquid storage box 20) are all mounted on the support frame 13, allowing for continuous operation of a single mechanism. The airbag ring's flexible sealing is superior to that of a mechanical capsule. The collection net + tray 6 + liquid pipe 19 form a closed-loop water circulation system, preventing direct discharge of rock cuttings.

[0052] Example 2

[0053] This embodiment has the same basic structure as Embodiment 1. The difference is that this embodiment is applied to the pre-fracture operation of the roof and sidewall weakening in underground horizontal or gently inclined roadways, and the fixing method of the actuator and the adjustment of the drilling angle have been adapted.

[0054] Specifically, at each of the four bottom corners of the support frame 13, an independently extendable hydraulic outrigger 23 (not shown in the figure) is added. The lower end of the hydraulic outrigger 23 is provided with an anti-slip base. The hydraulic outrigger 23 is used to replace the lateral support function of the first hydraulic cylinder 12 and the top plate 10 in Embodiment 1. It can extend vertically downward through the hydraulic control system to press against the tunnel floor, thereby stably supporting the entire device on the horizontal or gently sloping ground. At the same time, the mounting frame 18 and the support frame 15 are rotatably connected by a slewing bearing 24 (not shown in the figure), and a servo motor 25 (not shown in the figure) is fixedly mounted on the support frame 13. The output shaft of the servo motor 25 meshes with the internal gear ring of the slewing bearing 24 through a gear transmission pair, thereby driving the mounting frame 18 to drive the drill rod 1 to achieve arbitrary angle adjustment within the range of 0° to 90° in the vertical plane.

[0055] The operation steps in this embodiment are as follows:

[0056] S1. Hoist the device to the predetermined position in the horizontal roadway where the pre-fracture needs to be weakened, activate the four hydraulic outriggers 23 to extend them downwards synchronously until the anti-slip base is in close contact with and presses against the roadway floor. Ensure that the support frame 13 is in a horizontal state through the leveling system, thus completing the horizontal positioning and stabilization of the device.

[0057] S2. According to the pre-designed drilling inclination parameters, start the servo motor 25 and drive the mounting frame 18 to rotate through the slewing bearing 24, so that the drill rod 1 is aligned with the predetermined drilling direction of the target rock layer (e.g., upward elevation angle of 30° or horizontal direction).

[0058] S3. Start the second hydraulic cylinder 17 and motor 22, and complete the drilling operation according to step S2 in Example 1. During the drilling process, the drilling angle can be finely adjusted in real time by servo motor 25 as needed.

[0059] S4. After drilling is completed, the mounting bracket 18 is reset to the initial position by the servo motor 25, and then the insertion tube 2 is inserted into the drilled hole. The air pump is started to inflate the airbag ring 3 to complete the sealing operation.

[0060] S5. Start water pump 7 and suction pump 15 to perform high-pressure water injection and rock cuttings recovery operations. During this process, the muddy and sandy water flushed out from the hole falls into tray 6 and is sucked in under the combined action of gravity and the negative pressure generated by suction pump 15. After preliminary filtration by collection screen 5, the coarser rock cuttings remain on collection screen 5, while the water containing fine sand enters water tank 9 for sedimentation. The upper layer of clear water is recycled by suction pump 15, and the concentrated slurry at the bottom is periodically discharged into storage box 20.

[0061] Comparative Example 1

[0062] CN118327584A discloses a staged natural caving mining method combining deep-hole pre-fracturing and hydraulic fracturing in steeply inclined thin ore bodies. The on-site implementation is as follows: ① Constructing a fan-shaped medium-deep hole at the boundary of the mining area, with a diameter of Φ76~115mm and a depth of 30~50m; ② Filling the fan-shaped hole with emulsion explosives for blasting and pre-fracturing to form an initial weakened boundary; ③ Constructing directional hydraulic fracturing holes within the ore body, with a depth generally greater than the pre-fracturing holes; ④ Transporting the high-pressure fracturing pump truck, sealing device, and return pipeline to the fracturing hole opening, with the sealing device using mechanical expansion capsules or cement mortar to seal the hole section; ⑤ Starting the fracturing pump to inject high-pressure water into the hole, with an injection pressure generally of 15~25MPa, inducing the expansion of fractures in the ore body; ⑥ The return water carrying rock cuttings flows out from the hole opening, is discharged through a simple diversion channel to the roadway drainage ditch, and finally flows into the central water tank underground. Rock cuttings deposited in the drainage ditch need to be manually cleaned periodically. ⑦ After fracturing is completed, the equipment is dismantled and moved to the next borehole location to repeat steps ① to ⑥. Throughout the process, drilling is completed by an independent rock drilling rig, blasting is completed by a charging rig, and fracturing is completed by a fracturing pump truck. There is no dedicated integrated mechanism for sealing and flowback. The equipment for each process is separate and frequently moved between locations.

[0063] It uses explosive blasting as the primary pre-fracture method, which has problems such as blasting vibration disturbing the surrounding rock and blasting fumes polluting the underground environment; hydraulic fracturing is only used as an auxiliary fracturing method, and drilling, blasting, fracturing, and flowback are completed step by step by multiple independent equipment, which takes a long time to switch between processes; the sealing uses mechanical expansion capsules or cement mortar, which are prone to slippage under high pressure; the flowback water has no orifice for receiving and recycling, and rock cuttings are directly discharged into the roadway.

[0064] The results for each case are shown in the table below.

[0065] Core rock breaking method Pure high-pressure water jetting of fissures, without explosion Pure high-pressure water jetting of fissures, without explosion Explosive fracturing is the primary method for pre-fracture, while hydraulic fracturing is only used as an auxiliary method for fracturing enhancement. Applicable Scenarios Downhole vertical roof collapse operation, upward hole natural collapse operation Roof / Sidewall Pre-splitting in Horizontal and Gently Inclined Roadways Deep-hole fan-shaped pre-splitting and downward deep-hole drilling of steeply dipping thin ore bodies Overall fixed structure Dual-sided first hydraulic cylinders + top plate lateral bracing and positioning Four sets of retractable hydraulic outriggers at the bottom provide ground support, and are equipped with a leveling system. Without an integrated support structure, the rock drilling and fracturing equipment are arranged separately. Drilling angle adjustment The drill pipe is fed vertically only, and the angle is not adjustable. Equipped with a slewing bearing and servo motor, adjustable tilt angle from 0° to 90°. Independent rock drilling rig construction, fracturing without angle adjustment mechanism Integration of drilling, water injection, sealing, and slag removal equipment All mechanisms are integrated into a single support frame, enabling continuous operation of a single unit. All mechanisms are integrated into a single support frame, enabling continuous operation of a single unit. Multiple separate pieces of equipment, including rock drilling rigs, explosives loading rigs, and fracturing pump trucks, require separate processes and frequent site relocation. Sealing structure The inflatable rubber airbag ring provides a flexible seal, adapting to the deformation of the hole wall. The inflatable rubber airbag ring provides a flexible seal, adapting to the deformation of the hole wall. Mechanical expansion capsules / rigid cement mortar sealing, high-pressure slip seals prone to leakage Sludge and wastewater recycling system Tray + Receiving Net + Negative Pressure Pump + Liquid Storage Box Closed-Loop Circulation; Coarse Sludge Retention, Clean Water Reuse, and Centralized Storage of Concentrated Slurry Tray + Receiving Net + Negative Pressure Pump + Liquid Storage Box Closed-Loop Circulation; Coarse Sludge Retention, Clean Water Reuse, and Centralized Storage of Concentrated Slurry There is no dedicated structure for receiving and recycling wastewater; the wastewater is directly discharged into the tunnel drainage ditch, and manual cleaning is required periodically. Downhole contamination and surrounding rock disturbance No blasting vibration, no blasting smoke, no dust pollution No blasting vibration, no blasting smoke, no dust pollution The blasting vibrations disturbed the surrounding rock, generating a large amount of blasting smoke and dust. Work process Support positioning → drilling → airbag sealing → high-pressure water injection fracturing + synchronous negative pressure slag removal, all completed continuously by one set of equipment. Landing and leveling → angle calibration → drilling → airbag sealing → high-pressure water injection fracturing + synchronous negative pressure slag removal – all completed continuously by one set of equipment. Drilling fan-shaped blasting holes → charging and blasting → drilling separate independent fracturing holes → transferring fracturing equipment for sealing and water injection → direct discharge of wastewater, multi-equipment, step-by-step construction. Water recycling Clean water is continuously circulated to supply the high-pressure water pump, resulting in high water resource utilization. Clean water is continuously circulated to supply the high-pressure water pump, resulting in high water resource utilization. There is no water circulation; all wastewater is discharged into the central water tank underground.

[0066] Summary of comparison between Examples 1 and 2 and the comparative examples:

[0067] 1. The core advantages of both embodiments of the present invention compared to the prior art (Comparative Example 1)

[0068] (1) Safety and environmental advantages: The pre-explosive blasting process is eliminated. High-pressure water jetting is used to expand rock fissures and induce natural collapse, eliminating the disturbance and damage of blasting vibration to the surrounding rock. At the same time, the generation of blasting smoke and dust is avoided, improving the underground working environment and reducing the risk of blasting safety management.

[0069] (2) Integrated equipment and efficient operation: The drilling, angle adjustment, flexible sealing, high pressure water injection, and negative pressure slag collection and water circulation functions are integrated into a single integrated actuator, eliminating the need for alternating transfer of multiple sets of equipment for rock drilling, blasting, and fracturing, simplifying the construction process and significantly shortening the on-site operation cycle.

[0070] (3) Higher sealing reliability: The flexible sealing structure of the inflatable rubber airbag ring can adapt to the small deformation of the borehole wall. Compared with mechanical capsules and rigid cement mortar sealing, it is less likely to fail to seal or leak under high pressure water injection conditions, and is suitable for high water pressure hydraulic fracturing construction requirements.

[0071] (4) Green and intensive treatment of slag and water: The system is equipped with trays, collection nets, negative pressure suction pumps and storage boxes to form a closed-loop water circulation system. Rock cuttings and mud generated by drilling are filtered and collected on site, and the upper layer of clean water is recycled and reused. Only the high-concentration slurry at the bottom is centrally stored and transported. Slag-containing wastewater is prevented from being directly discharged into the roadway, reducing the amount of manual dredging work underground and improving the utilization rate of water resources.

[0072] 2. Explanation of the differences in applicable scenarios between Example 1 and Example 2

[0073] Example 1 relies on lateral hydraulic roof support, suitable only for upward drilling conditions with vertical roofs. It features a simple structure and lower manufacturing cost. Example 2 eliminates the lateral support, replacing it with ground-mounted hydraulic outriggers and an angle adjustment mechanism. It can adapt to multi-angle pre-splitting construction of roofs and sidewalls in horizontal and gently inclined roadways, making it applicable to a wider range of roadway types and offering greater equipment versatility. Both structures retain the core innovative structures of integrated hydraulic fracturing, closed-loop slag collection, and flexible airbag sealing. The core technical solutions are consistent; only the support and angle adjustment mechanisms are adapted to different underground roadway conditions.

[0074] 3. Summary of inherent defects in Comparative Example 1

[0075] Existing solutions rely on blasting pre-splitting, which causes significant disturbance and pollution to the surrounding rock; multiple equipment are used for separate construction, making site relocation cumbersome and inefficient; rigid sealing has poor pressure resistance and is prone to leakage; there is no supporting slag and water recycling structure, resulting in direct discharge of wastewater and rock debris into the tunnel, leading to significant problems of underground dredging and water waste. Overall, the safety, convenience, and environmental friendliness of the construction are all inferior to the present invention.

[0076] This embodiment, by adding an adjustable-angle drilling mechanism and a ground support structure, enables the actuator to be flexibly applied to weakening operations at different locations in the roof, sidewalls, or inclined sections of underground horizontal roadways, thus broadening the applicability of the equipment and improving the flexibility of underground operations.

[0077] As described above, the present invention can be well implemented. The above embodiments are only the best implementations of the present invention, but the implementation of the present invention is not limited to the above embodiments. Other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention should be considered equivalent substitutions and are all included within the protection scope of the present invention.

Claims

1. A downhole high-pressure hydraulic fracturing actuator for inducing spontaneous collapse, characterized in that... Includes drill pipe (1), insertion tube (2), airbag ring (3), first connecting pipe (4), receiving net (5), tray (6), water pump (7), second connecting pipe (8), water tank (9), top plate (10), and first piston rod (11). The system consists of a first hydraulic cylinder (12), a support frame (13), a bracket (14), a suction pump (15), a third connecting pipe (16), a second hydraulic cylinder (17), a mounting frame (18), a fluid passage pipe (19), a storage box (20), a second piston rod (21), and a motor (22). A tray (6) with a collecting mesh (5) in the middle is integrated with a water tank (9). A support frame (13) with a bracket (14) at the bottom is mounted under the tray (6). Storage boxes (20) are symmetrically mounted on both sides of the support frame (13). A fluid passage pipe (19) is installed between the storage box (20) and the tray (6). A second hydraulic cylinder with a second piston rod (21) is located on the left bottom side of the support frame (13). The mounting bracket (18) of the cylinder (17) has a motor (22) with a drill rod (1) on the shaft at the top of the second piston rod (21); the top of the water tank (9) has a water pump (7) with an outer airbag ring (3) and a tube (2) inserted into it, and the airbag ring (3) is connected to a first connecting pipe (4); the water pump (7) is connected to the water tank (9) with a second connecting pipe (8); the bottom of the water tank (9) is equipped with a suction pump (15); the suction pump (15) is connected to the water tank (9) with a third connecting pipe (16); the support frame (13) has vertical plates on both sides in the middle, and the vertical plates are fitted with a first hydraulic cylinder (12) with a first piston rod (11) with a top plate (10) on the outside, which can perform downhole high-pressure hydraulic splitting.

2. The mechanism according to claim 1, characterized in that: The diameter of the drill rod (1) is slightly larger than that of the hollow insertion tube (2) that communicates with the water pump (7).

3. The mechanism according to claim 1, characterized in that: The airbag ring (3) is a hollow ring made of rubber material and is connected to the first connecting pipe (4). The side of the water tank (9) is provided with an air pump connected to the first connecting pipe (4).

4. The mechanism according to claim 1, characterized in that: The receiving net (5) has a mesh structure and is connected to the hollow tray (6). The outlet pipe of the suction pump (15) is connected to the liquid storage box (20).

5. The mechanism according to claim 1, characterized in that: The outer side of the top plate (10) is fixedly covered with an anti-slip and wear-resistant pad layer made of high wear-resistant rubber or polyurethane material, and its surface is provided with a mesh pattern or conical protrusion to increase friction.

6. The mechanism according to claim 1, characterized in that: The mounting bracket (18) is a tripod, which is fixed to the second hydraulic cylinder (17) with fastening screws.

7. The mechanism according to claim 1, characterized in that: Assembly steps as follows: S1. Fix the device to the top of the well that needs to be split, and by controlling the first hydraulic cylinder (12), the top plate (10) is supported on both side walls to achieve the positioning of the device; S2. Control the second hydraulic cylinder (17) and the motor (22). The motor (22) drives the drill rod (1). Through the cooperation of the second hydraulic cylinder (17) and the motor (22), the drill rod (1) drills while the second hydraulic cylinder (17) controls the insertion and withdrawal of the drill rod (1) to realize the drilling operation. S3. After drilling is completed, insert the cannula (2) into the drilled hole, start the air pump corresponding to the airbag ring (3) to inflate the airbag ring (3) and seal the airbag ring (3) at the junction of the cannula (2) and the drilled hole. S4. Perform water filling operation, high pressure water filling, turn on the switch of water pump (7), spray water into the drilled hole through the insertion pipe (2). Because there are gaps with fine sand or soil in the well wall, the high pressure water flushes the gaps while the suction pump (15) generates suction on the top of the well through the tray (6), which accelerates the water and fine sand in the gaps to fall down, and then flows to the storage box (20) through the tray (6) and the liquid pipe (19). Most of the water will continue to flow to the water tank (9). Repeated flushing by water will increase the gaps in the well wall, gradually flushing away the fine sand and soil in the gaps, and then loosening the split well wall until it collapses.

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