Method and device for preventing and controlling rock burst caused by high-energy fluid impact fracture and pressure relief

Abstract

The present invention discloses a high-energy fluid impact fracturing pressure relief rock pressure prevention and control device, comprising a connecting rod (1): used to send a high-energy fluid generating chamber (3) and a plugging system (2) into a borehole (101), supply fluid and lead out a wire; a plugging system (2): used to plug the borehole (101); a high-energy fluid generating chamber (3): used to generate high-energy fluid; and a repetitive pressure relief end (4) and a shaped projectile (5). The present invention also discloses a method for using a high-energy fluid impact fracturing pressure relief rock pressure prevention and control device. The present invention provides a device and method for artificially relieving pressure on a coal seam roof to prevent and control rock pressure, which can replace traditional blasting and hydraulic fracturing. The present invention can effectively solve the rock pressure risk faced by hard roof mining areas. The method has low impact stress, weak vibration, less dust and convenient construction.

Description

Technical Field

[0001] The invention belongs to the technical field of coal mining, and in particular relates to a method and device for preventing and controlling high-energy fluid impact fracturing and pressure relief impact ground pressure. Background Art

[0002] With the continuous increase in the depth and intensity of coal mining in my country, mine rock burst accidents have gradually become one of the main disasters affecting safe mining. In the process of coal mining, as the working face advances, the roof needs to be cut off at certain intervals to relieve pressure. In most cases, the advancement of the mechanized working face is accompanied by the fall of the direct roof, and the roof will cut off automatically at certain intervals. However, in coal mines in Datong, Shanxi and other places, there are hard roofs, which need to be forced to release the roof to relieve pressure. Generally, explosives or hydraulic fracturing are used to forcibly cut the roof.

[0003] However, the traditional method of cutting off the roof by blasting has disadvantages such as strong vibration, large dust and easy to cause support failure. In addition, the management of explosives used in blasting is complicated and easy to leak, which may cause danger. Hydraulic fracturing cannot reach high pressure when there are many cracks in the coal rock mass. Water will flow out of the cracks in the unfractured state. However, if the roof is not forced to be cut, when the roof is large-scale (more than 1000m) and continuous, it will eventually unload pressure by itself, causing dynamic disturbance and triggering rock burst. Therefore, it is necessary to implement forced artificial cutting of the roof when the cutting distance is reached, and prevent the occurrence of rock burst by artificial unloading. Therefore, it is necessary to study a device and method that can replace traditional blasting to artificially unload the pressure on the coal seam roof to prevent rock burst. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a high-energy fluid impact fracturing and pressure relief rock burst prevention and control device, which can effectively solve the rock burst risk faced by hard roof mining areas.

[0005] At the same time, the present invention provides a method for using a high-energy fluid impact fracturing pressure relief impact ground pressure prevention and control device. This method has small impact stress, weak vibration, less dust and convenient construction. In addition, during the high-energy fluid impact fracturing process, the crack development under the impact stress is more complex, and volume fracturing can be achieved.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0007] The high-energy fluid impact fracturing pressure relief impact ground pressure prevention and control device comprises a connecting rod: used for sending the high-energy fluid generating chamber and the plugging system into the borehole, supplying the fluid and leading out the conductor;

[0008] Sealing system: used to seal the borehole;

[0009] High-energy fluid generating chamber: used to generate high-energy fluid;

[0010] Repeated pressure relief end: installed at the end of the high-energy fluid generating compartment, used for repeated opening and closing and releasing high-energy fluid to fracture the rock mass;

[0011] Shaped charge projectile: installed inside the high-energy fluid generating chamber, used to generate a large amount of heat, heat the fluid to increase its temperature and pressure, and form a high-energy fluid.

[0012] A fluid conduit and a wire conduit are arranged inside the connecting rod, and the connecting rod passes through the blocking system and is connected to the high-energy fluid generating cabin; a blocking system water inlet is arranged on the outer wall of the fluid conduit located inside the blocking system, and the end of the fluid conduit is a water supply port for the high-energy fluid generating cabin;

[0013] The high-energy fluid generating chamber comprises a high-energy fluid generating chamber body, and the high-energy fluid generating chamber body comprises an end portion two for connecting with the blocking system, and the end portion two is penetrated by a fluid one-way valve for connecting with the water supply port of the high-energy fluid generating chamber; the end portion two is also provided with a threaded column, and the threaded column is provided with a wire and a sensor wire group, and the wire and the sensor wire group comprise a wire located inside the threaded column and a temperature and pressure sensor located on the surface of the threaded column and connected to the wire, and the wire passes through the end portion two and extends to the wire guide tube; the end of the threaded column is provided with a repetitive ignition head for exciting the shaped energy projectile; the repetitive ignition head is connected to the wire; the middle part of the threaded column is provided with an external thread; the side of the high-energy fluid generating chamber body opposite to the end portion two is provided with an opening for threaded connection with the repetitive pressure relief end;

[0014] The repetitive pressure relief end portion comprises a threaded portion for connecting with the opening, a sealing portion is integrally connected to the inner side of the threaded portion, a sealing groove for placing a sealing ring is arranged on the sealing portion, a pressure relief portion is integrally connected to the outer side of the threaded portion, a fluid channel is arranged inside the repetitive pressure relief end portion, the fluid channel comprises two symmetrically arranged fluid channels one, the head end of the fluid channel one is connected to the interior of the high-energy fluid generating chamber, the end of the fluid channel one extends to the pressure relief portion and is connected to the head end of the fluid channel two, the end of the fluid channel two opens to the rock mass to be fractured; the fluid channel one and the fluid channel two are arranged perpendicularly; a blocking groove is arranged at the connection between the fluid channel one and the fluid channel two, the inner diameter of the blocking groove is larger than the diameter of the fluid channel one, a magnetic blocking block is arranged in the blocking groove; a spring is arranged below the magnetic blocking block;

[0015] The energy-gathering projectile includes a threaded pipe section used to be connected to the external thread of the threaded column, the threaded pipe section is integrally connected to the repetitive ignition head docking interface, a projectile shell is arranged outside the repetitive ignition head docking interface, and an energy-gathering agent is arranged inside the projectile shell; when the energy-gathering projectile is connected to the repetitive ignition head, the repetitive ignition head docking interface contacts the repetitive ignition head located inside the projectile shell.

[0016] The plugging system is a plugging fluid chamber, which includes two end portions one for penetrating the connecting rod, a connecting rod welding point is between the connecting rod and the end portions one, and a high-pressure expansion portion connects the two end portions one to form the plugging fluid chamber.

[0017] The high-pressure expansion part is a hydrogenated nitrile rubber tube, and the surface of the hydrogenated nitrile rubber tube is processed with a plurality of annular protrusions.

[0018] The outer diameters of the sealing portion, the threaded portion and the pressure relief portion increase sequentially.

[0019] The spring is a high-elasticity spring; the high-elasticity spring is a 65Mn spring; a support column with a top flush with the bottom surface of the block groove is arranged at the center of the high-elasticity spring, an iron block is welded on the outer surface of the end of the fluid channel one, and the magnetic blocking block is a strong neodymium iron boron magnet; the materials of the high-energy fluid generating cabin and the repetitive pressure relief end are both Hastelloy C-4 alloy.

[0020] The material of the repetitive ignition head is tungsten-copper alloy; the material of the projectile shell is polypropylene plastic.

[0021] The sealing ring is a perfluoroether rubber O-type sealing ring; the outside of the wire is wrapped with aerogel felt.

[0022] The method of using a high-energy fluid impact fracturing pressure relief rock burst prevention and control device comprises the following steps:

[0023] S1, drilling a hole using a drilling rig, assuming that the diameter of the plugging system of the device is D, the diameter of the drill hole is D+10 mm, and the drill hole is driven from the coal mining face through the coal seam into the rock stratum roof until the center line of the rock stratum roof;

[0024] S2, installation, during assembly, first sprinkle magnesium powder on the interface of the repetitive ignition head and the repetitive ignition head, then apply high-temperature sealant on the connection between the threaded column and the threaded pipe section, then screw the shaped projectile on the repetitive ignition head, then install the sealing ring on the repetitive pressure relief end and install it on the high-energy fluid generating cabin;

[0025] S3, using a connecting rod to send the device into the borehole until it reaches the bottom of the borehole;

[0026] S4, after reaching the bottom of the borehole, use a booster pump to pump the fluid through the fluid conduit of the connecting rod and the water inlet of the plugging system into the plugging system, and then into the high-energy fluid generating chamber through the water supply port of the high-energy fluid generating chamber. Continue to pump the fluid until the pressure reaches 20 MPa, and then close the fluid check valve between the booster pump and the fluid conduit;

[0027] S5, the fluid check valve of the high-energy fluid generating chamber is closed to preserve the 20MPa high-pressure fluid, the wire is led out and the power is turned on, the temperature and pressure sensor is connected to the data acquisition instrument and displayed on the computer;

[0028] S6, the power supply is turned on, the repetitive ignition head is stimulated, the high temperature is generated to ignite the magnesium powder and the energy-gathering agent, a large amount of heat is released, the fluid is heated, the temperature and pressure are increased, and a high-energy fluid is obtained;

[0029] S7, when the pressure rises to the release pressure, the magnetic sealing block is opened to the sealing block groove, and the high-energy fluid is released instantly through the fluid channel, generating a shock wave and releasing a large amount of high-energy fluid to fully fracture the rock mass and complete the top cutting;

[0030] S8, when the pressure relief is completed, the elastic force of the spring makes the magnetic sealing block return to its original position, wait for the top plate of the rock formation to fall behind, open the fluid check valve between the booster pump and the fluid conduit, relieve the pressure of the sealing system, and the entire device withdraws from the borehole.

[0031] The fluid includes water, CO2 or N2; the high temperature sealant is MT331 high temperature resistant red sealant.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The present invention provides a device and method for artificially relieving pressure on the coal seam roof to prevent and control rock burst, which can replace traditional blasting and hydraulic fracturing. The present invention can well solve the rock burst risk faced by hard roof mining areas. The method has small impact stress, weak vibration, less dust and convenient construction.

[0034] In the present invention, after the plugging system is filled with fluid, the high-pressure expansion part expands and seals the borehole, thereby ensuring that the high-energy fluid is fully used to fracture the rock mass during pressure relief. The structure of the repetitive pressure relief end, the block groove is used to accommodate the magnetic block that is lowered during pressure relief; the fluid channel is the channel for the high-pressure fluid to leak out; the magnetic block can rely on magnetic attraction to prevent the high-pressure fluid from leaking out; the spring can return the magnetic block to its original position after pressure relief. The combination of these structures realizes the repetitive pressure relief of the present invention and can also prevent the magnetic block from being damaged due to excessive impact force. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a structural schematic diagram of the present invention;

[0036] Figure 2 It is a structural schematic diagram of the connecting rod in the present invention;

[0037] Figure 3 It is a structural schematic diagram of the blocking system in the present invention;

[0038] Figure 4 It is a schematic diagram of the structure of the high-energy fluid generating cabin in the present invention;

[0039] Figure 5 It is a structural schematic diagram of the repetitive pressure relief end in the present invention;

[0040] Figure 6 It is a schematic diagram of the structure of the shaped charge projectile in the present invention;

[0041] Figure 7 It is a structural schematic diagram of the high pressure expansion part in the present invention;

[0042] Figure 8 It is a structural schematic diagram of the spring in the present invention;

[0043] Fig. 9 Schematic diagram of the method of the present invention. DETAILED DESCRIPTION

[0044] The present invention will be further described below in conjunction with the accompanying drawings.

[0045] like Figure 1 As shown, a high-energy fluid impact fracturing pressure relief impact ground pressure prevention and control device comprises: a connecting rod 1, a plugging system 2, a high-energy fluid generating chamber 3, a repetitive pressure relief end 4 and a shaped energy projectile 5; the connecting rod 1 is used to send the high-energy fluid generating chamber 3 and the plugging system 2 into the borehole 101 and supply fluid and lead out the wire; the plugging system 2 is used to plug the borehole 101; the high-energy fluid generating chamber 3 is used to generate high-energy fluid; the repetitive pressure relief end 4 is installed at the end of the high-energy fluid generating chamber 3, and can realize repetitive opening and closing, and release fluid under a certain pressure to fracture the rock mass; the shaped energy projectile 5 is used to generate a large amount of heat to heat the fluid to increase its temperature and pressure.

[0046] like Figure 2 As shown, the connecting rod 1 includes: a fluid conduit 11, a sealing system water inlet 12, a wire conduit 13 and a high-energy fluid generating chamber water supply port 14, the fluid conduit 11 is used to supply fluid to the high-energy fluid generating chamber 3 and the sealing system 2; the sealing system water inlet 12 is a channel for the fluid to enter the sealing system 2; the wire conduit 13 is used to lead out the wires in the high-energy fluid generating chamber 3; the high-energy fluid generating chamber water supply port 14 and the fluid one-way valve 32 are used to inject high-pressure fluid into the high-energy fluid generating chamber 3.

[0047] like Figure 3As shown, the plugging system 2 includes: a connecting rod welding part 21, a plugging fluid chamber 22, a high-pressure expansion part 23 and an end part 24. The connecting rod welding part 21 ensures that the connecting rod 1 is seamlessly connected to the plugging system 2; the plugging fluid chamber 22 is used to accommodate the plugging fluid; the high-pressure expansion part 23 is filled with high-pressure fluid in the plugging fluid chamber 22 and then expands circumferentially to contact the wall of the borehole 101 to achieve hole sealing; the end part 24 provides a connection part for the connecting rod 1.

[0048] like Figure 4 As shown, the high-energy fluid generating chamber 3 includes: a wire and sensor wire group 31, a fluid one-way valve 32, a temperature and pressure sensor 33, a threaded column 34, a repetitive ignition head 35 and a high-energy fluid generating chamber body 36; the fluid one-way valve 32 is a channel for injecting fluid and can prevent the fluid from leaking out after ignition; the temperature and pressure sensor 33 can collect the pressure and temperature in the high-energy fluid generating chamber 3; the threaded column 34 is used for the installation of the shaped projectile 5; the repetitive ignition head 35 is used to excite the shaped projectile 5 and can be used repeatedly; the high-energy fluid generating chamber body 36 is used to contain high-temperature and high-pressure fluid.

[0049] like Figure 5 As shown, the repetitive pressure relief end 4 includes: a sealing groove 41, a blocking groove 42, a fluid channel 43, a magnetic blocking block 44 and a spring 45; the sealing groove 41 is used to place a sealing ring to achieve high-pressure sealing; the blocking groove 42 is used to accommodate the magnetic blocking block 44 that is lowered during pressure relief; the fluid channel 43 is a channel for high-pressure fluid to leak out; the magnetic blocking block 44 can rely on magnetic attraction to prevent the high-pressure fluid from leaking out; the spring 45 can return the magnetic blocking block 44 to its original position after pressure relief.

[0050] like Figure 6 As shown, the energy-gathering projectile 5 includes: a threaded pipe section 51, a repetitive ignition head docking port 52, a projectile shell 53 and an energy-gathering agent 54; the repetitive ignition head docking port 52 is used to closely contact with the repetitive ignition head 35 to ignite the energy-gathering agent 54; the projectile shell is used to accommodate the energy-gathering agent and pyrolyzes after the energy-gathering agent burns, which is beneficial to the release of heat; the energy-gathering agent is used for rapid combustion and heat supply, and due to its high density, it burns quickly and releases a large amount of heat.

[0051] Specifically, a fluid conduit 11 and a wire conduit 13 which are parallel to each other are arranged inside the connecting rod 1, and the connecting rod 1 passes through the blocking system 2 and is connected to the high-energy fluid generating chamber 3; a blocking system water inlet 12 is provided on the outer wall of the fluid conduit 11 located inside the blocking system 2, and the end of the fluid conduit 11 is a high-energy fluid generating chamber water supply port 14.

[0052] The plugging system 2 is a plugging fluid chamber 22, which includes two end portions 24 for penetrating the connecting rod 1. The two end portions 24 are arranged opposite to each other. A connecting rod welding point 21 is between the connecting rod 1 and the end portions 24. A high-pressure expansion portion 23 connects the two end portions 24 to form the plugging fluid chamber 22.

[0053] The high-energy fluid generating chamber 3 includes a high-energy fluid generating chamber body 36, which includes an end portion 2 for connecting to the blocking system 2, and a fluid one-way valve 32 for connecting to the water supply port 14 of the high-energy fluid generating chamber is penetrated by the end portion 2; a threaded column 34 is also provided on the end portion 2, and a wire and sensor wire group 31 is provided on the threaded column 34, and the wire and sensor wire group 31 includes a wire located inside the threaded column 34 and a temperature and pressure sensor 33 located on the surface of the threaded column 34 and connected to the wire, and the temperature and pressure sensor 33 is connected to a data acquisition instrument, and the data acquisition instrument is connected to a computer; the wire passes through the end portion 2 and extends to the wire conduit 13 and is connected to an external power supply; a repetitive ignition head 35 for exciting the shaped energy projectile 5 is provided at the end of the threaded column 34; the repetitive ignition head 35 is connected to the wire; an external thread is provided in the middle of the threaded column 34; an opening for threaded connection with the repetitive pressure relief end 4 is provided on the side of the high-energy fluid generating chamber body 36 opposite to the end portion 2. The outer diameters of end one 24 and end two are the same.

[0054] The repetitive pressure relief end 4 includes a threaded portion for connecting with an opening, a sealing portion is integrally connected to the inner side of the threaded portion, a sealing groove 41 for placing a sealing ring is arranged on the sealing portion, and a pressure relief portion is integrally connected to the outer side of the threaded portion, and the outer diameters of the sealing portion, the threaded portion and the pressure relief portion increase successively; a fluid channel 43 is arranged inside the repetitive pressure relief end 4, and the fluid channel 43 includes two symmetrically arranged fluid channels one, the head end of the fluid channel one is connected to the interior of the high-energy fluid generating chamber 3, the end of the fluid channel one extends to the pressure relief portion and is connected to the head end of the fluid channel two, and the end of the fluid channel two opens to the rock mass to be fractured; the fluid channel one and the fluid channel two are arranged perpendicularly; a blocking groove 42 is arranged at the connection between the fluid channel one and the fluid channel two, the inner diameter of the blocking groove 42 is larger than the diameter of the fluid channel one, and a magnetic blocking block 44 is arranged in the blocking groove 42; a spring 45 is arranged below the magnetic blocking block 44.

[0055] The energy-gathering projectile 5 includes a threaded pipe section 51 for connecting to the external thread of the threaded column 34. The threaded pipe section 51 is integrally connected to the repetitive ignition head docking interface 52. A projectile shell 53 is arranged outside the repetitive ignition head docking interface 52, and an energy-gathering agent 54 is arranged inside the projectile shell 53. When the energy-gathering projectile 5 is connected to the repetitive ignition head 35, the repetitive ignition head docking interface 52 contacts the repetitive ignition head 35 located inside the projectile shell 53.

[0056] Preferably, the repetitive ignition head 35 uses a tungsten-copper alloy, which has high hardness, high melting point, and excellent high-temperature working performance, is suitable for high-temperature working conditions, and can be reused.

[0057] Preferably, the high-energy fluid generating chamber 36 and the repetitive pressure relief end 4 are both made of Hastelloy C-4 alloy. Hastelloy C-4 alloy has good toughness and corrosion resistance at 650°C-1040°C, can withstand high temperatures and be used for a long time.

[0058] Preferably, the magnetic blocking block 44 uses a strong neodymium iron boron magnet, which has the advantages of small size, light weight and strong magnetism.

[0059] Preferably, argon arc welding is used for welding the plugging system 2 and the connecting rod 1, so as to achieve a dense and high-quality welded joint under the protection of argon inert gas.

[0060] Preferably, the sealing ring used in the sealing groove 41 of the repetitive pressure relief end 4 is a special perfluoroether rubber O-ring, which is resistant to high temperature and high pressure and solvent corrosion, and can reduce the number of replacement times.

[0061] Preferably, when the threaded pipe section 51 of the shaped projectile 5 is assembled with the threaded column 34 of the high-energy fluid generating chamber 3, high-temperature sealant needs to be applied to prevent the high-temperature fluid from invading the shaped projectile 5 and making the shaped agent 54 ineffective and unable to ignite. The high-temperature sealant is MT331 high-temperature resistant red glue.

[0062] Preferably, the spring 45 of the repetitive pressure relief end 4 is a high-elasticity spring, and the high-elasticity spring is a 65Mn spring made of oil-quenched carbon spring steel wire material, which has the advantages of high strength and good toughness and can be used repeatedly.

[0063] Preferably, the high-pressure expansion part 23 of the plugging system 2 is made of hydrogenated nitrile butadiene rubber, which has good heat resistance and corrosion resistance.

[0064] Preferably, if Figure 7 As shown, the surface of the high-pressure expansion portion 23 is processed with a plurality of annular protrusions 232, and the angle of the protruding portion is 45°. The advantage of such processing is that multiple sealing layers can be achieved to ensure the sealing effect, and at the same time, the friction force can be increased to reduce the stress at the welding point between the sealing system 2 and the connecting rod 1.

[0065] Preferably, a layer of magnesium powder needs to be sprinkled on the repetitive ignition head docking interface 52 of the shaped-energy projectile 5 when it is assembled with the repetitive ignition head 35. This active metal powder burns quickly after being excited at high temperature by the repetitive ignition head 35, and can ignite the shaped-energy agent 54 evenly and quickly.

[0066] Preferably, the wires and the sensor wire group 31 are wrapped with aerogel felt. Aerogel felt, a new type of thermal insulation material, has a low thermal conductivity and can isolate the wires from damage caused by the ultra-high temperature of the high-temperature fluid.

[0067] Preferably, if Figure 8 As shown, the contact portion of the magnetic blocking block 44 of the repetitive pressure relief end 4 is welded with an iron block 451. Since the Hastelloy C-4 alloy does not have magnetic attraction, the iron block 451 needs to be welded in order to achieve the self-sealing function.

[0068] Preferably, if Figure 8 As shown, a support column 452 flush with the bottom surface of the blocking block groove 42 is provided at the center of the spring 45 of the repetitive pressure relief end 4, for supporting the magnetic blocking block 44 to prevent the magnetic blocking block 44 from being damaged due to excessive impact force.

[0069] like Fig. 9 As shown, a method for using a high-energy fluid impact fracturing pressure relief rock burst prevention and control device comprises the following steps:

[0070] S1. Drill hole 101 using a drilling rig. Assuming that the diameter of the device used is D and the diameter of the drill hole 101 is D+10 mm, drill hole 101 from coal mining face 102 through coal seam 103 into rock stratum roof 104 until the center line of rock stratum roof 104;

[0071] S2. Install the device in the following steps: sprinkle magnesium powder on the shaped projectile 5, apply high-temperature sealant, screw it on the repetitive ignition head 35, and then install the repetitive pressure relief end 4 with a sealing ring and install it on the high-energy fluid generating chamber 3; specifically: during assembly, first sprinkle magnesium powder on the repetitive ignition head docking interface 52 and the repetitive ignition head 35, then apply high-temperature sealant on the connection between the threaded column 34 and the threaded pipe section 51, then screw the shaped projectile 5 on the repetitive ignition head 35, and then install the repetitive pressure relief end 4 with a sealing ring and install it on the high-energy fluid generating chamber 3;

[0072] S3, using the connecting rod 1 to send the device into the borehole 101, extending it to the bottom of the borehole 101;

[0073] S4. After reaching the bottom of the borehole 101, use a booster pump to pass the fluid through the fluid conduit 11 of the connecting rod 1 through the plugging system water inlet 12 into the plugging system 2 (the fluid can be water, CO2, or N2), and enter the high-energy fluid generating cabin 3 through the high-energy fluid generating cabin water supply port 14. Continue to feed the fluid until the pressure reaches 20 MPa, and then close the fluid check valve 32 between the booster pump and the fluid conduit 11;

[0074] S5, the fluid check valve 32 of the high-energy fluid generating chamber 3 is closed to preserve the 20MPa high-pressure fluid, the wire is led out and the power is turned on, the temperature and pressure sensor 33 is connected to the data acquisition instrument and displayed on the computer;

[0075] S6, the power supply is turned on to excite the repetitive ignition head 35, generating high temperature to ignite the magnesium powder and the energy-gathering agent 54, releasing a large amount of heat, heating the fluid, and increasing its temperature and pressure;

[0076] S7, when the pressure rises to the release pressure, the magnetic blocking block 44 is pushed open to the blocking block groove 42, and the fluid is released instantly through the fluid channel 43, generating a shock wave and releasing a large amount of high-energy fluid to fully fracture the rock mass, completing the top cutting;

[0077] S8. After the pressure relief is completed, the elastic force of the spring 45 returns the magnetic blocking block 44 to its original position, and after the top plate is stepped down, the fluid one-way valve 32 between the booster pump and the fluid conduit 11 is opened to relieve the pressure of the blocking system 2, and the entire device withdraws from the borehole 101.

[0078] In the description provided herein, a large number of specific details are described. However, it is understood that embodiments of the present invention can be practiced without these specific details. In some instances, well-known methods, structures and techniques are not shown in detail so as not to obscure the understanding of this description.

[0079] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by the terms "up", "down", "front", "back", "left", "right", etc. are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0080] Similarly, it should be understood that in order to streamline the present disclosure and aid in understanding one or more of the various inventive aspects, in the above description of exemplary embodiments of the present invention, various features of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. However, this disclosed method should not be interpreted as reflecting the intention that the claimed invention requires more features than those expressly recited in each claim. Rather, as reflected in the claims, inventive aspects lie in less than all of the features of the individual embodiments previously disclosed. Therefore, the claims that follow the detailed description are hereby expressly incorporated into the detailed description, with each claim itself serving as a separate embodiment of the present invention.

[0081] As used herein, unless otherwise specified, the use of ordinal numbers "first," "second," "third," etc. to describe common objects merely indicates that different instances of similar objects are involved, and is not intended to imply that the objects so described must have a given order in time, space, order, or in any other manner.

[0082] Although the present invention has been described according to a limited number of embodiments, it will be apparent to those skilled in the art, with the benefit of the above description, that other embodiments may be envisioned within the scope of the invention thus described. In addition, it should be noted that the language used in this specification is selected primarily for readability and teaching purposes, rather than for explaining or defining the subject matter of the present invention. Therefore, many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the appended claims. The disclosure of the present invention is illustrative, not restrictive, with respect to the scope of the present invention, which is defined by the appended claims.

[0083] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A device for preventing and controlling rock pressure caused by high-energy fluid impact fracturing and pressure relief, characterized in that: It comprises a connecting rod (1) used for delivering a high-energy fluid generating chamber (3) and a plugging system (2) into a borehole (101), supplying fluid and leading out a conductor; A plugging system (2): used for plugging the borehole (101); High-energy fluid generating chamber (3): used for generating high-energy fluid; Repeated pressure relief end (4): installed at the end of the high-energy fluid generating chamber (3), used for repeatedly opening and closing and releasing high-energy fluid to fracture the rock mass; The shaped projectile (5) is installed inside the high-energy fluid generating chamber (3) to generate a large amount of heat, heat the fluid to increase its temperature and pressure, and form a high-energy fluid; A fluid channel (43) is arranged inside the repetitive pressure relief end (4), and the fluid channel (43) includes two symmetrically arranged fluid channels one, the head end of the fluid channel one is connected to the inside of the high-energy fluid generating chamber (3), the end of the fluid channel one extends to the pressure relief portion and is connected to the head end of the fluid channel two, and the end of the fluid channel two opens to the rock mass to be fractured; the fluid channel one and the fluid channel two are arranged perpendicularly; a blocking groove (42) is arranged at the connection point between the fluid channel one and the fluid channel two, the inner diameter of the blocking groove (42) is larger than the diameter of the fluid channel one, and a magnetic blocking block (44) is arranged in the blocking groove (42); and a spring (45) is arranged below the magnetic blocking block (44); The high-energy fluid generating chamber (3) comprises a repetitive ignition head (35), and the shaped-energy projectile (5) comprises a repetitive ignition head docking interface (52) and a projectile shell (53), wherein an energy-gathering agent (54) is arranged in the projectile shell (53); when the shaped-energy projectile (5) is connected to the repetitive ignition head (35), the repetitive ignition head docking interface (52) contacts the repetitive ignition head (35) located inside the projectile shell (53).

2. The high-energy fluid impact fracturing pressure relief device according to claim 1, characterized in that: A fluid conduit (11) and a wire conduit (13) are arranged inside the connecting rod (1), and the connecting rod (1) penetrates the plugging system (2) and is connected to the high-energy fluid generating chamber (3); a plugging system water inlet (12) is provided on the outer wall of the fluid conduit (11) located inside the plugging system (2), and the end of the fluid conduit (11) is a water supply port (14) of the high-energy fluid generating chamber; The high-energy fluid generating chamber (3) comprises a high-energy fluid generating chamber body (36), the high-energy fluid generating chamber body (36) comprising an end portion (2) for connecting to the plugging system (2), the end portion (2) being penetrated by a fluid check valve (32) for connecting to a water supply port (14) of the high-energy fluid generating chamber; the end portion (34) is also provided with a threaded column (34), the threaded column (34) being provided with a wire and a sensor wire group (31), the wire and the sensor wire group (31) comprising a wire and a sensor wire group (31) located inside the threaded column (34) A temperature and pressure sensor (33) is located on the surface of the threaded column (34) and connected to a wire, the wire passing through the second end and extending to the wire guide tube (13); a repetitive ignition head (35) for exciting the shaped energy projectile (5) is provided at the end of the threaded column (34); the repetitive ignition head (35) is connected to the wire; an external thread is provided in the middle of the threaded column (34); an opening for threaded connection with the repetitive pressure relief end (4) is provided on a side of the high-energy fluid generating chamber (36) opposite to the second end; The repetitive pressure relief end (4) comprises a threaded portion for connecting to an opening, a sealing portion is integrally connected to the inner side of the threaded portion, a sealing groove (41) for accommodating a sealing ring is provided on the sealing portion, and a pressure relief portion is integrally connected to the outer side of the threaded portion; The shaped charge projectile (5) comprises a threaded pipe section (51) for connecting to the external thread of the threaded column (34); the threaded pipe section (51) is integrally connected to the repetitive ignition head docking interface (52).

3. The high-energy fluid impact fracturing pressure relief rock pressure prevention and control device according to claim 2, characterized in that: The plugging system (2) is a plugging fluid chamber (22), the plugging fluid chamber (22) comprising two end portions (24) for penetrating the connecting rod (1), a connecting rod welding portion (21) between the connecting rod (1) and the end portions (24), and a high-pressure expansion portion (23) connecting the two end portions (24) to form the plugging fluid chamber (22).

4. The high-energy fluid impact fracturing pressure relief device according to claim 3 is characterized in that: The high-pressure expansion portion (23) is a hydrogenated nitrile rubber tube (231), and a surface of the hydrogenated nitrile rubber tube (231) is processed to have a plurality of annular protrusions (232).

5. The high-energy fluid impact fracturing pressure relief rock pressure prevention and control device according to claim 2, characterized in that: The outer diameters of the sealing portion, the threaded portion and the pressure relief portion increase in sequence.

6. The high-energy fluid impact fracturing pressure relief rock pressure prevention and control device according to claim 2, characterized in that: The spring (45) is a high-elasticity spring; the high-elasticity spring is a 65Mn spring; a support column (452) with a top flush with the bottom surface of the block groove (42) is arranged at the center of the high-elasticity spring; an iron block (451) is welded to the outer surface of the end of the fluid channel 1; the magnetic blocking block (44) is a strong neodymium iron boron magnet; the high-energy fluid generating chamber (3) and the repetitive pressure relief end (4) are both made of Hastelloy C-4 alloy.

7. The high-energy fluid impact fracturing pressure relief rock pressure prevention and control device according to claim 2, characterized in that: The material of the repetitive ignition head (35) is tungsten copper alloy; the material of the projectile shell (53) is polypropylene plastic.

8. The high-energy fluid impact fracturing pressure relief rock pressure prevention and control device according to claim 2, characterized in that: The sealing ring is a perfluoroether rubber O-type sealing ring; the outside of the wire is wrapped with aerogel felt.

9. A method for using the high-energy fluid impact fracturing pressure relief rock burst prevention and control device according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1, drilling a hole (101) using a drilling machine, assuming that the diameter of the plugging system (2) of the device is D, the diameter of the drill hole (101) is D+10 mm, and the drill hole (101) is driven from the coal mining face (102) through the coal seam (103) into the rock formation roof (104) until the center line of the rock formation roof (104); S2, installation, during assembly, first sprinkle magnesium powder on the repetitive ignition head interface (52) and the repetitive ignition head (35), then apply high-temperature sealant on the connection between the threaded column (34) and the threaded pipe section (51), then screw the shaped projectile (5) onto the repetitive ignition head (35), then install the sealing ring on the repetitive pressure relief end (4) and install it on the high-energy fluid generating chamber (3); S3, using the connecting rod (1) to push the device into the borehole (101), extending it to the bottom of the borehole (101); S4, after reaching the bottom of the borehole (101), a booster pump is used to push the fluid through the fluid conduit (11) of the connecting rod (1) and the plugging system water inlet (12) into the plugging system (2), and then into the high-energy fluid generating chamber (3) through the high-energy fluid generating chamber water supply port (14). The fluid is continuously fed until the pressure reaches 20 MPa, and the fluid check valve (32) between the booster pump and the fluid conduit (11) is closed; S5, the fluid check valve (32) of the high-energy fluid generating chamber (3) is closed to retain the 20 MPa high-pressure fluid, the wire is led out and connected to the power supply, the temperature and pressure sensor (33) is connected to the data acquisition instrument and displayed using a computer; S6, the power source is turned on, the repetitive ignition head (35) is excited, a high temperature is generated to ignite the magnesium powder and the energy-gathering agent (54), a large amount of heat is released, the fluid is heated, the temperature and pressure thereof are increased, and a high-energy fluid is obtained; S7, when the pressure rises to the release pressure, the magnetic sealing block (44) is pushed open to the sealing block groove (42), and the high-energy fluid is instantly released through the fluid channel (43), generating a shock wave and releasing a large amount of high-energy fluid to fully fracture the rock mass, thereby completing the top cutting; S8, when the pressure relief is completed, the elastic force of the spring (45) causes the magnetic blocking block (44) to return to its original position, and after waiting for the top plate (104) of the rock formation to be stepped over, the fluid check valve (32) between the booster pump and the fluid conduit (11) is opened to relieve the pressure of the blocking system (2), and the entire device is withdrawn from the borehole (101).

10. The method according to claim 9, characterized in that The fluid includes water, CO2 or N2; the high temperature sealant is MT331 high temperature resistant red sealant.

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