Mine borehole presplitting device, method and system

Abstract

The application discloses a mine drilling pre-splitting device, method and system. The device comprises a packer controller, a pre-splitting module and a flow guide. The pre-splitting module comprises a plurality of packers and at least one jetting device, and the jetting device is arranged between every two packers. One end of the packer controller is connected with one end of a head packer in the pre-splitting module. The packer controller sprays high-pressure liquid flowing into the device through the jetting device to slit and pre-split a mine drilling hole needing pre-splitting, and the high-pressure liquid flows into the packer to expand the packer to seal the area between the outer surface of the jetting device and the inner surface of the drilling hole. One end of the flow guide is connected with one end of a tail packer in the pre-splitting module, and the flow guide is used for flowing the high-pressure liquid out of the device after the rock mass is cracked. Through the technical scheme, the high-pressure liquid can be sprayed from the jetting device to cut and pre-split the surrounding rock wall.

Description

Technical Field

[0001] This application relates to the field of mining technology, and in particular to a pre-fracture device, method and system for mine boreholes. Background Technology

[0002] In related technologies, double-end plugging hydraulic fracturing technology or directional hydraulic fracturing technology is usually used to pre-fracture the borehole. However, the construction procedures of double-end plugging hydraulic fracturing technology and directional hydraulic fracturing technology are complicated, requiring multiple disassemblies of the drill rod, and the double-end plugging hydraulic fracturing technology requires a higher fracturing pressure. Summary of the Invention

[0003] This application provides a pre-fracture device, method, and system for mine boreholes. It allows for the cutting of surrounding rock walls by ejecting high-pressure liquid from an ejector, and the pre-fracture of the rock walls using an expansion capsule that expands under the pressure of the high-pressure liquid.

[0004] In a first aspect, embodiments of this application provide a mine borehole pre-fracture device, comprising: a packer controller, a pre-fracture module, and a diverter, wherein the pre-fracture module includes multiple packers and at least one jetter, with the jetter disposed between every two packers; one end of the packer controller is connected to one end of the first packer in the pre-fracture module; wherein the packer controller sprays high-pressure liquid flowing into the device through the jetter to cut and pre-fracture the mine borehole requiring pre-fracture, and directs the high-pressure liquid into the packers, causing the packers to expand and seal the area between the outer surface of the jetter and the inner surface of the borehole; one end of the diverter is connected to one end of the tail packer in the pre-fracture module, and the diverter is used to drain the high-pressure liquid out of the device after the rock mass has fractured.

[0005] In this technical solution, high-pressure liquid can be ejected from the jet injector to cut the surrounding rock wall, and an expansion capsule that can expand under the pressure of the high-pressure liquid can be used to pre-crack the rock wall.

[0006] In one implementation, the packer includes an inflatable capsule and a central tube. The ejector has a first through hole, a second through hole, and a third through hole. The central tube is disposed inside the inflatable capsule. A cavity is formed between the outer surface of the central tube and the inner surface of the inflatable capsule. The central tubes of two adjacent packers are connected through the first through hole. The cavities of two adjacent packers are connected through the second through hole. The inner surface of the first through hole is connected to the outer surface of the ejector through the third through hole. A first control valve that can be opened under pressure is disposed in the third through hole.

[0007] In one optional implementation, the expansion capsule is connected to the containment controller, the jet injector, and the drainer via a locking head, the locking head comprising a clamp, a first auxiliary return spring, and a sliding base, wherein the clamp is connected to the sliding base; one end of the first auxiliary return spring is connected to the containment controller, the jet injector, and the drainer; the other end of the first auxiliary return spring is connected to the sliding base; and the end of the expansion capsule is clamped between the sliding base and the clamp.

[0008] In one optional implementation, the packer controller has a fourth through hole and a fifth through hole, wherein the fourth through hole is connected to the central tube of the head packer; one end of the fifth through hole is connected to the cavity of the head packer; the other end of the fifth through hole is connected to the fourth through hole; and a second control valve that can be opened under pressure is provided in the fifth through hole.

[0009] In one optional implementation, the drain has a sixth through hole and a seventh through hole, wherein the sixth through hole is connected to the central tube of the tail packer; one end of the seventh through hole is connected to the cavity of the tail packer; the other end of the seventh through hole is connected to the outer surface of the drain; and a third control valve that can be closed under pressure is provided in the seventh through hole.

[0010] In one implementation, the device further includes an adapter and a wall scraping module, wherein one end of the adapter can be connected to the injection drill rod, and the high-pressure liquid in the injection drill rod can flow into the device through the adapter; the other end of the adapter is connected to the other end of the packing controller; and the other end of the drainer is connected to the wall scraping module.

[0011] This technical solution enables the completion of jet cutting and controlled fracturing operations within the borehole without removing the drill rod during drilling operations, achieving the integration and streamlining of the "drill-cut-fracturing" process.

[0012] In one optional implementation, the wall scraping module includes a wall scraping blade and a wall scraping drill bit, wherein the wall scraping blade is disposed on the outer surface of the wall scraping drill bit; the wall scraping drill bit has an eighth through hole; the eighth through hole communicates with the drainer; and a fourth control valve that can be closed under pressure is disposed in the eighth through hole.

[0013] Secondly, this application provides a method for pre-fracture of mine boreholes, characterized in that the method is based on the mine borehole pre-fracture device described in the first aspect, and the method includes: when the device reaches the pre-fracture position in the borehole where pre-fracture is required, continuously injecting high-pressure liquid into the central tube; controlling the pressure of the high-pressure liquid to close the fourth control valve and open the first control valve, thereby causing the high-pressure liquid to spray out from the ejector and rotate the device to form radial cracks in the borehole; stopping the rotation of the device and continuing to control the pressure of the high-pressure liquid to force the second control valve to open, thereby causing the high-pressure liquid to enter the pre-fracture module, and the expansion capsule to expand under pressure and crack the rock mass around the borehole; stopping the injection of the high-pressure liquid, closing the first control valve and the second control valve, and opening the third control valve and the fourth control valve, thereby discharging the high-pressure liquid in the mine borehole pre-fracture device and completing the mine borehole pre-fracture.

[0014] In one implementation, before placing the mine borehole pre-fracture device into the mine borehole to be pre-fractured, the method further includes: using the scraping module to perform drilling operations in the mine to obtain the mine borehole to be pre-fractured.

[0015] Thirdly, embodiments of this application provide a mine borehole pre-fracturing system, characterized in that it includes: a mine borehole pre-fracturing device as described in the first aspect; a fluid injection drill rod connected to the mine borehole pre-fracturing device; and a high-pressure pump set connected to the fluid injection drill rod.

[0016] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this application, nor is it intended to limit the scope of this application. Other features of this application will become readily apparent from the following description. Attached Figure Description

[0017] The accompanying drawings are provided for a better understanding of this solution and do not constitute a limitation of this application. Wherein:

[0018] Figure 1 This is a schematic diagram of the structure of a mine borehole pre-fracturing device provided in an embodiment of this application;

[0019] Figure 2 This is a schematic diagram of another mine borehole pre-fracturing device provided in the embodiments of this application;

[0020] Figure 3 This is a schematic diagram of the structure of another mine borehole pre-fracturing device provided in the embodiments of this application;

[0021] Figure 4 This is a schematic diagram of a mine borehole pre-fracturing method provided in an embodiment of this application;

[0022] Figure 5 This is a schematic diagram of a mine borehole pre-fracturing system provided in an embodiment of this application. Detailed Implementation

[0023] The following description, in conjunction with the accompanying drawings, illustrates exemplary embodiments of this application, including various details to aid understanding. These should be considered merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of this application. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.

[0024] In this application, the various numerical designations such as "first" and "second" are used only for ease of description and are not intended to limit the scope of the embodiments of this application, nor do they indicate the order of events.

[0025] It should be noted that, in the description of this application, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0026] Please see Figure 1 , Figure 1 This is a schematic diagram of the structure of a mine borehole pre-fracturing device provided in an embodiment of this application. Figure 1 As shown, the device includes a packer controller 11, a pre-splitting module 12, and a drainer 13. The pre-splitting module includes multiple packers 121 and at least one jetter 122, with a jetter 122 disposed between every two packers 121. One end of the packer controller 11 is connected to one end of the first packer 121 in the pre-splitting module 12.

[0027] It should be noted that, in the embodiments of this application, the pre-splitting module 12 includes two packers 121 and one jet injector 122 as an example.

[0028] The packer controller 11 sprays the high-pressure liquid flowing into the device through the jet injector 122 to cut and pre-fracture the mine borehole that needs to be pre-fractured, and then flows the high-pressure liquid into the packer 121, causing the packer 121 to expand and seal the area between the outer surface of the jet injector and the inner surface of the borehole; one end of the drain 13 is connected to one end of the tail packer 121 in the pre-fracturing module 12, and the drain 13 is used to drain the high-pressure liquid out of the device after the rock mass is fractured.

[0029] In one implementation, the packer 121 includes an expansion capsule 1211 and a central tube 1212. The ejector 122 has a first through hole 1221, a second through hole 1222, and a third through hole 1223. The central tube 1212 is disposed inside the expansion capsule 1211. A cavity is formed between the outer surface of the central tube 1212 and the inner surface of the expansion capsule 1211. The central tubes 1212 of two adjacent packers 121 are connected through the first through hole 1221. The cavities of two adjacent packers 121 are connected through the second through hole 1222. The inner surface of the first through hole 1221 is connected to the outer surface of the ejector 122 through the third through hole 1223. A first control valve 1224 that can be opened under pressure is disposed in the third through hole 1223.

[0030] For example, one end of the expansion capsule 1211 is connected to the sealing controller 11 or the drainer 13, and the other end is connected to the ejector 122; the expansion capsule 1211 has a hollow structure, so the central tube 1212 can be disposed inside the expansion capsule 1211, and the components connected to both ends of each central tube 1212 are the same as the components connected to both ends of the expansion capsule 1211 in which the central tube 1212 is located, so that a cavity is formed between the outer surface of each central tube 1212 and the inner surface of the expansion capsule 1211 in which the central tube 1212 is located (i.e., Figure 1 In the area shown (B), the central tubes 1212 of two adjacent packers 121 are connected through a first through hole 1221 on the ejector 122 between the two packers 121; the cavities of two adjacent packers 121 are connected through a second through hole 1222 on the ejector 122 between the two packers 121; the inner surface of the first through hole 1221 and the outer surface of the ejector 122 are connected through a third through hole 1223; a first control valve 1224 is provided in the third through hole 1223, which can automatically open when the pressure it withstands is greater than or equal to a first pressure threshold.

[0031] As an example, the first pressure threshold can be 5 MPa (Million Pascal).

[0032] In some embodiments of this application, the outermost layer of the expanding capsule 1211 is an outer rubber layer, which should have certain anti-wear properties, and the expansion rate should be greater than or equal to 20%, the permanent deformation rate after multiple expansions should be less than 5%, and the rated working pressure should be greater than or equal to 70 MPa.

[0033] In some embodiments of this application, the material of the central tube 1212 may be a high-strength material of R780 or higher, and the wall thickness may be no less than 100 mm (millimeters) to ensure the pressure-bearing capacity of the central tube 1212.

[0034] In an alternative implementation, the expansion capsule 1211 is connected to the containment controller 11, the ejector 122, and the drainer 13 via locking mechanisms. See also, as an example, [link to example]. Figure 2 , Figure 2 This is a schematic diagram of another mine borehole pre-fracturing device provided in the embodiments of this application. Figure 2 The area shown is Figure 1 Region A is shown in the diagram. (As shown in the diagram...) Figure 2 As shown, the lock head includes a pipe clamp 21, a first auxiliary return spring 22, and a sliding base 23, wherein the pipe clamp 21 is connected to the sliding base 23; one end of the first auxiliary return spring 22 is connected to the sealing controller 11, the jet injector 122, and the drainer 13 respectively; the other end of the first auxiliary return spring 22 is connected to the sliding base 23; and the end of the expansion capsule 1211 is sandwiched between the sliding base 23 and the pipe clamp 21.

[0035] It is understood that one end of the pipe clamp 21 is connected to one end of the sliding base 23, and one end of the first auxiliary return spring 22 is connected to the sealing controller 11, the ejector 122 and the drainer 13 respectively according to the actual connection situation. The other end of the first auxiliary return spring 22 is connected to the sliding base 23. The sliding base 23 slides on the sealing controller 11, the ejector 122 and the drainer 13 respectively according to the actual connection situation, and keeps sealed with the sealing controller 11, the ejector 122 and the drainer 13 respectively to prevent high pressure liquid leakage. The end of the expansion capsule 1211 is clamped between the sliding base 23 and the pipe clamp 21. Thus, when the expansion capsule 1211 is compressed and expands, it drives the pipe clamp 21 and the sliding base 23 to move horizontally.

[0036] As an example, please see Figure 3 , Figure 3 This is a schematic diagram of another mine borehole pre-fracturing device provided in this application embodiment. The mine borehole pre-fracturing device shown in the schematic diagram is in the pre-fracturing working state. Figure 3 As shown, when the mine borehole pre-fracturing device is in the pre-fracturing working state, the expansion capsule 1211 is compressed and expands, which drives the pipe clamp 21 and the sliding base 23 to move horizontally, and the sliding base pulls the first auxiliary return spring 22 to stretch.

[0037] In some embodiments of this application, a sliding sealing gasket is provided between the sliding base and the sealing controller 11, the jet injector 122 and the drainer 13 respectively.

[0038] In one alternative implementation, the packer controller 11 has a fourth through hole 111 and a fifth through hole 112. The fourth through hole 111 is connected to the central tube 1212 of the head packer 121. One end of the fifth through hole 112 is connected to the cavity of the head packer 121. The other end of the fifth through hole 112 is connected to the fourth through hole 111. A second control valve 113 that can be opened under pressure is provided in the fifth through hole 112.

[0039] For example, the packer controller 11 has a fourth through hole 111 and a fifth through hole 112. The fourth through hole 111 is connected to the central tube 1212 of the packer 121 located at the head of the pre-fracture module 12, so that the high-pressure liquid flowing into the packer controller 11 can flow into the central tube 1212 of the head packer 121 through the fourth through hole 111. One end of the fifth through hole 112 is connected to the cavity of the packer 121 located at the head of the pre-fracture module 12, so that the high-pressure liquid flowing into the packer controller 11 can flow into the cavity of the head packer 121 through the fifth through hole 112. A second control valve 113 is provided in the fifth through hole 112, which can automatically open when the pressure it withstands is greater than or equal to a second pressure threshold.

[0040] It should be noted that, in the embodiments of this application, the second pressure threshold is greater than the first pressure threshold.

[0041] As an example, the second pressure threshold could be 45 MPa.

[0042] In one alternative implementation, the drain 13 is provided with a sixth through hole 131 and a seventh through hole 132, wherein the sixth through hole 131 is connected to the central tube 1212 of the tail packer 121; one end of the seventh through hole 132 is connected to the cavity of the tail packer 121; the other end of the seventh through hole 132 is connected to the outer surface of the drain 13; and a third control valve 133 that can be closed under pressure is provided in the seventh through hole 132.

[0043] For example, the drainer 13 has a sixth through hole 131 and a seventh through hole 132. The sixth through hole 131 is in sealed communication with the central tube 1212 of the packer 121 located at the tail of the pre-crack module 12, so that the high-pressure liquid in the central tube 1212 of the tail packer 121 can flow into the drainer 13. One end of the seventh through hole 132 is in communication with the cavity of the packer 121 located at the tail of the pre-crack module 12, and the other end of the seventh through hole 132 is in communication with the outer surface of the drainer 13. The seventh through hole 132 is provided with A third control valve 133 is provided, which can automatically close when the pressure it withstands is greater than or equal to a third pressure threshold. Thus, when high-pressure liquid flows into the cavity, the second through hole 1222 and the fifth through hole 112 through the second control valve, the air in the cavity, the second through hole 1222 and the fifth through hole 112 is discharged through the seventh through hole 132. After the high-pressure liquid fills the cavity, the second through hole 1222 and the fifth through hole 112, and the pressure of the high-pressure liquid is greater than the third threshold, the third control valve 133 is closed.

[0044] In one embodiment of this application, the third pressure threshold is greater than the second pressure threshold. Thus, after the injection of high-pressure liquid into the device stops, when the pressure of the liquid in the device drops to less than the second pressure threshold, the second control valve 113 closes and the third control valve 133 opens, allowing the liquid remaining in the cavity, the second through hole 1222 and the fifth through hole 112 to flow out of the device from the third control valve.

[0045] As an example, the third pressure threshold could be 46 MPa.

[0046] In one implementation, the device further includes an adapter 14 and a wall scraping module 15, wherein one end of the adapter 14 can be connected to the injection drill rod, and the high-pressure liquid in the injection drill rod can flow into the device through the adapter 14; the other end of the adapter 14 is connected to the other end of the packing controller 11; and the other end of the drainer 13 is connected to the wall scraping module 15.

[0047] For example, the above-mentioned device can be connected to the injection drill rod via adapter 14, so that the injection drill rod drives the scraping module to perform drilling operations, and the high-pressure liquid injected into the injection drill rod is introduced into the mine borehole pre-fracture device during or after drilling, so as to use the high-pressure liquid to perform borehole pre-fracture, thereby realizing the completion of borehole jet cutting and sealing fracturing operations without withdrawing the drill rod during drilling operations, realizing the integration and process of "drilling-cutting-fracture".

[0048] In one optional implementation, the wall scraping module 15 includes a wall scraping blade 151 and a wall scraping drill bit 152, wherein the wall scraping blade 151 is disposed on the outer surface of the wall scraping drill bit 152; the wall scraping drill bit 152 has an eighth through hole 153; the eighth through hole 153 communicates with the drainer 13; and a fourth control valve 154 that can be closed under pressure is disposed in the eighth through hole 153.

[0049] For example, the fourth control valve 154 is connected to the second auxiliary return spring 154; the second auxiliary return spring 154 is connected to the surface of the eighth through hole 153; the eighth through hole 153 is connected to the sixth through hole 131 of the drain 13, so that when the high-pressure liquid flows into the eighth through hole 153 from the sixth through hole 131, the fourth control valve 154 is forced to close, thereby sealing the eighth through hole 153 and preventing the high-pressure liquid from flowing out of the device from the eighth through hole 153; after the injection of high-pressure liquid into the device stops, the fourth control valve 154 can be opened under the action of the second auxiliary return spring 154, so that the high-pressure liquid flows out of the device through the eighth through hole 153.

[0050] In the embodiments of this application, the fourth pressure threshold needs to be greater than the mine water pressure.

[0051] As an example, the underground water pressure in a mine is generally 2MPa to 4MPa, so the fourth pressure threshold can be 5MPa.

[0052] Please see Figure 4 , Figure 4 This is a schematic diagram of a mine borehole pre-fracturing method provided in an embodiment of this application. This method is implemented based on the mine borehole pre-fracturing device provided in any embodiment of this application. Figure 4 As shown, the method may include, but is not limited to, the following steps:

[0053] Step S401: When the device reaches the pre-fracture position in the borehole where pre-fracture is required, high-pressure liquid is continuously injected into the central tube.

[0054] Step S402: Increase the pressure of the high-pressure liquid to close the fourth control valve and open the first control valve, thereby causing the high-pressure liquid to be ejected from the ejector and the rotating device to form radial cracks in the borehole.

[0055] For example, increasing the pressure of the high-pressure liquid so that its current pressure is greater than a first pressure threshold and less than a second pressure threshold opens the first control valve, and the high-pressure liquid is ejected from the ejector to form a high-pressure water line. At the same time, the rotating device causes the high-pressure water line to cut the borehole, forming a radial crack.

[0056] Step S403: Stop the rotating device and continue to increase the pressure of the high-pressure liquid to force the second control valve to open, so that the high-pressure liquid enters the pre-crack module, and the expansion capsule expands under pressure to seal the area between the outer surface of the jet injector and the inner surface of the borehole.

[0057] For example, after the radial crack is cut, the rotating device is stopped, and the pressure of the high-pressure liquid is increased so that the current pressure of the high-pressure liquid is greater than the second pressure threshold. The second control valve is opened, and the high-pressure liquid enters the cavity between the expansion capsule and the central tube in the pre-crack module, allowing air to be discharged through the third control valve. Then the third control valve is closed, and the expansion capsule expands under pressure to seal the area between the outer surface of the ejector and the inner surface of the borehole. The radial crack further cracks under the action of the high-pressure liquid ejected by the ejector, forming a large area of ​​pressure fracturing fracture.

[0058] Step S404: Stop injecting high-pressure liquid, close the first and second control valves, and open the third and fourth control valves to discharge the high-pressure liquid in the mine borehole pre-fracturing device, thus completing the mine borehole pre-fracturing.

[0059] For example, stopping the injection of high-pressure liquid into the device reduces the pressure of the remaining high-pressure liquid, thereby closing the first and second control valves and opening the third and fourth control valves. The high-pressure liquid is then discharged from the device through the sixth and eighth through holes, completing the pre-fracturing of the mine borehole.

[0060] By implementing the embodiments of this application, the pressure of the high-pressure liquid in the injection device can be adjusted to control the high-pressure liquid to be ejected from the ejector to cut the surrounding rock wall, and an expansion capsule that can expand under the pressure of the high-pressure liquid can be used to pre-fracture the rock wall. This allows for rapid and precise pre-fracture of the rock wall surrounding the borehole.

[0061] In some embodiments of this application, before placing the mine borehole pre-fracture device in the mine borehole to be pre-fractured, the method further includes: using a wall-scraping drill bit to perform drilling operations in the mine to obtain the mine borehole to be pre-fractured.

[0062] As an example, the above-mentioned device is connected to the injection drill rod via an adapter, so that the injection drill rod drives the wall scraping module to perform drilling operations. When the drilling depth reaches the shallowest pre-fracture position required for pre-fracture in the designed drilling, pre-fracture is performed according to the aforementioned method. After the pre-fracture is completed, drilling is performed again. When the drilling depth reaches the next adjacent pre-fracture position, pre-fracture is performed again according to the aforementioned method. The above steps are repeated until the drilling depth reaches the designed depth.

[0063] As another example, the above-mentioned device is connected to the injection drill rod via an adapter. The injection drill rod drives the wall scraping module to complete the drilling operation according to the designed depth and then stops drilling. The above-mentioned device is withdrawn from the borehole to the deepest pre-fracture position in the borehole where pre-fracture is required, and pre-fracture is performed according to the aforementioned method. Then, the above-mentioned device is withdrawn to the next adjacent pre-fracture position and pre-fracture is performed according to the aforementioned method. The above steps are repeated until pre-fracture is completed at all pre-fracture positions in the borehole.

[0064] By implementing the embodiments of this application, it is possible to complete the jet cutting and sealing fracturing operations in the borehole without removing the drill rod during drilling operations, thereby achieving the integration and streamlining of the "drill-cut-fracturing" process.

[0065] Based on the embodiments of this application, this application also provides a mine borehole pre-fracturing system, including: a mine borehole pre-fracturing device provided in any embodiment of this application; a fluid injection drill rod connected to the mine borehole pre-fracturing device; and a high-pressure pump set connected to the fluid injection drill rod.

[0066] As an example, please see Figure 5 , Figure 5 This is a schematic diagram of a mine borehole pre-fracturing system provided in an embodiment of this application. Figure 5 As shown, the system may include a mine borehole pre-fracturing device, a high-pressure injection drill rod (i.e., the aforementioned injection drill rod), and a high-pressure pump set connected to the high-pressure injection drill rod.

[0067] In some embodiments of this application, the high-pressure pump set may further include multiple control valves that can be controlled by a central control unit to control the pressure of the high-pressure liquid provided by the high-pressure pump set; and a data acquisition substation for acquiring drilling data and pre-fracture data.

[0068] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this application can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this application can be achieved, and this is not limited herein.

[0069] The specific embodiments described above do not constitute a limitation on the scope of protection of this application. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A pre-fracturing device for mine boreholes, characterized in that, include: The components include a packer controller, a pre-splitting module, and a drain device. The pre-fracture module includes multiple packers and at least one jet injector, with the jet injector disposed between every two packers. One end of the packer controller is connected to one end of the first packer in the pre-splitting module; wherein, the packer controller sprays the high-pressure liquid flowing into the device through the jet to cut and pre-split the mine borehole that needs to be pre-splitted, and flows the high-pressure liquid into the packer, causing the packer to expand and seal the area between the outer surface of the jet and the inner surface of the borehole. One end of the diverter is connected to one end of the tail packer in the pre-splitting module. The diverter is used to drain the high-pressure liquid out of the device after the rock mass is fractured. The packer includes an inflatable capsule and a central tube, and the jet injector has a first through-hole, a second through-hole, and a third through-hole, wherein... The central tube is disposed inside the expansion capsule; A cavity is formed between the outer surface of the central tube and the inner surface of the expanding capsule; The central tubes of two adjacent packers are connected through the first through hole; The cavities of two adjacent packers are connected through the second through hole; The inner surface of the first through hole is connected to the outer surface of the jet injector through the third through hole; A first control valve that can be opened under pressure is provided in the third through hole; The expansion capsule is connected to the containment controller, the ejector, and the drainer via locking heads. Each locking head includes a clamp, a first auxiliary return spring, and a sliding base. The pipe clamp is connected to the sliding base; One end of the first auxiliary return spring is connected to the sealing controller, the jet injector, and the drain injector, respectively; The other end of the first auxiliary return spring is connected to the sliding base. The end of the expansion capsule is clamped between the sliding base and the tube clamp; The isolation controller has a fourth through hole and a fifth through hole, wherein... The fourth through hole is connected to the central tube of the head packer; One end of the fifth through hole is connected to the cavity of the head packer; The other end of the fifth through hole is connected to the fourth through hole; A second control valve that can be opened under pressure is provided in the fifth through hole; The drainage device has a sixth through hole and a seventh through hole, wherein... The sixth through hole is connected to the central tube of the tail packer; One end of the seventh through hole is connected to the cavity of the tail packer; The other end of the seventh through hole is connected to the outer surface of the drainer; A third control valve that can be closed under pressure is provided in the seventh through hole.

2. The apparatus as claimed in claim 1, characterized in that, The device also includes an adapter and a wall scraping module, wherein, One end of the adapter is connected to the injection drill rod, and the high-pressure liquid in the injection drill rod can flow into the device through the adapter; The other end of the adapter is connected to the other end of the isolation controller; The other end of the drain is connected to the wall scraping module.

3. The apparatus as described in claim 2, characterized in that, The wall scraping module includes a wall scraping blade and a wall scraping drill bit, wherein... The wall scraper is disposed on the outer surface of the wall scraper drill bit; The wall-scraping drill bit is provided with an eighth through hole; The eighth through hole is connected to the drainer; A fourth control valve that can be closed under pressure is provided in the eighth through hole.

4. A method for pre-fracking mine boreholes, characterized in that, The method is based on the mine borehole pre-fracturing device as described in claim 3, and the method includes: When the device reaches the pre-fracture position in the borehole where pre-fracture is required, high-pressure liquid is continuously injected into the central tube; The pressure of the high-pressure liquid is controlled to close the fourth control valve and open the first control valve, thereby causing the high-pressure liquid to be ejected from the ejector and the device to be rotated to form radial cracks in the borehole; Stop rotating the device and continue to control the pressure of the high-pressure liquid to force the second control valve to open, thereby allowing the high-pressure liquid to enter the pre-fracture module. The expansion capsule expands under pressure and seals the area between the outer surface of the jet injector and the inner surface of the borehole. Stop injecting the high-pressure liquid, open the third control valve and the fourth control valve, thereby discharging the high-pressure liquid in the mine borehole pre-fracturing device and completing the mine borehole pre-fracturing.

5. The method as described in claim 4, characterized in that, Before placing the mine borehole pre-fracking device into the mine borehole to be pre-fracking, the method further includes: The scraping module is used to perform drilling operations in the mine to obtain the pre-fractured mine borehole.

6. A mine borehole pre-fracturing system, characterized in that, include: The mine borehole pre-fracturing device as described in any one of claims 1 to 3; The injection drill rod is connected to the pre-fracturing device for mine boreholes; A high-pressure pump unit connected to the injection drill pipe.

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