A device and method for testing the development degree of mining fissures

Abstract

The application provides a device and method for testing development degree of mining fissure, which comprises a testing pipe, a drill bit detachably connected to the distal end of the testing pipe, and a drill rod detachably connected to the proximal end of the testing pipe; a bag is arranged at the distal end and the middle of the testing pipe, and a testing hole is arranged on the side wall of the testing pipe between the two bags; a bag water injection pipeline extends along the inside of the testing pipe and is connected in series with the two bags; a testing water injection pipeline extends along the inside of the testing pipe to inject water to a designated position through the testing hole; the drill rod and the double-end water stopper are combined into one, the testing pipe is used as the drill rod, and the testing can be directly started after drilling to a certain hole depth; the drill rod and the double-end water stopper do not need to be replaced during the testing and drilling processes, the pipeline can be effectively protected from being abraded by the rock fragments in the borehole, and the pipeline winding condition during the testing process can be prevented.

Description

Technical Field

[0001] This invention belongs to the technical field of water-conducting fracture zone observation, specifically relating to a device and method for testing the development degree of mining-induced fractures. Background Technology

[0002] Underground coal mining causes the movement and destruction of the overburden strata at the working face, resulting in the formation of water-conducting fracture zones within the overburden. The formation of these fracture zones leads to the loss of regional water resources and can also cause underground water hazards, endangering the safe and efficient production of the mine. Therefore, it is necessary to monitor the development height of the water-conducting fracture zones in the overburden. Currently, the main method for detecting fracture size is to obtain rock permeability indicators through borehole water injection. This method involves drilling a hole into the overburden strata with a drilling rig, then sealing a section of the borehole with a double-ended water plug and injecting water into it. The water will seep into the overburden strata through the fractures. Once the water injection is saturated, the size of the fractures in the overburden strata is determined based on the actual leakage, thereby predicting the development height of the fractures.

[0003] However, in practical applications, the drilling depth is usually large, and the repeated replacement of drill rods and double-ended water plugs takes up a lot of working time, resulting in low testing efficiency.

[0004] Therefore, there is a need to provide an improved technical solution that addresses the shortcomings of the existing technology. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art. This invention provides an apparatus and method for testing the degree of development of mining-induced fractures.

[0006] To achieve the above objectives, the present invention provides the following technical solution: An apparatus for testing the degree of development of mining-induced fractures, comprising: The test tube has a drill bit detachably connected to its distal end and a drill rod detachably connected to its proximal end. The test tube has a bag at its distal end and a bag at its middle. The side wall of the test tube has a water inlet hole corresponding to each bag. The side wall of the test tube has at least one test hole in the part between two bags. A water injection pipeline for the bladder bag extends along the inside of the test tube and connects two bladder bags in series; A test water injection pipeline is used, which extends along the inside of the test tube to inject water into a designated location through the test hole; The water injection pump is connected to the water injection pipeline of the bladder and the test water injection pipeline via a T-joint.

[0007] Preferably, the test tube is a multi-segment structure with threaded connections, consisting of a first segment, a second segment, and a third segment from far to near; Wherein, the first segment and the third segment respectively correspond to two bags, and the test hole is located in the second segment; The distal end of the first segment is a sealed end, and the proximal end is provided with a first plug; the distal end of the third segment is provided with a second plug, and the proximal end is an open end that connects to the drill pipe; the proximal end of the drill pipe is connected to the tee connector through a double-hole diverter. The drill rod has a central pipe inside. One of the outlets of the dual-hole diverter is connected to the near end of the first pipe through the central pipe. The far end of the first pipe passes through the second plug and connects to the second section to form a test water injection pipeline with the test hole. The other outlet of the dual-hole diverter is connected to the third section through the gap between the central pipe and the inner wall of the drill rod, and forms a bag-type water injection pipeline connecting the first section and the third section with the second pipe that passes through the first plug and the second plug at both ends respectively.

[0008] Preferably, the drill pipe comprises multiple sections, each section of the drill pipe has a central pipe inside, and the central pipes in two adjacent sections of the drill pipe are connected by a quick-connect coupling; The quick-connector includes a male quick-connector and a female quick-connector. The two ends of each drill rod section are fixed with support rings, and the central pipe is connected between the male quick-connector and the female quick-connector. The support ring has multiple notches evenly distributed around its circumference, and the drill rod end is provided with a stepped platform corresponding to the support ring.

[0009] Preferably, the dual-hole diverter is a tubular structure with a closed proximal end, and its distal end is connected to the proximal end of the drill rod by a threaded connection. The dual-hole diverter is provided with a quick-connect female head that is adapted to the proximal end of the drill rod. The inner wall of the dual-hole diverter is connected to the support ring through a stepped platform. The side wall of the dual-hole diverter is provided with a first water inlet pipe to connect the bag water injection pipeline through the gap between the dual-hole diverter and the quick-connect female head. The dual-hole diverter is provided with a second water inlet pipe at its proximal end, which is connected to the proximal end of the quick-connect female connector.

[0010] Preferably, the three-way connector is connected to the water injection pipeline of the bladder via a first flexible hose, and the first flexible hose is provided with a first pressure relief valve, a first valve, a first pressure gauge and a second pressure relief valve in sequence from the proximal end to the distal end; The three-way connector is connected to the test water injection pipeline via a second flexible hose. The second flexible hose is provided with a third pressure relief valve, a second valve, a second pressure gauge, a flow meter, and a fourth hydraulic valve in sequence from the proximal end to the distal end.

[0011] Preferably, the pouch is a tubular elastic element fitted onto the test tube, and both ends of the pouch are fixed by ring clamps.

[0012] A method for testing the degree of development of mining-induced fractures, comprising the following steps, using any of the aforementioned devices for testing the degree of development of mining-induced fractures: Step S1: Assemble the test tube and push the assembled test tube into the test hole section. Step S2: Turn on the water pump and inject water into the test borehole section through the test water injection pipeline. Stop water injection and close the pipeline when the water pressure is greater than the expected theoretical elevation static pressure. Use the water pressure at this time as the elevation static pressure of the borehole section. Step S3: Inject water into the two bags through the bag water injection pipeline to block the test hole section. Stop water injection and close the pipeline when the water pressure is greater than the elevation static pressure by 0.5MPa. Step S4: Re-inject water into the test hole section through the test water injection pipeline until the water injection pressure is greater than the elevation static pressure by 0.2 MPa, then stop water injection and maintain the pressure. Step S5: After the water pressure stabilizes, inject water for one unit time period and then stop, and record the water injection volume during that unit time period to obtain the water leakage data. Step S6: Open the water injection line of the bladder to depressurize the bladder and release the blockage; Step S7: Advance the test hole depth and test the next test hole segment.

[0013] Preferably, the near end of the test tube is threaded to a drill rod, which is connected to a drilling machine to advance the test hole to a certain depth.

[0014] Preferably, the main body of the dual-hole diverter is a hollow tubular structure. A sealing plate is provided inside the main body. A first water inlet pipe and a second water inlet pipe are provided on the sealing plate. The far ends of the first water inlet pipe and the second water inlet pipe are water outlets, and the other ends are respectively connected to detachable water supply hoses. A notch corresponding to the proximal ends of the first and second water inlet pipes is provided on the side wall of the main body, and the water supply hose is removed when the test hole is advanced to the required depth.

[0015] Preferably, the test method also includes: Step S8: Plot the water leakage data observed in each test well section against the corresponding test well depth, analyze the changes in water leakage in the test well, and determine the height of the water-conducting fracture zone.

[0016] Beneficial effects: By combining the drill rod and the double-ended water plug into one unit, and using the test tube as the drill rod, testing can begin directly after drilling to a certain depth. There is no need to replace the drill rod and the double-ended water plug during the testing and drilling process. The water pipe built into the test tube can effectively protect the pipe from being worn by the rock fragments in the borehole, and at the same time prevent the long pipe from getting tangled during the testing process.

[0017] The test tube uses a separate dual-channel water passage, and the two water passages do not affect each other. As the hole depth continues to advance, drill rods can be stacked to meet the depth requirements of the test hole section. Attached Figure Description

[0018] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. Wherein: Figure 1 This is a simplified structural diagram of the testing device in a specific embodiment of the present invention; Figure 2 This is a simplified cross-sectional view of the test tube in a specific embodiment provided by the present invention; Figure 3 for Figure 2 Enlarged view of point A in the middle; Figure 4 for Figure 2 Enlarged view at point B in the middle; Figure 5 A simplified structural diagram of the dual-hole distributor with a bit provided in a specific embodiment of the present invention; Figure 6 The graph shows the leakage rate of the bottom plate borehole measured according to the specific embodiments provided in this invention. Figure 7 This is a bar chart showing the leakage of the bottom plate through drilling, as measured according to a specific embodiment of the present invention.

[0019] In the diagram: 1. Drill bit; 2. Drill bag; 3. Second section; 4. Threaded sleeve; 5. Test hole; 6. Ring collar; 7. Drill pipe; 8. Third section; 9. First section; 10. Dual-hole diverter; 11. First hose; 12. Second hose; 13. Second pressure relief valve; 14. First pressure gauge; 15. First valve; 16. First pressure relief valve; 17. T-connector; 18. Water pump; 19. Third pressure relief valve; 20. 21. Second valve; 22. Second pressure gauge; 23. Flow meter; 24. Fourth hydraulic valve; 25. First plug; 26. Second pipe; 27. Second plug; 28. First pipe; 29. ​​Quick connector; 101. Center pipe; 102. Screwdriver bit; 103. Body; 104. Notch; 105. First water inlet pipe; 281. Second water inlet pipe; 282. Quick connector male; 283. Quick connector female; 284. Support ring. Detailed Implementation

[0020] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0021] In the description of this invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," and "bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and do not require the invention to be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on the invention. The terms "connected" and "linked" used in this invention should be interpreted broadly. For example, they can refer to a fixed connection or a detachable connection; they can refer to a direct connection or an indirect connection through intermediate components. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0022] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0023] like Figure 1-7 As shown, an apparatus for testing the development degree of mining-induced fractures includes a test tube, a water injection pipe for a bag 2, a test water injection pipe, and a water injection pump 18. In this application, the end extending into the test hole 5 is the distal end. The distal end of the test tube is provided with a drill bit 1 detachably connected to it. The hole diameter of the drill bit 1 is larger than the outer diameter of the test tube by a certain distance, which should at least ensure that the bag 2 has a distance of more than 0.5 cm from the hole wall when it is not inflated. The proximal end of the test tube is connected to the drill rod 7 to realize the drilling function. The bag 2 is provided on the test tube to realize the sealing function of the set hole depth. Specifically, there are two bags 2, which are located at the distal end and the middle of the test tube, respectively. The bag 2 located at the distal end is close to the drill bit 1. The distance between the two bags 2 is adapted to the height range of the preset test hole 5 depth.

[0024] Each bag 2 is provided with a water inlet hole on the side wall of the test tube. Under the high pressure of the water pump 18, water can pass through the water inlet hole and enter the bag 2, thereby inflating the bag 2 and pressing it against the inner wall of the test hole 5, thus achieving the sealing function. At least one test hole 5 is provided on the side wall of the test tube between two bags 2. The water discharged from the test hole 5 can be directly injected into the crack corresponding to the test hole section, thereby realizing the water injection operation.

[0025] The water injection pipeline of the two bags 2 extends along the inside of the test tube and connects the two bags 2 in series. The two bags 2 are supplied with water through independent pipelines located inside the test tube, ensuring synchronous pressurization and depressurization of the two bags 2. The test water injection pipeline extends along the inside of the test tube to inject water into the designated location through the test hole 5. Both pipelines are located inside the test tube, which can effectively protect the pipeline from being worn by the gravel in the rock borehole, and at the same time prevent the excessively long pipeline from getting tangled during the test.

[0026] The water pump 18 is connected to the water injection line of the bag 2 and the test water injection line via a T-joint 17. In this embodiment, the water injection line of the bag 2 and the test water injection line are connected to the two outlet ends of the T-joint 17 via connecting hoses, and the water pump is connected to the inlet end of the T-joint 17 via a hose.

[0027] In an optional embodiment, to reduce the manufacturing difficulty of the test tube and facilitate the layout of the water injection pipeline of the bag 2 and the test water injection pipeline, the test tube is a multi-segment structure with threaded connections, consisting of a first segment 9, a second segment 3, and a third segment 8 from far to near. The first segment 9, the second segment 3, and the third segment 8 are connected by threaded male and female ends, or by threaded sleeves 4. Taking the first segment 9 and the second segment 3 as examples, the threaded sleeve 4 has internal threads at both ends to form a threaded female end, and the first segment 9 and the second segment 3 have external threads corresponding to the threaded sleeve 4 as threaded male ends, thereby achieving connection.

[0028] The first segment 9 and the third segment 8 correspond to two bags 2 respectively. The lengths of the first segment 9 and the third segment 8 are adapted to the lengths of the bags 2. The test hole 5 is located in the second segment 3.

[0029] There can be multiple test holes 5, which are evenly distributed in the circumferential and radial directions of the second segment 3. The second segment 3 has multiple specifications to be adjusted according to the actual required test hole length.

[0030] The distal end of the first segment 9 is a sealed end and is connected to the drill bit 1 by a threaded connection. A first plug 24 is provided at the proximal end of the first segment 9. The first plug 24 is a cap-shaped or cylindrical body with external threads on its outer wall. It is assembled inside the first segment 9 by a threaded connection and is located at the proximal end of the inner cavity of the first segment 9.

[0031] The distal end of the inner cavity of the third segment 8 is provided with a second plug 26. The second plug 26 is a cap-shaped or cylindrical body with external threads on its outer wall, and is thus assembled into the interior of the third segment 8 by means of threaded connection. The proximal end of the third segment 8 is an open end that connects to the drill rod 7. The proximal end of the drill rod 7 is connected to the tee connector 17 through a double-hole diverter 10. The double-hole diverter 10 has two water inlet pipes, and the two water inlet pipes are respectively connected to the tee connector 17 through flexible hoses. The drill pipe 7 has a central pipe 29 inside. The two ends of the central pipe 29 are respectively provided with quick-connect male connector 281 and quick-connect female connector 282. One of the outlet ends of the dual-hole diverter 10 is connected to the proximal end of the first pipe 27 through the central pipe 29. The first pipe 27 and the central pipe 29 are connected by quick-connect connector 28 (the proximal end of the first pipe 27 is quick-connect male connector 281, and the distal end of the central pipe 29 is quick-connect female connector 282). The distal end of the first pipe 27 passes through the second plug 26 and connects to the second segment 3. Specifically, the second plug 26 is provided with a threaded hole, and the distal end of the first pipe 27 is provided with a threaded connector. The threaded connector is threaded into the threaded hole to connect to the inner cavity of the second segment 3 and form a test water injection pipeline with the test hole 5.

[0032] Another outlet of the dual-hole diverter 10 is connected to the third section 8 through the central pipe 29 and the inner wall of the drill rod 7. The outlet uses the inner cavity of the drill rod 7 as a flow channel. A threaded through hole corresponding to the second pipe 25 is provided on the second plug 26. A threaded joint corresponding to the threaded through hole is provided at the proximal end of the second pipe 25. Correspondingly, a threaded through hole corresponding to the distal end of the second pipe 25 is provided on the first plug 24. A threaded joint corresponding to the threaded through hole on the first plug 24 is provided at the distal end of the second pipe 25. In this way, the second pipe 25 passes through the inside of the second section 3 and forms a water injection pipeline of the bag 2 that connects the first section 9 and the third section 8.

[0033] In an optional embodiment, the drill rod 7 includes multiple sections that can be extended as needed for drilling the test hole 5. The distal end of the drill rod 7 is provided with a threaded male end, and the proximal end is provided with a threaded female end. Correspondingly, the proximal end of the third stage is provided with a threaded female end.

[0034] Each drill pipe section has a central pipe 29 inside. The central pipes 29 in two adjacent drill pipe sections are connected by quick connectors 28. The quick connectors 28 include a quick male connector 281 and a quick female connector 282. The quick male connector 281 and quick female connector 282 are fixed at both ends of each drill pipe section 7 by support rings 283, specifically the quick female connector 282 at the far end and the quick male connector 281 at the near end. The central pipe 29 is connected between the quick male connector 281 and quick female connector 282. As the adjacent two drill pipe sections are threaded together, the quick male connector 281 and quick female connector 282 are connected after being inserted.

[0035] The central pipe 29 has male connectors extending from both ends. The quick-connect male connector 281 and quick-connect female connector 282 are each provided with a female connector at one end of the corresponding male connector, so as to realize the connection between the central pipe 29 and the quick-connect male connector 281 and quick-connect female connector 282. At least one sealing ring is provided on the outer wall of the male connector.

[0036] The support ring 283 has multiple notches 103 evenly distributed around its circumference, and the drill rod 7 has a stepped platform at its end corresponding to the support ring 283, so that water can pass through the notches 103 and the inner wall of the stepped platform.

[0037] In an optional embodiment, the dual-hole diverter 10 is a tubular structure with a closed proximal end, and its distal end is connected to the proximal end of the drill rod 7 by a threaded connection. The dual-hole diverter 10 is provided with a quick-connect female head 282 that is adapted to the proximal end of the drill rod 7. The inner wall of the dual-hole diverter 10 is connected to the support ring 283 (with the same structure and assembly as the drill rod 7) through a stepped platform. The side wall of the dual-hole diverter 10 is provided with a first water inlet pipe 104 to connect the water injection pipeline of the bag 2 through the gap between the dual-hole diverter 10 and the quick-connect female head 282. The proximal end of the dual-hole diverter 10 is provided with a second water inlet pipe 105, and the distal end of the second water inlet pipe 105 extends into the dual-hole diverter 10 and is connected to the proximal end of the quick-connect female connector 282.

[0038] In this embodiment, the first hose 11 is connected to the first water inlet pipe 104, and the second hose 12 is connected to the second water inlet pipe 105.

[0039] In an optional embodiment, the three-way connector 17 is connected to the water injection pipeline of the bag 2 via a first flexible hose 11. The first flexible hose 11 is provided with a first pressure relief valve 16, a first valve 15, a first pressure gauge 14 and a second pressure relief valve 13 in sequence from the proximal end to the distal end. The three-way connector 17 is connected to the test water injection pipeline via the second flexible hose 12. The second flexible hose 12 is equipped with a third pressure relief valve 19, a second valve 20, a second pressure gauge 21, a flow meter 22, and a fourth hydraulic valve 23 in sequence from the near end to the far end.

[0040] In an optional embodiment, the pouch 2 is a tubular elastic element fitted onto the test tube, specifically made of rubber. When the pouch 2 is not inflated, its inner diameter matches the outer diameter of the corresponding segment of the test tube. Both ends of the pouch 2 are fixed by ring clamps 6, which seal both ends of the pouch 2. When water is injected through the water injection hole, the pouch 2 inflates and blocks the test hole 5 at the corresponding position.

[0041] In another optional embodiment, the present invention also provides a method for testing the degree of development of mining-induced fractures, wherein the test is performed using an apparatus for testing the degree of development of mining-induced fractures, and the test method includes the following steps: Step S1: Assemble the test tube and push the assembled test tube into the test hole section. Step S2: Turn on the water injection pump 18 and inject water into the test hole section through the test water injection pipeline. Stop the water injection and close the pipeline when the water pressure is greater than the expected theoretical elevation static pressure. Specifically, the theoretical elevation static pressure is determined by the elevation static pressure value of 100m water head as 1MPa. The water pressure at this time is taken as the elevation static pressure of the hole section.

[0042] Step S3: Inject water into the two bags 2 through the water injection pipeline of bag 2 to block the test hole section. Stop water injection and close the pipeline when the water pressure is greater than the expected theoretical elevation static pressure of 0.5MPa. When the pressure is too high, it can be adjusted by adjusting the pressure relief valve.

[0043] Step S4: Re-inject water into the test hole section through the test water injection pipeline until the water injection pressure is 0.2 MPa higher than the theoretical elevation static pressure, then stop water injection and maintain the pressure. Step S5: After the water pressure stabilizes, inject water for one unit time period and then stop, and record the water volume injected during that unit time period to obtain the water leakage data; a specific unit time period can be 60 seconds.

[0044] Step S6: Open the water injection pipe of the bag 2. Under the pressure relief, the volume of the bag 2 that bulges in the test hole 5 shrinks rapidly, and the water stored in the hole section is discharged. In this way, the blockage of the test hole 5 is released by depressurizing the bag 2. Step S7: Advance the test hole to a depth of 5 and test the next test hole section. By testing the water leakage of different test hole sections, the degree of fracture development in different layers can be quantitatively determined, and the maximum development height of the water-conducting fracture zone can be further determined.

[0045] In an optional embodiment, the three-way connector 17 is connected to the water injection pipeline of the bag 2 via a first flexible hose 11. The first flexible hose 11 is provided with a first pressure relief valve 16, a first valve 15, a first pressure gauge 14 and a second pressure relief valve 13 in sequence from the proximal end to the distal end. The three-way connector 17 is connected to the test water injection pipeline via the second flexible hose 12. The second flexible hose 12 is equipped with a third pressure relief valve 19, a second valve 20, a second pressure gauge 21, a flow meter 22, and a fourth hydraulic valve 23 in sequence from the near end to the far end.

[0046] The preferred specific experimental steps are: Step S1: Assemble the test tube and push the assembled test tube into the test hole section. Step S2: Start the water injection pump 18, open the second valve 20, and observe the second pressure gauge 21. When the second pressure gauge 21 is greater than the expected theoretical elevation static pressure, close the second valve 20. At this time, the second pressure gauge 21 represents the elevation static pressure value of this test borehole section. Specifically, the theoretical elevation static pressure is determined using a 100m water head elevation static pressure value of 1MPa. Step S3: Open the first valve 15 to supply water to the two bags 2. Stop water injection and close the pipeline when the water pressure is greater than the elevation static pressure by 0.5 MPa. When the pressure is too high, it can be adjusted by opening the first pressure relief valve 16.

[0047] Step S4: Open the second valve 20 again, and stop water injection and maintain pressure by adjusting the fourth hydraulic valve 23 or by making the water injection pressure in the pipeline 0.2 MPa higher than the theoretical elevation static pressure. Step S5: Observe the water pressure. After the water pressure stabilizes, record the values ​​of the second pressure gauge 21 and flow meter 22. After 60 seconds, close the second valve 20 and record the values ​​of the second pressure gauge 21 and flow meter 22 again. The flow rate within 1 minute can be obtained by subtracting the two values. This allows us to obtain the water leakage data.

[0048] Step S6: Open the second pressure relief valve 13. Under the pressure relief effect, the volume of the bulging bag 2 in the test hole 5 shrinks rapidly, and the water stored in the hole section is discharged. In this way, the pressure is released through the bag 2 to release the blockage of the test hole 5. Step S7: At this time, start the drilling rig and continue to advance the test tube by 1.5m to test the next test hole section. By testing the water leakage of different test hole sections, the degree of fracture development in different layers can be quantitatively determined, and the maximum development height of the water-conducting fracture zone can be further determined.

[0049] In this embodiment, the third pressure relief valve 19 is an adjustable pressure relief valve, which can maintain pressure in the pipeline by adjusting the pressure relief of the third pressure relief valve 19.

[0050] In an optional implementation, the testing method further includes step S8, which involves plotting the observed water leakage data of each test borehole segment against the corresponding test borehole 5 depth to analyze the changes in water leakage within the test borehole 5, thereby determining the height of the water-conducting fracture zone and further understanding the development pattern of the "upper three zones" in the ultra-wide working face. In an optional embodiment, the proximal end of the test tube is threaded with a drill rod 7, which is correspondingly connected to a drilling machine to advance the test hole 5 to a certain depth via the drilling machine and the drill bit 1.

[0051] In another embodiment, the distal end of the dual-hole diverter 10 is connected to the proximal end of the drill rod 7 by a threaded assembly. The distal end of the dual-hole diverter 10 is provided with a threaded male end corresponding to the drill rod 7, which is connected to the threaded female end of the proximal end of the drill rod 7. The proximal end of the dual-hole diverter 10 is provided with a screwdriver bit 101 (or a coupling) for connecting to the drill spindle, which can be directly connected to the drill.

[0052] The main body 102 of the dual-hole diverter 10 is a hollow tubular structure. Inside the main body 102, there is a sealing plate located near the quick-connect female 282. The sealing plate is preferably located near the quick-connect female 282 inside the dual-hole diverter 10. The sealing plate is provided with a first water inlet pipe 104 and a second water inlet pipe 105. The first water inlet pipe and the second water inlet pipe pass through the sealing plate and extend a certain length, preferably 3-5mm, from both ends to the near end of the sealing plate.

[0053] The second inlet pipe 105 is located at the center of the sealing plate and is connected to the quick-connect female connector via a male connector, thus connecting to the quick-connect male connector near the center pipe. The first inlet pipe 104 is located at the edge of the sealing plate and connects the gap between the body 102 of the dual-hole diverter 10 and the quick-connect female connector 282, thus connecting to the water injection pipeline of the bag 2. Of course, the first and second inlet pipes can also be symmetrically distributed on the sealing plate, with the second inlet pipe connected to the quick-connect female connector 282 via a flexible hose, thus connecting to the quick-connect male connector near the center pipe.

[0054] The first water inlet pipe 104 does not need to extend beyond the far side of the sealing plate; it only needs to extend to its far side wall. The second water inlet pipe 105 passes through the sealing plate and is connected to the plug-in female head, which is used to connect to the central pipe 29 inside the drill rod 7.

[0055] A notch 103 is provided on the side wall of the main body 102 corresponding to the proximal end of the first water inlet pipe 104 and the second water inlet pipe 105. The notch 103 is located on the distal end of the bit 101, so that the hose can be connected without removing the bit 101. The first water inlet pipe 104 and the second water inlet pipe 105 are detachably connected to the first hose 11 and the second hose 12, so that the experiment can be carried out without removing the dual-hole diverter 10, further improving the testing efficiency.

[0056] A notch 103 corresponding to the proximal ends of the first and second water inlet pipes is provided on the side wall of the main body 102. When the test hole 5 is advanced to a depth, the water supply hose is removed. To avoid tangling, the hose at the water inlet end can be removed during drilling. The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention shall be within the scope of protection of the pending claims of the present invention.

Claims

1. A device for testing the degree of development of mining-induced fractures, characterized in that, include: The test tube has a drill bit detachably connected to its distal end and a drill rod detachably connected to its proximal end. The test tube has a bag at its distal end and a bag at its middle. The side wall of the test tube has a water inlet hole corresponding to each bag. The side wall of the test tube has at least one test hole in the part between two bags. A water injection pipeline for the bladder bag extends along the inside of the test tube and connects two bladder bags in series; A test water injection pipeline is used, which extends along the inside of the test tube to inject water into a designated location through the test hole; The water injection pump is connected to the bag water injection pipeline and the test water injection pipeline via a T-connector. The test tube is a multi-segment structure with threaded connections, consisting of the first segment, the second segment, and the third segment from far to near. Wherein, the first segment and the third segment respectively correspond to two bags, and the test hole is located in the second segment; The distal end of the first segment is a sealed end, and the proximal end is provided with a first plug; the distal end of the third segment is provided with a second plug, and the proximal end is an open end that connects to the drill pipe; The proximal end of the drill pipe is connected to the tee connector via a double-hole diverter; The drill rod has a central pipe inside. One of the outlets of the dual-hole diverter is connected to the near end of the first pipe through the central pipe. The far end of the first pipe passes through the second plug and connects to the second section to form a test water injection pipeline with the test hole. The other outlet of the dual-hole diverter is connected to the third section through the gap between the central pipe and the inner wall of the drill rod, and forms a bag-filled water injection pipeline connecting the first section and the third section with the second pipe that passes through the first plug and the second plug at both ends respectively; The drill pipe includes multiple sections, and the central pipes in two adjacent sections of the drill pipe are connected by quick connectors. The quick connectors include quick male connectors and quick female connectors. The two ends of the central pipes have plug-in male connectors, and the quick male connectors and quick female connectors are each provided with a plug-in female connector at one end corresponding to the plug-in male connector. The dual-hole diverter is a tubular structure with a closed proximal end. Its distal end is connected to the proximal end of the drill rod via a threaded connection. The dual-hole diverter has a quick-connect female head that matches the proximal end of the drill rod. The inner wall of the dual-hole diverter is connected to the support ring via a stepped platform. The side wall of the dual-hole diverter has a first water inlet pipe to connect the bag water injection pipeline through the gap between the dual-hole diverter and the quick-connect female head. The proximal end of the dual-hole diverter is provided with a second water inlet pipe, which is connected to the proximal end of the quick-connect female connector. The far end of the dual-hole diverter is provided with a threaded male end corresponding to the drill rod, which mates with the threaded female end near the drill rod. The near end of the dual-hole diverter is provided with a bit that connects to the drill spindle, which mates with the drill. The main body of the dual-hole diverter is a hollow tubular structure. Inside the main body, there is a sealing plate located near the end of the quick-connect female connector. The sealing plate has a first water inlet pipe and a second water inlet pipe. The first water inlet pipe and the second water inlet pipe pass through the sealing plate and extend a certain length from both ends to the end of the sealing plate. The second water inlet pipe is located at the center of the sealing plate. After passing through the sealing plate, it is inserted into the quick-connect female connector via a male connector, thereby connecting to the quick-connect male connector near the center pipe. The first water inlet pipe is located at the edge of the sealing plate. The first water inlet pipe extends to the far side wall of the sealing plate and connects the gap between the body of the dual-hole diverter and the quick-connect female connector, thereby connecting the bag water injection pipeline. A notch is provided on the side wall of the main body corresponding to the proximal ends of the first and second water inlet pipes. The notch is located on the far end of the bit, so that the hose can be connected without removing the bit. The first and second water inlet pipes are detachably connected to the first and second hoses.

2. The apparatus for testing the degree of development of mining-induced fractures according to claim 1, characterized in that, The two ends of each drill pipe section are fixed with quick-connect male and quick-connect female connectors by support rings, and the central pipe is connected between the quick-connect male and quick-connect female connectors respectively. The support ring has multiple notches evenly distributed around its circumference, and the drill rod end is provided with a stepped platform corresponding to the support ring.

3. The apparatus for testing the degree of development of mining-induced fractures according to claim 1, characterized in that, The three-way connector is connected to the water injection pipeline of the bladder via a first flexible hose. The first flexible hose is provided with a first pressure relief valve, a first valve, a first pressure gauge and a second pressure relief valve in sequence from the proximal end to the distal end. The three-way connector is connected to the test water injection pipeline via a second flexible hose. The second flexible hose is provided with a third pressure relief valve, a second valve, a second pressure gauge, a flow meter, and a fourth hydraulic valve in sequence from the proximal end to the distal end.

4. The apparatus for testing the degree of development of mining-induced fractures according to claim 1, characterized in that, The bag is a tubular elastic element that is fitted onto the test tube, and both ends of the bag are fixed by ring clamps.

5. A method for testing the degree of development of mining-induced fractures, wherein the test is performed using the apparatus for testing the degree of development of mining-induced fractures as described in any one of claims 1-4, characterized in that, The testing method includes the following steps: Step S1: Assemble the test tube and push the assembled test tube into the test hole section. Step S2: Turn on the water pump and inject water into the test borehole section through the test water injection pipeline. Stop water injection and close the pipeline when the water pressure is greater than the expected theoretical elevation static pressure. Use the water pressure at this time as the elevation static pressure of the borehole section. Step S3: Inject water into the two bags through the bag water injection pipeline to block the test hole section. Stop water injection and close the pipeline when the water pressure is greater than the elevation static pressure by 0.5MPa. Step S4: Re-inject water into the test hole section through the test water injection pipeline until the water injection pressure is greater than the elevation static pressure by 0.2 MPa, then stop water injection and maintain the pressure. Step S5: After the water pressure stabilizes, inject water for one unit time period and then stop, and record the water injection volume during that unit time period to obtain the water leakage data. Step S6: Open the water injection line of the bladder to depressurize the bladder and release the blockage; Step S7: Advance the test hole depth and test the next test hole segment.

6. The method for testing the degree of development of mining-induced fractures according to claim 5, characterized in that, The testing methods also include: Step S8: Plot the water leakage data observed in each test well section against the corresponding test well depth, analyze the changes in water leakage in the test well, and determine the height of the water-conducting fracture zone.

Images