Decompression type water flowing fractured zone height observation system

Abstract

The utility model relates to a pressure reduction type water flowing fractured zone height observation system which comprises a double-end water plugging and water flowing fractured zone observation instrument and a water pressure pressure reduction device, the double-end water plugging and water flowing fractured zone observation instrument is provided with a water injection exploring tube and two swelling air bags, and the two swelling air bags are arranged at the two ends of the water injection exploring tube; a section of closed space can be closed in the drill hole, and water is injected into the closed space in the drill hole through the water injection probe tube so as to obtain the leakage amount in unit time; the water pressure reducing device is connected between two adjacent drill rods, and / or is connected between the drill rods and the double-end water plugging and guiding fissure zone observation instrument; the water pressure reducing device is configured to adjust the water pressure in the drill rod to be lower than the swelling pressure of the swelling air bag. According to the invention, the height observation of the water flowing fractured zone under the special condition of large-height inclined drilling is realized.

Description

Technical Field

[0001] The present application belongs to the technical field of water-conducting fracture zone height observation instruments, and specifically relates to a pressure-reducing water-conducting fracture zone height observation system. Background Art

[0002] When there are medium or higher water-rich aquifers or other water body threats on the coal seam roof, the height of the collapse zone and water-conducting fracture zone should be measured, and a special design should be carried out to determine the size of the water-proof coal (rock) pillar. When mining the lower layer of the coal seam at close distance, if the underground inclined drilling is used to measure the height of the water-conducting fracture zone, the drill hole needs to pass through the goaf, and the construction technology is difficult. Generally, it is necessary to drill from the ground and use a variety of methods such as the drilling fluid leakage method, transient electromagnetic method and borehole peek method to jointly determine the height of the water-conducting fracture zone.

[0003] When measuring the height of the water-conducting fracture zone during mining of the lower coal seam in close proximity, most mines use a combination of borehole flushing fluid loss and other methods to measure the height. However, the borehole flushing fluid loss method is cumbersome and requires testing while drilling. Severe leaks in the upper goaf require prompt plugging, which impacts the accuracy of other tests. This slows down drilling and increases the time required. To mitigate the impact of plugging, transient electromagnetic and borehole peek-through methods must be used before plugging, increasing the number of testing steps and the project duration. Post-mining drilling for measuring the height of the water-conducting fracture zone requires drilling through multiple goafs. The longer the drilling time, the more likely the rock strata above the working face will shift and collapse, leading to borehole collapse and drilling rig accidents such as stuck drill pipes, stuck drill pipes, and drill drops.

[0004] The double-ended water-blocking fracture zone height observation instrument measures the height of the water-blocking fracture zone. Generally, after the borehole is completed, the leakage of each rock layer in the borehole is tested in sections. The test cycle is short and does not affect the test results of the transient electromagnetic method and the borehole peek method. However, the existing double-ended water-blocking fracture zone height observation instruments all use downhole drilling to measure the height of the water-blocking fracture zone, controlling the water pressure at around 0.1MPa and the air pressure of the double-ended water-blocking airbag at 0.2-0.3MPa. Instructions for observing water-blocking fractures in ground drilling ZSU240550CN

[0005] During drilling, if the depth exceeds 30m, the water pressure within the drill pipe exceeds the pressure of the double-ended water-blocking airbags. The inflated airbags are compressed, and the seal between the airbags and the borehole wall deteriorates, failing to achieve water blocking. Therefore, existing water-conducting fracture zone height observation instruments cannot be used properly for observing the height of water-conducting fracture zones in high-altitude, inclined boreholes. Utility Model Content

[0006] In view of the above analysis, the embodiments of the present invention aim to provide a decompression type water-conducting fracture zone height observation system to solve one or more of the above problems existing in the prior art.

[0007] The purpose of this utility model is achieved in this way:

[0008] A decompression type water-conducting fracture zone height observation system, comprising:

[0009] A double-ended water-blocking and water-conducting fracture zone observation instrument comprises a water injection probe and two inflatable air bags. The two inflatable air bags are arranged at both ends of the water injection probe and can seal off a closed space in the borehole. Water is injected into the closed space in the borehole through the water injection probe to obtain the leakage rate per unit time.

[0010] A water pressure reducing device is connected between two adjacent drill pipes and / or between a drill pipe and a double-ended water-blocking and water-conducting fracture zone observation instrument; the water pressure reducing device is configured to adjust the water pressure in the drill pipe to below the inflation pressure of the inflatable airbag.

[0011] Furthermore, the water injection probe is a hollow structure, a plurality of water injection holes are opened on the wall of the water injection probe, and the water injection probe is connected to the water injection console through a water injection pipeline.

[0012] Furthermore, the double-end water-blocking and water-conducting fracture zone observation instrument further includes an expansion pipeline, which is connected to an expansion console and two inflation air bags.

[0013] Furthermore, the drill rod has a rod head and a rod tail, and the structure of the tail of the double-end water-blocking and water-conducting fracture zone observer is the same as that of the rod tail, and can be directly connected to the rod head.

[0014] Furthermore, the water pressure reducing device comprises a hollow protective shell and a water pressure reducing valve arranged in the protective shell, and the axial head end of the protective shell has the same structure as the rod head.

[0015] Instruction manual ZSU240550CN

[0016] The axial tail end of the protective shell has the same structure as the tail end of the rod.

[0017] Furthermore, the protective shell has an internal cavity and axial openings at both ends connected to the internal cavity. A side wall mounting port is provided on the side wall of the protective shell, and the side wall mounting port is connected to the internal cavity of the protective shell. The water pressure reducing valve is fixedly installed in the internal cavity of the protective shell, and the two valve ports of the water pressure reducing valve are respectively connected to the axial openings at both ends of the protective shell, and a part of the water pressure reducing valve extends from the side wall mounting port.

[0018] Furthermore, the water pressure reducing valve is welded to the inner space of the protective shell, or the water pressure reducing valve is fixed to the inner space of the protective shell using epoxy resin glue.

[0019] Furthermore, there are multiple water pressure reducing devices, and there are multiple drill rods. The multiple water pressure reducing devices are dispersedly arranged on the multiple serially connected drill rods according to set distances.

[0020] Furthermore, the water pressure reducing valve adopts a piston-type branch pipe reducing valve or a piston-type adjustable reducing valve.

[0021] Furthermore, the double-end water-blocking and water-conducting fracture zone observation instrument, the water pressure reducing device and the drill pipe are connected in series by threaded connection.

[0022] Compared with the prior art, the decompression type water-conducting fracture zone height observation system provided by the utility model can achieve at least one of the following beneficial effects:

[0023] A) The decompression-type water-conducting fracture zone height observation system provided by the utility model realizes the observation of the height of the water-conducting fracture zone in the special case of a high-altitude inclined borehole. It can realize the observation of the height of the water-conducting fracture from the ground borehole. By closing a certain section in the borehole and injecting water to observe the development of the fracture, the tedious construction steps of the borehole flushing fluid loss method are eliminated, and the drilling construction efficiency is greatly improved. It is more efficient and safe, and does not affect the test results of the transient electromagnetic method and the borehole peek method. After the drilling construction is completed, the borehole peek, transient electromagnetic method observation and borehole loss observation are carried out simultaneously, shortening the construction period, reducing the risk of hole collapse, reducing the probability of drilling rig accidents, and reducing the risk of project implementation.

[0024] B) The utility model provides a pressure-reducing water-conducting fracture zone height observation system. The water pressure reducing device can be connected between the drill pipe and the drill pipe, and / or, between the drill pipe and the double-end water-blocking water-conducting fracture zone observation instrument; by pre-adjusting the water pressure to control the water pressure brought by the deepening of the drill pipe. Instruction manual ZSU240550CN

[0025] The water pressure reducing device is flexible to use and can be connected in series by connecting one device at a distance of several drill rods according to the height change, thereby ensuring that a stable output water pressure can be controlled regardless of the height change, and finally realizing the entire actual measurement process of observing the height of water-conducting fissures from the ground drilling. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of this specification or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the embodiments of this specification. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0027] Figure 1 This is a schematic diagram of the structure of the decompression type water-conducting fracture zone height observation system provided by the utility model;

[0028] Figure 2 This is a schematic diagram of the structure of the double-end water blocking and water-conducting fracture zone observation instrument provided by the utility model;

[0029] Figure 3 This is a structural diagram of the water pressure reducing device provided by the utility model connected between the double-end water-blocking and water-conducting fracture zone observation instrument and the drill pipe;

[0030] Figure 4 This is a schematic diagram of the structure of the water pressure reducing device provided by the utility model connected between two drill rods;

[0031] Figure 5 A schematic structural diagram of the water pressure reducing valve provided by the utility model;

[0032] Figure 6 This is a schematic cross-sectional view of the water pressure reducing valve provided by the utility model.

[0033] Reference numerals:

[0034] 1. Double-end water-blocking and water-conducting fracture zone observation instrument; 11. Water injection probe; 12. Inflation airbag; 13. Pneumatic hose;

[0035] 2. Water pressure reducing device; 21. Protective housing; 22. Water pressure reducing valve; 221. Cover cap; 222. Adjusting screw; 223. Valve cover; 224. Adjusting spring; 225. Valve plug; 226. O-ring; 227. Piston; 228. Filter; 229. Valve body; 2210. Bottom cover; 2211. Valve core;

[0036] 3. Drill rod; 31. Rod head; 32. Rod tail.

[0037] Instruction manual ZSU240550CN DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. It should be noted that, in the absence of conflict, the embodiments in this disclosure and the features in the embodiments can be combined, separated, interchanged and / or rearranged with each other. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0039] In the accompanying drawings, the sizes and relative sizes of components may be exaggerated for clarity and / or descriptive purposes. When the exemplary embodiments can be implemented differently, the specific process sequence may be performed in a different order than described. For example, two processes described in succession may be performed substantially simultaneously or in a reverse order from the described order. In addition, the same reference numerals represent the same components.

[0040] When a component is referred to as being “on,” “over,” “connected to,” or “coupled to” another component, the component may be directly on, directly connected to, or directly coupled to the other component, or intervening components may be present. However, when a component is referred to as being “directly on,” “directly connected to,” or “directly coupled to” another component, there are no intervening components present. For this purpose, the term “connected” may refer to a physical connection, an electrical connection, etc., with or without intervening components.

[0041] For descriptive purposes, the present disclosure may use spatially relative terms such as "top", "bottom", "under", "beneath", "under", "lower", "over", "upper", "above", "higher", etc., relative to components to describe the relationship of one component to another (other) components as shown in the accompanying drawings.

[0042] The terminology used herein is for the purpose of describing particular embodiments and is not intended to be limiting. As used herein, the singular forms "a", "an", "an" and "the" are used unless the context clearly dictates otherwise.

[0043] Instruction manual ZSU240550CN

[0044] The terms "including" and "the" and "the" are also intended to include plural forms. In addition, when the terms "comprise" and / or "comprising" and their variations are used in this specification, it specifies the presence of the stated features, integers, steps, operations, parts, components and / or groups thereof, but does not preclude the presence or addition of one or more other features, integers, steps, operations, parts, components and / or groups thereof. It is also noted that, as used herein, the terms "substantially," "approximately," and other similar terms are used as terms of approximation and not as terms of degree, and as such, they are used to account for the inherent deviations in measured, calculated, and / or provided values ​​that would be recognized by those of ordinary skill in the art.

[0045] Example 1

[0046] When observing the height of the water-conducting fracture zone, as the observation depth in the measuring borehole continues to deepen, the water pressure in the borehole will also increase. If the water pressure is too high, it will compress the inflatable airbag, which will affect the sealing between the inflatable airbag and the borehole wall.

[0047] Based on this, a specific embodiment of the present invention is as follows: Figures 1 to 4 As shown, a decompression type water-conducting fracture zone height observation system is disclosed, which is a decompression type water-conducting fracture zone height observation system suitable for tilting test of water-conducting fracture zone height. The decompression type water-conducting fracture zone height observation system includes a double-end water-blocking water-conducting fracture zone observation instrument 1 and a water pressure decompression device 2.

[0048] Among them, the double-end water-blocking and water-conducting fracture zone observation instrument 1 has a water injection probe 11 and two inflatable air bags 12. The two inflatable air bags 12 are arranged at both ends of the water injection probe 11. The inflatable air bags 12 at both ends can be used to seal a closed space in the borehole. For example, the closed length is 0.5 to 2 meters. Water is injected into the closed section of the borehole through the water injection probe 11, and the leakage per unit time is measured.

[0049] The hydraulic pressure reducing device 2 is connected between two adjacent drill pipes 3 and / or between the drill pipe 3 and the double-end water-blocking and water-conducting fracture zone observation instrument 1. The hydraulic pressure reducing device 2 is configured to adjust the water pressure within the drill pipe 3 to below the inflation pressure of the inflatable airbag 12. While ensuring that water is supplied to the double-end water-blocking and water-conducting fracture zone height observation instrument without leakage, the water pressure within the drill pipe 3 is reduced to below the inflation pressure of the inflatable airbag 12, thereby ensuring that the inflatable airbag 12 has a good water-blocking effect. The inflation pressure refers to the air pressure inside the inflatable airbag when it is inflated.

[0050] In this embodiment, the inflatable airbag 12 can be a steel braided rubber tube that can expand when inflated to achieve the specification ZSU240550CN

[0051] It makes sealing contact with the wall of the drilled hole, thereby achieving sealing.

[0052] In this embodiment, the double-end water-blocking water-conducting fracture zone observation instrument 1 further includes an expansion pipeline. The pneumatic hose 13 wrapped around the water injection probe 11 serves as the expansion pipeline, connecting the expansion console and the two expansion air bags 12.

[0053] In this embodiment, the water injection probe 11 is hollow and has several water injection holes formed in its wall. The probe 11 is connected to a water injection control console via a water injection pipeline. During use, the double-ended water-blocking and water-conducting fracture zone observation instrument 1 is inserted into a borehole. The expansion pipeline and the water injection pipeline are used to control the expansion of the inflation bladder 12 within a certain section of the borehole (e.g., 0.5-2 meters). Water is then injected into the closed section of the borehole through the water injection probe 11, and the amount of water lost per unit time is measured.

[0054] In this embodiment, the double-ended water-blocking and water-conducting fracture zone observation instrument 1, the hydraulic pressure reducing device 2, and the drill pipe 3 are connected in series using a threaded connection. The tail portion of the double-ended water-blocking and water-conducting fracture zone observation instrument 1 has the same structure as the rod tail portion 32, meaning that the tail portion of the double-ended water-blocking and water-conducting fracture zone observation instrument 1 can be directly connected to and communicate with the rod head 31. Optionally, the tail portion's inflatable airbag 12 is sheathed over the tail portion of the water injection probe 11, exposing the tail end of the water injection probe 11, allowing the tail end of the water injection probe 11 to be directly connected to the rod head 31.

[0055] In this embodiment, Figure 5 As shown, the water pressure reducing device 2 includes a hollow protective housing 21 and a water pressure reducing valve 22 disposed within the protective housing 21. The axial ends of the protective housing 21 have the same structure as the ends of the drill rod 3. That is, the drill rod 3 has a rod head 31 and a rod tail 32. The axial head end of the protective housing 21 has the same structure as the rod head 31, and the axial tail end of the protective housing 21 has the same structure as the rod tail 32. This allows the protective housing 21 to be connected and communicated with the tail end of the drill rod 3 and the double-end water-blocking water-conducting fracture zone observation instrument 1. The water pressure of the water pressure reducing valve 22 is pre-regulated by design based on the ground drilling depth, the length of the drill rod 3, etc. The water pressure reducing valve 22 is then assembled with the hollow protective housing 21 into an integral body. The assembled water pressure reducing device 2 is then connected between two adjacent drill rods 3 and / or between the drill rod 3 and the double-end water-blocking water-conducting fracture zone observation instrument 1.

[0056] Specifically, if Figure 6 As shown, the protective housing 21 has an internal cavity and the internal cavity is

[0057] The axial ends of the cavity are connected, and a side wall mounting port is provided on the side wall of the protective shell 21. The side wall mounting port is connected to the internal cavity of the protective shell 21. The water pressure reducing valve 22 is fixedly installed in the internal cavity of the protective shell 21, and the two valve ports of the water pressure reducing valve 22 are respectively connected to the axial ends of the protective shell 21, and a part of the water pressure reducing valve 22 extends from the side wall mounting port.

[0058] Optionally, both ends of the water pressure reducing valve 22 are welded to the inner space of the protective shell 21, or epoxy resin glue is used to fix the water pressure reducing valve 22 to the inner space of the protective shell 21 to ensure stability and watertightness.

[0059] In one optional embodiment, the water pressure reducing valve 22 can be a piston-type branch pipe pressure reducing valve, or a piston-type adjustable pressure reducing valve, which can regulate the outlet water pressure of the water pressure reducing valve 22. The piston-type branch pipe pressure reducing valve is an improved branch pipe pressure reducing valve, which is improved from the traditional diaphragm structure to a piston structure, so that the service life is longer and the performance is more reliable. For example, Figure 6 As shown, the piston-type branch pressure reducing valve includes parts such as a cap 221, an adjusting screw 222, a valve cover 223, an adjusting spring 224, a valve plug 225, an O-ring 226, a piston 227, a filter 228, a valve body 229, a bottom cover 2210, and a valve core 2211, and the main material is brass. Valve body 229 has an inlet and an outlet for fluid flow, serving as its two valve ports. A piston 227 is located within valve body 229, with a valve core 2211 located at its lower end. Adjustment springs 224 are located at both ends of piston 227. Specifically, a first spring is connected to the upper end of piston 227, while a second spring is connected to the lower end. An adjustment screw 222 is coaxially positioned above piston 227 and abuts the top of the first spring, enabling piston 227 to be pushed downward by screwing. A second spring is sleeved around valve core 2211, which is connected to the inner wall of valve body 229 via the second spring. Valve body 229 also features a pressure gauge mounting port for installing a pressure gauge, which is fitted with a valve plug 225. The working principle of the piston-type branch pressure reducing valve is that the valve plug 225 can be removed to allow installation of a pressure gauge, making it easier to observe the pressure downstream of the valve and facilitate commissioning. Unscrew top cap 221 and use an Allen wrench to turn adjusting screw 222 clockwise. This compresses adjusting spring 224, generating thrust that pushes piston 227 downward, opening valve core 2211. Fluid flows from the inlet to the outlet, and downstream pressure begins to rise. The outlet pressure acts beneath piston 227, pushing it upward until it balances the force of adjusting spring 224.

[0060] Instruction manual ZSU240550CN

[0061] The valve core 2211 is kept at a certain opening, and the pressure after the valve is kept stable. Turning the adjusting screw 222 clockwise increases the outlet pressure, and turning it counterclockwise reduces the outlet medium pressure.

[0062] In order to extend the double-ended water-blocking water-conducting fracture zone observation instrument 1 to the depth of the borehole, multiple drill rods 3 are connected in series to achieve the required length for observation in the borehole. The water pressure reducing device 2 can be used to regulate the water pressure in the drill rod 3, which increases with depth, to below the inflation pressure of the inflatable airbag 12, to prevent the inflatable airbag 12 from being compressed, thereby ensuring that the airbag always maintains a good water-blocking effect during the observation process, so as to complete the entire actual measurement process of observing the height of the water-conducting fracture from the ground borehole. Since the water pressure reducing device 2 can control the output water pressure at a certain distance, when multiple drill rods 3 are connected in series, multiple water pressure reducing devices 2 can be connected in series with multiple drill rods 3, and multiple water pressure reducing devices 2 can be dispersed to enable flexible control of the output water pressure at each height.

[0063] During the measurement process, the inflation pipeline inflates the inflation bladder 12 via the pneumatic hose 13, creating a closed space within the borehole. Water is then injected through the water injection pipeline, passing through the drill pipe 3 and reaching the hydraulic pressure reducing device 2. The hydraulic pressure reducing device 2 regulates the water pressure within the drill pipe 3, ensuring that the outlet water pressure remains constant at a safe value. Finally, the water is injected into the closed space formed within the borehole to complete the measurement. For example, for a high-altitude, pitched borehole with a depth of 500m, each drill pipe 3 is 10m long. The maximum air pressure of the inflation bladders 12 at each end of the double-ended water-blocking, water-conducting fracture zone height observation instrument is 0.2MPa-0.3MPa. The required water pressure within the closed space formed by the two inflation bladders 12 within the borehole is 0.1MPa. The maximum input water pressure at the inlet of the piston-type branch pressure reducing valve is 2.5MPa, while the water pressure at the bottom of the water injection probe 11 is 5MPa, far exceeding these requirements. Therefore, a series connection can be used.

[0064] Compared with the prior art, the decompression-type water-conducting fracture zone height observation system provided in this embodiment can achieve the following beneficial effects:

[0065] 1. It realizes the height observation of water-conducting fracture zones in the special case of high-altitude inclined boreholes; it can realize the observation of water-conducting fracture height from ground drilling, and observe the development of fractures by closing a certain section in the borehole and injecting water, eliminating the tedious construction steps of the borehole flushing fluid loss method, greatly improving the efficiency of drilling construction, making it more efficient and safer, and not affecting the test results of transient electromagnetic method and borehole peek method; after the drilling construction is completed, borehole peek, transient electromagnetic method observation and borehole loss observation are implemented at the same time, shortening the construction period, reducing construction costs, reducing the risk of hole collapse, reducing the probability of drilling rig accidents, and reducing the risk of project implementation.

[0066] 2. The water pressure reducing device can be connected between drill pipes and / or between the drill pipe and a double-end water-blocking water-conducting fracture zone observation instrument; by pre-adjusting the water pressure to control the water pressure change brought about by the deepening of the drill pipe, the capsules at both ends of the water injection probe can be normally expanded to achieve a sealing effect; the water pressure reducing device is flexible to use and can be connected to several drill pipes at a distance according to the height change, so that multiple water pressure reducing devices can be connected in series, thereby ensuring that a stable output water pressure can be controlled regardless of the height change, and ultimately realizing the entire actual measurement process of observing the height of the water-conducting fracture from the ground drilling.

[0067] The specific implementation methods described above further illustrate the purpose, technical solutions and beneficial effects of this application. It should be understood that the above description is only the specific implementation methods of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application should be included in the scope of protection of this application.

Claims

1. A decompression type water-conducting fracture zone height observation system, characterized in that: include: A double-end water-blocking and water-conducting fracture zone observation instrument (1) is provided, wherein the double-end water-blocking and water-conducting fracture zone observation instrument (1) comprises a water injection probe (11) and two inflation air bags (12). The two inflation air bags (12) are arranged at both ends of the water injection probe (11) and can seal off a closed space in a borehole. Water is injected into the closed space in the borehole through the water injection probe (11) to obtain the amount of leakage per unit time. A water pressure reducing device (2) is connected between two adjacent drill pipes (3) and / or between the drill pipe (3) and a double-end water-blocking and water-conducting fracture zone observation instrument (1); the water pressure reducing device (2) is configured to adjust the water pressure in the drill pipe (3) to below the inflation pressure of the inflation airbag (12).

2. The decompression type water-conducting fracture zone height observation system according to claim 1, characterized in that: The water injection probe (11) is a hollow structure, a plurality of water injection holes are opened on the wall of the water injection probe (11), and the water injection probe (11) is connected to the water injection control console via a water injection pipeline.

3. The decompression type water-conducting fracture zone height observation system according to claim 1, characterized in that: The double-end water-blocking and water-conducting fracture zone observation instrument (1) further comprises an expansion pipeline, which is connected to an expansion console and two expansion air bags (12).

4. The decompression type water-conducting fracture zone height observation system according to any one of claims 1 to 3, characterized in that: The drill rod (3) comprises a rod head (31) and a rod tail (32); the tail of the double-end water-blocking and water-conducting fracture zone observation instrument (1) has the same structure as the rod tail (32) and can be directly connected to the rod head (31).

5. The decompression type water-conducting fracture zone height observation system according to claim 4, characterized in that: The water pressure reducing device (2) comprises a hollow protective shell (21) and a water pressure reducing valve (22) arranged in the protective shell (21); the axial head end of the protective shell (21) has the same structure as the rod head (31); and the axial tail end of the protective shell (21) has the same structure as the rod tail (32).

6. The decompression type water-conducting fracture zone height observation system according to claim 5, characterized in that: The protective shell (21) has an internal cavity and axial two-end openings connected to the internal cavity. A side wall mounting port is provided on the side wall of the protective shell (21), and the side wall mounting port is connected to the internal cavity of the protective shell (21). The water pressure reducing valve (22) is fixedly installed in the internal cavity of the protective shell (21), and the two valve ports of the water pressure reducing valve (22) are respectively connected to the axial two end openings of the protective shell (21), and a part of the water pressure reducing valve (22) extends out from the side wall mounting port.

7. The decompression type water-conducting fracture zone height observation system according to claim 6, characterized in that: The water pressure reducing valve (22) is welded to the inner space of the protective shell (21), or the water pressure reducing valve (22) is fixed to the inner space of the protective shell (21) using epoxy resin glue.

8. The decompression type water-conducting fracture zone height observation system according to claim 1, characterized in that: There are multiple water pressure reducing devices (2), and there are multiple drill rods (3). The multiple water pressure reducing devices (2) are dispersedly arranged on the multiple serially connected drill rods (3) according to a set distance.

9. The decompression type water-conducting fracture zone height observation system according to any one of claims 5 to 7, characterized in that: The water pressure reducing valve (22) is a piston-type branch pipe reducing valve or a piston-type adjustable reducing valve.

10. The decompression type water-conducting fracture zone height observation system according to claim 1, characterized in that: The double-end water-blocking and water-conducting fracture zone observation instrument (1), the water pressure reducing device (2) and the drill rod (3) are connected in series by threaded connection.

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