Advanced segmented treatment guiding device and method for coal seam roof water disasters

Abstract

The invention discloses a segmented guiding device and method for advanced treatment of coal seam roof water disasters. The segmented guiding device comprises a free rotator, a middle centralizer, a jet assembly, a jet connector, a pressure bearing device and an upper centralizer which are coaxially communicated. The ejection assembly comprises a gravity orientator and an ejector which are integrally and coaxially communicated, the gravity orientator comprises a gravity orientator upper semicircular body and a gravity orientator lower semicircular body which are integrally arranged in a butt joint mode, a sliding groove extending in the circumferential direction is formed in the inner wall of the gravity orientator lower semicircular body, and a balancing weight is arranged in the sliding groove in a sliding mode; the ejector comprises an ejector upper semicircular body and an ejector lower semicircular body which are integrally arranged in a butt joint mode, and a plurality of spraying holes are formed in the ejector upper semicircular body in a penetrating mode. Upward perforation is achieved through the gravity orientator and the ejector, and the effect of directionally guiding the trend of a fracturing crack can be achieved; a channel between each target water-containing body and a roof directional long drill hole of a roof coal seam is opened through directional guide staged fracturing, and effective drainage of the multiple target water-containing bodies is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of mine roof water prevention and control, and particularly relates to a segmented guiding device and method for advanced treatment of coal seam roof water hazards. Background Art

[0002] Karst caves or water-bearing bodies often have uneven distribution in the same plane or vertical direction. Due to the strong development of karst, karst depressions, faults, fissures, sinkholes, and underground rivers are common features. Furthermore, well-developed limestone, marl-bearing limestone, and argillaceous limestone are also highly water-rich rock formations. The mechanism of water inrush in coal seam roof aquifers is primarily due to the release of energy from stress after coal mining, which causes the rock layer to fracture upward, forming a water-conducting fracture zone. This in turn connects with aquifers, faults, and underground rivers, causing a sudden release of water. In severe cases, this can flood the well and pose a serious threat to mine safety.

[0003] The main approaches to addressing these issues include long-distance underground roof drainage and controlling the height of water-conducting fracture zones. The former only allows for localized drainage when drilling holes can reveal specific locations, while the latter directly limits production at the coal face, resulting in a passive approach with a low return on investment.

[0004] Therefore, the existing mine roof prevention and control technologies and methods have strong limitations, are difficult to meet the essential requirements of safe production in modern mines, and cannot fully release the advanced production capacity of mines. Summary of the Invention

[0005] In response to the defects and shortcomings in the existing technology, the present invention provides a segmented guidance device and method for advanced control of coal seam roof water hazards, so as to solve the technical problems in the existing technology that the prevention and control of mine roofs are limited and difficult to meet the requirements of safe production, and realize multi-target positioning, segmented guidance and directional drilling of coal mine roof water.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A segmented guiding device for advanced treatment of coal seam roof water hazard, comprising a free rotator, a middle centralizer, a jet assembly, a jet connector, a pressure bearing and an upper centralizer, which are coaxially connected from back to front;

[0008] The injection assembly includes a gravity director and an injector that are coaxially connected and integrated. The gravity director includes an upper semicircular body and a lower semicircular body that are integrally connected and docked. A circumferentially extending slide groove is provided on the inner wall of the lower semicircular body of the gravity director, and a counterweight block is slidably provided in the slide groove.

[0009] The injector comprises an upper semicircular body and a lower semicircular body which are integrally connected and arranged. A plurality of spray holes are formed through the upper semicircular body.

[0010] The present invention also has the following technical features:

[0011] Specifically, the rear end of the free rotator is also connected in sequence with an upper connector, a hydraulic anchor, a lower connector, a lower centralizer and a release handle;

[0012] The front end of the upper centralizer is also coaxially connected with a plug and an inverted cone.

[0013] Furthermore, the injection connector includes a first connecting section, a reduced diameter section and a second connecting section that are integrally connected. A first step is formed at the connection between the first connecting section and the second connecting section, and a second step is formed at the connection between the reduced diameter section and the second connecting section. A first guide groove is circumferentially provided on the outer wall of the reduced diameter section near the second step, and a second guide groove is circumferentially provided on the inner wall of the rear end of the pressure bearing device. The first guide groove and the second guide groove are symmetrically arranged; a plurality of first grooves are circumferentially equally spaced in the first guide groove, and a plurality of second grooves are circumferentially equally spaced in the second guide groove. The first grooves and the second grooves are arranged correspondingly, and a ball is embedded in each of the first grooves.

[0014] Furthermore, an inner cavity with two ends open is circumferentially provided in the pressure vessel, an inflatable airbag is provided in the inner cavity, and an air inlet of the inflatable airbag is connected to an outlet of the second connecting section extending into the pressure vessel.

[0015] Furthermore, the plurality of spray holes are arranged at equal intervals.

[0016] The present invention also provides a method for advanced control of coal seam roof water hazard by segmented guidance, which is implemented by the above-mentioned device for advanced control of coal seam roof water hazard by segmented guidance, and comprises the following steps:

[0017] This embodiment provides a segmented guidance method for advanced control of coal seam roof water hazard, which is implemented by the above-mentioned segmented guidance device for advanced control of coal seam roof water hazard, and includes the following steps:

[0018] Step 1: Determine the advanced treatment area of ​​the coal seam roof aquifer and the locations of all target water bodies within the advanced treatment area of ​​the coal seam roof aquifer based on the previous exploration results, and complete the calibration of the locations of all target water bodies;

[0019] Step 2: Determine the number and locations of directional long boreholes in the coal seam roof based on the locations of all the determined target water bodies; set up an underground construction drilling site and complete the drilling of all directional long boreholes in the coal seam roof;

[0020] Step 3: Using an oil pipe, transport the coal seam roof water hazard advanced control segmented guide device to a directional long drill hole in the coal seam roof below the first target water body;

[0021] Step 4: Using the coal seam roof water hazard advanced control segmented guiding device, an upward guided jetting seam-making operation is carried out on the first target water-bearing body to form an upward guiding hole;

[0022] Step 5: completing the communication between the long directional drill hole in the coal seam roof and the first target water body through hydraulic fracturing to form the first section of hydraulic fracturing cracks;

[0023] Step 6: After the pressure is released, the coal seam roof water hazard advance control segmented guide device is removed to drain the first target water body until the water output from the orifice of the directional long drill hole in the coal seam roof is less than the set value;

[0024] Step 7: Run the oil pipe into the long directional borehole in the coal seam roof, perform well flushing operations, and then pull out the oil pipe to complete the guided drainage of the first target water body;

[0025] Step 8: Using the oil pipe, transport the coal seam roof water hazard advanced control segmented guide device to the coal seam roof directional long drill hole below the second target water body;

[0026] Step 9: Use the second target water body as the first target water body and repeat steps 4 to 8 until the guided drainage of all target water bodies is completed.

[0027] Furthermore, the setting value in step 6 is 3 to 5 m 3 / d.

[0028] Furthermore, the upward-directed jet-forming operation described in step 4 uses clean water as the jet liquid, and the jet displacement is 1.0 to 2.5 m 3 / min.

[0029] Compared with the prior art, the present invention has the following technical effects:

[0030] (1) The device of the present invention realizes upward perforation by connecting and coordinating multiple components arranged in a coaxial manner, especially by the structural design of the gravity director and the ejector arranged in an integrated coaxial manner. The device has a simple structure and is easy to use, and can achieve the effect of directional guidance of the fracturing crack direction.

[0031] (2) The method of the present invention constructs a channel between the target water-bearing body and the directional long drill hole of the roof of the coal seam through directional guided segmented fracturing, thereby realizing the effective drainage of all target water-bearing bodies in the advanced treatment area of ​​the coal seam roof aquifer; thereby realizing the complete drainage of the refined water-bearing bodies of the coal mining working face without limit on the number of times and sections, greatly reducing safety hazards.

[0032] (3) The drainage mode of the target water-bearing body in the entire section of the directional long drilling hole in the roof established by the method of the present invention can provide safety protection for the underground coal mining working face, greatly reduce the water inflow from the mine roof, provide guarantee for the safe mining of the coal mining working face, and thus fully release the advanced production capacity of the mine. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a schematic diagram of the overall structure of the segmented guidance device for advanced control of coal seam roof water hazards;

[0034] Figure 2 This is a partial structural section of the segmented guide device for advanced control of coal seam roof water hazards;

[0035] Figure 3 This is a schematic diagram of the layout of directional long drilling holes in the coal seam roof in Example 2;

[0036] Figure 4 This is a schematic diagram of the first target water body drainage in Example 2;

[0037] Figure 5 This is a schematic diagram of the second target water body discharge in Example 2.

[0038] Meaning of reference numerals:

[0039] 1-free rotator, 2-middle centralizer, 3-jet assembly, 4-jet connector, 5-pressure bearing, 6-upper centralizer, 7-upper connector, 8-hydraulic anchor, 9-lower connector, 10-lower centralizer, 11-release handle, 12-plug, 13-inverted cone, 14-inflatable airbag, 15-ball, 16-coal seam, 17-first target water body, 18-second target water body, 19-coal seam roof directional long drilling, 20-underground construction drilling site, 21-guide hole;

[0040] 31-gravity director, 32-ejector;

[0041] 41-first connecting section, 42-reduced diameter section, 43-second connecting section, 44-first step, 45-second step;

[0042] 311- upper semicircular body of the gravity orienter, 312- lower semicircular body of the gravity orienter, 313- counterweight;

[0043] 321-injector upper semicircular body, 322-injector lower semicircular body; 323-injection hole;

[0044] 3121-chute. DETAILED DESCRIPTION

[0045] Specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent modifications made on the basis of the technical solution of this application fall within the protection scope of the present invention.

[0046] The terms "upper", "lower", "front", "back", "top", "bottom", etc. used in the present invention to indicate directions or positional relationships are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operate in a specific direction. "Inside" and "outside" refer to the inside and outside of the contour of the corresponding component, and the above terms cannot be understood as limiting the present invention.

[0047] Furthermore, the terms "first," "second," and other ordinal numbers are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the technical features being referenced. Thus, a feature designated "first" or "second" may explicitly or implicitly include one or more of the features.

[0048] In the present invention, unless otherwise specified, terms such as "mounted," "connected," "connect," and "fixed" should be interpreted broadly. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0049] Unless otherwise specified, the components involved in the present invention, such as the free rotator, the centralizer, the jet connector, the pressure receiver, the plug, the hydraulic anchor and the inverted cone, are all commercially available.

[0050] Example 1

[0051] Following the above technical solution, Figure 1 and Figure 2 As shown, this embodiment provides a segmented guiding device for advanced treatment of coal seam roof water hazard, comprising a free rotator 1, a middle centralizer 2, a jet assembly 3, a jet connector 4, a pressure bearing 5 and an upper centralizer 6, which are coaxially connected from back to front.

[0052] The free rotator 1 can rotate freely under the drive of the drilling equipment; the middle stabilizer 2 and the upper stabilizer 6 are installed in the middle of the segmented guide device to ensure that the segmented guide device remains centered in the borehole, prevent the segmented guide device from eccentrically rubbing against the hole wall, reduce the risk of drill sticking, and assist in controlling the wellbore trajectory and maintaining the drilling direction; the injection assembly 3 is used for injection operations; the pressure bearer 5 is used to withstand the high-pressure environment inside and outside the segmented guide device to ensure sealing and structural integrity.

[0053] The injection assembly 3 includes a gravity director 31 and an injector 32 that are integrated and coaxially connected. The gravity director 31 includes an upper semicircular body 311 of the gravity director and a lower semicircular body 312 of the gravity director that are integrated and docked. A slide groove 3121 extending along the circumferential direction is provided on the inner wall of the lower semicircular body 312 of the gravity director. A counterweight block 313 is slidably provided in the slide groove 3121. When the device is stationary, the position of the gravity director 31 can be driven by the sliding of the counterweight block 313 in the slide groove 3121.

[0054] The injector 32 includes an upper semicircular body 321 and a lower semicircular body 322 that are integrally connected. A plurality of spray holes 323 are formed through the upper semicircular body 321 .

[0055] When the gravity director 31 reaches the set position, the segmented guiding device remains stationary for a period of time, and the counterweight block 313 can slide along the slide groove 3121 to the bottom of the lower semicircular body 312 of the gravity director under the action of gravity, thereby driving the upper semicircular body 311 of the gravity director upward, that is, the spray hole 323 can spray upward.

[0056] As a preferred solution of this embodiment, the rear end of the free rotator 1 is also connected in sequence with an upper connector 7, a hydraulic anchor 8, a lower connector 9, a lower centralizer 10 and a release handle 11;

[0057] The front end of the upper centralizer 6 is also coaxially connected with a plug 12 and an inverted cone 13. The plug 12 is used to block the fluid channel in the coal seam roof water hazard advance control segmented guide device to ensure that the fluid is ejected from the spray hole 323 and sprayed upward during the injection operation.

[0058] As a preferred solution of this embodiment, the injection connector 4 includes a first connecting section 41, a reduced diameter section 42 and a second connecting section 43 that are connected in an integrated manner. The first connecting section 41 and the second connecting section 42 are connected to form a first step, and the reduced diameter section 42 and the second connecting section 43 are connected to form a second step. Figure 2 As shown, a first guide groove is circumferentially formed on the outer wall of the reduced diameter section 42 near the second step, and a second guide groove is circumferentially formed on the inner wall of the rear end of the pressure bearing 5; the first guide groove and the second guide groove are symmetrically arranged, and a plurality of first grooves are circumferentially evenly spaced in the first guide groove, and a plurality of second grooves are circumferentially evenly spaced in the second guide groove, and the first grooves are arranged one-to-one with the second grooves, and a ball 15 is embedded in each first groove;

[0059] The pressure bearing 5, the ball 15 and the second connecting section 43 form a bearing-like structure. When the injection connector 4 rotates, the ball 15 rolls in the first guide groove and the second guide groove, but the pressure bearing 5 does not rotate.

[0060] As a preferred solution of this embodiment, an inner cavity with two ends open is provided in the circumferential direction inside the pressure vessel 5 , an inflatable airbag 14 is provided in the inner cavity, and the air inlet of the inflatable airbag 14 is connected to the outlet of the second connecting section 43 extending into the pressure vessel 5 .

[0061] The inflatable airbag 14 is similar to a balloon. Before being pressurized, the inflatable airbag 14 has no contact or partial contact with the inner wall of the pressure vessel 5. After the segmented guiding device for advanced control of coal seam roof water hazards is pressurized, the fluid can enter the inflatable airbag 14 through the outlet of the injection connector 4. After the inflatable airbag 14 is inflated, it fits with the inner wall of the pressure vessel 5.

[0062] As a preferred solution of this embodiment, the plurality of spray holes 324 are arranged at equal intervals.

[0063] When using this device:

[0064] Connect the oil pipe and the coal seam roof water hazard advance control segmented guide device on the drilling equipment, and use the drilling equipment and oil pipe to push the segmented guide device to the bottom of the calibrated target water body in the horizontal section of the coal seam roof directional long borehole set in the coal seam roof rock layer; start pressurizing at the hole mouth, and after reaching the first pressure P1, the hydraulic anchor 8 is sealed on the well wall to fix the segmented guide device. At this time, under the coordinated action of the free rotator 1, the ball 15 and the guide slot, the gravity director 31 and the ejector 32 can realize free rotation and stand still below the calibrated target water body. After a period of time, the counterweight block 313 slides downward along the slide groove under the action of gravity, and eventually all the spray holes 323 on the upper semicircular body 312 of the gravity director are facing upward; continue to pressurize to reach the second pressure P2 required for the expansion of the inflatable airbag, and the inflatable airbag 36 begins to expand and deform, and after expansion, it contacts the pressure bearer 35. At this time, the ejector 32, the ejection connector 4, the pressure bearer 5, and the upper stabilizer 6 are connected as one to achieve expansion locking; continue to pressurize to reach the ejection pressure P3 of the ejector 32, and then start the ejection operation to form a guide hole, where P1<P2<P3.

[0065] Example 2

[0066] Following the above technical solution, Figures 3 to 5 As shown, this embodiment provides a segmented guidance method for advanced treatment of coal seam roof water hazard, which is implemented by the segmented guidance device for advanced treatment of coal seam roof water hazard provided in Example 1, and includes the following steps:

[0067] Step 1: Determine the advanced treatment area of ​​the coal seam roof aquifer and the locations of all target water bodies within the advanced treatment area of ​​the coal seam roof aquifer based on the previous exploration results, and complete the calibration of the locations of all target water bodies;

[0068] Step 2: Determine the number and locations of the long directional drill holes 19 in the coal seam roof based on the locations of all the determined target water bodies; set up an underground construction drilling site 20 to complete the drilling of all the long directional drill holes 19 in the coal seam roof, and ensure that each long directional drill hole 19 in the coal seam roof is drilled to the designed depth; the long directional drill holes 19 in the coal seam roof obtained after the construction is completed can be used as drainage holes in the drainage operation, as drainage channels for the target water bodies;

[0069] Step 3: Using the oil pipe, transport the coal seam roof water hazard advanced control segmented guide device to the coal seam roof directional long drill hole 19 below the first target water body 17;

[0070] In this embodiment, Figure 3 When calibrating the positions of multiple target water bodies, the positions are calibrated and numbered from near the bottom of the hole to near the hole mouth. When dredging, a backward dredging operation is adopted.

[0071] Step 4: Using the coal seam roof water hazard advanced control segmented guiding device, an upward guiding jet seam-making operation is performed on the first target water-bearing body 17 to form an upward guiding hole 21;

[0072] As a preferred solution of this embodiment, the upward-guided jet seam-making operation adopts a large-volume, directional sandblasting perforation method, with clean water as the jet liquid, and the jet displacement is 1.0 to 2.5 m 3 / min.

[0073] Step 5: Complete the communication between the long directional drill hole 19 on the coal seam roof and the first target water body 17 through hydraulic fracturing to form the first section of hydraulic fracturing cracks;

[0074] Step 6: After the pressure is released, the coal seam roof water hazard advance control segmented guiding device is removed to drain the first target water body 17 until the water output from the orifice of the directional long drill hole 19 in the coal seam roof is less than the set value;

[0075] As a preferred solution of this embodiment, the setting value is 3 to 5m 3 / d.

[0076] Step 7: Run the oil pipe into the long directional borehole 19 in the coal seam roof, perform well flushing operations, and then pull out the oil pipe to complete the guided drainage of the first target water body 17;

[0077] Step 8: Using the oil pipe, transport the coal seam roof water hazard advanced control segmented guide device to the coal seam roof directional long drill hole 19 below the second target water body 18;

[0078] Step 9: Use the second target water body 18 as the first target water body and repeat steps 4 to 8 until the guided drainage of all target water bodies is completed.

[0079] The segmented guidance method for advanced treatment of coal seam roof water hazards provided in this embodiment constructs a channel between the target water-bearing body and the directional long drill hole of the roof of the coal seam through directional guided segmented fracturing, thereby realizing the effective drainage of all target water-bearing bodies in the advanced treatment area of ​​the coal seam roof aquifer; thereby realizing the thorough drainage of refined water-bearing bodies of the coal mining working face for an unlimited number of times and in an unlimited number of sections, greatly reducing the water gushing from the mine roof, providing guarantee for the safe mining of the coal mining working face, and thus fully releasing the advanced production capacity of the mine.

[0080] The above implementation process is merely an example to clearly illustrate the present application and is not intended to limit the implementation methods. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications derived therefrom remain within the scope of protection of this application.

Claims

1. A segmented guiding device for advanced control of coal seam roof water hazard, characterized in that: It comprises a free rotator (1), a middle centralizer (2), an injection assembly (3), an injection connector (4), a pressure bearing (5) and an upper centralizer (6) which are coaxially connected from back to front; The injection assembly (3) comprises a gravity orienter (31) and an injector (32) which are coaxially connected and integrated. The gravity orienter (31) comprises an upper semicircular body (311) and a lower semicircular body (312) of the gravity orienter which are integrally connected and connected. A chute (3121) extending in a circumferential direction is provided on the inner wall of the lower semicircular body (312). A counterweight (313) is slidably provided in the chute (3121). The injector (32) comprises an injector upper semicircular body (321) and an injector lower semicircular body (322) which are integrally connected and arranged. A plurality of spray holes (323) are formed through the injector upper semicircular body (321).

2. The segmented guiding device for advanced control of coal seam roof water hazard according to claim 1 is characterized in that: The rear end of the free rotator (1) is also connected in sequence with an upper connector (7), a hydraulic anchor (8), a lower connector (9), a lower centralizer (10) and a release handle (11); The front end of the upper centralizer (6) is also coaxially connected with a plug (12) and an inverted cone (13).

3. The segmented guiding device for advanced control of coal seam roof water hazard according to claim 1 is characterized in that: The injection connector (4) comprises a first connecting section (41), a reduced diameter section (42) and a second connecting section (43) which are connected in an integrated manner. A first step (44) is formed at the connection between the first connecting section (41) and the second connecting section (42), and a second step (45) is formed at the connection between the reduced diameter section (42) and the second connecting section (43). A first guide slot is provided on the outer wall of the reduced diameter section (42) near the second step (45) along the circumferential direction, and a second guide slot is provided on the inner wall of the rear end of the pressure bearing (5) along the circumferential direction. The first guide slot is symmetrically arranged with the second guide slot; a plurality of first grooves are provided in the first guide slot at equal intervals along the circumferential direction, and a plurality of second grooves are provided in the second guide slot at equal intervals along the circumferential direction. The first grooves are corresponding to the second grooves, and a ball (15) is embedded in each of the first grooves.

4. The segmented guiding device for advanced control of coal seam roof water hazard according to claim 3 is characterized in that: An inner cavity with two open ends is provided in the pressure bearing (5) along the circumferential direction, an inflatable airbag (14) is provided in the inner cavity, and an air inlet of the inflatable airbag (14) is connected to an outlet of a second connecting section (43) extending into the pressure bearing (5).

5. The segmented guiding device for advanced control of coal seam roof water hazard according to claim 1, characterized in that: The plurality of spray holes (324) are arranged at equal intervals.

6. A segmented guidance method for advanced control of coal seam roof water hazards, characterized in that: The method is implemented by the coal seam roof water hazard advance control segmented guiding device according to any one of claims 1 to 5, comprising the following steps: Step 1: Determine the advanced treatment area of ​​the coal seam roof aquifer and the locations of all target water bodies within the advanced treatment area of ​​the coal seam roof aquifer based on the previous exploration results, and complete the calibration of the locations of all target water bodies; Step 2: Determine the number and locations of directional long boreholes in the coal seam roof based on the locations of all the determined target water bodies; set up an underground construction drilling site and complete the drilling of all directional long boreholes in the coal seam roof; Step 3: Using an oil pipe, transport the coal seam roof water hazard advanced control segmented guide device to a directional long drill hole in the coal seam roof below the first target water body; Step 4: Using the coal seam roof water hazard advanced control segmented guiding device, an upward guided jetting seam-making operation is carried out on the first target water-bearing body to form an upward guiding hole; Step 5: completing the communication between the long directional drill hole in the coal seam roof and the first target water body through hydraulic fracturing to form the first section of hydraulic fracturing cracks; Step 6: After the pressure is released, the coal seam roof water hazard advance control segmented guide device is removed to drain the first target water body until the water output from the orifice of the directional long drill hole in the coal seam roof is less than the set value; Step 7: Run the oil pipe into the long directional borehole in the coal seam roof, perform well flushing operations, and then pull out the oil pipe to complete the guided drainage of the first target water body; Step 8: Using the oil pipe, transport the coal seam roof water hazard advanced control segmented guide device to the coal seam roof directional long drill hole below the second target water body; Step 9: Use the second target water body as the first target water body and repeat steps 4 to 8 until the guided drainage of all target water bodies is completed.

7. The segmented guidance method for advanced control of coal seam roof water hazard according to claim 6, characterized in that: The setting value in step 6 is 3 to 5m 3 / d.

8. The segmented guidance method for advanced control of coal seam roof water hazard according to claim 6, characterized in that: The upward guided jet seam making operation described in step 4 uses clean water as the jet liquid, and the jet displacement is 1.0 to 2.5m 3 / min.

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