A high-position directional long borehole layout horizon exploration system and a horizon determination method

Abstract

The present invention discloses a high-position directional long borehole layout horizon exploration system and a horizon determination method. The exploration system includes a test unit arranged on a support, and a negative pressure unit, a gas supply unit, a water supply unit and a water outlet unit are further connected to the test unit; the exploration system is used to simulate the clear water loss rate during the drilling of the borehole in the goaf fracture zone and the gas leakage effect during the later extraction. The determination method is to characterize the gas extraction effect of the optimal horizon through the water loss rate and the orifice water return rate, and then determine the upper and lower boundary points of each branch borehole at the optimal borehole layout horizon by monitoring the orifice water return rate, so as to determine the optimal layout horizon of the high-position directional long borehole. When designing a high-position directional long borehole in the adjacent mining face in the later stage, the borehole can be designed within the optimal layout horizon, so as to obtain a better gas extraction effect.

Description

Technical Field

[0001] The invention belongs to the technical field of underground coal mine drilling, and particularly relates to a high-position directional long-borehole layout horizon exploration system and a horizon determination method. Background Technique

[0002] The roof high-position directional long-borehole technology is becoming more and more important in the gas control of coal mine goaf and upper corner. The "using boreholes instead of roadways" with large-diameter long boreholes has been popularized and applied in many mining areas, and good application effects have been achieved. The high-position directional long boreholes are mainly arranged in the roof fissure zone based on the "O"-ring theory. Due to the different coal seam thicknesses, roof rock lithology combinations, key layer positions and coal mining methods in each mining area, the ranges of the fissure zones are different, resulting in large differences between different coal mines in the same mining area. At present, the exploration methods for the working face roof fissure zone mainly include empirical formula method, theoretical calculation method, similar model test method, stress monitoring method and instrument actual measurement method, etc. In the determination of the horizon of the high-position directional long borehole, the empirical formula method is mainly used for the exploration of the working face roof fissure zone. However, due to many influencing factors in the exploration process, the layout horizon of the directional long borehole obtained by this method is inaccurate, and the obtained layout horizon may not be the optimal horizon.

[0003] Therefore, it is urgent to develop a high-precision exploration test system and horizon determination method for the layout horizon of high-position directional long boreholes to overcome the above deficiencies in view of the problems and deficiencies in the precise exploration method for the fissure zone. Summary of the Invention

[0004] In view of the defects and deficiencies in the prior art, the invention provides a directional long-borehole layout horizon exploration system and a horizon determination method to solve the technical problem of inaccurate positioning of the layout horizon of the directional long borehole caused by the inability to accurately explore the range of the working face roof fissure zone in the prior art.

[0005] To achieve the above object, the invention adopts the following technical solutions:

[0006] A high-position directional long-borehole layout horizon exploration system includes a test unit arranged on a support, and a negative pressure unit, a gas supply unit, a water supply unit and a water outlet unit are also connected to the test unit;

[0007] The test unit includes a cylinder with an open top, a top cover capable of being hermetically disassembled and connected to the cylinder is arranged above the cylinder, a drain port and an air inlet are opened on the bottom plate of the cylinder, and a water inlet and an exhaust port are opened on the top cover;

[0008] The negative pressure unit includes a negative pressure pump, and the negative pressure pump is connected to the exhaust port through a negative pressure pipeline;

[0009] The gas supply unit includes a gas cylinder, and the gas cylinder is connected to the air inlet through a gas supply pipeline;

[0010] The water supply unit includes a water supply pump, and the water supply pump is connected to the water inlet through a water supply pipeline;

[0011] The drainage unit includes a drainage pipeline connected to the drainage port, and a liquid flow meter is arranged on the drainage pipeline.

[0012] The present invention has the following technical features:

[0013] Specifically, the bracket includes a base and two columns symmetrically arranged above the base. An installation plate is rotatably mounted on the columns, and an installation hole for installing a cylinder body is formed on the installation plate.

[0014] Furthermore, a gas detector and a first stop valve are arranged on the negative pressure pipeline; a liquid pressure gauge and a second stop valve are arranged on the water supply pipeline; a gas pressure gauge and a third stop valve are arranged on the gas supply pipeline.

[0015] Furthermore, a groove is circumferentially formed on the inner wall of the top cover, and a sealing ring is arranged in the groove.

[0016] Furthermore, the water supply pressure of the water supply pump is less than 0.5MP, and the negative pressure range generated by the negative pressure pump is 0-13KPa.

[0017] A method for determining the layer position of high-position directional long boreholes. The method is realized by means of the above-mentioned high-position directional long borehole layer position exploration system, and includes the following steps:

[0018] Step 1, prepare several specimens with different fracture rates;

[0019] Step 2, perform a leakage test and a gas leakage test on each specimen by means of the high-position directional long borehole layer position exploration system to obtain the water loss rate and gas flow rate of each specimen;

[0020] Step 3, determine the water return rate that can meet the best layer position extraction effect according to the law between the gas flow rate and the water loss rate, and then determine the upper limit threshold and the lower limit threshold of the orifice water return rate;

[0021] Step 4, excavate a directional drill site in the working face of the target mining area, and construct a first directional long borehole in the adjacent goaf of the working face;

[0022] Step 5, complete the drilling of the branch holes of the first directional long borehole by using the backward branch opening method. During the drilling process of the branch holes, collect the real-time orifice water return rate; take the collection position where the real-time orifice water return rate is the same as the upper limit threshold of the water return rate as the upper boundary point of the branch hole layout, and take the collection position where the real-time orifice water return rate is the same as the lower limit threshold of the water return rate as the lower boundary point of the branch hole layout;

[0023] Step 6: After the drilling of all branch holes is completed, the plane formed by the upper boundary points of the layout of all branch holes is used as the top surface of the layout layer of the second directional long borehole arranged in the working face, and the plane formed by the lower boundary points of the layout of all branch holes is used as the bottom surface of the layout layer of the second directional long borehole arranged in the working face, thus completing the determination of the layout layer of the high-level directional long borehole.

[0024] Furthermore, the specific content of step 3 is as follows: The water return rate at a water loss rate of 100% is used as the lower threshold value of the orifice water return rate, and the gas flow rate corresponding to the lower threshold value of the orifice water return rate is determined; the water return rate corresponding to half of the gas flow rate corresponding to the lower threshold value of the orifice water return rate is used as the upper threshold value of the orifice water return rate.

[0025] Furthermore, the main extension layer of the first directional long borehole is the stable rock layer in the bending subsidence zone.

[0026] Furthermore, the main extension layer of the second directional long borehole is within the fracture zone.

[0027] Compared with the prior art, the present invention has the following technical effects:

[0028] (1) Through the cooperation among the test unit, negative pressure unit, air supply unit, water supply unit and water outlet unit set in the device of the present invention, and through step-by-step tests, it is possible to simulate the water loss situation during the drilling of the branch holes of the directional long borehole in the fracture zone. The deeper the branch borehole, the more developed the fractures of the rock layer exposed at the bottom of the hole, and the greater the water loss rate; at the same time, the gas extraction effect of the rock layer with the corresponding fracture rate is obtained, and the law between the water leakage at the bottom of the hole and the gas seepage is obtained through research. Finally, it is transformed into reverse positioning of the fracture development degree at the bottom of the branch hole by monitoring the water return rate parameter. The system structure of the present invention is simple and easy to operate.

[0029] (2) By using the method of the present invention, it is possible to determine the optimal layout layer of the high-level directional long borehole located in the fracture zone of the goaf, so as to ensure that the borehole can be arranged in this layer during the construction period of the mining working face, so that during the later coal mining process, the integrity of the borehole can be maintained, thereby ensuring the smoothness of the gas extraction channel; at the same time, it can improve the extraction volume of the high-level directional long borehole and maximize the effect of the high-level directional long borehole in controlling the goaf and the gas in the upper corner. Description of the Drawings

[0030] Figure 1 It is a schematic structural diagram of a high-level directional long borehole layout layer exploration system;

[0031] Figure 2 It is a schematic structural diagram of a cylinder;

[0032] Figure 3 It is a schematic plan view of the layout of the first directional long borehole;

[0033] Figure 4 The regular curve graph between the water loss rate and the gas flow rate obtained in Example 2;

[0034] Figure 5 The schematic sectional view of the layout of the first directional long borehole;

[0035] Figure 6 The gas drainage effect diagram after constructing the high-level directional long borehole in the layout horizon determined in Example 2.

[0036] Meanings of the reference numerals:

[0037] 1 - support, 2 - cylinder body, 3 - top cover, 4 - negative pressure pump, 5 - negative pressure pipeline, 6 - gas cylinder, 7 - gas supply pipeline, 8 - water supply pump, 9 - water supply pipeline, 10 - drainage pipeline, 11 - liquid flowmeter, 12 - gas detector, 13 - first stop valve, 14 - liquid pressure gauge, 15 - second stop valve, 16 - gas pressure gauge, 17 - third stop valve, 18 - sealing ring, 19 - drainage stop valve; 23 - caving zone, 24 - fissure zone, 25 - bending subsidence zone, 26 - stable rock horizon, 27 - drill site, 28 - first directional long borehole; 101 - base, 102 - column, 103 - mounting plate. Detailed implementation manners

[0038] The present invention will be described in detail below in conjunction with the drawings and embodiments, so that those skilled in the art can better understand the present invention. It should be particularly noted that in the following description, when the detailed descriptions of known functions and designs may dilute the main content of the present invention, these descriptions will be omitted here.

[0039] The following terms related to the present invention are explained:

[0040] High-level directional long borehole: It is a group of directional long boreholes constructed from a directional drill site in the return airway or adjacent airway of the coal mining face towards the coal seam roof, aiming to drain the gas in the mining-induced fissures of the working face or the high-concentration gas accumulated in the goaf, so as to achieve the purpose of gas control in the working face.

[0041] The design idea of the method of the present invention is: By establishing a high-level directional long borehole layout horizon exploration system to simulate the water loss rate during the drilling of the borehole in the fissure zone of the goaf and the gas leakage effect during the subsequent gas drainage, and then determine the relationship between the water loss rate and the gas flow rate when the branch borehole drills at different height positions in the fissure zone, and characterize the gas flow rate that can meet the best layer drainage effect through the water loss rate and the water return rate at the borehole mouth.

[0042] In the process of determining the high-level directional long borehole layout horizon of adjacent gob areas, first, comb-shaped high-level directional boreholes are designed in the gob area. Then, the upper limit threshold and lower limit threshold of each branch hole are determined by monitoring the water return rate at the orifice, and further, the optimal layout horizon of the high-level directional long borehole is determined. The determined optimal layout horizon is used to lay out the high-level directional long boreholes in the adjacent mining face, that is, the high-level directional long boreholes in the adjacent mining face are designed within the optimal layout horizon. Usually, there are multiple boreholes arranged according to the designed spacing, which are used to control the upper corner or gob gas during the mining of the working face, achieving better gas drainage effect and reaching the purpose of "using boreholes instead of roadways".

[0043] Embodiment 1

[0044] Complying with the above technical solution, as Figure 1 shown, this embodiment provides a high-level directional long borehole layout horizon exploration system, which includes a test unit arranged on the support 1. A negative pressure unit, a gas supply unit, a water supply unit, and a water outlet unit are also connected to the test unit;

[0045] The test unit includes a cylinder body 2 with an open top. A top cover 3 that can be detachably sealedly connected to the cylinder body 2 is arranged above the cylinder body 2. A drain port and an air inlet are opened on the bottom plate of the cylinder body 2, and a water inlet and an exhaust port are opened on the top cover;

[0046] The negative pressure unit includes a negative pressure pump 4. The negative pressure pump 4 is connected to the exhaust port through a negative pressure pipeline 5; the negative pressure pump 4 is used to provide negative pressure to pump out the gas entering the cylinder body 2.

[0047] The gas supply unit includes a gas cylinder 6. The gas cylinder 6 is connected to the air inlet through a gas supply pipeline 7; the gas cylinder 6 is used to provide gas for the test unit;

[0048] The water supply unit includes a water supply pump 8. The water supply pump 8 is connected to the water inlet through a water supply pipeline 9; the water supply pump 8 is used to pump water into the test unit; preferably, a metering pump can be used as the water supply pump.

[0049] The drainage unit includes a drainage pipeline 10 connected to the drain port, and a liquid flowmeter 11 is arranged on the drainage pipeline.

[0050] As a preferred solution of this embodiment, the support 1 includes a base 101 and two columns 102 symmetrically arranged above the base 101. An installation plate 103 is rotatably mounted on the columns 102. An installation hole for installing the cylinder body 2 is opened on the installation plate 103. The installation plate 103 is connected to the column 102 through a rotating shaft and can rotate relative to the column under the drive of the rotating shaft, and can be fastened to the column 102 through bolts after rotating to a set angle.

[0051] As a preferred solution of this embodiment, a gas detector 12 and a first stop valve 13 are provided on the negative pressure pipeline 5; a liquid pressure gauge 14 and a second stop valve 15 are provided on the water supply pipeline 9; a gas pressure gauge 16 and a third stop valve 17 are provided on the gas supply pipeline 7. Among them, the gas detector 12 is used to detect the gas flow rate; the liquid pressure gauge 14 is used to detect the water supply pressure; the gas pressure gauge 16 is used to detect the pressure of the negative pressure pipeline.

[0052] As a preferred solution of this embodiment, as Figure 2 shown, a groove is circumferentially formed on the inner wall of the top cover 3, and a sealing ring 18 is arranged in the groove.

[0053] As a preferred solution of this embodiment, the water supply pressure of the water supply pump 8 is less than 0.5 MP, and the negative pressure range generated by the negative pressure pump 4 is 0 - 13 KPa.

[0054] When this system is in use, it mainly includes the following steps:

[0055] (1) Complete the connection and installation of the system components;

[0056] (2) Place the specimen into the hollow cylindrical container, then place the container into the cylinder body 2, install the sealing ring in the groove of the top cover 3, and then fasten the top cover 3 and the cylinder body 2 with bolts;

[0057] (3) Place the cylinder body 2 into the installation hole, rotate the installation plate according to the branch hole inclination angle determined by the test plan, so that the angle between the installation plate and the horizontal plane is the branch hole inclination angle, and then fix the installation plate;

[0058] (4) Close the first stop valve 13 and the third stop valve 17; open the second stop valve 15 and the drain stop valve 19;

[0059] (5) Conduct a leakage test: Turn on the water supply pump 8 to supply water into the cylinder body 2, record the water supply system pressure through the liquid pressure gauge 14, record the water outlet flow rate through the liquid flowmeter 19, and stop the pump after the test is completed;

[0060] (6) Conduct a gas leakage test: Drain the water that has entered the cylinder body 2 during the leakage test, close the second stop valve 15 and the drain stop valve 19; open the first stop valve 13 and the third stop valve 17, turn on the negative pressure pump 4, open the gas cylinder 6 to supply gas into the cylinder body 2, record the gas supply pressure through the gas pressure gauge 16, monitor the gas leakage flow rate through the gas detector 12, and close the gas cylinder and the negative pressure pump after the test is completed;

[0061] (7) After completing all the tests, clean the cylinder body.

[0062] Using this experimental device, leakage tests and gas seepage tests can be carried out on specimens with different fracture rates, so as to obtain bottom - hole water leakage data and gas seepage data.

[0063] Example 2

[0064] As Figure 3 shown, this embodiment provides a method for determining the layout horizon of high-level directional long boreholes. The method is implemented by means of the above-mentioned exploration system for the layout horizon of high-level directional long boreholes, and includes the following steps:

[0065] Step 1: Prepare several specimens with different fracture rates;

[0066] In this embodiment, specimens with fracture rates of 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, and 50% are prepared to simulate the bottom-hole formation conditions with fracture rates of 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, and 50% respectively, denoted as Specimen 1, Specimen 2, Specimen 3, Specimen 4, Specimen 5, Specimen 6, Specimen 7, Specimen 8, Specimen 9, and Specimen 10.

[0067] Step 2: Conduct a leakage test and a gas leakage test on each specimen by means of the exploration system for the layout horizon of high-level directional long boreholes to obtain the water loss rate and gas flow rate of each specimen, and then establish a relationship curve between the water loss rate and the gas flow rate;

[0068] First, measure the drainage volume of the cylinder through the liquid flowmeter on the drainage pipeline, calculate the ratio of the drainage volume to the water supply volume, that is, obtain the water loss rate. The return water volume is obtained by subtracting the drainage volume from the pump volume of the metering pump, and the percentage of the return water volume in the water supply volume can be calculated, that is, the return water rate;

[0069] The gas flow rate can be monitored and obtained by a gas detector.

[0070] Step 3: Determine the return water rate that can meet the best horizon gas drainage requirements according to the relationship curve between the water loss rate and the gas flow rate, and then determine the upper threshold value and the lower threshold value of the orifice return water rate;

[0071] Under conventional test conditions, when the water loss rate is 100%, take the return water rate at this time as 0, and determine it as the lower threshold value of the orifice return water rate, and obtain the corresponding gas flow rate as F; then determine the water loss rate corresponding to the point where the gas flow rate is F / 2 as the upper threshold value of the orifice return water rate; specifically as Figure 4 shown, in this embodiment, through experiments, the water loss rate of Specimen 9 is 100%, that is, the return water rate is 0, and the corresponding gas flow rate at this time is 9m 3 / min, that is, the lower limit value of the orifice return water rate is 0%. At this time, all the water has leaked out, so Specimen 10 will also leak out completely, and there is no need to do experiments anymore. According to the nine groups of experimental data obtained, a relationship curve between the water loss rate and the gas flow rate can be established. From the established relationship curve between the water loss rate and the gas flow rate, it can be seen that when the gas flow rate is 4.5m 3When the water loss rate is 77% at / min, the corresponding orifice water return rate is 23%. Thus, the upper threshold value of the orifice water return rate is determined to be 23%.

[0072] Because according to the test, when the water return rate is 0, the gas leakage effect of the formation has met the requirements of gas extraction, the fracture rate of the formation is relatively large, and a larger fracture rate is prone to collapse and it is difficult to maintain the gas extraction channel of the borehole. That is, the area below the layer will enter the caving zone and it is not suitable to arrange high-level directional long boreholes anymore. At the same time, considering that the directional long boreholes will be stratified and drilled in the optimal layer in the later stage, according to the height requirements of borehole arrangement and the law of water loss rate and gas seepage, combined with construction experience, when half of the gas flow rate, the upper threshold value of the orifice water return rate basically meets the requirements of borehole gas extraction. The upper threshold value of the orifice water return rate is the water return rate corresponding to half of the gas flow rate corresponding to the lower threshold value of the orifice water return rate.

[0073] Step 4: Excavate a directional drill site in the working face of the target mining area, and construct the first directional long borehole in the adjacent goaf of the working face;

[0074] First, based on the coal mine geological data, roadway driving geological conditions and working face mining conditions, preliminarily determine the heights of the caving zone, fracture zone and bending subsidence zone in the adjacent goaf of the coal mine working face. Select a stable rock layer position in the bending subsidence zone. The plane of the directional long borehole is arranged 30 m inside the return airway of the goaf, and it is constructed with a positive dip angle in the stable rock layer position to ensure the success rate of subsequent open-hole branch construction and ensure that the water return during the subsequent branch borehole construction will not be diverted or lost from the already constructed branch boreholes.

[0075] Step 5: Use the backward branch opening method to complete the drilling of the branch boreholes of the first directional long borehole. During the drilling of the branch boreholes, collect the real-time orifice water return rate; use the collection position where the real-time orifice water return rate is the same as the upper threshold value of the water return rate as the upper boundary point of the branch borehole arrangement, and use the collection position where the real-time orifice water return rate is the same as the lower threshold value of the water return rate as the lower boundary point of the branch borehole arrangement. In this implementation, a total of 6 branch boreholes as shown in Figure 5 were completed for drilling.

[0076] That is, use the position with an orifice water return rate of 23% as the upper boundary point of the corresponding branch borehole arrangement, and use the position with an orifice water return rate of 0 as the lower boundary point of the corresponding branch borehole arrangement;

[0077] During the construction of the branch boreholes, to ensure the stable water supply for directional drilling, install an orifice water return metering device at the orifice to accurately measure the reduced amount of water return, and the reduced water volume will seep into the goaf through the fracture zone.

[0078] Step 6: After drilling all the branched holes, the plane formed by the upper boundary points of all the branched hole layouts is used as the top surface of the layout horizon of the second directional long borehole arranged in the working face, and the plane formed by the lower boundary points of all the branched hole layouts is used as the bottom surface of the layout horizon of the second directional long borehole arranged in the working face, thus completing the determination of the layout horizon of the high-level directional long borehole.

[0079] Specifically, as Figure 5 shown, n branched holes are equally spacedly arranged in the first directional long borehole. The branched holes drill downward into the fissure zone, and then the upper boundary points a 1 ~a n of each branched hole layout and the lower boundary points b 1 ~b n of each branched hole layout are respectively recorded;

[0080] Connect the points a 1 ~a n to form the top surface of the layout horizon of the second directional long borehole,

[0081] Connect the points b 1 ~b n to form the bottom surface of the layout horizon of the second directional long borehole.

[0082] When setting the second directional long borehole in the adjacent working face of the goaf where the first branched hole is located, it should be ensured that the main extension horizon of the second directional long borehole is within the above-mentioned layout horizon of the second directional long borehole.

[0083] As Figure 6 shown, in this embodiment, when arranging the second long borehole in the unmined B working face, the borehole is arranged within the layout horizon of the high-level directional long borehole determined according to the above method.

[0084] Verified, by arranging the borehole in this area, during the later coal mining process of the working face, the borehole can maintain integrity, and there will be no borehole collapse causing the gas drainage channel to be blocked. The gas flow rate can reach 11 m 3 / h, and the gas drainage effect is good.

[0085] Furthermore, the main extension horizon of the first directional long borehole is the stable rock stratum in the bending subsidence zone.

[0086] Furthermore, the main extension horizon of the second directional long borehole is within the fissure zone.

[0087] The above implementation process is only an example clearly illustrating the present application, and is not a limitation on the implementation mode. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation modes here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present application type.

Claims

1. A method for determining the layout horizon of high-level directional long boreholes, characterized in that, it includes the following steps: Step 1: Prepare several specimens with different fracture rates; Step 2: Use the high-level directional long borehole layout horizon exploration system to conduct a leakage test and a gas leakage test on each specimen, obtain the water loss rate and gas flow rate of each specimen, and then establish a relationship curve between the water loss rate and the gas flow rate; Step 3: Determine the water return rate that can meet the best gas drainage requirements of the horizon according to the relationship curve between the water loss rate and the gas flow rate, and then determine the upper threshold value and the lower threshold value of the orifice water return rate; Step 4: Excavate a directional drill site in the working face of the target mining area, and construct the first directional long borehole in the adjacent goaf of the working face; Step 5: Use the backward branch opening method to complete the drilling of the branch holes of the first directional long borehole. During the drilling of the branch holes, collect the real-time orifice water return rate; Take the collection position where the real-time orifice water return rate is the same as the upper threshold value of the water return rate as the upper boundary point of the branch hole layout, and take the collection position where the real-time orifice water return rate is the same as the lower threshold value of the water return rate as the lower boundary point of the branch hole layout; Step 6: After completing the drilling of all branch holes, take the surface formed by all the upper boundary points of the branch hole layout as the top surface of the layout horizon of the second directional long borehole set in the working face, and take the surface formed by all the lower boundary points of the branch hole layout as the bottom surface of the layout horizon of the second directional long borehole set in the working face, and complete the determination of the layout horizon of the high-level directional long borehole; The high-level directional long borehole layout horizon exploration system includes a test unit arranged on the support (1), and a negative pressure unit, a gas supply unit, a water supply unit and a water outlet unit are also connected to the test unit; The test unit includes a cylinder body (2) with an open top. A top cover (3) that can be detachably sealed and connected to the cylinder body (2) is arranged above the cylinder body (2). A drain port and an air inlet are opened on the bottom plate of the cylinder body (2), and a water inlet and an exhaust port are opened on the top cover; The negative pressure unit includes a negative pressure pump (4), and the negative pressure pump (4) is connected to the exhaust port through a negative pressure pipeline (5); The gas supply unit includes a gas cylinder (6), and the gas cylinder (6) is connected to the air inlet through a gas supply pipeline (7); The water supply unit includes a water supply pump (8), and the water supply pump (8) is connected to the water inlet through a water supply pipeline (9); The water outlet unit includes a drain pipeline (10) connected to the drain port, and a liquid flow meter (11) and a drain stop valve (19) are arranged on the drain pipeline.

2. The method for determining the layout horizon of high-level directional long boreholes according to claim 1, characterized in that, the support (1) includes a base (101) and two columns (102) symmetrically arranged above the base (101). An installation plate (103) is rotatably mounted on the columns (102), and an installation hole for installing the cylinder body (2) is opened on the installation plate (103).

3. The method for determining the layout horizon of high-level directional long boreholes according to claim 1, characterized in that, A gas detector (12) and a first stop valve (13) are provided on the negative pressure pipeline (5); a liquid pressure gauge (14) and a second stop valve (15) are provided on the water supply pipeline (9); a gas pressure gauge (16) and a third stop valve (17) are provided on the gas supply pipeline (7).

4. The method for determining the layout horizon of the high-position directional long borehole according to claim 1, characterized in that, a groove is circumferentially formed on the inner wall of the top cover (3), and a sealing ring (18) is arranged in the groove.

5. The method for determining the layout horizon of the high-position directional long borehole according to claim 1, characterized in that, the water supply pressure of the water supply pump (8) is less than 0.5MP, and the negative pressure range generated by the negative pressure pump (4) is 0-13KPa.

6. The method for determining the layout horizon of the high-position directional long borehole according to claim 1, characterized in that, step 3 specifically includes: taking the water return rate at a water loss rate of 100% as the lower limit threshold of the orifice water return rate, and determining the gas flow rate corresponding to the lower limit threshold of the orifice water return rate; taking the water return rate corresponding to half of the gas flow rate corresponding to the lower limit threshold of the orifice water return rate as the upper limit threshold of the orifice water return rate.

7. The method for determining the layout horizon of the high-position directional long borehole according to claim 1, characterized in that, the main extension horizon of the first directional long borehole is the stable rock stratum in the bending subsidence zone.

8. The method for determining the layout horizon of the high-position directional long borehole according to claim 1, characterized in that, the main extension horizon of the second directional long borehole is located in the fissure zone.

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