A controlled directional drilling under-angled borehole plugging device and method

Abstract

The application discloses a controlled directional drilling lower inclined borehole plugging device and method, the device comprises a tap connected with a drill rod in a threaded mode, a lower end of the tap is connected with a borehole plugging device, the borehole plugging device comprises a connecting rod connected with the lower end of the tap, an outer thread of a lower end of the connecting rod is connected with a hole sweeping drill bit, a tapered fishbone rubber ring is sleeved on the connecting rod, a lower end of the tapered fishbone rubber ring is provided with a reverse stopper sleeved on the connecting rod, and an upper end of the tapered fishbone rubber ring is provided with a limiting stop ring sleeved on the connecting rod; the method adopts the borehole plugging device to form a reliable sealing and good plugging effect artificial plug in the borehole, solves the technical problem of directional drilling failure caused by the abnormal phenomena of sudden falling of a drilling tool, sudden drop of a drilling rod feeding force and torque and mud loss in the process of controlled directional drilling, and reopens a branch hole to continue directional drilling to a target horizon without changing a main borehole track of the controlled directional drilling, so that the drilling cost is reduced.

Description

Technical Field

[0001] This invention belongs to the field of underground water control technology, specifically relating to a controlled directional drilling downslope borehole plugging device and method. Background Technology

[0002] Controlled directional drilling technology has the advantages of directional bending of the borehole, reaching the target formation, avoiding surface obstacles, correcting the deviation of the wellbore, or bypassing objects that have fallen into the well for side-drilling. It also has the advantages of precise branch hole opening and strong clustering ability. It is widely used in oil and gas drilling engineering, coal seam exploration, coal seam gas extraction, downhole (surface) water exploration and drainage, and shale gas extraction.

[0003] However, regardless of the field, when controlled directional drilling encounters unknown strata, such as underground caverns, cavities, karst formations, or mined-out areas, abnormal phenomena often occur, such as a sudden drop in drill rod feed force and torque, a large amount of mud loss, and a large amount of formation water flowing into the borehole. These phenomena can prevent the borehole from proceeding normally, fail to reach the target stratum, increase drilling costs, or even cause the entire controlled directional drilling project to fail, affecting the entire controlled borehole directional drilling project.

[0004] Chinese utility model patent CN215630731U discloses a branch hole sealing and adjustment device for engineering construction. This device utilizes a sealing and adjustment mechanism placed inside the borehole. A motor drives a spray pipe on the control box to perform rotary grouting inside the borehole to seal the branch hole. However, placing the branch hole sealing and adjustment device inside the borehole makes troubleshooting and maintenance time-consuming and costly. The rotary grouting covers a large area of ​​the branch hole surface, which is problematic when encountering underground caverns, cavities, karst formations, or mined-out areas with unknown geological formations. This not only consumes a large amount of material and increases sealing costs, but also results in poor sealing effects for large spaces such as cavities and caverns. Furthermore, the sealing device has many components, leading to high costs. Its reliability is poor when driving and starting up in deep geological spaces, and blockages in the spraying system cannot be resolved promptly. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, the present invention aims to provide a controlled directional drilling downslope borehole plugging device and method. By leaving the designed borehole plug inside the original drill string, the conical fishbone rubber ring of the plug expands upon contact with water, forming a reliable and effective artificial plug inside the borehole. This effectively solves the technical problem of directional drilling failure caused by abnormal phenomena such as sudden drop of the drill string, sudden decrease in drill rod feed force and torque, and mud loss during controlled directional drilling. At the same time, without changing the trajectory of the main borehole in the controlled directional drilling, branch holes can be reopened to continue directional drilling, effectively ensuring that the controlled borehole reaches the target stratum and reducing drilling costs.

[0006] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows:

[0007] A controlled directional drilling downsloping borehole plugging device includes a connector 2 threadedly connected to a drill rod 1. The lower end of the connector 2 is connected to a borehole plugging device 17. The borehole plugging device 17 includes a connecting rod 3 connected to the lower end of the connector 2. The external thread at the lower end of the connecting rod 3 is connected to a hole-sweeping drill bit 8. A conical herringbone rubber ring 5 is fitted on the connecting rod 3. A check valve 6 fitted on the connecting rod 3 is provided at the lower end of the conical herringbone rubber ring 5. A limiting stop ring 4 fitted on the connecting rod 3 is provided at the upper end of the conical herringbone rubber ring 5.

[0008] The total length l of the borehole plug 17 is 500-600mm; the upper end of the connecting rod 3 is a convex square rod, which is connected to the concave square hole at the lower end of the connector 2. Its length is consistent with the depth of the concave square hole at the lower end of the connector 2. The length of the convex square rod at the upper end of the connecting rod 3 is 100-150mm, and its cross-section is square. The side length of the cross-section is half the outer diameter of the drill rod 1.

[0009] The conical fishbone rubber ring 5 is a hollow rubber ring. The material of the conical fishbone rubber ring 5 is water-absorbing and expanding rubber. Its shape is a tapered structure that gradually narrows from top to bottom. The effective diameter of the end of the tapered structure near the drilling bit 8 is the same as the diameter of the drilling bit 8, and the effective diameter of the other end is 1.1-1.2 times the diameter of the drilling bit 8. Its hollow inner diameter is 5mm smaller than the outer diameter of the connecting rod 3. The length of the conical fishbone rubber ring 5 is 250-350mm.

[0010] The anti-reverse device 6 is a hollow tube with an inner diameter 5mm smaller than the outer diameter of the connecting rod 3. Four conical contacts 7 are evenly arranged in a ring at the same height on the outer circumference of the tube in two rows. The conical contacts 7 are spring steel bars. The effective diameter of the limiting stop ring 4 is the same as the diameter of the hole-sweeping drill bit 8.

[0011] The connector 2, connecting rod 3, and drilling bit 8 are all made of rubber or steel, while the anti-reverse device 6 and contact 7 are both made of steel.

[0012] A method for plugging leaks in a controlled directional drilling downsloping borehole includes the following steps:

[0013] Step 1: During normal geological drilling, the feed force P and torque T at the tip of the drill rod 1 of the drilling rig 9 are maintained at a certain peak value, forcing the drill rod 1 to drill normally along the designed directional drilling trajectory 10 to the target layer 12; the feed force P and torque T applied to different lithological strata are recorded using the following formula:

[0014]

[0015] In the formula, P iThe feed force applied to the tip of drill pipe 1 is measured in N; T i The torque at the tip of drill pipe 1 is expressed in Nm.

[0016] When the applied geological drilling parameters, feed force P and torque T, change at time t during directional drilling, it indicates that the drill bit at the front of drill rod 1 has encountered an abnormal formation 11.

[0017]

[0018] In the formula, Q 出 This refers to the volume of drilling mud circulated back to the surface from the borehole, expressed in meters (m). 3 ;

[0019] At this point, reverse drill rig 9 until drill rig 9 is lowered to point N. i All drill pipe 1 is withdrawn from the ground; record the distance N from withdrawal. i The cumulative length L of the drill rod is the spatial trajectory length of the drill hole from the ground drilling rig 9 in the abnormal strata 11 encountered during the directional drilling process.

[0020] Step 2: Replace the drilling bit at the lower end of the drill rod 1 of the drilling rig 9, install the borehole plug 17 at the lower end of the drill rod 1 of the drilling rig 9, and lower N along the directional drilling trajectory 10 designed in Step 1. i With drill rod 1 in place, lower the hole plug 17 to the hole plugging section 15 and stop drilling. At this point, first adjust the feed force P applied to the top of drill rod 1, and the torque T is the peak value of the following formula:

[0021]

[0022] When the drill rod 1 is 100-150mm out of the ground, the connector 2 at the top of the drill rod 1 is completely separated from the borehole plug 17, leaving the borehole plug 17 in the formation.

[0023] Readjust the feed force P applied to the top of drill pipe 1, and the torque T is the peak value of the following formula:

[0024]

[0025] To retract drill rod 1 until it is lowered into borehole N. i All drill rods 1 were removed from the ground, and the installation of the borehole plug 17 was completed.

[0026] Step 3: After plugging the abnormal formation 11 encountered in Step 1, replace the drill bit of the drilling rig 9 with a drilling bit and continue drilling along the directional drilling trajectory 10 designed in Step 1 until the distance between the lower end of the drill bit of the drilling rig 9 and the last installed hole plug 17 in Step 2 is 10000mm. Then, reopen the downward branch hole and drill along the newly opened downward branch hole drilling trajectory 16 to the target formation 12.

[0027] In step 2, three borehole plugs 17 are sequentially lowered into the plugging section 15 inside the borehole. The three borehole plugs 17 form a group, and at least one group of borehole plugs 17 is installed in the directional borehole. The borehole plugs 17 are installed at intervals using air columns. The spatial distance between adjacent borehole plugs 17 within a group is 500-600mm, and the spatial distance between adjacent borehole plugs 17 between groups is 1000-2000mm.

[0028] The specific locations of the drilling and plugging sections 15 of the three drilling plugs 17 in step 2 are as follows:

[0029] Drilling stopper #17 is lowered to a distance d from the abnormal formation 11 in step 1. Therefore, the N-type hole plugger is lowered into the formation. i The cumulative length L1 of drill rod 1 is Ld, which gives the spatial trajectory length of the #1 borehole plug 17 from the ground drilling rig 9; the spatial length d is 1000-2000mm.

[0030] Drilling stopper #2 (17) is lowered to a distance b from drill hole plugper #17 (17), and drilling is then stopped. Therefore, the N-type hole plug is lowered into the formation. i The cumulative length L2 of drill rod 1 is L1-b, which gives the spatial trajectory length of the #2 borehole plug 17 from the ground drilling rig 9; the spatial length b is 500-600mm.

[0031] Drilling of borehole plug #3 17 was stopped at a distance b from the distance of borehole plug #2 17. Therefore, the N that was lowered into the formation... i The cumulative length L3 of drill rod 1 is L2-b, which gives the spatial trajectory length of the #3 borehole plug 17 from the ground drilling rig 9; the spatial length b is 500-600mm.

[0032] The abnormal stratum 11 is a stratum cavity or a goaf.

[0033] The feed force P and torque T at the top of the drill pipe 1 are displayed by the directional drilling monitoring instrument.

[0034] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0035] 1. This invention, by leaving a borehole plug inside the original drill bit, allows the conical fishbone rubber ring of the borehole plug to expand upon contact with water, forming a reliable and effective artificial plug inside the borehole. This effectively solves the technical problem of directional drilling failure caused by abnormal phenomena such as sudden drop of the drill bit, sudden decrease in drill rod feed force and torque, and mud loss during controlled directional drilling.

[0036] 2. The borehole plug designed in this invention has a simple structure, low cost, strong controllability in deep formations, and does not require additional personnel or equipment during installation, ensuring the smooth progress of drilling work. Furthermore, the installation of multiple sets of borehole plugs in the same borehole provides high safety redundancy and enables effective plugging of boreholes near unfavorable formations.

[0037] 3. The plugging method of the present invention can reopen branch holes and continue directional drilling without changing the trajectory of the main borehole of the controlled directional drilling. It can adjust the drilling trajectory in a timely manner, avoid special geological conditions such as goaf and stratum cavities, ensure that the controlled borehole reaches the target stratum, and reduce the drilling costs caused by adverse geological conditions. Attached Figure Description

[0038] Figure 1 This is a cross-sectional schematic diagram of the drilling and plugging device provided by the present invention.

[0039] In the diagram: 1-Drill rod, 2-Hand, 3-Connecting rod, 4-Limiting stop ring, 5-Conical fishbone rubber ring, 6-Anti-reverse device, 7-Touch, 8-Sweeping drill bit.

[0040] Figure 2 This is a schematic diagram of the borehole trajectory when a controlled directional drilling downslope borehole encounters an abnormal formation.

[0041] In the diagram: 9-Drilling rig, 10-Spatial trajectory of directional drilling borehole, 11-Abnormal formation, 12-Target formation, 13-Point where the borehole encounters abnormal formation, 14-Spatial trajectory of borehole that was not drilled before encountering abnormal formation.

[0042] Figure 3 This is a schematic diagram of the borehole trajectory profile after a controlled directional drilling downslope borehole was used to seal an abnormal formation.

[0043] In the figure: 9-Drilling rig, 10-Spatial trajectory of directional drilling borehole, 11-Abnormal formation, 12-Target formation, 13-Point where the borehole encounters abnormal formation, 14-Spatial trajectory of the borehole before encountering abnormal formation, 15-Borehole plugging section, 16-Spatial trajectory of the newly opened downsloping branch borehole. Detailed Implementation

[0044] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings.

[0045] like Figure 1As shown, a controlled directional drilling downslope borehole plugging device includes a connector 2 threadedly connected to a drill rod 1. The lower end of the connector 2 is connected to a borehole plugging device 17. The borehole plugging device 17 includes a connecting rod 3 connected to the lower end of the connector 2. The external thread at the lower end of the connecting rod 3 is connected to a hole-sweeping drill bit 8. A conical herringbone rubber ring 5 is fitted on the connecting rod 3. A check valve 6 fitted on the connecting rod 3 is provided at the lower end of the conical herringbone rubber ring 5. A limiting stop ring 4 fitted on the connecting rod 3 is provided at the upper end of the conical herringbone rubber ring 5. The total length of the borehole plugging device is 500mm. The drill rod 1 and the connector 2 are used to deliver the borehole plugging device 17 to the abnormal formation 11.

[0046] The upper end of the connector 2 is threaded, and the lower end is a concave square hole.

[0047] The upper end of the connecting rod 3 is a convex square rod, the length of which is consistent with the depth of the concave square hole at the lower end of the connector 2. The length of the convex square rod at the upper end of the connecting rod 3 is 100mm, and its cross-section is square, with the side length of the cross-section being half the outer diameter of the drill rod 1.

[0048] The effective diameter of the limiting stop ring 4 is the same as the diameter of the hole-sweeping drill bit 8.

[0049] The conical fishbone rubber ring 5 is a hollow rubber ring. It is inserted into and fixed to the connecting rod 3 from the threaded end. The material of the conical fishbone rubber ring 5 is water-absorbing and expandable rubber. Its shape is a tapered structure that gradually narrows from top to bottom. The effective diameter of the end of the tapered structure near the drilling bit 8 is the same as the diameter of the drilling bit 8, and the effective diameter of the other end is 1.1-1.2 times the diameter of the drilling bit 8. Its hollow inner diameter is 5mm smaller than the outer diameter of the connecting rod 3. The length of a single conical fishbone rubber ring 5 is 300mm.

[0050] The anti-reverse device 6 is a hollow tube with an inner diameter 5mm smaller than the outer diameter of the connecting rod 3. Four conical tentacles 7 are uniformly welded in a ring at the same height on the outer circumference of the tube, arranged in two rows. The conical tentacles 7 are spring steel bars, which can advance normally in the drilling direction and expand outward to grip the rock wall when pressed in the opposite direction of the drilling.

[0051] The connector 2, connecting rod 3, and drilling bit 8 are all made of rubber or steel, while the anti-reverse device 6 and contact 7 are both made of steel.

[0052] like Figure 2 and Figure 3 As shown, a method for plugging leaks in a controlled directional drilling downslope borehole includes the following steps:

[0053] Step 1: During normal geological drilling, the feed force P and torque T at the tip of drill rod 1 of drilling rig 9 are maintained at a certain peak value, forcing drill rod 1 to drill normally along the designed directional drilling trajectory 10 to the target layer 12. The peak values ​​of feed force P and torque T applied to different lithological strata are different. For the same lithological stratum, the peak values ​​of feed force P and torque T applied also vary with drilling depth. The feed force P and torque T applied to different lithological strata are recorded using the following formula:

[0054]

[0055] In the formula, P i The feed force applied to the tip of drill pipe 1 is measured in N; T i The torque at the tip of drill pipe 1 is expressed in Nm.

[0056] At time t during directional drilling, when the applied geological drilling parameters, the feed force P and torque T, change as shown in the following formula, it indicates that the drill bit at the front of drill rod 1 has encountered an abnormal formation 11.

[0057]

[0058] In the formula, Q 出 This refers to the volume of drilling mud circulated back to the surface from the borehole, expressed in meters (m). 3 ;

[0059] At this point, reverse drill rig 9 until drill rig 9 is lowered to point N. i All drill pipe 1 is withdrawn from the ground; record the distance N from withdrawal. i The cumulative length L of the drill rod is the spatial trajectory length of the drill hole from the ground drilling rig 9 in the abnormal strata 11 encountered during the directional drilling process.

[0060] Step 2: Replace the drilling bit at the lower end of the drill rod 1 of the drilling rig 9, install the borehole plug 17 at the lower end of the drill rod 1 of the drilling rig 9, and lower N along the directional drilling trajectory 10 designed in Step 1. i With drill rod 1 in place, lower the hole plug 17 to the hole plugging section 15 and stop drilling. At this point, first adjust the feed force P applied to the top of drill rod 1, and the torque T is the peak value of the following formula:

[0061]

[0062] When the drill rod 1 is 100-150mm out of the ground, the connector 2 at the top of the drill rod 1 is completely separated from the borehole plug 17, leaving the borehole plug 17 in the formation.

[0063] Readjust the feed force P applied to the top of drill pipe 1, and the torque T is the peak value of the following formula:

[0064]

[0065] To retract drill rod 1 until it is lowered into borehole N. i All drill rods 1 were removed from the ground, and the installation of the borehole plug 17 was completed.

[0066] Repeat the above operation to lower three borehole plugs 17 into the plugging section 15 inside the borehole in sequence. The three borehole plugs 17 form a group, and at least one group of borehole plugs 17 is installed in the directional borehole. The borehole plugs 17 are installed at intervals using air columns. The spatial distance between adjacent borehole plugs 17 within a group is 500mm, and the spatial distance between adjacent borehole plugs 17 between groups is 1000mm.

[0067] The specific locations of the three borehole plugging devices 17 in the borehole plugging section 15 are as follows:

[0068] Drilling stopper #17 is lowered to a distance d from the abnormal formation 11 in step 1. Therefore, the N-type hole plugger is lowered into the formation. i The cumulative length L1 of drill rod 1 is Ld, which gives the spatial trajectory length of the #1 borehole plug 17 from the ground drilling rig 9; the spatial length d is 1000mm.

[0069] Drilling stopper #2 (17) is lowered to a distance b from drill hole plugper #17 (17), and drilling is then stopped. Therefore, the N-type hole plug is lowered into the formation. i The cumulative length L2 of drill rod 1 is L1-b, which gives the spatial trajectory length of borehole plug 17 from the ground drilling rig 9; the spatial length b is 500mm.

[0070] Drilling of borehole plug #3 17 was stopped at a distance b from the distance of borehole plug #2 17. Therefore, the N that was lowered into the formation... i The cumulative length L3 of drill rod 1 is L2-b, which gives the spatial trajectory length of the #3 borehole plug 17 from the ground drilling rig 9; the spatial length b is 500mm.

[0071] Step 3: After plugging the abnormal formation 11 encountered in Step 1, replace the drill bit of the drilling rig 9 with a drilling bit and continue drilling along the directional drilling trajectory 10 designed in Step 1 until the distance between the lower end of the drill bit of the drilling rig 9 and the last installed hole plug 17 in Step 2 is 10000mm. Then, reopen the downward branch hole and drill along the newly opened downward branch hole drilling trajectory 16 to the target formation 12.

[0072] The abnormal stratum 11 is a stratum cavity or a goaf; the feed force P and torque T at the top of the drill rod 1 are displayed by the directional drilling monitoring instrument.

Claims

1. A controlled directional drilling down-angle borehole plugging device, comprising a connector (2) threadedly connected to a drill rod (1), the lower end of the connector (2) being connected to a borehole plug (17), characterized in that: The borehole plugging device (17) includes a connecting rod (3) connected to the lower end of the connector (2). The external thread at the lower end of the connecting rod (3) is connected to the hole-sweeping drill bit (8). A conical fishbone rubber ring (5) is sleeved on the connecting rod (3). A check valve (6) sleeved on the connecting rod (3) is provided at the lower end of the conical fishbone rubber ring (5). A limiting stop ring (4) sleeved on the connecting rod (3) is provided at the upper end of the conical fishbone rubber ring (5). The conical fishbone rubber ring (5) is a hollow rubber ring. The material of the conical fishbone rubber ring (5) is water-absorbing and expanding rubber. Its shape is a conical structure that gradually narrows from top to bottom. The effective diameter of the conical structure near the hole-sweeping drill bit (8) is the same as the diameter of the hole-sweeping drill bit (8), and the effective diameter of the other end is 1.1-1.2 times the diameter of the hole-sweeping drill bit (8). Its hollow inner diameter is 5mm smaller than the outer diameter of the connecting rod (3). The length of the conical fishbone rubber ring (5) is 250-350mm. The anti-reverse device (6) is a hollow tube with an inner diameter 5 mm smaller than the outer diameter of the connecting rod (3). Four conical contacts (7) are evenly arranged in a ring at the same height on the outer circumference of the tube in two rows. The conical contacts (7) are spring steel bars. The effective diameter of the limiting stop ring (4) is the same as the diameter of the hole-sweeping drill bit (8).

2. The controlled directional drilling down-angle borehole plugging device according to claim 1, characterized in that: The total length of the borehole plug (17) The length is 500-600mm; the upper end of the connecting rod (3) is a convex square rod, which is connected to the concave square hole at the lower end of the connector (2). Its length is consistent with the depth of the concave square hole at the lower end of the connector (2). The length of the convex square rod at the upper end of the connecting rod (3) is 100-150mm, and its cross-section is square. The side length of the cross-section is half of the outer diameter of the drill rod (1).

3. The controlled directional drilling down-angle borehole plugging device according to claim 1, characterized in that: The handle (2), connecting rod (3) and drilling bit (8) are made of rubber or steel, while the anti-reverse device (6) and contact (7) are made of steel.

4. A method for plugging leaks in a controlled directional drilling downsloping borehole, characterized in that, The controlled directional drilling down-angle borehole plugging device according to any one of claims 1-3 includes the following steps: Step 1: During normal geological drilling, the drill rod (1) tip of the drilling rig (9) is fed with a feed force. Torque Maintaining a certain peak value forces the drill pipe (1) to drill normally to the target formation (12) along the designed directional drilling trajectory (10); the feed force applied to different lithological formations Torque Record it using the following formula: In the formula, The feed force is applied to the top of the drill pipe (1), in N; The torque at the top of the drill pipe (1) is in Nm; During directional drilling At any given time, the applied geological drilling parameters give rise to the drilling force. Torque When the following changes occur, it indicates that the drill bit at the front of the drill rod (1) has encountered an abnormal formation (11). In the formula, This refers to the volume of drilling mud circulated back to the surface from the borehole, expressed in meters (m). 3 ; At this point, reverse the drilling rig (9) until the drilling rig (9) is lowered. All drill rods (1) were removed from the ground, and the distance from the ground was recorded. Cumulative length of drill pipe , that is, the spatial trajectory length of the abnormal strata (11) encountered during the directional drilling process from the ground drilling rig (9); Step 2: Replace the drilling bit at the lower end of the drill rod (1) of the drilling rig (9), install the borehole plug (17) at the lower end of the drill rod (1) of the drilling rig (9), and lower it along the directional drilling trajectory (10) designed in Step 1. With the drill rod (1) in place, lower the hole plug (17) to the hole plug section (15) and stop drilling. At this time, first adjust the feed force applied to the top of the drill rod (1). Torque The peak value is given by the following formula: When the drill rod (1) is 100~150mm out of the ground, the connector (2) at the top of the drill rod (1) is completely separated from the borehole plug (17), leaving the borehole plug (17) in the formation. Readjust the feed force applied to the top of the drill pipe (1). Torque The peak value is given by the following formula: To retract the drill rod (1) until it is lowered into the borehole. All drill rods (1) were removed from the ground, and the installation of the borehole plug (17) was completed. Step 3: After completing the plugging of the abnormal formation (11) encountered in Step 1, replace the drill bit of the drilling rig (9) with a drilling bit and continue drilling along the directional drilling trajectory (10) designed in Step 1 until the distance between the lower end of the drill bit of the drilling rig (9) and the last installed hole plug (17) in Step 2 is 10000mm. Then, reopen the downward branch hole and drill along the drilling trajectory (16) of the newly opened downward branch hole to the target formation (12).

5. The method for plugging leaks in a controlled directional drilling down-angle borehole according to claim 4, characterized in that: In step 2, three borehole plugs (17) are sequentially lowered into the plugging section (15) inside the borehole. The three borehole plugs (17) form a group, and at least one group of borehole plugs (17) is installed in the directional borehole. The borehole plugs (17) are installed at intervals using air columns. The spatial distance between adjacent borehole plugs (17) within a group is 500-600mm, and the spatial distance between adjacent borehole plugs (17) between groups is 1000-2000mm.

6. The method for plugging leaks in a controlled directional drilling down-angle borehole according to claim 5, characterized in that, The specific locations of the drilling and plugging sections (15) of the three drilling plugs (17) in step 2 are as follows: Drilling stops when the #1 borehole plug (17) is lowered to a distance d from the abnormal formation (11) in step 1. Therefore, the plug is lowered into the formation. Root drill pipe (1) cumulative length The spatial trajectory length of the #1 borehole plug (17) from the ground drilling rig (9) is obtained; the spatial length d is 1000-2000mm; Drilling stopped when the No. 2 borehole plug (17) was lowered to a distance b from the No. 1 borehole plug (17). Therefore, it was lowered into the formation. Root drill pipe (1) cumulative length The spatial trajectory length of the #2 borehole plug (17) from the ground drilling rig (9) is obtained; the spatial length b is 500-600mm; The #3 borehole plug (17) was lowered to a distance b from the #2 borehole plug (17) and drilling was stopped. Therefore, it was lowered into the formation. Root drill pipe (1) cumulative length The spatial trajectory length of the 3# borehole plug (17) from the ground drilling rig (9) is obtained; the spatial length b is 500-600mm.

7. The method for plugging leaks in a controlled directional drilling down-angle borehole according to claim 4, characterized in that: The abnormal stratum (11) is a stratum cavity or a goaf.

8. The method for plugging leaks in a controlled directional drilling down-angle borehole according to claim 4, characterized in that: The drill pipe (1) is fed with a feed force at its tip. and torque Displayed by the directional drilling monitoring instrument.

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