Flexible inner-guided hollow drill rod for low-permeability sandstone uranium reservoir and its construction method

Abstract

The present invention discloses a flexible internally guided hollow drill rod for low-permeability sandstone uranium reservoirs, comprising a ball head, a ball socket, an internal guiding mechanism, a hollow hydraulic transducer, and a drill bit; the ball head and the ball socket are staggered and interconnected along the drilling direction; the upper end of the ball head is in a tip-recessed form so that it can be inserted into the lower end of the ball socket and can swing relative to the ball socket under the action of an external force; the upper end of the ball socket is inserted into the lower end of the ball head and fixedly connected by fasteners to achieve assembly of the lower ball socket and the upper ball head; the internal guiding mechanism comprises an upper bearing module, a lower bearing module, and a steering module located between the two bearing modules; the upper bearing module is adapted to be installed with the upper inner wall of the ball socket located above and can drive the upper ball head to swing; the lower bearing module is adapted to be installed with the upper inner wall of the ball socket located below and can drive the lower ball head to swing. The present invention realizes internal guidance of the drill rod through the combined action of the flexible drill rod body and the internal guiding mechanism, and can flexibly turn during the drilling process.

Description

Technical Field

[0001] The present invention relates to the technical field of nuclear material mining, in particular to a flexible inner-guided hollow drill rod for a low-permeability sandstone uranium ore reservoir and a construction method thereof. Background Art

[0002] Existing uranium deposits are primarily stored in low-permeability sandstone, requiring reservoir fracturing followed by in-situ leaching. Guided drilling of rock reservoirs is essential for fracturing. Currently, the fracturing and permeability enhancement effect of excavating a single vertical shaft is limited, and the cost of combined fracturing of multiple vertical shafts is high. Furthermore, multiple operations such as lifting and charging during drill pipe drilling not only easily lead to hole collapse but also significantly impact the timeliness of blasting fracturing. Horizontal well blasting fracturing in the oil and gas sector can easily penetrate the top or bottom of the reservoir, leading to resource loss. Therefore, it is necessary to develop drilling methods within low-permeability sandstone uranium reservoirs to improve the uniformity of fracturing in low-permeability reservoirs.

[0003] Currently, drill pipes used in rock drilling primarily focus on the following: 1) Rigid drill pipe with extremely small turning angles, suitable for drilling vertical shafts or deep horizontal laterals with small turning angles, requiring the use of a guide or deflector for fixed-angle drilling; 2) Solid flexible drill pipe with snap-on or node-connected connections that enable torque transmission, featuring a small turning radius and a solid structure, relying on a pre-placed guide within the wellbore. However, common implementation issues with these drill pipe technologies include: ① Guide failure due to the falling or insecure fixation of the deflector; ② Insufficient reaction force from the external guide mechanism at large turning angles, resulting in insufficient guide angles; and ③ Solid drill pipe makes it impossible to perform operations such as hole washing and explosive loading during drilling, increasing the need for drill lifting before loading explosives. Therefore, it is necessary to provide a flexible, internally guided hollow drill pipe and its construction method to facilitate guided excavation of low-permeability sandstone uranium reservoirs in deep formations. Summary of the Invention

[0004] The main purpose of the present invention is to provide a flexible internally guided hollow drill rod for low-permeability sandstone uranium reservoirs, which can achieve flexible steering during drilling. Accordingly, the present invention also proposes a construction method for the drill rod.

[0005] The technical solution adopted in the present invention is:

[0006] A flexible internally guided hollow drill rod for a low-permeability sandstone uranium reservoir, comprising a ball head, a ball socket, an internal guiding mechanism, a hollow hydraulic transducer and a drill bit; the ball head and the ball socket are staggered and connected to each other along the drilling direction, the ball head and the ball socket are respectively hollow special-shaped cylindrical structures, wherein the upper end of the ball head is in the form of a pointed end so that it can be inserted into the lower end of the ball socket and can swing relative to the ball socket under the action of external force, the middle of the ball socket is provided with a fixing ring protruding toward the axis, and the fixing ring is circumferentially arranged with fixing hooks extending downward, the upper end of the ball head is inserted into the lower end of the ball socket from between the inner wall of the lower end of the ball socket and the fixing hook, and the fixing hook hooks the hanging ear provided on the inner wall of the ball head to realize the assembly of the lower ball head and the upper ball socket; the upper end of the ball socket is inserted into the lower end of the ball head and fixed through a fastener The fixed connection realizes the assembly of the lower ball socket and the upper ball head; the inner guide mechanism includes an upper bearing module, a lower bearing module and a steering module located between the two bearing modules, the steering module is used to drive the upper bearing module and the lower bearing module to swing relative to each other to produce an angle difference to realize steering; the inner guide mechanism is arranged as a whole inside the assembled ball head and ball socket, wherein the upper bearing module is adapted to be installed with the upper inner wall of the ball socket located above, and can drive the ball head located above to swing; the lower bearing module is adapted to be installed with the upper inner wall of the ball socket located below, and can drive the ball head located below to swing; the upper interface of the hollow hydraulic transducer is fixedly connected to the lowest ball head, and the lower interface is fixedly connected to the drill bit.

[0007] In the above scheme, the steering module includes an upper fixed head, an upper motor support, a connecting sleeve, a lower motor support and a lower fixed head which are arranged in sequence from top to bottom; the upper fixed head is fixedly connected to the upper bearing module, the upper motor support is fixedly connected to the upper fixed head, and an upper motor is provided in the upper motor support, the lower motor support is fixedly connected to the lower fixed head, and a lower motor is provided in the lower motor support, and the upper motor and the lower motor are respectively connected to the connecting sleeve through gear transmission; when the upper motor rotates, the connecting sleeve and the lower fixed head are driven to rotate relative to the upper fixed head, and when the lower motor rotates, the connecting sleeve and the upper fixed head are driven to rotate relative to the lower fixed head; the surfaces of the upper motor support, the lower motor support and the connecting sleeve in contact are all inclined surfaces, and the contact surface of the lower motor support and the lower fixed head is an inclined surface; the lower fixed head is fixedly connected to the lower bearing module.

[0008] In the above solution, the inner guide mechanism further includes a fixing cable module located above the upper bearing module, and the signal lines of the upper motor and the lower motor pass through the fixing cable module.

[0009] In the above scheme, the drill rod also includes an external bevel guide, which includes three annular inflatable structures, namely an inner air cavity, a middle air cavity and an outer air cavity; wherein, the inner air cavity is installed on the outer wall of the socket, the center of the middle air cavity is located to the right of the center of the inner air cavity, and the center of the outer air cavity is located below the center of the inner air cavity.

[0010] In the above solution, the drill rod further includes a drill rod transition piece, and the lower end of the drill rod transition piece is fixedly matched with the upper end of the ball socket.

[0011] In the above solution, the outer diameters of the ball head, ball socket, hollow hydraulic transducer, and drill pipe transition piece are the same.

[0012] In the above solution, a through liquid channel is provided inside the drill pipe, and the liquid channel is connected to the hollow hydraulic transducer.

[0013] In the above scheme, a plurality of ball head slides are arranged circumferentially on the outer wall of the upper end of the ball head, and a ball socket slide corresponding to the ball head slide is arranged circumferentially on the inner wall of the lower end of the ball socket. During assembly, the ball head slide is inserted into the ball socket slide; a plurality of ball socket slides are arranged circumferentially on the outer wall of the upper end of the ball socket, and a ball head slide corresponding to the ball socket slide is arranged circumferentially on the inner wall of the lower end of the ball head. During assembly, the ball socket slide is inserted into the ball head slide.

[0014] In the above solution, the drill bit includes a drill base and cutter teeth, the upper interface of the drill base is fixedly matched with the lower interface of the hollow hydraulic transducer; the drill base and the bottom of the cutter teeth are fixedly matched.

[0015] Accordingly, the present invention also proposes a construction method for the flexible inner guide hollow drill rod in the low permeability sandstone uranium reservoir, comprising the following steps:

[0016] S1, assembling the flexible inner guide hollow drill rod of the low permeability sandstone uranium reservoir;

[0017] S2, connecting the drill rod transition piece at the upper end of the flexible inner guide hollow drill rod of the low permeability sandstone uranium reservoir to the drilling guide rod, and placing the hollow drill rod into the rock drill hole to the depth to be guided through the drilling guide rod;

[0018] S3, filling gas into the outer deflectors on the outer sides of the ball socket through the external cylinders, so that the outer deflectors are in contact with the inner wall of the borehole;

[0019] S4, controlling the steering module of the inner guide mechanism to operate so as to generate an angle difference between the upper bearing module and the lower bearing module;

[0020] S5. Applying fluid pressure to the interior of the drilling guide rod causes the hollow hydraulic transducer to rotate the drill bit, and using the downward pressure of the drilling guide rod to apply forward thrust to the hollow drill rod, rotating and crushing the rock to produce a borehole at a certain angle to the rock borehole;

[0021] S6. Deflate the external whipstock. After reaching the position where the drill needs to turn, repeat steps S3-S5 to allow the hollow drill rod to drill to the target point.

[0022] S7. Rotate the drill rod in the opposite direction to remove the hollow drill rod.

[0023] The beneficial effects produced by the present invention are:

[0024] 1. The present invention provides a flexible internally guided hollow drill rod for low-permeability sandstone uranium reservoirs. The flexible drill rod body and the internal guiding mechanism work together to achieve internal guidance of the drill rod, thereby enabling flexible steering during the drilling process. Fluid or granular material can be injected into the target reservoir through the internal hollow drill rod, and drilling, hole washing, and blasting and filling operations in the reservoir to be developed can be achieved without lifting the drill, thus avoiding energy waste caused by repeated drilling.

[0025] 2. The external deflector used in the present invention includes three annular air-filled structures: an inner air cavity, a middle air cavity, and an outer air cavity. The inner air cavity is mounted on the outer wall of the socket, the center of the middle air cavity is located to the right of the center of the inner air cavity, and the center of the outer air cavity is located below the center of the inner air cavity. The external deflector adopts an asymmetric design, applying forces in different directions by filling different air cavities with air to accommodate different steering directions. Each air cavity can be inflated individually or in combination. In addition, the air cavity structure of the external deflector can also contact the rock wall to achieve the purpose of fixing the hollow drill pipe.

[0026] 3. The drill rod of the present invention is designed for guided excavation and charge filling of wellbores in low-permeability sandstone uranium reservoirs in deep formations to improve sandstone permeability and uranium mining efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 This is a schematic diagram of the overall structure of the flexible inner guide hollow drill rod for low permeability sandstone uranium reservoir of the present invention;

[0029] Figure 2 This is an overall cross-sectional view of a flexible inner-guided hollow drill rod for a low-permeability sandstone uranium reservoir according to the present invention;

[0030] Figure 3 yes Figure 1 Schematic diagrams of the structure of the ball head of the drill pipe at two different angles;

[0031] Figure 4 yes Figure 1 A schematic structural diagram of the ball socket of the drill rod shown;

[0032] Figure 5It is a three-dimensional diagram of the assembled state of the ball head and ball socket;

[0033] Figure 6 It is a cross-sectional view of the ball head and ball socket in the assembled state;

[0034] Figure 7 yes Figure 1 A three-dimensional structural diagram of the inner guide mechanism of the drill rod;

[0035] Figure 8 yes Figure 1 a cross-sectional view of the inner guide mechanism of the drill pipe shown;

[0036] Figure 9 is a schematic diagram of different steering angles of the inner guide mechanism;

[0037] Figure 10 This is a schematic diagram of the installation of the inner guide mechanism;

[0038] Figure 11 yes Figure 1 A schematic structural diagram of the external deflector of the drill pipe is shown;

[0039] Figure 12 yes Figure 1 A schematic structural diagram of the drill bit of the drill rod shown;

[0040] Figure 13 yes Figure 1 Schematic diagram of the structure of the drill pipe transition piece of the drill pipe shown.

[0041] In the figure: 1, ball head; 11, mounting ear; 12, ball head slide; 13, ball head slide;

[0042] 2. Ball socket; 21. Fixing ring; 22. Fixing hook; 23. Ball socket slide; 24. Ball socket slide;

[0043] 3. External deflector; 31. Inner air cavity; 32. Middle air cavity; 33. Outer air cavity;

[0044] 4. Internal guide mechanism; 41. Upper bearing module; 42. Lower bearing module; 43. Steering module; 431. Upper fixing head; 432. Upper motor support; 433. Connecting sleeve; 434. Lower motor support; 435. Lower fixing head; 436. Upper motor; 437. Lower motor; 44. Fixed cable module; 45. Ball ring; 46. Hollow bearing element;

[0045] 5. Hollow hydraulic transducer;

[0046] 6. Drill bit; 61. Drill bit base; 62. Cutting teeth;

[0047] 7. Drill pipe transition piece. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0049] It should be noted that the illustrations provided in the embodiments of the present invention are only schematic illustrations of the basic concept of the present invention. Therefore, the drawings only show components related to the present invention and are not drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component can be changed at will, and the component layout type may also be more complicated.

[0050] In the present invention, it should also be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" and the like are used to indicate positions or locations based on those shown in the accompanying drawings. These terms are intended solely to facilitate the description of the present application and to simplify the description. They are not intended to indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limiting the present application. Furthermore, the terms "first" and "second" are used solely for descriptive and distinguishing purposes and should not be construed as indicating or implying relative importance.

[0051] like Figure 1-2 As shown, a flexible inner-guide hollow drill rod for low-permeability sandstone uranium reservoir according to a preferred embodiment of the present invention includes a ball head 1, a ball socket 2, an inner guide mechanism 4, a hollow hydraulic transducer 5 and a drill bit 6.

[0052] like Figure 3-6 As shown, the ball head 1 and the ball socket 2 are staggered and connected to each other along the drilling direction. The ball head 1 and the ball socket 2 are respectively hollow special-shaped cylindrical structures, wherein the upper end of the ball head 1 is in the form of a pointed end so that it can be inserted into the lower end of the ball socket 2 and can swing relative to the ball socket 2 under the action of external force. A fixing ring 21 protruding toward the axis is provided in the middle of the ball socket 2, and downward-extending fixing hooks 22 are arranged circumferentially on the fixing ring 21. The upper end of the ball head 1 is inserted into the lower end of the ball socket 2 between the inner wall of the lower end of the ball socket 2 and the fixing hook 22, and the fixing hook 22 hooks the hanging ear 11 provided on the inner wall of the ball head 1 to realize the assembly of the lower ball head 1 and the upper ball socket 2; the upper end of the ball socket 2 is inserted into the lower end of the ball head 1 and fixedly connected by fasteners (such as pins or bolts) to realize the assembly of the lower ball socket 2 and the upper ball head 1.

[0053] In one embodiment of the present invention, a plurality of ball head slides 12 are arranged circumferentially on the outer wall of the upper end of the ball head 1, and a ball socket slideway 24 is arranged circumferentially on the inner wall of the lower end of the ball socket 2, corresponding one to each of the ball head slides 12. During assembly, the ball head slides 12 are inserted into the ball socket slideways 24. A certain gap is left between the ball head slides 12 and the ball socket slideways 24 to achieve flexible relative swing.

[0054] In one embodiment of the present invention, a plurality of ball socket slides 23 are arranged circumferentially on the outer wall of the upper end of the ball socket 2, and a ball head slide 13 corresponding to the ball socket slide 23 is arranged circumferentially on the inner wall of the lower end of the ball head 1. During assembly, the ball socket slide 23 is inserted into the ball head slide 13.

[0055] like Figure 7-9 As shown, the inner guide mechanism 4 includes an upper bearing module 41, a lower bearing module 42 and a steering module 43 located between the two bearing modules. The steering module 43 is used to drive the upper bearing module 41 and the lower bearing module 42 to swing relative to each other to produce an angle difference to achieve steering. The steering module 43 includes an upper fixed head 431, an upper motor support 432, a connecting sleeve 433, a lower motor support 434 and a lower fixed head 435, which are arranged in sequence from top to bottom. The upper fixed head 431 is fixedly connected to the upper bearing module 41, the upper motor support 432 is fixedly connected to the upper fixed head 431, and an upper motor 436 is provided in the upper motor support 432. The lower motor support 434 is fixedly connected to the lower fixed head 435, and a lower motor 437 is provided in the lower motor support 434. The upper motor 436 and the lower motor 437 are respectively connected to the connecting sleeve 433 through gear transmission. When the upper motor 436 rotates, it drives the connecting sleeve 433 and the lower fixed head 435 relative to the upper fixed head. The head 431 rotates, and when the lower motor 437 rotates, it drives the connecting sleeve 433 and the upper fixed head 431 to rotate relative to the lower fixed head 435; the surfaces of the upper motor support 432, the lower motor support 434 and the connecting sleeve 433 in contact are all inclined surfaces, and the contact surface between the lower motor support 434 and the lower fixed head 435 is an inclined surface, so an angle difference can be generated when the lower fixed head 435 and the upper fixed head 431 rotate relative to each other; the lower fixed head 435 is fixedly connected to the lower bearing module 42.

[0056] The inner guide mechanism 4 is integrally arranged inside the assembled ball head 1 and ball socket 2, wherein the upper bearing module 41 is adapted to be installed on the upper inner wall of the ball socket 2 and can drive the ball head 1 located above to swing; the lower bearing module 42 is adapted to be installed on the upper inner wall of the ball socket 2 located below and can drive the ball head 1 located below to swing. Figure 10As shown, taking the installation of the uppermost inner guide mechanism 4 as an example, the uppermost ball socket 2-1 is fixedly connected to the drill rod transition piece 7, the ball head 1-1 is inserted into the lower end of the ball socket 2-1, and then the ball socket 2-2 is installed into the lower inner wall of the ball head 1-1, and then the upper bearing module 41 of the inner guide mechanism 4 is installed into the upper inner wall of the ball socket 2-2, and then the ball head 1-2 is installed. At this time, the steering module 43 of the inner guide mechanism 4 is located near the upper inner wall of the ball head 1-2, and then the ball socket 2-3 is installed so that its upper inner wall is assembled with the lower bearing module 42 of the inner guide mechanism 4. In this way, the ball head 1-1 and the ball head 1-2 can respectively swing under the action of the inner guide mechanism 4 to achieve flexible steering. By analogy, the installation of the remaining ball heads 1, ball sockets 2 and inner guide mechanisms 4 is completed in sequence, so that each ball head 1 of the drill rod of the present invention can swing. It should be noted that in order to see the assembly method of the ball head 1 and the ball socket 2 clearly, Figure 1 Only the uppermost inner guide mechanism 4 is shown.

[0057] In one embodiment of the present invention, the upper bearing module 41 and the lower bearing module 42 are both composed of a hollow bearing member 46 and three ball rings 45 mounted thereon.

[0058] In one embodiment of the present invention, the inner guide mechanism 4 further includes a fixing cable module 44 fixed above the upper bearing module 41 , and signal lines of the upper motor 436 and the lower motor 437 pass through the fixing cable module 44 .

[0059] The upper interface of the hollow hydraulic transducer 5 is fixedly connected to the lowermost ball head 1 (the two can be fixed by screws, etc.), and the lower interface is fixedly connected to the drill bit 6.

[0060] like Figure 11 As shown, the flexible inner guide hollow drill pipe for low-permeability sandstone uranium reservoir also includes an outer bevel guide 3, which includes three annular air-filled structures, namely an inner air cavity 31, a middle air cavity 32, and an outer air cavity 33; wherein, the inner air cavity 31 is installed on the outer wall of the ball socket 2, the center of the middle air cavity 32 is located to the right of the center of the inner air cavity 31, and the center of the outer air cavity 33 is located below the center of the inner air cavity 31. The outer bevel guide 3 adopts an asymmetric design, and applies forces in different directions by filling different air cavities with air to adapt to different steering directions. Each air cavity can be inflated separately or in combination. In addition, the outer bevel guide 3 adopts an air cavity structure and can also contact the rock wall to achieve the effect of fixing the hollow drill pipe.

[0061] It should be noted that each air cavity of the outer whipstock 3 is connected to the air cylinder on the ground through an air pipe.

[0062] like Figure 12As shown, the flexible inner guide hollow drill pipe for low permeability sandstone uranium reservoir further includes a drill pipe transition piece 7, the lower end of the drill pipe transition piece 7 is fixedly matched with the upper end of the ball socket 2 (the two can be fixed by pins, etc.).

[0063] like Figure 13 As shown, the drill bit 6 includes a drill bit base 61 and a cutter tooth 62 . The upper interface of the drill bit base 61 is fixedly matched with the lower interface of the hollow hydraulic transducer 5 ; the bottom of the drill bit base 61 and the cutter tooth 62 are fixedly matched.

[0064] In one embodiment of the present invention, the outer diameters of the ball head 1 , the ball socket 2 , the hollow hydraulic transducer 5 , and the drill pipe transition piece 7 are the same.

[0065] The construction method of the flexible inner guide hollow drill rod in the low permeability sandstone uranium reservoir comprises the following steps:

[0066] S1. Assemble a flexible, internally guided hollow drill pipe for low-permeability sandstone uranium reservoirs. Specifically, select the number of ball heads 1 and sockets 2 based on the drilling depth, and equip a corresponding number of internal guide mechanisms 4 and external deflectors 3. Assemble the ball head 1, sockets 2, and internal guide mechanisms 4 into an integrated structure as described above. Secure the external deflector 3 to the outer wall of the socket 2. Securely connect the hollow hydraulic transducer 5, which is connected to the drill bit 6, to the lowermost socket 2. Securely connect the drill pipe transition piece 7 to the uppermost socket 2.

[0067] S2. Connecting the drill rod transition piece 7 at the upper end of the flexible inner guide hollow drill rod in the low-permeability sandstone uranium reservoir to the drilling guide rod, and inserting the hollow drill rod into the rock drill hole through the drilling guide rod to the depth to be guided (this refers to the position after which the steering is required);

[0068] S3. Filling the inner air cavity 31, the middle air cavity 32, and the outer air cavity 33 of the outer deflector 3 outside the ball socket 2 with air through an external air cylinder, so that the outer deflector 3 contacts the inner wall of the borehole;

[0069] S4, controlling the steering module 43 of the inner guide mechanism 4 to operate so as to generate an angle difference between the upper bearing module 41 and the lower bearing module 42;

[0070] S5. Apply fluid pressure to the inside of the drilling guide rod, so that the hollow hydraulic transducer 5 drives the drill bit 6 to rotate, and uses the downward pressure of the drilling guide rod to apply forward thrust to the hollow drill rod, rotating and crushing the rock to produce a drill hole at a certain angle to the rock drill hole.

[0071] S6, deflate the external whipstock 3, and after reaching the position where the drill needs to turn, repeat the operations of steps S3-S5 to allow the hollow drill rod to drill to the target point;

[0072] S7. Rotate the drill rod in the opposite direction to pull out the hollow drill rod.

[0073] It should be pointed out that, according to the needs of implementation, the various steps / components described in this application can be split into more steps / components, or two or more steps / components or partial operations of steps / components can be combined into new steps / components to achieve the purpose of the present invention.

[0074] The size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0075] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all such improvements and changes should fall within the scope of protection of the appended claims of the present invention.

Claims

1. A flexible inner guide hollow drill rod for low permeability sandstone uranium reservoir, characterized in that: It includes a ball head, a ball socket, an internal guide mechanism, a hollow hydraulic transducer and a drill bit; The ball head and the ball socket are staggered and connected to each other along the drilling direction. The ball head and the ball socket are respectively hollow special-shaped cylindrical structures, wherein the upper end of the ball head is in the form of a pointed end so that it can be inserted into the lower end of the ball socket and can swing relative to the ball socket under the action of external force. A fixing ring protruding toward the axis is provided in the middle of the ball socket, and fixing hooks extending downward are arranged circumferentially on the fixing ring. The upper end of the ball head is inserted into the lower end of the ball socket from between the inner wall of the lower end of the ball socket and the fixing hook, and the fixing hook hooks the hanging ear provided on the inner wall of the ball head to realize the assembly of the lower ball head and the upper ball socket; the upper end of the ball socket is inserted into the lower end of the ball head and fixedly connected by fasteners to realize the assembly of the lower ball socket and the upper ball head; The inner guide mechanism includes an upper bearing module, a lower bearing module and a steering module located between the two bearing modules, the steering module is used to drive the upper bearing module and the lower bearing module to swing relative to each other to produce an angle difference to achieve steering; the inner guide mechanism is arranged as a whole inside the assembled ball head and ball socket, wherein the upper bearing module is adapted to be installed with the upper inner wall of the ball socket located above, and can drive the ball head located above to swing; the lower bearing module is adapted to be installed with the upper inner wall of the ball socket located below, and can drive the ball head located below to swing; the steering module includes an upper fixed head, an upper motor support, a connecting sleeve, a lower motor support and a lower fixed head arranged in sequence from top to bottom; the The upper fixed head is fixedly connected to the upper bearing module, the upper motor support is fixedly connected to the upper fixed head, and an upper motor is provided in the upper motor support, the lower motor support is fixedly connected to the lower fixed head, and a lower motor is provided in the lower motor support, the upper motor and the lower motor are respectively connected to the connecting sleeve through gear transmission; when the upper motor rotates, it drives the connecting sleeve and the lower fixed head to rotate relative to the upper fixed head, and when the lower motor rotates, it drives the connecting sleeve and the upper fixed head to rotate relative to the lower fixed head; the contact surfaces of the upper motor support, the lower motor support and the connecting sleeve are all inclined inclined surfaces, and the contact surface of the lower motor support and the lower fixed head is an inclined surface; the lower fixed head is fixedly connected to the lower bearing module; The upper interface of the hollow hydraulic transducer is fixedly connected to the lowermost ball head, and the lower interface is fixedly connected to the drill bit; The drill pipe also includes an external deflector, which includes three annular inflatable structures, namely an inner air cavity, a middle air cavity and an outer air cavity; wherein the inner air cavity is installed on the outer wall of the socket, the center of the middle air cavity is located to the right of the center of the inner air cavity, and the center of the outer air cavity is located below the center of the inner air cavity.

2. The flexible inner guide hollow drill rod for low permeability sandstone uranium reservoir according to claim 1, characterized in that: The inner guide mechanism further includes a fixing cable module located above the upper bearing module, and the signal lines of the upper motor and the lower motor pass through the fixing cable module.

3. The flexible inner guide hollow drill rod for low permeability sandstone uranium reservoir according to claim 1, characterized in that: The drill rod further comprises a drill rod transition piece, the lower end of which is fixedly matched with the upper end of the ball socket.

4. The flexible inner guide hollow drill rod for low permeability sandstone uranium reservoir according to claim 3, characterized in that: The outer diameters of the ball head, ball socket, hollow hydraulic transducer and drill pipe transition piece are the same.

5. The flexible inner guide hollow drill rod for low permeability sandstone uranium reservoir according to claim 1, characterized in that: A through liquid channel is provided inside the drill rod, and the liquid channel is connected to the hollow hydraulic transducer.

6. The flexible inner guide hollow drill rod for low permeability sandstone uranium reservoir according to claim 1, characterized in that: A plurality of ball head slides are arranged circumferentially on the outer wall of the upper end of the ball head, and a ball socket slideway corresponding to the ball head slide is arranged circumferentially on the inner wall of the lower end of the ball socket. The ball head slide is inserted into the ball socket slide during assembly; a plurality of ball socket slides are arranged circumferentially on the outer wall of the upper end of the ball socket, and a ball head slideway corresponding to the ball socket slide is arranged circumferentially on the inner wall of the lower end of the ball head. The ball socket slide is inserted into the ball head slide during assembly.

7. The flexible inner guide hollow drill rod for low permeability sandstone uranium reservoir according to claim 1, characterized in that: The drill bit comprises a drill bit base and cutter teeth. The upper interface of the drill bit base is fixedly matched with the lower interface of the hollow hydraulic transducer; the drill bit base is fixedly matched with the bottom of the cutter teeth.

8. The method for constructing a flexible inner-guided hollow drill rod in a low-permeability sandstone uranium reservoir according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1, assembling the flexible inner guide hollow drill rod of the low permeability sandstone uranium reservoir; S2, connecting the drill rod transition piece at the upper end of the flexible inner guide hollow drill rod of the low permeability sandstone uranium reservoir to the drilling guide rod, and placing the hollow drill rod into the rock drill hole to the depth to be guided through the drilling guide rod; S3, filling gas into the outer deflectors on the outer sides of the ball socket through the external cylinders, so that the outer deflectors are in contact with the inner wall of the borehole; S4, controlling the steering module of the inner guide mechanism to operate so as to generate an angle difference between the upper bearing module and the lower bearing module; S5. Applying fluid pressure to the interior of the drilling guide rod causes the hollow hydraulic transducer to rotate the drill bit, and using the downward pressure of the drilling guide rod to apply forward thrust to the hollow drill rod, rotating and crushing the rock to produce a borehole at a certain angle to the rock borehole; S6. Deflate the external whipstock. After reaching the position where the drill needs to turn, repeat steps S3-S5 to allow the hollow drill rod to drill to the target point. S7. Rotate the drill rod in the opposite direction to remove the hollow drill rod.

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