A back off drill rod driven by mud pressure and method of use

Abstract

The application discloses a mud pressure driven anti-loose drill rod and a use method thereof, and relates to the technical field of drill rods.The application comprises drill rod bodies, male joints and female joints fixed at the two ends of the drill rod bodies respectively, the two drill rod bodies are connected through the male joints and the female joints, a plurality of inner notches are arranged on the outer circumferential surface of the front end of the male joint, a plurality of block embedding mechanisms are arranged in the wall thickness of the end of the female joint close to the drill rod body, the plurality of block embedding mechanisms correspond to the plurality of inner notches one by one, and the female joint is provided with independent front through holes and rear through holes at the positions corresponding to each block embedding mechanism.The block embedding mechanisms on the female joint and the inner notches of the male joint are matched, the circumferential mechanical block is provided when the drill rod bears the reverse torque or the vibration impact after the connection, the anti-loose effect is achieved, the safety redundancy is provided, the whole system takes the inherent mud pressure in the drill string as the power source, the complete automation of the locking and the unlocking is realized, and the seamless integration with the drilling operation process is achieved.

Description

Technical Field

[0001] This invention belongs to the field of drill pipe technology, and in particular relates to an anti-loosening drill pipe driven by mud pressure and its usage method. Background Technology

[0002] Drill pipe is the core drill string component in oil and gas drilling operations, which transmits torque, transports drilling fluid, and deepens the wellbore. A single drill pipe is typically 9-10 meters long, with a male connector and a female connector welded to both ends. Adjacent drill pipes are connected by screwing the external thread on the male connector into the internal thread on the female connector.

[0003] Currently, drill pipe joints generally adopt a tapered thread connection structure. The external thread of the male joint and the internal thread of the female joint are both tapered. After the two are screwed together, the preload is generated by the interference of the tapered surface. At the same time, a shoulder surface (single shoulder) or two shoulder surfaces (double shoulder) are set at the root of the thread. After the shoulder surfaces are pressed together, a metal-to-metal hard seal is formed, which bears most of the torque transmitted by the drill pipe.

[0004] However, in actual drilling operations, especially in complex conditions such as ultra-deep wells, extended reach wells, and horizontal wells, the torque fluctuations, axial vibrations, bending stresses, and reverse torsional loads that the drill string bears are extremely complex. When abnormal situations such as stuck drill, formation reverse torque, or drill string rebound occur downhole, the joint threads may rotate slightly relative to each other. After long-term accumulation, this can lead to thread loosening or even drill string falling off, causing huge economic losses and safety hazards.

[0005] Existing technologies incorporate anti-loosening and anti-torsion structures to address the aforementioned problems, but limitations still exist: 1. Add a mechanical locking element to the outside of the joint: For example, the patent application number 202180006091.8 discloses a drill pipe connector, which is provided with a locking bolt on the sleeve-shaped receiving part and is radially moved between the unlocked position and the locked position by a gravity adjustment mechanism. For example, the radial locking type marine drill pipe threaded joint disclosed in application number 201510379065.6 uses the connecting ring surface and frustum-shaped connecting channel at the end of the external threaded joint to achieve radial locking; Such solutions all require additional components to be installed outside the joint, resulting in problems such as exposed structure, increased radial dimensions, susceptibility to well wall scratches, and inability to automatically synchronize locking and unlocking actions with drilling conditions.

[0006] 2. A mechanical locking mechanism is set inside the joint: such as the mining drill rod with anti-dumping function disclosed in application number 202010847869.5, which uses the anti-dumping connecting rod in the male joint, the variable cross-section pin in the female joint, the spring and the locking pin to lock the joint when the male joint is screwed in. For example, the quick self-locking anti-drop connector disclosed in application number 201610783613.6 uses steel balls and springs in conjunction with the steel ball groove on the anti-drop linkage to achieve locking. This type of solution relies on the mechanical action during locking to trigger locking once, but unlocking requires special tools or additional operations. In the long-term high-vibration environment downhole, there is a risk of mechanical parts jamming or failure, and once the internal parts are damaged, the connector cannot be disassembled normally.

[0007] In summary, the existing drill pipe joint anti-loosening technology mainly has the following problems that urgently need to be solved: (1) The locking and unlocking operations cannot be automatically synchronized with the drilling conditions, requiring manual intervention or special tools, which increases the operation time and operational risks; (2) Purely mechanical parts are prone to jamming, wear or fatigue failure in the high temperature, high pressure and high vibration environment of underground mines, resulting in insufficient reliability; (3) The anti-loosening mechanism is integrated with the connector body. Once the internal components are damaged, there is a lack of reliable forced disassembly methods, which may cause the connector to fail to be properly unfastened, increasing the difficulty of handling accidents. (4) Some solutions require the addition of components outside the joint, which increases the radial dimension of the joint, affects the passage of the drill string in the wellbore, and the exposed components are easily scraped by the well wall or eroded by mud. Summary of the Invention

[0008] The purpose of this invention is to provide a drill pipe anti-loosening mechanism driven by mud pressure. Through the cooperation of the insert mechanism on the female connector and the concave opening of the male connector, it provides circumferential mechanical resistance after docking and when the drill pipe is subjected to reverse torque or vibration impact, thus playing an anti-loosening role and providing safety redundancy. At the same time, the entire system uses the inherent mud pressure in the drill string as a power source, realizing the complete automation of locking and unlocking, and seamlessly integrating with the drilling operation process.

[0009] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution: This invention relates to an anti-loosening drill rod driven by mud pressure, comprising a drill rod body, wherein a male connector and a female connector are fixed at both ends of the drill rod body, and two drill rod bodies are connected through the male connector and the female connector; The male connector has several recessed openings on its outer peripheral surface at the front end, and the female connector has several insert mechanisms in the wall thickness at the end near the drill rod body. Each of the insert mechanisms corresponds to one of the recessed openings. Each female connector has an independent front opening and a rear opening at the position corresponding to each insert structure. The inner end of the rear opening is provided with an inner retaining ring, and the outer ends of both the rear opening and the front opening are provided with threaded openings. An adapter is provided between the front opening and the rear opening. The insert mechanism includes an insert post and a piston sleeve; The threaded opening of the rear port is connected to a first plug. The piston sleeve is installed in the rear port and its two ends are in contact with the first plug and the inner retaining ring, respectively. The piston sleeve is provided with a through-hole for connection with the adapter. A piston body is slidably connected inside the piston sleeve. A filter screen is fixed at the inner end of the piston sleeve. The embedded column is a T-shaped rod. The embedded column is slidably disposed in the front opening. The embedded column has an inner cavity. The front opening is threaded with a second plug. The second plug has a sliding rod extending into the inner cavity. The inner end of the sliding rod is fixed with a sliding piece that slides along the inner cavity. A spring is fixed between the sliding piece and the top end of the embedded column. The piston sleeve cavity at the outer end of the piston body, the adapter, the cavity between the insert and the second plug together constitute a medium cavity filled with fluid medium. When the female connector and the male connector are mated, the recessed opening is concentric with the front opening. When the spring is in a free state, the insert is located inside the front opening. When the spring is in a compressed state, the inner end of the insert slides into the recessed opening.

[0010] Furthermore, the piston sleeve has a strip groove on its peripheral side that is parallel to the piston sleeve axis, and the inner wall of the rear opening has a guide rib that cooperates with the strip groove.

[0011] Furthermore, the piston body has a locking rod with an outer diameter smaller than the outer diameter of the piston body at one end near the first plug, and the distance between the through-hole and the first plug is less than the length of the locking rod.

[0012] Furthermore, the outer peripheral surface of the male connector is a conical structure, and the two ends of the conical structure are respectively provided with a first front transition surface and a first rear transition surface with smooth surface structure. A male connector thread is provided between the first front transition surface and the first rear transition surface, and a plurality of the inner recesses are provided on the first front transition surface.

[0013] Furthermore, the inner hole of the female connector is a tapered hole structure, and the two ends of the tapered hole structure are respectively provided with a second front transition surface and a second rear transition surface with smooth surface structure. A female connector thread is provided between the second front transition surface and the second rear transition surface. When the female connector is mated with the male connector, the second front transition surface is attached to the outside of the first rear transition surface, and the second rear transition surface is attached to the outside of the first front transition surface.

[0014] Furthermore, the male connector is provided with an outer step at the connection between the male connector and the drill pipe body. When the female connector and the male connector are mated, the front end face of the female connector fits into the outer end face of the outer step to form an outer shoulder surface.

[0015] Furthermore, the female connector is provided with a connecting part at the connection between the female connector and the drill pipe body, and an inner step is formed between the connecting part and the second rear transition surface of the female connector. When the female connector and the male connector are mated, the front end face of the male connector fits with the inner step to form an inner shoulder surface.

[0016] Furthermore, several of the front openings are located at the position of the second rear transition surface, and several of the rear openings are located at the position of the connecting portion.

[0017] Furthermore, the female connector has a concave section on one side of the drill pipe near the drill pipe body, and a sleeve is welded and fixed to the outside of the concave section, the sleeve covering the outside of all the first plugs and the second plugs.

[0018] A method for using anti-loosening drill pipe driven by mud pressure includes the following steps: SS01 Connection steps: Screw the male connector of one drill pipe body into the female connector of another drill pipe body, apply a tight torque, and after mating, align the inner recess with the radially inserted post; SS02 Locking Step: After the drill pipe body is inserted into the borehole, the mud pump is turned on. The mud pressure in the drill string increases and the pressure is transmitted to the piston body through the rear port. The piston body compresses the medium in the piston sleeve and transmits it to the front port through the adapter. The increased pressure in the front port drives the insert to embed into the concave opening, forming a circumferential mechanical block. SS03 Unlocking Steps: When the drill pipe body needs to be disassembled, the male and female connectors that need to be unlocked have been moved out of the drill hole, which is equivalent to connecting to the atmosphere. There is no mud pressure in the drill pipe body. The spring force drives the insert to retract back to the front port. Similarly, the piston body is reset through the adapter, and the male and female connectors return to their free state. At this time, the male and female connectors can be disassembled. SS04 Forced unlocking procedure: When the insert mechanism is damaged and cannot be reset or unlocked, cut the sleeve and unscrew the first and second plugs to leave space for forced disassembly of the piston sleeve and insert body.

[0019] The present invention has the following beneficial effects: 1. This invention utilizes the interlocking block mechanism on the female connector and the inner recess of the male connector to provide circumferential mechanical resistance after docking and when the drill pipe is subjected to reverse torque or vibration impact, preventing relative rotation of the threads. It also provides a certain torque transmission function, protecting the threaded connection surface, improving torque bearing capacity, and providing safety redundancy while preventing loosening. The two mechanisms are mutually independent and complementary, ensuring the torque transmission capacity of the connector and significantly improving the reliability of the anti-loosening mechanism. Furthermore, the entire system uses the inherent mud pressure within the drill string as a power source, achieving complete automation of locking and unlocking. It seamlessly integrates with the drilling operation process without adding any extra steps, providing a system-level solution for drill string safety in complex conditions such as deep wells, ultra-deep wells, and extended reach wells.

[0020] 2. This invention utilizes the mud pressure inherent in the drill string during drilling as the locking power source. When the pump is started and drilling begins, the mud pressure automatically pushes the piston body, which transmits the pressure to the insert via the adapter, causing it to automatically extend into the inner recess to complete the locking. When the pump is stopped and the drill string is pulled out, the mud pressure disappears, and the spring automatically drives the insert to retract and return to its original position, thus unlocking. The entire locking and unlocking process is completely synchronized with the drilling operation process. It automatically locks during drilling and automatically unlocks when the pump is stopped, requiring no additional intervention from the operator and without adding any operation steps or time.

[0021] 3. This invention forms an outer shoulder surface by fitting the outer stepped part of the male connector with the front end face of the female connector, and forms an inner shoulder surface by fitting the front end face of the male connector with the inner stepped part of the female connector. The double shoulder structure bears the main torque and axial load during normal drilling of the drill pipe, and at the same time provides double metal-to-metal seals to prevent drilling fluid leakage. The engagement of the insert and the concave opening serves as an anti-loosening mechanism independent of the shoulder, providing circumferential mechanical resistance when the drill pipe is subjected to reverse torque or vibration impact. The shoulder is responsible for the main load bearing, and the insert is responsible for anti-loosening protection. The two have clear division of labor and complementary functions. The insert mechanism reduces its own failure risk and extends its service life because it does not have to bear extreme torque.

[0022] 4. The present invention has a piston body and a piston sleeve inside the rear port. The mud pressure only acts on the piston body. The piston body transmits pressure by compressing the clean fluid medium inside the piston sleeve. Physical isolation is achieved between the mud and the locking cavity where the insert is located. Solid particles such as rock cuttings and barite powder in the mud will not enter the sliding pair of the insert and the front port, which fundamentally avoids jamming or wear failure caused by the intrusion of solid particles and greatly improves the reliability of the mechanism in long-term downhole service.

[0023] 5. This invention provides a welded sleeve covering all plugs on the outer circumference of the female connector. When the insert mechanism fails to unlock properly due to accidental damage, the sleeve can be cut to expose the plugs. After unscrewing the plugs, the piston sleeve and insert can be forcibly removed, thus achieving forced disassembly of the connector. This provides a reliable safety redundancy for downhole accident handling and avoids the extreme situation where the drill string cannot be disassembled due to the locking mechanism being stuck.

[0024] 6. All the structures of this invention are arranged inside the wall thickness of the female connector. The external dimensions of the female connector are the same as those of a conventional connector. No additional components are required on the outside of the connector. This will not affect the passage of the drill string in the wellbore, nor will it increase the risk of scraping and colliding with the well wall. The structure is compact and highly adaptable.

[0025] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the structure of an anti-loosening drill rod driven by mud pressure according to the present invention after half of the axis has been removed. Figure 2 for Figure 1 A magnified view of a section at point A in the middle; The attached diagram lists the components represented by each number as follows: 1-Drill pipe body, 2-Male connector, 3-Female connector, 4-Inserted post, 5-Piston sleeve, 6-Casing, 201-Inner notch, 202-First front transition surface, 203-First rear transition surface, 204-Male connector thread, 205-Outer step, 301-Front port, 302-Rear port, 303-Inner retaining ring, 304-Threaded port, 305-Adapter, 306-First plug, 307-Second front transition surface, 308-Second rear transition surface, 309-Female connector thread, 310-Connecting part, 401-Inner cavity, 402-Second plug, 403-Sliding rod, 404-Sliding plate, 405-Spring, 501-Through, 502-Piston body, 503-Filter screen, 504-Locking rod. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] Please see Figure 1-2 As shown, the present invention is an anti-loosening drill rod driven by mud pressure, including a drill rod body 1, with a male connector 2 and a female connector 3 fixed at both ends of the drill rod body 1, and the two drill rod bodies 1 are connected through the male connector 2 and the female connector 3. The male connector 2 has several recesses 201 on its outer peripheral surface at the front end. The female connector 3 has several insert mechanisms in the wall thickness at one end near the drill rod body 1. The several insert mechanisms correspond one-to-one with the several recesses 201. The female connector 3 is provided with an independent front port 301 and a rear port 302 at the position corresponding to each insert structure. The inner end of the rear port 302 is provided with an inner retaining ring 303. The outer ends of the rear port 302 and the front port 301 are both provided with threaded ports 304. A transition interface 305 is provided between the front port 301 and the rear port 302. The insert mechanism includes an insert post 4 and a piston sleeve 5; The threaded port 304 of the rear port 302 is internally threaded to a first plug 306. The piston sleeve 5 is installed in the rear port 302 and its two ends are in contact with the first plug 306 and the inner retaining ring 303, respectively. The piston sleeve 5 is provided with a through port 501 that is connected to the adapter 305. The piston body 502 is slidably connected inside the piston sleeve 5. A filter screen 503 is fixed at the inner end of the piston sleeve 5. The structure of the filter screen 503 prevents impurities in the mud from flowing into the piston sleeve 5 and causing blockage. The embedded column 4 is a T-shaped rod. The embedded column 4 is slidably disposed in the front opening 301. The embedded column 4 has an inner cavity 401. A second plug 402 is threadedly connected to the front opening 301. A slide rod 403 extending into the inner cavity 401 is provided on the second plug 402. A slide piece 404 that slides along the inner cavity 401 is fixed at the inner end of the slide rod 403. A spring 405 is fixed between the slide piece 404 and the top end of the embedded column 4. like Figure 2 As shown, a locking neck is provided on the outer circumferential surface of the piston body 502 for installing a seal. Similarly, a sealing groove is opened on the outer circumferential surface of the four large-diameter sections of the insert body or on the inner wall of the front opening 301, and a sealing element is also provided for sealing. Wherein, the position where the slide bar 403 passes through the end of the small diameter section of the insert 4 does not need to be sealed, but a preset port for the fluid medium to flow in can be set. At the same time, a notch is also set on the outer periphery of the slide plate 404 to avoid the problem of negative pressure or back pressure causing the inner cavity 401 of the insert 4 to form a completely sealed space and thus preventing movement. Since the fluid medium is a clean medium isolated by the piston body and does not contain solid particles, the above gaps or micropores will not be blocked. Both the first plug 306 and the second plug 402 are provided with hexagonal openings for screwing. During initial installation, glue is filled at the connection between the first plug 306 and the second plug 402 and their corresponding threaded openings 304 to seal and reinforce them. Welding can even be performed at the connection for permanent fixation. The inner cavity of the piston sleeve 5 at the outer end of the piston body 502, the adapter 305, the cavity between the insert 4 and the second plug 402 together constitute a medium cavity filled with fluid medium. The fluid medium is a clean fluid medium, namely hydraulic oil or inert gas. When the female connector 3 and the male connector 2 are connected, the inner recess 201 and the front opening 301 are concentrically opposite each other. When the spring 405 is in a free state, the insert 4 is located in the front opening 301. When the spring 405 is in a compressed state, the inner end of the insert 4 slides into the inner recess 201.

[0030] The piston sleeve 5 has a strip groove on its circumferential side that is parallel to the axis of the piston sleeve 5, and the inner wall of the rear opening 302 has a guide rib that matches the strip groove. This structure ensures that the opening 501 is correctly oriented and will not be misaligned, thus preventing the piston sleeve 5 from rotating.

[0031] Among them, such as Figure 1-2 As shown, the piston body 502 has a locking rod 504 with an outer diameter smaller than the outer diameter of the piston body 502 at one end near the first plug 306. The distance between the through-hole 501 and the first plug 306 is less than the length of the locking rod 504. The locking rod 504 is provided to prevent the piston body 502 from blocking the through-hole 501 when it moves to the outer end of the piston sleeve 5.

[0032] Among them, such as Figure 1-2 As shown, the outer peripheral surface of the male connector 2 is a conical structure. The two ends of the conical structure are respectively provided with a first front transition surface 202 and a first rear transition surface 203 with smooth surface structures. A male connector thread 204 is provided between the first front transition surface 202 and the first rear transition surface 203. Several recesses 201 are provided on the first front transition surface 202.

[0033] Among them, such as Figure 1-2 As shown, the inner hole of the female connector 3 is a tapered hole structure. The two ends of the tapered hole structure are respectively provided with a second front transition surface 307 and a second rear transition surface 308 with smooth surface structure. A female connector thread 309 is provided between the second front transition surface 307 and the second rear transition surface 308. When the female connector 3 is connected to the male connector 2, the second front transition surface 307 is attached to the outside of the first rear transition surface 203, and the second rear transition surface 308 is attached to the outside of the first front transition surface 202.

[0034] Among them, such as Figure 1-2 As shown, the male connector 2 is provided with an outer step 205 at the connection between it and the drill pipe body 1. When the female connector 3 and the male connector 2 are connected, the front end face of the female connector 3 fits against the outer end face of the outer step 205 to form an outer shoulder surface.

[0035] Among them, such as Figure 1-2 As shown, a connecting part 310 is provided at the connection between the female connector 3 and the drill pipe body 1. An inner step is formed between the connecting part 310 and the second rear transition surface 308 of the female connector 3. When the female connector 3 and the male connector 2 are connected, the front end face of the male connector 2 fits with the inner step to form an inner shoulder surface.

[0036] Among them, such as Figure 1-2 As shown, several front openings 301 are located at the position of the second rear transition surface 308, and several rear openings 302 are located at the position of the connecting part 310.

[0037] Among them, such as Figure 1-2As shown, the female connector 3 has a concave section on one side of the circumference near the drill rod body 1. A sleeve 6 is welded and fixed to the outside of the concave section. The sleeve 6 covers the outside of all the first plugs 306 and the second plugs 402. This structure is optional and serves as a sealing and protection function.

[0038] A method for using anti-loosening drill pipe driven by mud pressure includes the following steps: SS01 Connection steps: Screw the male connector 2 of one drill pipe body 1 into the female connector 3 of another drill pipe body 1, apply a tightening torque, and after docking, the inner recess 201 and the insert 4 are radially aligned; SS02 Locking Step: After the drill pipe body 1 is inserted into the borehole, the mud pump is turned on. The mud pressure in the drill string increases and the pressure is transmitted from the rear port 302 to the piston body 502. The piston body 502 compresses the medium in the piston sleeve 5 and transmits it to the front port 301 through the adapter 305. The increased pressure in the front port 301 drives the insert 4 to embed into the inner recess 201, forming a circumferential mechanical block. SS03 Unlocking steps: When the drill pipe body 1 needs to be disassembled, the male connector 2 and female connector 3 that need to be unlocked have been moved out of the drill hole, which is equivalent to connecting to the atmosphere. There is no mud pressure inside the drill pipe body 1. The elastic force of the spring 405 drives the embedded column 4 to retract to the front port 301. Similarly, the piston body 502 is reset through the adapter 305, and the male and female connectors 3 return to their free state. At this time, the male connector 2 and female connector 3 can be disassembled. SS04 Forced unlocking procedure: When the insert mechanism is damaged and cannot be reset or unlocked, cut the sleeve 6 and unscrew the first plug 306 and the second plug 402 to leave space for forced disassembly of the piston sleeve 5 and the insert body 4.

[0039] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0040] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A drill rod with anti-loosening mechanism driven by mud pressure, comprising a drill rod body (1), wherein a male connector (2) and a female connector (3) are respectively fixed at both ends of the drill rod body (1), and the two drill rod bodies (1) are connected by the male connector (2) and the female connector (3), characterized in that: The male connector (2) has several recessed openings (201) on its outer peripheral surface at the front end. The female connector (3) has several insert mechanisms in the wall thickness at one end near the drill rod body (1). The several insert mechanisms correspond one-to-one with the several recessed openings (201). The female connector (3) is provided with an independent front opening (301) and a rear opening (302) at the position of each insert structure. The inner end of the rear opening (302) is provided with an inner retaining ring (303). The outer ends of the rear opening (302) and the outer ends of the front opening (301) are both provided with threaded openings (304). A transition interface (305) is provided between the front opening (301) and the rear opening (302). The insert mechanism includes an insert post (4) and a piston sleeve (5); The threaded opening (304) of the rear port (302) is internally threaded with a first plug (306). The piston sleeve (5) is installed in the rear port (302) and its two ends are in contact with the first plug (306) and the inner retaining ring (303) respectively. The piston sleeve (5) is provided with a through-hole (501) connected to the adapter (305). The piston body (502) is slidably connected inside the piston sleeve (5). A filter screen (503) is fixed at the inner end of the piston sleeve (5). The embedded column (4) is a T-shaped rod. The embedded column (4) is slidably disposed in the front opening (301). The embedded column (4) has an inner cavity (401). A second plug (402) is threadedly connected to the front opening (301). The second plug (402) has a slide rod (403) extending into the inner cavity (401). A slide piece (404) that slides along the inner cavity (401) is fixed at the inner end of the slide rod (403). A spring (405) is fixed between the slide piece (404) and the top end of the embedded column (4). The inner cavity of the piston sleeve (5) at the outer end of the piston body (502), the adapter (305), the cavity between the insert (4) and the second plug (402) together constitute a medium cavity filled with fluid medium; When the female connector (3) and the male connector (2) are connected, the recess (201) and the front opening (301) are concentrically opposite. When the spring (405) is in a free state, the insert (4) is located in the front opening (301). When the spring (405) is in a compressed state, the inner end of the insert (4) slides into the recess (201).

2. The anti-loosening drill pipe driven by mud pressure according to claim 1, characterized in that, The piston sleeve (5) has a strip groove on its circumferential side that is parallel to the axis of the piston sleeve (5), and the inner wall of the rear opening (302) has a guide rib that cooperates with the strip groove.

3. The anti-loosening drill pipe driven by mud pressure according to claim 1, characterized in that, The piston body (502) has a locking rod (504) with an outer diameter smaller than that of the piston body (502) at one end near the first plug (306), and the distance between the through hole (501) and the first plug (306) is less than the length of the locking rod (504).

4. The anti-loosening drill pipe driven by mud pressure according to claim 1, characterized in that, The outer peripheral surface of the male connector (2) is a conical structure. The two ends of the conical structure are respectively provided with a first front transition surface (202) and a first rear transition surface (203) with a smooth surface structure. A male connector thread (204) is provided between the first front transition surface (202) and the first rear transition surface (203). A plurality of the inner recesses (201) are provided on the first front transition surface (202).

5. A non-loosening drill pipe driven by mud pressure according to claim 4, characterized in that, The inner hole of the female connector (3) is a tapered hole structure. The two ends of the tapered hole structure are respectively provided with a second front transition surface (307) and a second rear transition surface (308) with a smooth surface structure. A female connector thread (309) is provided between the second front transition surface (307) and the second rear transition surface (308). When the female connector (3) is connected to the male connector (2), the second front transition surface (307) is attached to the outside of the first rear transition surface (203), and the second rear transition surface (308) is attached to the outside of the first front transition surface (202).

6. The anti-loosening drill pipe driven by mud pressure according to claim 1, characterized in that, The male connector (2) is provided with an outer step (205) at the connection between it and the drill rod body (1). When the female connector (3) and the male connector (2) are connected, the front end face of the female connector (3) fits against the outer end face of the outer step (205) to form an outer shoulder surface.

7. A non-loosening drill pipe driven by mud pressure according to claim 5, characterized in that, The female connector (3) is provided with a connecting part (310) at the connection between it and the drill pipe body (1). An inner step is formed between the connecting part (310) and the second rear transition surface (308) of the female connector (3). When the female connector (3) and the male connector (2) are connected, the front end face of the male connector (2) fits against the inner step to form an inner shoulder surface.

8. A non-loosening drill pipe driven by mud pressure according to claim 7, characterized in that, Several of the aforementioned front openings (301) are located at the position of the second rear transition surface (308), and several of the aforementioned rear openings (302) are located at the position of the connecting part (310).

9. A non-loosening drill pipe driven by mud pressure according to claim 1, characterized in that, The female connector (3) has a concave section on one side of the circumference near the drill rod body (1), and a sleeve (6) is welded and fixed to the outside of the concave section. The sleeve (6) covers the outside of all the first plugs (306) and the second plugs (402).

10. A method for using an anti-loosening drill pipe driven by mud pressure according to any one of claims 1-9, characterized in that, Includes the following steps: SS01 Connection steps: Screw the male connector (2) of one drill rod body (1) into the female connector (3) of another drill rod body (1), apply a tightening torque, and after docking, the inner recess (201) and the insert (4) are radially aligned; SS02 Locking Step: After the drill pipe body (1) after docking is sent into the borehole, the mud pump is turned on. The mud pressure in the drill string increases and the pressure is transmitted from the rear port (302) to the piston body (502). The piston body (502) compresses the medium in the piston sleeve (5) and transmits it to the front port (301) through the adapter (305). The pressure in the front port (301) increases and drives the insert (4) to be embedded in the inner recess (201) to form a circumferential mechanical block. SS03 Unlocking steps: When the drill pipe body (1) needs to be disassembled, the male connector (2) and female connector (3) that need to be unlocked have been moved out of the drill hole, which is equivalent to connecting to the atmosphere. There is no mud pressure in the drill pipe body (1). The elastic force of the spring (405) drives the insert (4) to retract to the front port (301). Similarly, the piston body (502) is reset through the adapter (305), and the male and female connectors (3) are restored to their free state. At this time, the male connector (2) and female connector (3) can be disassembled. SS04 Forced unlocking steps: When the insert mechanism is damaged and cannot be reset and unlocked, cut the sleeve (6) and unscrew the first plug (306) and the second plug (402) to leave space for forced disassembly of the piston sleeve (5) and insert (4).

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