A mud flush assembly for drilling

Abstract

This utility model discloses a drilling mud flushing assembly, including a mud flushing pipe connected between a gooseneck and a top drive rotating shaft. An upper packing box is provided on the upper outer surface of the mud flushing pipe, and a lower packing box is provided on the lower outer surface. A connector A is provided between the upper packing box and the gooseneck, and a connector B is provided between the lower packing box and the top drive rotating shaft. Annular cavities are formed between the upper packing box and the mud flushing pipe, and between the lower packing box and the mud flushing pipe. Through the design of a planetary reduction assembly, the internal gear ring remains stationary with the upper packing box, while the sun gear actively rotates with the top drive rotating shaft, driving the planetary gears to rotate, which in turn drive the mud flushing pipe to rotate at a reduced speed via the planetary carrier. This structure ensures that the mud flushing pipe rotates at a lower speed than the top drive rotating shaft, significantly reducing the relative friction between the mud flushing pipe and the packing, effectively delaying packing wear, avoiding frequent packing replacements, significantly extending the overall service life of the drilling mud flushing assembly, and ensuring the continuity of drilling operations.

Description

Technical Field

[0001] This utility model relates to the field of drilling and well workover technology, specifically to a drilling mud flushing assembly. Background Technology

[0002] The flushing assembly is one of the core components of the top drive unit. Its core function is to connect the stationary gooseneck tube with the rotating top drive shaft, creating a high-pressure mud delivery channel to ensure that the mud can be stably delivered to the bottom of the well, providing the necessary conditions for drilling operations.

[0003] In oil drilling operations, high-pressure mud is pumped out by a mud pump, transported via a water hose to the gooseneck of the top drive unit, and then passed down through the flushing assembly to the top drive rotary shaft, finally reaching the bottom of the well. The flushing assembly not only needs to withstand the impact of high-pressure, high-speed flowing mud for a long time, but also needs to achieve the dynamic-static transition from static to rotating. During this process, the outer surface of the rotating mud flushing assembly and the stationary flushing sealing packing will continuously generate relative friction.

[0004] Existing flushing assemblies, such as the patent document with publication number CN222909979U which discloses a top drive flushing assembly structure, can reduce friction between the flushing body and packing components during operation by setting grease grooves around the flushing body, thereby providing lubrication and reducing packing wear rate and extending service life. However, with the widespread use of PDC drill bits, drilling rig speeds have increased significantly, from about 100 revolutions per minute to about 200 revolutions per minute. Under high-speed operation, the wear rate of solid particles in the mud on the flushing sealing packing is significantly accelerated, resulting in frequent packing replacements. This severely disrupts the continuity of drilling operations, greatly reduces drilling efficiency, and makes it difficult to meet the current demand for high-efficiency drilling.

[0005] To address this, a drilling mud flushing assembly that can adapt to high-speed operating conditions and extend service life is proposed. Utility Model Content

[0006] The technical objective of this utility model is to address the above-mentioned shortcomings by providing a drilling mud flushing assembly to solve the problems mentioned above.

[0007] To achieve the above objectives, this utility model provides the following technical solution: A drilling mud flushing assembly includes a mud flushing pipe connected between a gooseneck and a top drive rotating shaft. An upper packing box is provided on the outer surface of the upper part of the mud flushing pipe, and a lower packing box is provided on the outer surface of the lower part of the mud flushing pipe. A connector A is provided between the upper packing box and the gooseneck, and a connector B is provided between the lower packing box and the top drive rotating shaft. Annular cavities are formed between the upper packing box and the mud flushing pipe, and between the lower packing box and the mud flushing pipe. A sealing assembly is provided within each annular cavity. An annular receiving cavity is provided on the side of the lower packing box facing the upper packing box, and a planetary reduction assembly is provided within the annular receiving cavity. An outer cover that protects the planetary reduction assembly is threaded onto the upper end of the lower packing box.

[0008] Preferably, the connector A includes an upper large nut positioned at the upper end of the mud flushing pipe. The inner wall of the upper large nut is threaded to the outer surface of the gooseneck pipe. The upper large nut is fixed to the upper packing box by a three-piece clamp. The connector B includes a lower large nut placed at the lower end of the mud flushing pipe. The inner wall of the lower large nut is threaded to the outer surface of the top drive rotating shaft. The lower large nut is fixed to the lower packing box by a three-piece clamp.

[0009] Preferably, the upper large nut on the side opposite to the upper packing box, the lower large nut on the side opposite to the lower packing box, and the upper and lower parts of the inner wall of the three-piece clamp are all provided with inclined surfaces. The inclined surface of the upper large nut opposite to the upper packing box is respectively attached to the inclined surface of the corresponding inner wall of the three-piece clamp, and the inclined surface of the lower large nut opposite to the lower packing box is respectively attached to the inclined surface of the corresponding inner wall of the three-piece clamp.

[0010] Preferably, the sealing assembly includes a plurality of packing rings and packing spacers sequentially sleeved within the annular cavity along the axial direction of the mud flushing pipe. The packing rings and packing spacers are interlocked. A clamping sleeve is respectively installed between the upper packing box and the uppermost packing spacer inside it, and between the lower packing box and the lowermost packing spacer inside it. The two clamping sleeves are respectively fixed to the upper packing box and the lower packing box by bolts. The upper end face of the mud flushing pipe is in contact with the lip of the uppermost packing spacer inside the upper packing box, and the lower end face of the mud flushing pipe is in contact with the lip of the lowermost packing spacer inside the lower packing box.

[0011] Preferably, O-rings are fitted into the uppermost packing spacer in the upper packing box, the lowermost packing spacer in the lower packing box, and the upper end of the outer surface of the lower packing box. One of the O-rings is tightly fitted to the lower end face of the gooseneck tube, another O-ring is tightly fitted to the upper end face of the top drive rotating shaft, and the last O-ring is tightly fitted to the inner wall surface of the outer cover.

[0012] Preferably, the planetary reduction assembly includes a sun gear sleeved on the upper end of the lower packing box and located in the annular receiving cavity. The sun gear and the lower packing box are connected by a saddle pin to restrict mutual rotation. The lower end of the upper packing box is fixedly connected to an internal gear ring holder by an anti-rotation pin. The lower end of the internal gear ring holder is fixedly connected to an internal gear ring by a connecting pin. A planetary gear meshes between the internal gear ring and the sun gear. The planetary gear is rotatably connected to a planetary carrier by a pin shaft. A flushing pipe support ring is connected to the planetary carrier and the mud flushing pipe by screws.

[0013] Preferably, the planetary gears are arranged in a ring with at least two equidistant parts.

[0014] Preferably, the outer surface of the mud flushing pipe is integrally formed with an annular step, and a spline assembly is provided between the annular step and the planetary carrier, wherein: The spline assembly includes a rectangular external spline disposed on an annular step, and the inner wall of the planetary carrier is provided with a rectangular internal spline adapted to the rectangular external spline.

[0015] Preferably, an oil seal A is fitted between the upper end face of the planet carrier and the sun gear, an oil seal B is fitted between the inner gear ring retainer and the inner wall surface of the outer cover, and an oil seal C is fitted between the inner wall surface of the planet carrier and the inner gear ring retainer.

[0016] Preferably, the inner diameters of oil seal A, oil seal C, and oil seal B increase sequentially. The lower packing box, planetary carrier, internal gear ring fixing bracket, outer cover, oil seal A, oil seal B, and oil seal C form a closed oil storage cavity that can store lubricating oil. The outer cover is provided with an oil injection cup that communicates with the lubricating oil channel, and the oil injection cup can inject lubricating oil into the oil storage cavity.

[0017] Compared with the prior art, the advantages and positive effects of this utility model are as follows: 1. This utility model, through the design of a planetary reduction assembly, ensures that the internal gear ring remains stationary with the upper packing box, while the sun gear actively rotates with the top drive shaft, driving the planetary gears to rotate passively, which in turn drives the mud flushing assembly to rotate at a reduced speed via the planetary carrier. This structure ensures that the mud flushing speed is lower than that of the top drive shaft, significantly reducing the relative friction between the mud flushing assembly and the packing, effectively delaying packing wear, avoiding frequent packing replacements, significantly extending the overall service life of the drilling mud flushing assembly, and ensuring the continuity of drilling operations; 2. In this utility model, the mud flushing pipe and the planetary carrier are connected by a rectangular external spline and a rectangular internal spline. The spline assembly can achieve precise positioning and reliable power transmission between the two, avoiding problems such as slippage and offset during transmission. At the same time, the planetary gears are distributed in a ring at equal intervals, which can evenly transmit the power of the sun gear to the planetary carrier, ensuring stable speed of the mud flushing pipe, ensuring precise and controllable deceleration effect, and further reducing additional wear caused by speed fluctuations. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic cross-sectional view of an embodiment of the present utility model; Figure 2 This is a three-dimensional structural schematic diagram of an embodiment of the present utility model; Figure 3 This is an exploded view of the structure of an embodiment of the present utility model; Figure 4 This is a schematic diagram of the BB direction structure of the planetary deceleration assembly according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the CC direction structure of the spline assembly according to an embodiment of the present invention.

[0020] In the diagram: 1. Gooseneck tube; 2. Top drive rotating shaft; 3. Upper large nut; 4. Lower large nut; 5. Upper packing box; 6. Lower packing box; 7. Three-piece clamp; 8. Packing; 9. Packing spacer; 10. Compression sleeve; 11. Mud flushing pipe; 12. Anti-rotation pin; 13. Flushing pipe support ring; 14. Planetary carrier; 15. Pin; 16. Planetary gear; 17. Saddle pin; 18. Sun gear; 19. Internal gear ring; 20. Connecting pin; 21. Internal gear ring fixing bracket; 22. Oil seal A; 23. Oil seal B; 24. Oil seal C; 25. Pressure injection cup; 26. Outer cover. Detailed Implementation

[0021] To better understand the above-mentioned objectives, features, and advantages of this utility model, the present utility model will be further described below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0022] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Example

[0023] like Figures 1-5As shown, a drilling mud flushing assembly according to an embodiment of the present invention includes a mud flushing pipe 11 connected between a gooseneck pipe 1 and a top drive rotating shaft 2. An upper packing box 5 is provided on the upper outer surface of the mud flushing pipe 11, and a lower packing box 6 is provided on the lower outer surface of the mud flushing pipe 11. A connector A is provided between the upper packing box 5 and the gooseneck pipe 1, and a connector B is provided between the lower packing box 6 and the top drive rotating shaft 2. An annular cavity with one end sealed and the other end open is formed between the upper packing box 5 and the mud flushing pipe 11, and between the lower packing box 6 and the mud flushing pipe 11. The openings of the two annular cavities face the gooseneck pipe 1 and the top drive rotating shaft 2, respectively. The rotating shaft 2 has a sealing component inside the annular cavity. The lower packing box 6 has an annular receiving cavity on the side facing the upper packing box 5, and a planetary reduction assembly is installed inside the annular receiving cavity. The upper end of the lower packing box 6 is threaded with an outer cover 26 that can protect the planetary reduction assembly. The annular cavity provides installation space for the sealing component, the planetary reduction assembly provides a structural basis for the deceleration rotation of the mud flushing pipe 11, and the outer cover 26 protects the planetary reduction assembly. The overall structure provides support for the core functions of stable connection, sealing and leak prevention, and deceleration and wear reduction, ensuring that the drilling mud flushing pipe assembly can adapt to high-speed drilling conditions. Example

[0024] like Figures 1-5 As shown, the drilling mud flushing assembly provided in this embodiment differs from that in Embodiment 1 in that: Connector A includes an upper large nut 3 located at the upper end of the mud flushing pipe 11. The inner wall of the upper large nut 3 is threaded to the outer surface of the gooseneck pipe 1. The upper large nut 3 is connected and fixed to the upper packing box 5 by a three-piece clamp 7. Connector B includes a lower large nut 4 located at the lower end of the mud flushing pipe 11. The inner wall of the lower large nut 4 is threaded to the outer surface of the top drive rotating shaft 2. The lower large nut 4 is connected and fixed to the lower packing box 6 by a three-piece clamp 7. Connector A is used to fix the upper packing box 5 to the gooseneck pipe 1. Connector B is used to fix the lower packing box 6 to the top drive rotating shaft 2. This design not only utilizes the reliability of the threaded connection to ensure the basic fixation between components, but also simplifies the disassembly and assembly process of the upper packing box 5 and the large nut 3, and the lower packing box 6 and the large nut 3 through the three-piece clamp 7. It takes into account both connection stability and maintenance convenience, and provides convenience for the installation and maintenance of this drilling mud flushing pipe assembly.

[0025] The upper large nut 3 has an inclined surface on the side opposite to the upper packing box 5, the lower large nut 4 has an inclined surface opposite to the lower packing box 6, and the upper and lower parts of the inner wall of the three-piece clamp 7. The inclined surfaces of the upper large nut 3 and the upper packing box 5 respectively fit into the inclined surfaces of the corresponding inner walls of the three-piece clamp 7, and the inclined surfaces of the lower large nut 4 and the lower packing box 6 respectively fit into the inclined surfaces of the corresponding inner walls of the three-piece clamp 7. The inclined surface structure can increase the contact area between components, improve the tightness of the fit, reduce the connection gap, and thus enhance the overall connection stability of connector A and connector B. At the same time, the inclined surface can disperse the force between components, avoid local stress concentration that may cause component deformation or damage, extend the service life of the connector, and further ensure the connection reliability of the drilling mud flushing assembly.

[0026] The sealing assembly includes several packing rings 8 and packing spacers 9 sequentially sleeved within the annular cavity along the axial direction of the mud flushing pipe 11. The packing rings 8 and packing spacers 9 are interlocked. A clamping sleeve 10 is fitted between the upper packing box 5 and its uppermost packing spacer 9, and between the lower packing box 6 and its lowermost packing spacer 9. The two clamping sleeves 10 are respectively bolted to the upper packing box 5 and the lower packing box 6. The upper end face of the mud flushing pipe 11 is fitted with the lip of the uppermost packing spacer 9 in the upper packing box 5, and the lower end face of the mud flushing pipe 11 is fitted with the lip of the lowermost packing spacer 9 in the lower packing box 6. The structure employs a layered design of packing 8 and packing spacer 9, forming a multi-layered sealing barrier that effectively enhances the sealing capability against high-pressure mud. Two clamping sleeves 10 are bolted to the upper packing box 5 and the lower packing box 6, respectively, ensuring a tight seal between the upper packing box 5 and the corresponding packing spacer 9, and between the lower packing box 6 and the corresponding packing spacer 9, preventing loosening of the sealing components and subsequent seal failure. Furthermore, the end face of the mud flushing pipe 11 fits against the lip of the packing spacer 9, further filling the gap between the mud flushing pipe 11 and the sealing components. These multiple design features collectively improve the sealing performance of the drilling mud flushing pipe assembly, preventing mud leakage.

[0027] O-rings are embedded in the uppermost packing spacer 9 inside the upper packing box 5, the lowermost packing spacer 9 inside the lower packing box 6, and the upper end of the outer surface of the lower packing box 6. One O-ring is tightly fitted to the lower end face of the gooseneck tube 1, another O-ring is tightly fitted to the upper end face of the top drive rotating shaft 2, and the last O-ring is tightly fitted to the inner wall of the outer cover 26. The O-rings have good elasticity and can tightly fill the tiny gaps between the components, further enhancing the sealing effect. This prevents mud from leaking from the gaps between the packing spacer 9 and the gooseneck tube 1, and between the packing spacer 9 and the top drive rotating shaft 2, and also prevents lubricating oil in the oil storage chamber from leaking from the gap between the lower packing box 6 and the outer cover 26, thus improving the overall sealing performance of the drilling mud flushing assembly.

[0028] The planetary reduction assembly includes a sun gear 18 fitted onto the upper end of the lower packing box 6 and located within the annular receiving cavity. The sun gear 18 and the lower packing box 6 are connected by a saddle pin 17 to restrict mutual rotation. An internal gear ring holder 21 is fixedly connected to the lower end of the upper packing box 5 via an anti-rotation pin 12. An internal gear ring 19 is fixedly connected to the lower end of the internal gear ring holder 21 via a connecting pin 20. A planetary gear 16 meshes between the internal gear ring 19 and the sun gear 18. The planetary gear 16 is rotatably connected to a planetary carrier 14 via a pin 15. A flushing pipe support ring 13 is screwed between the planetary carrier 14 and the mud flushing pipe 11. The sun gear 18 is fixed to the lower packing box 6 by the saddle pin 17. The lower packing box 6 is connected to the top drive rotating shaft 2. Therefore, the sun gear 18 rotates synchronously with the top drive rotating shaft 2. The internal gear ring 19 is stationary through the internal gear ring fixing bracket 21. The meshing transmission of the sun gear 18, internal gear ring 19 and planetary gear 16, as well as the connection between the planetary carrier 14 and the mud flushing pipe 11, ultimately realize the function of the top drive rotating shaft 2 rotating actively and the mud flushing pipe 11 rotating at a reduced speed. This structure can effectively reduce the rotation speed of the mud flushing pipe 11 and reduce its relative wear with the packing 8, providing core technical support for extending the service life of the drilling mud flushing pipe assembly. At least two planetary gears 16 are distributed in a ring at equal intervals. Multiple planetary gears 16 can evenly distribute the power transmitted by the sun gear 18, avoiding excessive force on a single planetary gear 16, which would lead to accelerated wear or damage. At the same time, the equal distribution can ensure that the planetary carrier 14 is subjected to balanced force, reduce the shaking or offset of the planetary carrier 14 when it rotates, ensure the stable speed of the mud flushing pipe 11, improve the transmission smoothness and load-bearing capacity of the planetary reduction assembly, and ensure the reliable operation of the reduction function.

[0029] The outer surface of the mud flushing pipe 11 is integrally formed with an annular step, and a spline assembly is provided between the annular step and the planetary carrier 14. The spline assembly includes a rectangular external spline on the annular step, and a rectangular internal spline that matches the rectangular external spline on the inner wall of the planetary carrier 14. The spline connection has the characteristics of precise positioning and large transmission torque, which can realize reliable power transmission between the planetary carrier 14 and the mud flushing pipe 11 and avoid problems such as slippage and misalignment during transmission. At the same time, the spline assembly facilitates the assembly and positioning of the mud flushing pipe 11 and the planetary carrier 14, ensuring that the two rotate synchronously and ensuring that the deceleration effect of the planetary reduction assembly is accurately transmitted to the mud flushing pipe 11, further reducing additional wear caused by unstable transmission.

[0030] An oil seal A22 is installed between the upper end face of the planetary carrier 14 and the sun gear 18, an oil seal B23 is installed between the inner wall of the internal gear ring holder 21 and the inner wall of the outer cover 26, and an oil seal C24 is installed between the inner wall of the planetary carrier 14 and the inner wall of the internal gear ring holder 21. Oil seal A22 can prevent the lubricating oil in the oil reservoir from leaking from the gap between the planetary carrier 14 and the sun gear 18. Oil seals B23 and C24 can respectively block external impurities from entering the oil reservoir and prevent lubricating oil from leaking from the gap between the planetary carrier 14 and the internal gear ring holder 21. The three oil seals work together to form a sealing and protection system for the oil reservoir, ensuring that the lubricating oil is clean and does not leak, and providing a stable lubrication environment for the planetary reduction assembly.

[0031] The inner diameters of oil seals A22, C24, and B23 increase sequentially. The lower packing box 6, planetary carrier 14, internal gear ring holder 21, outer cover 26, and oil seals A22, B23, and C24 form a closed oil reservoir capable of storing lubricating oil. The outer cover 26 is equipped with an oil injection cup 25 connected to the lubricating oil passage, which injects lubricating oil into the reservoir. The reservoir stores lubricating oil for the planetary reduction assembly. The oil injection cup 25 allows for convenient replenishment of lubricating oil to the reservoir, achieving on-demand lubrication. The increasing inner diameter design of oil seals A22, B23, and C24 adapts to the clearance dimensions of different components, ensuring a sealing effect and providing continuous, clean lubrication for the moving parts of the planetary reduction assembly. This reduces internal mechanical wear, extends the lifespan of the reduction assembly, and ensures its long-term stable operation.

[0032] The specific use and working principle of this utility model: I. Component Connection and Channel Construction: First, the upper packing box 5 and the gooseneck tube 1 are fixed by connector A. The inner wall of the upper large nut 3 is threaded to the outer wall of the gooseneck tube 1. The three-piece clamp 7 is fitted at the joint between the upper large nut 3 and the upper packing box 5, and the inclined surfaces of the two are used to achieve tight fixation. Similarly, the lower large nut 4 of connector B is threaded to the top drive rotating shaft 2 and fixed by the three-piece clamp 7, thus completing the connection between the lower packing box 6 and the top drive rotating shaft 2. The mud flushing pipe 11 is connected between the upper packing box 5 and the lower packing box 6 to form a mud conveying channel from the gooseneck tube 1 to the top drive rotating shaft 2. II. Planetary Reduction for Wear Reduction: When the top drive rotating shaft 2 rotates during drilling operations, it drives the sun gear 18, which is sleeved on the lower packing box 6, to rotate synchronously via the saddle pin 17. Since the internal gear ring fixing frame 21 is fixed to the upper packing box 5 by the anti-rotation pin 12, the internal gear ring 19 remains stationary through the internal gear ring fixing frame 21, allowing the sun gear 18 to drive the planetary gear 16 to revolve and rotate around the sun gear 18. The planetary gear 16 drives the planet carrier 14 to rotate via the pin 15, and the planet carrier 14 then transmits the power to the mud via the spline assembly. The slurry flushing pipe 11 rotates with the planetary carrier 14. Due to the transmission characteristics of the planetary reduction assembly, the rotational speed of the slurry flushing pipe 11 is lower than that of the top drive rotating shaft 2. If the number of teeth of the internal gear ring 19 is Zr and the number of teeth of the sun gear 18 is Zs, the reduction ratio between the sun gear 18 and the planetary carrier 14 is i=1+Zr / Zs. That is, the rotational speed ratio between the top drive rotating shaft 2 and the slurry flushing pipe 11 is i=1+Zr / Zs, which greatly reduces the relative friction between the outer surface of the slurry flushing pipe 11 and the packing 8 in the sealing assembly, and delays the wear of the packing 8. III. Multi-layer sealing to prevent leakage: In the sealing assembly, packing 8 and packing spacer 9 are stacked at intervals along the axial direction of mud flushing pipe 11 to form a multi-layer sealing barrier; two clamping sleeves 10 are fixed to the upper packing box 5 and the lower packing box 6 by bolts, which tightly press the packing 8 and packing spacer 9 to prevent the sealing assembly from loosening; at the same time, the packing spacer 9 in the upper packing box 5 and the lower packing box 6 respectively fits against the lower end face of gooseneck pipe 1 and the upper end face of top drive rotating shaft 2, and with the embedded O-ring seal, further fills the sealing gap, effectively preventing high-pressure mud from leaking from the annular cavity, and ensuring that the mud is stably delivered to the bottom of the well; IV. Lubrication and Protection Ensure Stability: The outer cover 26, threaded at the upper end of the lower packing box 6, together with the lower packing box 6, planetary carrier 14, and internal gear ring retainer 21, forms a closed oil reservoir. Lubricating oil can be injected into the oil reservoir through the injection cup 25 to provide lubrication for moving parts such as the sun gear 18, planetary gear 16, and pin shaft 15. Oil seals A22, B23, and C24 respectively prevent lubricating oil from leaking from the gaps between the planetary carrier 14 and the sun gear 18, the internal gear ring retainer 21 and the outer cover 26, and the planetary carrier 14 and the internal gear ring retainer 21. At the same time, they prevent external impurities from entering the oil reservoir, ensuring that the planetary reduction assembly operates stably in a clean and lubricated environment and extending its service life.

[0033] In summary, this drilling mud flushing assembly, through the coordinated efforts of its components, achieves efficient mud delivery, friction reduction during dynamic-to-static transition, reliable sealing and leak prevention, and adequate lubrication and protection. This enables the drilling mud flushing assembly to adapt to high-speed drilling conditions, improving operational continuity and efficiency.

[0034] Through the above specific embodiments, those skilled in the art can easily implement this utility model. However, it should be understood that this utility model is not limited to the specific embodiments described above. Based on the disclosed embodiments, those skilled in the art can arbitrarily combine different technical features to achieve different technical solutions.

Claims

1. A mud-purge assembly for use in drilling a well, characterized by, The system includes a mud flushing pipe (11) connected between a gooseneck tube (1) and a top drive rotating shaft (2). The upper outer surface of the mud flushing pipe (11) is provided with an upper packing box (5), and the lower outer surface of the mud flushing pipe (11) is provided with a lower packing box (6). A connector A is provided between the upper packing box (5) and the gooseneck tube (1), and a connector B is provided between the lower packing box (6) and the top drive rotating shaft (2). Annular cavities are formed between the upper packing box (5) and the mud flushing pipe (11), and between the lower packing box (6) and the mud flushing pipe (11). A sealing component is provided in the annular cavity. An annular receiving cavity is provided on the side of the lower packing box (6) facing the upper packing box (5). A planetary reduction assembly is provided in the annular receiving cavity. An outer cover (26) that can protect the planetary reduction assembly is threaded onto the upper end of the lower packing box (6).

2. The drilling mud flush pipe assembly of claim 1, wherein: The connector A includes an upper large nut (3) placed at the upper end of the mud flushing pipe (11). The inner wall of the upper large nut (3) is threaded to the outer surface of the gooseneck pipe (1). The upper large nut (3) is connected and fixed to the upper packing box (5) by a three-piece clamp (7). The connector B includes a lower large nut (4) placed at the lower end of the mud flushing pipe (11). The inner wall of the lower large nut (4) is threaded to the outer surface of the top drive rotating shaft (2). The lower large nut (4) is connected and fixed to the lower packing box (6) by a three-piece clamp (7).

3. The drilling mud flush pipe assembly of claim 2, wherein: The upper large nut (3) is backed by the upper packing box (5), the lower large nut (4) is backed by the lower packing box (6), and the upper and lower parts of the inner wall of the three-piece clamp (7) are all provided with inclined surfaces. The inclined surfaces of the upper large nut (3) and the upper packing box (5) are respectively attached to the inclined surfaces of the corresponding inner wall of the three-piece clamp (7), and the inclined surfaces of the lower large nut (4) and the lower packing box (6) are respectively attached to the inclined surfaces of the corresponding inner wall of the three-piece clamp (7).

4. The drilling mud flush pipe assembly of claim 1, wherein: The sealing assembly includes several packing rings (8) and packing spacers (9) sequentially sleeved in the annular cavity along the axial direction of the mud flushing pipe (11). The packing rings (8) and packing spacers (9) are interlocked. A clamping sleeve (10) is respectively installed between the upper packing box (5) and the uppermost packing spacer (9) inside it, and between the lower packing box (6) and the lowermost packing spacer (9) inside it. The two clamping sleeves (10) are respectively fixed to the upper packing box (5) and the lower packing box (6) by bolts. The upper end face of the mud flushing pipe (11) is in contact with the lip of the uppermost packing spacer (9) inside the upper packing box (5), and the lower end face of the mud flushing pipe (11) is in contact with the lip of the lowermost packing spacer (9) inside the lower packing box (6).

5. The drilling mud flush pipe assembly of claim 4, wherein: O-rings are fitted on the uppermost packing spacer (9) inside the upper packing box (5), the lowermost packing spacer (9) inside the lower packing box (6), and the upper end of the outer surface of the lower packing box (6). One of the O-rings is tightly fitted to the lower end face of the gooseneck tube (1), another O-ring is tightly fitted to the upper end face of the top drive rotating shaft (2), and the last O-ring is tightly fitted to the inner wall surface of the outer cover (26).

6. The drilling mud flush pipe assembly of claim 1, wherein: The planetary reduction assembly includes a sun gear (18) sleeved on the upper end of the lower packing box (6) and located in the annular cavity. The sun gear (18) and the lower packing box (6) are connected by a saddle pin (17) to restrict mutual rotation. The lower end of the upper packing box (5) is connected and fixed with an internal gear ring fixing bracket (21) by an anti-rotation pin (12). The lower end of the internal gear ring fixing bracket (21) is connected and fixed with an internal gear ring (19) by a connecting pin (20). A planetary gear (16) meshes between the internal gear ring (19) and the sun gear (18). The planetary gear (16) is rotatably connected to a planet carrier (14) by a pin shaft (15). The planet carrier (14) and the mud flushing pipe (11) are connected by a flushing pipe support ring (13) by screws.

7. The drilling mud flush pipe assembly of claim 6, wherein: The planetary gears (16) are arranged in a ring with at least two of them at equal intervals.

8. The drilling mud flush pipe assembly of claim 6, wherein: The outer surface of the mud flushing pipe (11) is integrally formed with an annular step, and a spline assembly is provided between the annular step and the planetary carrier (14), wherein: The spline assembly includes a rectangular external spline disposed on an annular step, and the inner wall of the planetary carrier (14) is provided with a rectangular internal spline adapted to the rectangular external spline.

9. The drilling mud flush pipe assembly of claim 6, wherein: An oil seal A (22) is fitted between the upper end face of the planetary carrier (14) and the sun gear (18), an oil seal B (23) is fitted between the inner gear ring fixing frame (21) and the inner wall surface of the outer cover (26), and an oil seal C (24) is fitted between the inner wall surface of the planetary carrier (14) and the inner gear ring fixing frame (21).

10. The drilling mud flush pipe assembly of claim 9, wherein: The inner diameters of oil seal A (22), oil seal C (24) and oil seal B (23) increase sequentially. The lower packing box (6), planetary carrier (14), internal gear ring fixing frame (21), outer cover (26), oil seal A (22), oil seal B (23) and oil seal C (24) form a closed oil storage cavity that can store lubricating oil. The outer cover (26) is provided with a pressure injection cup (25) that communicates with the lubricating oil channel. The pressure injection cup (25) can inject lubricating oil into the oil storage cavity.

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