Straight turbine drill

Abstract

The utility model relates to the technical field of petroleum drilling equipment, concretely relates to a straight turbine drilling tool, the straight turbine drilling tool includes: the casing assembly is provided with the input of installation cavity for going into the drilling fluid, the main shaft subassembly is set up in the installation cavity, the one end of main shaft subassembly is connected with casing assembly through turbine fixed -rotor subassembly close to the input, the other end of main shaft subassembly is used for connecting the drill bit, the casing assembly is connected by a plurality of partial casing in turn, and the conical thread structure is connected between two adjacent partial casings. The scheme adopts the conical thread structure, can effectively disperse load to can directly eliminate the stress concentration phenomenon of straight thread both ends, makes the casing assembly can bear greater axial, radial, vibration load, avoids the problem that the connecting part of two adjacent parts is easy to break. The scheme improves the reliability of drilling tool, prolongs the working life.

Description

Technical Field

[0001] This utility model relates to the field of oil drilling equipment technology, specifically to a straight turbine drill bit. Background Technology

[0002] Currently, when connecting the various parts of the housing of traditional turbine drill bits, straight threads are commonly used because it is easy to calculate the clamping force and tightening torque between the components.

[0003] However, when two adjacent components are connected by straight threads, there is a significant stress concentration at both ends of the straight thread, while the stress in the middle area is almost negligible. Therefore, when existing turbine drill bits with ordinary straight thread connections are operating downhole, adjacent components are prone to fracture under axial alternating loads, radial alternating loads, and various vibration loads, leading to turbine drill bit falls into the well. Simultaneously, when drilling fluid is introduced into the turbine drill bit, it directly washes against the top of the rotating shaft, easily generating eddies and thus losing hydraulic energy. Furthermore, the top of the rotating shaft is easily eroded and worn by the drilling fluid. Utility Model Content

[0004] In view of this, the present invention provides a straight turbine drill bit to solve the problems that adjacent components are prone to breakage and the top of the rotating shaft is easily eroded and worn by drilling fluid when the turbine drill bit is working downhole.

[0005] In a first aspect, this utility model provides a straight turbine drill bit, which includes: The housing assembly is provided with a mounting cavity, and the inlet of the mounting cavity is used to introduce drilling fluid; The spindle assembly is housed in the mounting cavity; one end of the spindle assembly near the input port is connected to the housing assembly via the turbine stator and rotor assembly, and the other end of the spindle assembly is used to connect the drill bit. The housing assembly is composed of multiple sub-housings connected in sequence, and the spindle assembly is composed of multiple drive shafts connected together; adjacent sub-housings are connected by a tapered thread structure.

[0006] Beneficial Effects: Traditional turbine drill bits use straight threads for all parts of the casing, resulting in high stress at both ends and no stress in the middle, leading to severe stress concentration. This solution uses a tapered thread structure. In practical applications, all threads of the tapered thread structure experience almost equal stress, effectively distributing the load and directly eliminating stress concentration at both ends of the straight thread. This allows the casing assembly to withstand greater axial, radial, and vibration loads, preventing the connection between adjacent components from easily breaking. Therefore, this solution improves drill bit reliability, extends service life, and meets drilling requirements.

[0007] In one alternative embodiment, the tapered thread structure includes a female tapered thread and a male tapered thread, with one of two adjacent housings having a female tapered thread and the other having a male tapered thread.

[0008] Beneficial effects: Due to the radial and / or axial clearances in straight threaded connections, stress concentration is easily exacerbated by dynamic loads. In this design, however, the female tapered thread and male tapered thread mesh to form a tight, clearance-free fit, thus preventing axial or radial movement of the spindle and housing. Simultaneously, the clearance-free fit further disperses the load, allowing it to withstand greater axial, radial, and vibration loads, thereby improving the reliability of the drilling tool, extending its service life, and meeting drilling requirements.

[0009] In one alternative implementation, the plurality of sub-shells include: A first housing, one end of which is used to introduce drilling fluid; The second housing has one end connected to the other end of the first housing via a tapered thread structure; The third housing, one end of which is connected to the other end of the second housing via a tapered thread structure; After the first housing, the second housing, and the third housing are connected, an installation cavity is formed inside.

[0010] In one alternative embodiment, a turbine stator and rotor assembly is disposed in the second housing, and the end of the main shaft assembly near the first housing is connected to the second housing via the turbine stator and rotor assembly.

[0011] In one alternative embodiment, a radial straightening bearing is further provided in the second housing, with the outer side of the radial straightening bearing connected to the second housing and the inner side of the radial straightening bearing connected to the spindle assembly.

[0012] Beneficial effects: During downhole drilling, the high-speed rotation of the drill bit breaking through the rock generates radial reaction force, i.e., radial load. Therefore, the radial centering bearing can constrain the entire spindle assembly, limiting its radial movement and directly bearing this radial load. This ensures the coaxiality of the spindle assembly, turbine stator / rotor assembly, and housing, preventing wear caused by friction between the spindle assembly and the turbine stator / rotor, thereby extending the service life of core components.

[0013] In one alternative embodiment, an axial thrust bearing is further provided in the second housing, with the outer side of the axial thrust bearing connected to the second housing and the inner side of the axial thrust bearing connected to the spindle assembly.

[0014] Beneficial effects: During downhole drilling, the axial thrust bearing directly bears the reverse axial force of the drill bit breaking rock. Therefore, the axial thrust bearing can limit the axial movement of the spindle assembly, preventing the spindle assembly from being stretched or compressed due to axial force. At the same time, it can also prevent loosening of connections caused by axial movement, ensuring uninterrupted power transmission and guaranteeing the normal operation of the entire equipment.

[0015] In one alternative implementation, the spindle assembly includes: A drive shaft, one end of which is near the first housing is connected to the second housing via the turbine rotor assembly; the other end of which is near the third housing is used to connect a drill bit. The drive shaft has a hollow structure at one end near the third housing, and a through hole is provided on the hollow structure, which connects the hollow structure to the mounting cavity.

[0016] In one alternative implementation, the spindle assembly includes: The input shaft is connected to the second housing via the turbine stator / rotor assembly; Output shaft; one end of the output shaft is connected to the input shaft through the tapered thread structure, and the other end of the output shaft is used to connect to the drill bit; the output shaft has a hollow structure and a through hole is provided on the output shaft, the through hole connecting the hollow structure to the mounting cavity.

[0017] Beneficial effects: In this embodiment, the spindle assembly is divided into an input shaft and an output shaft, so that the input shaft and the output shaft can be forged separately. Compared with directly forging a whole drive shaft, this can significantly reduce the processing difficulty and manufacturing cost, and also facilitate transportation and assembly.

[0018] In one alternative embodiment, a locking cap is provided at one end of the spindle assembly near the first housing, and the locking cap is connected to the spindle assembly via a tapered thread structure.

[0019] Beneficial effects: The ends of traditional input shafts are mostly cylindrical, which easily generates eddies when drilling fluid flows through the ends of the input shaft, thus losing hydraulic energy, and the rough surface is easily eroded and worn by the drilling fluid. In this embodiment, a locking cap is additionally provided at the upstream end of the spindle assembly, which can further reduce the erosion and wear of the spindle assembly by the drilling fluid and extend the service life of the spindle assembly.

[0020] In one alternative implementation, the outer diameter of the locking cap gradually increases along the flow direction of the drilling fluid.

[0021] Beneficial effects: By gradually increasing the outer diameter of the locking cap along the flow direction of the drilling fluid, the flow resistance of the drilling fluid can be reduced, allowing the drilling fluid to flow more smoothly to the turbine stator and rotor assembly, reducing the generated eddies, thereby improving the conversion efficiency of hydraulic energy to kinetic energy, and further reducing the wear of the locking cap by the drilling fluid. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the specific embodiments or related technologies of this utility model, the drawings used in the description of the specific embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the overall structure of the straight turbine drill bit according to Embodiment 1 of this utility model; Figure 2 This is a schematic diagram of the structure of the first housing in an embodiment of the present utility model; Figure 3 This is a schematic diagram of the structure of the second shell in an embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of the third housing in an embodiment of the present invention; Figure 5 This is a schematic diagram of the locking cap structure in an embodiment of the present invention; Figure 6 This is a schematic diagram of the first structural form of the spindle assembly in the embodiments of this utility model; Figure 7 This is the second structural form of the spindle assembly in the embodiments of this utility model; Figure 8 This is a schematic diagram of the input shaft structure in Embodiment 2 of this utility model; Figure 9 This is a schematic diagram of the output shaft in Embodiment 2 of this utility model.

[0024] Explanation of reference numerals in the attached figures: 1. Housing assembly; 11. Mounting cavity; 12. First housing; 13. Second housing; 14. Third housing; 2. Spindle assembly; 21. Input shaft; 22. Output shaft; 221. Through hole; 23. Drive shaft; 3. Turbine stator and rotor assembly; 4. Tapered thread structure; 41. Female tapered thread; 42. Male tapered thread; 5. Radial straightening bearing; 6. Axial thrust bearing; 7. Locking cap. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0026] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0027] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can also refer to the internal connection of two components; and they can refer to a wireless connection or a wired connection. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0028] Furthermore, the technical features involved in the different embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0029] The following is combined Figures 1 to 9 The following describes embodiments of the present invention.

[0030] According to an embodiment of the present invention, a straight turbine drill bit is provided, which includes a housing assembly 1, a spindle assembly 2, and a turbine stator / rotor assembly 3.

[0031] Specifically, in this embodiment, the housing assembly 1 is provided with a mounting cavity 11, in which the main shaft assembly 2, the turbine rotor assembly 3, and other assembly components are installed. The inlet of the mounting cavity 11 is used to introduce drilling fluid. The drilling fluid can be output through a surface pump set. After the surface pump set pressurizes the drilling fluid, it is delivered to the top of the mounting cavity 11. The drilling fluid flows downward along the mounting cavity 11 and reaches the turbine rotor assembly 3, where it completes the conversion of hydraulic energy into mechanical energy.

[0032] Of course, this embodiment is merely an example of the pumping method of drilling fluid, but it is not intended to limit the method. Those skilled in the art can make changes according to the actual situation, as long as the same technical effect can be achieved.

[0033] Furthermore, in this embodiment, the spindle assembly 2 is disposed in the mounting cavity 11, and one end of the spindle assembly 2 near the mounting cavity 11 is connected to the housing assembly 1 through the turbine rotor assembly 3, while the other end of the spindle assembly 2 is used to connect the drill bit.

[0034] In actual operation, the drilling fluid flows downward along the installation cavity 11 and reaches the turbine stator and rotor assembly 3. The turbine stator and rotor assembly 3 completes the conversion of hydraulic energy into rotational mechanical energy. Then, the spindle assembly 2 transmits the rotational mechanical energy to the drill bit, and the drill bit breaks the rock at the bottom of the well.

[0035] Furthermore, in this embodiment, the housing assembly 1 is composed of multiple sub-housing units connected in sequence, and adjacent sub-housing units are connected by a tapered thread structure 4.

[0036] Of course, the tapered thread structure 4 can also be used to connect only two adjacent sub-shells, or only a portion of the sub-shells. This embodiment is merely illustrative and is not intended to limit the scope. Those skilled in the art can modify it according to actual circumstances, as long as the same technical effect is achieved.

[0037] Furthermore, in this embodiment, the diameter of the upstream end of the spindle assembly 2 gradually increases along the flow direction of the drilling fluid. That is, the shape of the upstream end of the spindle assembly 2 can be conical or frustum-shaped. Of course, this embodiment is merely an example and is not intended to limit the scope. Those skilled in the art can make changes according to actual circumstances, as long as the same technical effect is achieved.

[0038] This design, where the housing assembly 1 of traditional turbine drill bits uses straight thread connections with a clearance fit, results in radial and axial clearances. This leads to high stress on the threads at both ends of the straight thread structure, while the threads in the middle area experience less or no stress, causing severe stress concentration. This solution uses a tapered thread structure 4. In practical applications, all threads of the tapered thread structure 4 experience almost equal stress, and because it has a zero-clearance fit, force transmission is continuous. The stress change from one thread to another is gradual, without sudden stress spikes, effectively distributing the load. This directly eliminates the stress concentration at the ends of the straight thread, allowing the housing assembly 1 to withstand greater axial, radial, and vibration loads, and preventing the easy breakage of adjacent components. Therefore, this solution improves drill bit reliability, extends service life, and meets drilling requirements.

[0039] Furthermore, in an optional embodiment, the tapered thread structure 4 includes a female tapered thread 41 and a male tapered thread 42, with one of two adjacent sub-shells having a female tapered thread 41 and the other having a male tapered thread 42.

[0040] For example, in two adjacent sub-shells, the tail of the first sub-shell is connected to the head of the second sub-shell. The tail of the first sub-shell can be a female tapered thread 41, and the head of the second sub-shell can be a male tapered thread 42. Of course, the tail of the first sub-shell can be a male tapered thread 42, and the head of the second sub-shell can be a female tapered thread 41. This embodiment is merely illustrative and is not intended to limit the scope. Those skilled in the art can make changes according to actual circumstances, as long as the same technical effect is achieved.

[0041] With this design, the radial clearance in the straight thread connection can easily exacerbate stress concentration due to load shifting. However, in this solution, the female tapered thread 41 and the male tapered thread 42 mesh together to form a tight, clearance-free fit, thus preventing axial or radial movement of the spindle and housing. Furthermore, the clearance-free fit further disperses the load, allowing it to withstand greater axial, radial, and vibration loads, thereby improving the reliability of the drilling tool, extending its service life, and meeting drilling requirements.

[0042] Furthermore, in an optional embodiment, the plurality of housings include a first housing 12, a second housing 13, and a third housing 14.

[0043] Specifically, in this embodiment, the first housing 12, the second housing 13, and the third housing 14 are connected sequentially along the flow direction of the drilling fluid. One end of the first housing 12 is used to introduce drilling fluid, one end of the second housing 13 is connected to the other end of the first housing 12 via a tapered thread structure 4, and one end of the third housing 14 is connected to the other end of the second housing 13 via a tapered thread structure 4. The first housing 12, the second housing 13, and the third housing 14 are all hollow structures, so that after the first housing 12, the second housing 13, and the third housing 14 are connected, an installation cavity 11 is formed inside.

[0044] Furthermore, in an optional embodiment, a turbine stator-rotor assembly 3 is provided in the second housing 13, and one end of the main shaft assembly 2 near the first housing 12 is connected to the inner wall of the second housing 13 through the turbine stator-rotor assembly 3.

[0045] Furthermore, in an optional embodiment, a radial straightening bearing 5 is also provided in the second housing 13. The outer side of the radial straightening bearing 5 is connected to the second housing 13, and the inner side of the radial straightening bearing 5 is connected to the spindle assembly 2. In this embodiment, the inner side of the radial straightening bearing 5 can be connected to the spindle assembly 2.

[0046] With this configuration, during drilling, the high-speed rotation of the drill bit breaking the rock will generate a radial reaction force, i.e., a radial load. Therefore, the radial centering bearing 5 can constrain the entire spindle assembly 2, limit the radial movement of the spindle assembly 2, and directly bear the radial load. This ensures the coaxiality of the spindle assembly 2 with the turbine stator and rotor assembly and the housing, and avoids wear of the spindle assembly 2 and the turbine stator and rotor due to friction, thereby extending the service life of the core components.

[0047] Furthermore, in an optional embodiment, an axial thrust bearing 6 is also provided in the second housing 13. The outer side of the axial thrust bearing 6 is connected to the second housing 13, and the inner side of the axial thrust bearing 6 is connected to the main shaft assembly 2. In this embodiment, the inner side of the radial straightening bearing 5 can be connected to the input shaft 21 of the main shaft assembly 2. Along the flow direction of the drilling fluid, the radial straightening bearing 5, the turbine stator / rotor assembly 3, and the axial thrust bearing 6 are arranged sequentially.

[0048] With this configuration, during drilling, the axial thrust bearing 6 directly bears the reverse axial force of the drill bit breaking rock. Therefore, the axial thrust bearing 6 can limit the axial movement of the spindle assembly 2, preventing the spindle assembly 2 from being stretched or compressed due to axial force. At the same time, it can also prevent loosening of the connection caused by axial movement, ensuring uninterrupted power transmission and guaranteeing the normal operation of the entire equipment.

[0049] Furthermore, such as Figure 1 and Figure 6As shown, in the first embodiment, the spindle assembly 2 includes a drive shaft 23, one end of which near the first housing 12 is connected to the second housing 13 via a turbine stator-rotor assembly 3. The end of the drive shaft 23 near the third housing 14 is used to connect a drill bit.

[0050] Furthermore, the end of the drive shaft 23 near the third housing 14 is hollow, and a through hole 221 is provided on the hollow structure, which connects the hollow structure to the mounting cavity 11.

[0051] Furthermore, such as Figures 7 to 9 As shown, in the second embodiment, the spindle assembly 2 includes an input shaft 21 and an output shaft 22.

[0052] Specifically, the input shaft 21 is connected to the second housing 13 via the turbine rotor assembly 3, one end of the output shaft 22 is connected to the input shaft 21 via a tapered thread structure 4, and the other end of the output shaft 22 is used to connect to the drill bit. The output shaft 22 has a hollow structure, and a through hole 221 is provided on the output shaft 22, so that the through hole 221 connects the hollow structure to the mounting cavity 11.

[0053] Similarly, the tail end of the input shaft 21 is connected to the head end of the output shaft 22. The tail end of the input shaft 21 can be a female tapered thread 41, and the head end of the output shaft 22 can be a male tapered thread 42. Of course, the tail end of the input shaft 21 can also be a male tapered thread 42, and the head end of the output shaft 22 can also be a female tapered thread 41. This embodiment is merely illustrative and is not intended to limit the scope. Those skilled in the art can make changes according to actual circumstances, as long as the same technical effect is achieved.

[0054] Furthermore, in an optional embodiment, a locking cap 24 is provided at one end of the spindle assembly 2 near the first housing 12, and the locking cap 24 is connected to the spindle assembly 2 via a tapered thread structure 4. Similarly, the tail of the locking cap 24 is connected to the head of the spindle assembly 2, and the tail of the locking cap 24 can be a female tapered thread 41, while the head of the spindle assembly 2 can be a male tapered thread 42. Of course, the tail of the locking cap 24 can also be a male tapered thread 42, and the head of the spindle assembly 2 can also be a female tapered thread 41. This embodiment is merely illustrative and is not intended to limit the scope. Those skilled in the art can make changes according to actual circumstances, as long as the same technical effect is achieved.

[0055] With this design, the end of the conventional input shaft 21 is mostly cylindrical, which easily generates eddies when drilling fluid flows through the end of the input shaft 21, thus losing hydraulic energy, and the rough surface is easily eroded and worn by the drilling fluid. In this embodiment, a locking cap 7 is additionally provided at the upstream end of the spindle assembly 2, which can further reduce the erosion and wear of the spindle assembly 2 by the drilling fluid and extend the service life of the spindle assembly 2.

[0056] Furthermore, in an alternative embodiment, the outer diameter of the locking cap 24 gradually increases along the flow direction of the drilling fluid.

[0057] With this configuration, the outer diameter of the locking cap 24 gradually increases along the flow direction of the drilling fluid, which reduces the flow resistance of the drilling fluid, allowing the drilling fluid to flow more smoothly to the turbine stator and rotor assembly 3, reducing the generated eddies, thereby improving the conversion efficiency of hydraulic energy to kinetic energy, and further reducing the wear of the locking cap 7 by the drilling fluid.

[0058] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A straight turbine drill bit, characterized in that, include: The housing assembly (1) is provided with a mounting cavity (11), the inlet of which is used to introduce drilling fluid; A spindle assembly (2) is disposed in the mounting cavity (11); one end of the spindle assembly (2) near the input port is connected to the housing assembly (1) via a turbine rotor assembly (3), and the other end of the spindle assembly (2) is used to connect a drill bit; The housing assembly (1) is composed of multiple sub-housing units connected in sequence; adjacent sub-housing units are connected by a tapered thread structure (4).

2. The straight turbine drill bit according to claim 1, characterized in that, The tapered thread structure (4) includes a female tapered thread (41) and a male tapered thread (42). One of the two adjacent sub-shells is provided with the female tapered thread (41), and the other is provided with the male tapered thread (42).

3. The straight turbine drill bit according to claim 1 or 2, characterized in that, Multiple housings include: A first housing (12) is provided at one end for introducing drilling fluid; The second housing (13) is connected at one end to the other end of the first housing (12) via the tapered thread structure (4); The third housing (14) is connected at one end to the other end of the second housing (13) via the tapered thread structure (4); After the first housing (12), the second housing (13) and the third housing (14) are connected, the mounting cavity (11) is formed inside.

4. The straight turbine drill bit according to claim 3, characterized in that, The turbine stator and rotor assembly (3) is provided in the second housing (13), and the end of the main shaft assembly (2) near the first housing (12) is connected to the second housing (13) through the turbine stator and rotor assembly (3).

5. The straight turbine drill bit according to claim 4, characterized in that, The second housing (13) is also provided with a radial straightening bearing (5), the outer side of which is connected to the second housing (13), and the inner side of which is connected to the spindle assembly (2).

6. The straight turbine drill bit according to claim 5, characterized in that, The second housing (13) is also provided with an axial thrust bearing (6), the outer side of which is connected to the second housing (13), and the inner side of which is connected to the spindle assembly (2).

7. The straight turbine drill bit according to any one of claims 4 to 6, characterized in that, The spindle assembly (2) includes: A drive shaft (23) is provided, with one end of the drive shaft (23) near the first housing (12) connected to the second housing (13) via the turbine rotor assembly (3); the end of the drive shaft (23) near the third housing (14) is used to connect a drill bit. The drive shaft (23) has a hollow structure at one end near the third housing (14), and a through hole (221) is provided on the hollow structure, which connects the hollow structure to the mounting cavity (11).

8. The straight turbine drill bit according to any one of claims 4 to 6, characterized in that, The spindle assembly (2) includes: The input shaft (21) is connected to the second housing (13) via the turbine rotor assembly (3); Output shaft (22); one end of the output shaft (22) is connected to the input shaft (21) through the tapered thread structure (4), and the other end of the output shaft (22) is used to connect the drill bit; the output shaft (22) has a hollow structure, and a through hole (221) is provided on the output shaft (22), and the through hole (221) connects the hollow structure to the mounting cavity (11).

9. The straight turbine drill bit according to any one of claims 4 to 6, characterized in that, The spindle assembly (2) is provided with a locking cap (24) at one end near the first housing (12), and the locking cap (24) is connected to the spindle assembly (2) through a tapered thread structure (4).

10. The straight turbine drill bit according to claim 9, characterized in that, Along the flow direction of the drilling fluid, the outer diameter of the locking cap (24) gradually increases.

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