A drilling coupling device with damping buffer and its usage method

Abstract

This invention discloses a drilling coupling device with a damping buffer and its usage method, belonging to the technical field of petroleum exploration equipment. A damping device is installed on the side wall of the casing, allowing compressed air in the piston chamber to be discharged through a damping hole during the piston's downward movement. This air discharge process is the buffering process, which greatly avoids damage to the drill string threads caused by collisions between the drill string joints during coupling. The process of venting gas through the damping device is equivalent to providing a gas spring for the piston, enabling a soft landing of the threads during drill string coupling, thus providing a buffering effect and ultimately protecting the drill string threads. This solves the problem in existing technologies where the lack of a buffering effect during coupling leads to damage to the drill string threads. This invention, from the perspective of the drill string coupling process, designs a coupling device with a damping buffer, improving coupling efficiency and greatly reducing the probability of thread damage during coupling, thereby increasing speed and efficiency.

Description

Technical Field

[0001] This invention belongs to the field of petroleum exploration equipment technology, specifically relating to a drilling coupling device with a damping buffer and its usage method. Background Technology

[0002] During drilling, the drill string alignment tool is one of the tools used to connect the drill string during drilling operations. It serves to align the drill string with the tools in the well, facilitating the alignment operation and reducing alignment time. Traditional alignment methods suffer from difficulties and low accuracy. Moreover, the weight of the drill string itself can cause damage to the internal and external threads and sealing surfaces during the alignment process. If this damage is not detected in time, it will increase the probability of thread and sealing surface failure in subsequent drilling operations. This can range from minor cracks in the drill string to serious leaks and breakage. Handling such accidents not only delays the project schedule but also consumes a lot of manpower, material resources, and financial resources.

[0003] Chinese patent CN2047711U discloses a guide coupling device for drilling operations. This drill pipe coupling device includes a guide bucket, a suspension body with an inner hook groove, a contact lever, and other components. However, this coupling device cannot effectively protect the sealing surface of the female thread and does not provide a buffering effect during coupling, which can lead to damage to the drill string threads. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, the present invention aims to provide a drilling coupling device with a damping buffer and a method of use, so as to solve the technical problem that the coupling device in the prior art cannot effectively protect the sealing surface of the female thread and does not play a buffering role during the coupling process, which will lead to damage to the drill thread.

[0005] To achieve the above objectives, the present invention employs the following technical solution:

[0006] A drilling coupling device with a damping buffer is provided, comprising: a damping device disposed on the side wall of the coupling housing, wherein a damping hole inside the damping device connects the piston chamber inside the housing to the outside of the housing.

[0007] Preferably, there are two housings, and the two housings are symmetrical to each other and can be closed or opened by joining or separating; the inner wall surface of the housing is provided with an inverted triangular step, and the triangular base of the inverted triangular step is in contact with the sealing surface of the drill bit female joint.

[0008] Preferably, the housing is further provided with a locking mechanism, which includes: a first connecting seat and a second connecting seat. The first connecting seat and the second connecting seat are respectively provided on the two housings. One end of the first connecting seat is hinged to a bolt, and the other end is provided with a threaded sleeve. The second connecting seat has a small opening groove near the first connecting seat where the bolt can be inserted, and a large opening groove at the other end that can accommodate the threaded sleeve. A locking surface is provided between the small opening groove and the large opening groove.

[0009] Preferably, the upper end of the housing is provided with a piston chamber, the upper end of the piston chamber is provided with a plurality of limit block mounting grooves, the lower end is provided with a piston chamber connecting hole for connecting the damping device, and the lower end is also provided with a limit hole for guiding.

[0010] Preferably, a guide bucket is provided above the housing, a bearing structure is provided in the middle of the inner side of the guide bucket, a piston that cooperates with the piston chamber is fixed at the lower end of the guide bucket, a number of limiting rods are provided at the lower end of the piston, and a return spring is provided on the outer sleeve of the limiting rod.

[0011] Preferably, a sealing groove is provided on the outer circumferential side of the piston, and a sealing ring is provided in the sealing groove.

[0012] Preferably, the damping device further includes: a valve sleeve; the valve sleeve is installed on the side wall of the housing, and a damping hole is provided through it along the axis of the valve sleeve. A plug is provided at one end of the damping hole near the side wall of the housing, and a cone is provided at the other end. The cone and the plug are connected by an adjusting rod, and the adjusting rod passes through the plug. A spring is also sleeved on the outside between the cone and the plug. An exhaust hole is provided at the end of the adjusting rod near the plug along the axis of the valve sleeve, and a connecting hole for connecting the damping hole and the exhaust hole is also provided in the radial direction of the adjusting rod.

[0013] Preferably, a damping device sealing ring is also provided between the housing and the valve sleeve.

[0014] Preferably, a handle is also provided on the outer wall of the housing.

[0015] This invention also discloses a method for using a drilling coupling device with a damping buffer, comprising the following steps:

[0016] The drill string begins to engage, and the air in the piston chamber is compressed under the influence of gravity;

[0017] Compressed gas is discharged to the external environment through the damping orifice in the damping device;

[0018] Under the buffering effect of gas, the drill string completes the coupling. Compared with the prior art, the present invention has the following beneficial effects:

[0019] This invention discloses a drilling coupling device with a damping buffer. A damping device is installed on the side wall of the housing, allowing compressed air in the piston chamber to escape through a damping hole during the piston's downward movement. This air escape from the damping hole constitutes the buffering process, significantly reducing the risk of drill string thread damage caused by drill string joint collisions during coupling. The process of venting gas through the damping device acts like a gas spring for the piston, enabling a soft landing of the threads during coupling and providing a buffering effect, ultimately protecting the drill string threads. This solves the technical problem in existing technologies where the lack of buffering during coupling leads to drill string thread damage. In drilling operations, drill string breakage and subsequent retrieval are frequent occurrences, resulting in time-consuming and costly operations. One cause of breakage is thread cracks or other damage. Therefore, this invention addresses the drilling string coupling process by designing a coupling device with a damping buffer, improving coupling efficiency and significantly reducing the probability of thread damage during coupling, thus increasing speed and efficiency.

[0020] Furthermore, the inner wall surface of the housing is provided with an inverted triangular step. The inverted triangular structure on the inner surface of the housing sits on the sealing surface of the female buckle, protecting the sealing surface of the female buckle end and solving the technical problem that the buckle device cannot effectively protect the sealing surface of the female buckle in the prior art.

[0021] Furthermore, the compressed gas in the piston chamber can act on the cone core surface through the damping orifice. When the pressure exceeds the thrust provided by the spring, the valve core starts to operate, and the compressed gas entering from the damping orifice can be discharged to the external environment through the connecting hole into the exhaust hole. This process provides a gas spring for the piston, enabling a soft landing of the threads during drill bit threading, thus providing a buffering effect and ultimately protecting the drill bit threads.

[0022] Furthermore, the drill string is aligned with the drill string in the well via the guide bucket on the upper part of the piston. After alignment, the drill string acts on the bearing surface on the upper part of the piston, driving the piston downward and downward. The limit rod connected to the piston ensures that the piston will not tilt during the downward movement and also ensures that the seals on the piston remain intact. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of the present invention in the closed state;

[0024] Figure 2 This is a schematic diagram of the structure of the present invention when the drill bit is engaged (halfway).

[0025] Figure 3 This is a schematic diagram of the assembly relationship between the piston and the housing in this invention;

[0026] Figure 4 This is a cross-sectional view of the damping device assembly in this invention;

[0027] Figure 5 This is a schematic diagram of the locking mechanism of the present invention.

[0028] In the diagram: 1-Guide bucket; 2-Shell; 3-Handle; 4-Damping device; 5-Bolt; 6-Threaded sleeve; 7-Second connecting seat; 8-First connecting seat; 9-Bearing structure; 10-Positioning block; 11-Drill tool male connector; 12-Inverted triangular step; 13-Drill tool female connector; 14-Drill tool female connector sealing surface; 15-Reset spring; 16-Piston; 17-Sealing groove and sealing ring; 18-Limiting rod; 19-Limiting hole; 20-Damping device mounting hole; 21-Piston chamber; 22-Limiting block mounting groove; 23-Piston chamber connecting hole; 24-Cone core; 25-Damping hole; 26-Damping device sealing ring; 27-Valve sleeve; 28-Block; 29-Adjusting rod; 30-Exhaust hole; 31-Connecting hole; 32-Spring; 33-Locking surface. Detailed Implementation

[0029] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. 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 should fall within the scope of protection of the present invention.

[0030] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0031] The present invention will now be described in further detail with reference to the accompanying drawings:

[0032] This invention discloses a drilling coupling device with a damping buffer. Unlike existing technologies, the coupling device of this invention has a damping device 4 installed on the side wall of the housing 2. The damping hole 25 inside the damping device 4 connects the piston chamber 21 inside the housing 2 with the external environment of the housing 2. During the piston's downward movement, the compressed air in the piston chamber 21 is discharged through the damping hole 25. This air discharge from the damping hole 25 is the buffering process, which greatly avoids damage to the drill string threads caused by collision of the drill string joints during coupling. The process of venting gas through the damping device 4 is equivalent to providing a gas spring for the piston, enabling a soft landing of the threads during drill string coupling, thus providing a buffering effect and ultimately protecting the drill string threads. This solves the technical problem in existing technologies where the lack of a buffering effect during coupling leads to damage to the drill string threads. In drilling operations, it is common for drill bits to break and fall into the well, resulting in time-consuming and costly retrieval operations. One of the causes of breakage is cracks or other damage to the threads. Therefore, this invention addresses the issue of drill bit coupling by designing a coupling device with a damping buffer to improve coupling efficiency and significantly reduce the probability of thread damage during coupling, thereby increasing speed and efficiency.

[0033] A method for using a drilling coupling with a damping buffer device includes the following steps:

[0034] S1: The drill string begins to engage, and the air in the piston chamber 21 is compressed under the action of gravity;

[0035] S2: Compressed gas is discharged to the external environment through the damping hole 25 in the damping device 4;

[0036] S3: Under the action of gas buffer, the drill string completes the connection.

[0037] As a preferred embodiment, there are two housings 2, which are symmetrical to each other and can be closed or opened by engaging or disengaging. The inner wall surface of the housing 2 is provided with an inverted triangular step 12, and the triangular base of the inverted triangular step 12 contacts the sealing surface 14 of the drill bit female connector. By having the inverted triangular step 12 on the inner surface of the housing 2 sit on the sealing surface of the female connector, the sealing surface of the female connector is protected, which solves the technical problem that the coupling device in the prior art cannot effectively protect the sealing surface of the female connector.

[0038] As a preferred embodiment, the damping device 4 further includes: a valve sleeve 27; the valve sleeve 27 is mounted on the side wall of the housing 2, and a damping hole 25 is provided through it along the axis. A plug 28 is provided at one end of the damping hole 25 near the side wall of the housing 2, and a conical core 24 is provided at the other end. The conical core 24 and the plug 28 are connected by an adjusting rod 29, and the adjusting rod 29 passes through the plug 28. A spring 32 is also sleeved on the outside between the conical core 24 and the plug 28. An exhaust hole 30 is provided along the axis at the end of the adjusting rod 29 near the plug 28, and a connecting hole 31 for connecting the damping hole 25 and the exhaust hole 30 is also provided radially. The compressed gas in the piston chamber 21 can act on the surface of the conical core 24 through the damping hole 25. When the pressure is greater than the thrust provided by the spring 32, the valve core starts to work, and the compressed gas entering from the damping hole 25 can enter the exhaust hole 30 through the connecting hole 31 and be discharged to the external environment. This process provides a gas spring for piston 16, enabling the threads to land softly during the drill bit engagement process, thus providing a buffer and ultimately protecting the drill bit threads.

[0039] As a preferred embodiment, a guide bucket 1 is provided above the housing 2, and a bearing structure 9 is provided in the middle of the inner side of the guide bucket 1. A piston 16 that cooperates with the piston chamber 21 is fixed at the lower end of the guide bucket 1. Several limiting rods 18 are provided at the lower end of the piston 16, and a return spring 15 is provided on the outer sleeve of the limiting rods 18. The drill string is aligned with the drill string in the well through the guide bucket on the upper part of the piston. After alignment, the drill string acts on the bearing surface on the upper part of the piston, driving the piston to move downward. The limiting rods connected to the piston ensure that the piston will not tilt during the downward movement, and also ensure that the seals on the piston are intact.

[0040] As a preferred option, see Figures 1-5 This invention provides a device that combines drill string alignment guidance and buffering functions, and a drilling alignment device with a damping buffer, which can reduce drill string alignment time and protect drill string threads and sealing surfaces. It includes a housing 2, a piston 16, a piston chamber 21, a sealing ring 17, a limiting rod 18, a return spring 15, a damping hole 25, a damping device, and a locking mechanism.

[0041] Two housings 2, the two housings are symmetrical, and the two housings are closed or open by joining or separating them;

[0042] Two pistons 16 are detachably connected to the piston chamber 21, and the pistons 16 can move downward or upward within the piston chamber 21;

[0043] The piston chamber 21 corresponding to the piston 16 is a space with a smooth inner wall that is axially machined on the housing 2. The piston chamber 21 provides stroke for the piston 16 when it moves up / down.

[0044] Four sealing rings are installed in sealing grooves on their respective pistons;

[0045] Six return springs 15, with a 60° interval between them, are connected to the housing 2 and the piston 16.

[0046] The limiting rod 18, which is a cylindrical rod, is corresponding to the reset spring 15 and is connected to the piston 16 and the limiting hole 19 on the housing 2.

[0047] Two damping holes 25 are provided, which are opened at the bottom of the piston chamber 21 and lead out from the outer surface of the housing 2;

[0048] The damping device 4 is connected to the damping hole 25, which extends from the outer surface of the housing 2.

[0049] A locking mechanism is symmetrically distributed on both sides of the housing 2. The locking mechanism is used to lock the two ends of the two housings together when they are closed.

[0050] Optionally, a connection method is provided for the housing 2 and the sealing surface of the drill joint female, wherein an inverted triangular step is provided on the inner surface of the housing, and the step surface of the inverted triangular step is vulcanized or inlaid with a rubber layer.

[0051] Optionally, for ease of handling, each of the two housings 2 is provided with a handle 3.

[0052] Optionally, the upper part of the piston 16 includes a guide bucket 1, which can be welded to the piston or pinned to it, and its taper is about 60°.

[0053] The bearing structure 9, where the guide bucket 1 is located, is in contact with the male thread sealing surface of the drill bit. The bearing structure 9 is vulcanized or inlaid with a rubber layer.

[0054] Optionally, a specific positioning is provided for the piston 16 and the housing 2. A circumferential positioning block 10 is provided on the outer edge of the top of the housing 2. The positioning block 10 is installed in the mounting groove 22 of the housing and connected by a pin.

[0055] Optionally, a connection method is provided for the piston 16 and the limiting rod 18, wherein the piston 16 has a circumferential connecting hole at the bottom and is connected by threads.

[0056] Optionally, a connection method is provided for the limiting rod 18 and the housing 2, wherein a circumferential connecting hole is provided at the bottom of the piston chamber to connect with the limiting rod 18.

[0057] Optionally, the damping device includes a valve sleeve 27, a valve core, and a plug 28;

[0058] The valve core includes a cone core 24, a spring 32, and an adjusting rod 29;

[0059] The valve sleeve 27 is provided with a damping hole 25, which allows the piston chamber 21 to communicate with the assembly hole of the valve core of the damping device 4.

[0060] The valve sleeve 27 is connected to the valve sleeve mating hole by a thread, thereby connecting the damping device 4 to the piston chamber communication hole 23.

[0061] The cone core 24 and the spring 32 are installed in the valve core assembly hole;

[0062] The adjusting rod 29 is connected to the cone core 24 by a thread, and the adjusting rod 29 is hollow with several small holes on its side, forming a one-way valve core that conducts unidirectionally from the piston chamber to the valve core.

[0063] The plug 28 is connected to the sleeve by a thread.

[0064] Optionally, a sealing method is provided for the installation of the damping device, wherein a sealing groove is provided on the surface of the counterbore of the damping hole, and a matching damping device sealing ring 26 is installed when the damping device is connected to the damping hole.

[0065] Optionally, a specific structure is provided for the locking mechanism, which includes four connecting seats, two bolts, and two threaded sleeves;

[0066] The four connecting seats are connected to the housing in pairs, and the two sets of connecting seats are symmetrically distributed.

[0067] The set of connectors includes a first connector 8 and a second connector 7;

[0068] One end of the bolt is hinged to the first connecting seat 8;

[0069] The second connecting seat 7 is provided with a small opening groove for the bolt 5 to be inserted;

[0070] The threaded sleeve 6 is provided with an external hexagonal structure;

[0071] The threaded sleeve 6 is connected to the bolt 5 by threads. Rotating the bolt 5 causes the bolt 5 to be inserted into the small opening groove, and the housing 2 is locked by screwing the threaded sleeve 6 against the second connecting seat 7.

[0072] like Figure 2As shown, the guide bucket 1 serves as a guide, enabling the drill bit male connector 11 and the female connector 13 to be aligned quickly; the bearing structure 9, whose surface is vulcanized or inlaid with a rubber layer, can protect the sealing surface of the drill bit male connector 11 from damage when it sits on the bearing structure 9.

[0073] like Figure 3 As shown, the piston body 16 is provided with a sealing groove, and a sealing ring 17 is provided in the sealing groove. After installation, the piston body 16 is connected to the piston chamber 21 and sealed by the sealing ring 17. When the drill bit is aligned, the drill bit male connector 11 sits on the bearing structure 9, and the bearing structure 9 transmits the weight of the drill bit downward. At the same time, under the action of the limiting rod 18 and the limiting hole 19, the piston body 16 is ensured not to tilt during the downward movement. The return spring 15 mainly plays the role of resetting the piston body 16 when it moves upward during operation.

[0074] like Figure 1 As shown, the piston body 16 is fixed to the housing 2 by screws using a positioning block 10, thereby limiting the maximum height of the piston's upward movement.

[0075] like Figure 2 As shown, the inner surface of the housing 2 is provided with the inverted triangular step 12, and its surface is vulcanized or inlaid with a rubber layer so that the housing 2 can sit on the sealing surface 14 of the drill bit female connector 13; at the same time, the two housings 2 are respectively connected to the handle 3.

[0076] like Figure 4 As shown, the damping device 4 includes a cone core 24, a spring 32, an adjusting rod 29, and a plug 28;

[0077] The cone core 24 is not a cone with an upper part and a cylinder with a lower part, but a certain part of the material is cut off from both sides to ensure that the piston chamber communication hole 23 and the exhaust hole 30 remain in a connected state when the drill bit male connector 11 and the female connector 13 are aligned.

[0078] The compressed gas in the piston chamber 21 can act on the surface of the cone core 24 through the damping hole. When the pressure is greater than the thrust provided by the spring 32, the valve core starts to work. The compressed gas entering from the damping hole 25 can enter the exhaust hole 30 through the connecting hole 31 and be discharged to the external environment.

[0079] like Figure 5 As shown, the locking device includes a first connecting seat 8, a second connecting seat 7, a bolt 5, a threaded sleeve 6, and a locking surface 33;

[0080] The bolt 5 is hinged to the first connecting seat 8 and threaded to the threaded sleeve 6. When the threaded sleeve 6 rotates to the vicinity of the locking surface 33 of the second connecting seat 7, the threaded sleeve 6 is rotated so that it can press against the locking surface 33 to achieve a locking effect.

[0081] In summary, when the two housings 2 are closed, they sit on the sealing surface 14 of the drill bit female connector 13 via the inverted triangular step 12. The two housings 2 are locked onto the drill bit female connector 13 by adjusting the threaded sleeve 6. During mating, the male connector 11 quickly aligns with the female connector 13 via the guide bucket 1 and sits on the bearing structure 9. The weight of the upper drill bit is transmitted downwards through the bearing structure 9, causing the piston body 16 to descend. The air in the piston chamber 21 is compressed. When the pressure acting on the cone core 24 is greater than the thrust provided by the spring 32, the air in the piston chamber 21 is discharged to the external environment through the damping hole 25 and then through the connecting hole 31 into the exhaust hole 30. Additionally, the exhaust speed of the damping device can be adjusted via the adjusting rod 29. This process of venting gas through the damping device is equivalent to providing a gas spring for the piston, enabling a soft landing of the threads during drill bit mating, providing a buffering effect, and ultimately protecting the drill bit threads.

[0082] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A coupling device with damping buffer for drilling, characterized in that, include: Damping device (4) is installed on the side wall of the housing (2) of the fastener. The damping hole (25) inside the damping device (4) connects the piston chamber (21) inside the housing (2) with the outside of the housing (2). The upper end of the housing (2) is provided with piston chamber (21). A guide bucket (1) is provided above the housing (2). A bearing structure (9) is provided in the middle of the inner side of the guide bucket (1). A piston (16) that cooperates with piston chamber (21) is fixed at the lower end of the guide bucket (1). The damping device (4) further includes: a valve sleeve (27); the valve sleeve (27) is installed on the side wall of the housing (2), and the valve sleeve (27) has a damping hole (25) through it along the axis. A plug (28) is provided at one end of the damping hole (25) near the side wall of the housing (2), and a cone core (24) is provided at the other end. The cone core (24) and the plug (28) are connected by an adjusting rod (29), and the adjusting rod (29) passes through the plug (28). A spring (32) is also sleeved on the outside between the cone core (24) and the plug (28). An exhaust hole (30) is provided at one end of the adjusting rod (29) near the plug (28) along the axis, and a connecting hole (31) is also provided in the radial direction for connecting the damping hole (25) and the exhaust hole (30).

2. A drilling coupling with a damping buffer device according to claim 1, characterized in that, There are two shells (2), and the two shells (2) are symmetrical to each other and can be closed or opened by joining or separating; the inner wall surface of the shell (2) is provided with an inverted triangular step (12), and the triangular base of the inverted triangular step (12) is in contact with the sealing surface (14) of the drill bit female connector.

3. A drilling coupling with a damping buffer device according to claim 2, characterized in that, The housing (2) is also provided with a locking mechanism, which includes a first connecting seat (8) and a second connecting seat (7). The first connecting seat (8) and the second connecting seat (7) are respectively provided on the two housings (2). One end of the bolt (5) is hinged on the first connecting seat (8), and a threaded sleeve (6) is provided on the other end of the bolt (5). A small opening groove is provided on the second connecting seat (7) near the first connecting seat (8), into which the bolt (5) can be inserted. A large opening groove is provided on the other end of the second connecting seat (7), which can accommodate the threaded sleeve (6). A locking surface (33) is provided between the small opening groove and the large opening groove.

4. A drilling coupling with a damping buffer device according to claim 1, characterized in that, The piston chamber (21) has several limit block mounting slots (22) at the upper end and a piston chamber connecting hole (23) for connecting the damping device (4) at the lower end. It also has a limit hole (19) for guiding.

5. A drilling coupling with a damping buffer device according to claim 4, characterized in that, The piston (16) has several limit rods (18) at its lower end, and a return spring (15) is provided on the outer sleeve of the limit rods (18).

6. A drilling coupling with a damping buffer device according to claim 5, characterized in that, The piston (16) has a sealing groove on its outer circumference, and a sealing ring (17) is provided in the sealing groove.

7. A drilling coupling with a damping buffer device according to claim 1, characterized in that, A damping device sealing ring (26) is also provided between the housing (2) and the valve sleeve (27).

8. A drilling coupling with a damping buffer device according to claim 1, characterized in that, The outer wall of the shell (2) is also provided with a handle (3).

9. A method of using a drilling coupling device with a damping buffer as described in any one of claims 1 to 8, characterized in that, Includes the following steps: As the drill string begins to engage, the air in the piston chamber (21) is compressed under the influence of gravity; Compressed gas is discharged to the external environment through the damping hole (25) in the damping device (4); With the gas buffering effect, the drill bit completes the connection.

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