Cam type locking and unlocking buffer device for plunger gas lifting operation

Abstract

The present application relates to the technical fields of plunger gas lift locking buffer device, and is a cam type locking and unlocking buffer device for plunger gas lift operation, which comprises a fishing head, a buffer spring seat, a buffer spring, a long bolt, and a flow tube, an inner ring table is arranged on the upper end of the flow tube, the lower part of the long bolt is located on the lower side of the inner ring table, the upper end of the long bolt is located above the flow tube, a shear pin seat is sleeved on the outer side of the upper part of the flow tube, the buffer spring seat is sleeved on the outer side of the upper part of the long bolt, the fishing head is fixedly installed on the outer side of the upper end of the long bolt through a set screw, and the buffer spring is arranged between the lower part of the buffer spring seat and the upper end of the shear pin seat. The present application has reasonable and compact structure, is convenient to use, adopts a blocked locking mechanism, is stable in stress, and through the setting of the locking mechanism, the position of the steel shear pin, and the position of the locking shaft, the locking shaft is located inside the locking mechanism when locking, so that the locking mechanism is stably pushed out, and the locking stability is ensured.

Description

Technical Field

[0001] This invention relates to the technical field of plunger air lift locking and buffering devices, and is a cam-type locking and unlocking buffering device for plunger air lift operation. Background Technology

[0002] In the plunger gas lift liquid discharge process, the process design requires the plunger to stop descending to a certain depth. Therefore, a blocking device must be installed at a certain position inside the tubing. At the same time, to prevent damage to the blocking device from the kinetic energy of the descent of the plunger, a buffer device is needed to absorb the downward kinetic energy of the plunger.

[0003] In order to ensure the normal operation of plunger gas lift liquid discharge production, the most commonly used method is to combine a two-tooth elastic locking device with a buffer device.

[0004] Chinese invention patent CN112523708A discloses a downhole locking device, characterized by comprising: an operating column; an operating head connected to one end of the operating column; a vortex generator disposed on the outer circumferential surface of the operating column and extending spirally around the operating column; a movable ring sleeved on the operating column; and at least two locking arms, each locking arm including a fixed end and a free end opposite to each other, the fixed end being connected to the movable ring, and the operating head being located between each of the locking arms; wherein, the operating head is configured to reciprocate between a locking position away from the movable ring and a standby position close to the movable ring; the operating head is configured such that when it is in the locking position, the free ends are far apart; and the free ends are configured such that when the operating head is in the standby position, they are close together.

[0005] The two-tooth locking device uses a slender, elastic arm with protruding locking teeth at the lower end to engage with the annular groove in the middle of the tubing coupling under elastic force. However, the slender rod mechanism itself is unstable under axial force. Furthermore, during the locking process, the locking teeth can easily slip past the coupling annular groove. When lowering the device for locking, friction between the locking teeth and the tubing wall can cause the tool string to quickly descend and shear the pin, but it may fail to engage with the inner conical surface of the locking teeth, resulting in locking failure. The tool string must then be removed from the wellhead, readjusted, and the locking operation repeated. Summary of the Invention

[0006] This invention provides a cam-type locking and unlocking buffer device for plunger air lift operation, which overcomes the shortcomings of the prior art. It can effectively solve the problems of unstable force on the slender rod structure of the two-tooth locking device and the accidental locking and shearing pin breakage during the lower locking time in the existing plunger air lift locking buffer device.

[0007] The technical solution of this invention is achieved through the following measures: A cam-type locking and unlocking buffer device for plunger gas lift operation includes a retrieval head, a buffer spring seat, a buffer spring, a long bolt, and a flow tube. An inner ring platform is provided on the inner side of the upper end of the flow tube. The lower part of the long bolt is located below the inner ring platform, and the upper end of the long bolt is located above the flow tube. A shear pin seat is fitted on the outer side of the upper part of the flow tube. A buffer spring seat is fitted on the outer side of the upper part of the long bolt. The retrieval head is fixedly installed on the outer side of the upper end of the long bolt by a set screw. A buffer spring is provided between the outer side of the lower part of the buffer spring seat and the upper end of the shear pin seat. The buffer spring is fitted on the outer side of the long bolt and the upper part of the flow tube. A locking mechanism that restricts the movement direction of the flow tube is fixedly installed on the outer side of the lower end of the shear pin seat. An outer sleeve is threadedly connected to the outer side of the locking mechanism. A first flow hole penetrating through the inner and outer sides is provided at the lower part of the flow tube. A second flow hole penetrating through the inner and outer sides is provided on the outer sleeve corresponding to the position above the first flow hole. A position... The upper conical sleeve inside the outer cylinder has two sets of first and second sliding grooves spaced vertically along its outer circumference. Steel and copper scissors are installed on the outer sleeve corresponding to each set of first sliding grooves. The inner ends of each steel and copper scissors are located at the upper and lower ends of the corresponding first sliding groove, respectively. The outer sleeve corresponding to the upper part of each second sliding groove has through-holes. Cam assemblies are connected to these holes via pins. The inner end of the cam assembly is located within the second sliding groove. A locking shaft with its lower end located below is threaded onto the inner side of the lower part of the upper conical sleeve. At least two locking mechanisms are spaced along the circumference on the outer side of the upper part of the locking shaft. The locking shaft can push the locking mechanisms to lock. A booster assembly is provided at the lower part of the locking shaft. The booster assembly can push the locking shaft upwards and release the locking mechanisms. An adjusting sleeve is fitted on the outer side of the lower part of the booster assembly. The lower end of the outer sleeve is located above the adjusting sleeve, and the inner side of the lower end of the outer sleeve is threadedly connected to the outer side of the lower part of the booster assembly.

[0008] The following are further optimizations and / or improvements to the above-mentioned technical solution:

[0009] The aforementioned cam assembly may include a cam, a pin, and a leaf spring. The cam is smaller at the top and larger at the bottom. The cam is rotatably connected to the inner side of the mounting hole of the outer sleeve via the pin. A leaf spring capable of expanding outward is fixedly installed on the outer side of the upper tapered sleeve at the upper end of the cam by screws. The lower inner side of the leaf spring abuts against the upper end of the cam, keeping the cam tilted and giving it a tendency to rotate outward from the top.

[0010] The aforementioned locking mechanism may include locking blocks and locking bosses. Four locking blocks are evenly distributed around the circumference of the upper outer side of the locking shaft. The upper outer side of the locking blocks is tapered, with the upper end being smaller than the lower end, and the lower outer side of the locking blocks is tapered, with the upper end being larger than the lower end. The upper outer side of the locking blocks matches the lower inner side of the upper tapered sleeve. Each locking block has a locking boss integrally provided on the middle outer side. A square locking hole is provided on the outer sleeve corresponding to the position of each locking boss, with the outer end of the locking boss located inside the locking hole. A tapered section and an extension section are integrally provided on the outer side of the locking shaft corresponding to the lower end of the locking block. The outer diameter of the tapered section is smaller at the top and larger at the bottom, and the outer diameter of the extension section is the same as the outer diameter of the lower end of the tapered section.

[0011] The aforementioned booster assembly may include a lower conical sleeve, a locking spring, and a locking spring seat. The lower conical sleeve is threadedly connected to the outer side of the lower end of the locking shaft. The inner side of the upper end of the lower conical sleeve is conical with a larger inner diameter at the top and a smaller inner diameter at the bottom. A locking spring seat is provided below the lower conical sleeve, with the lower outer side threadedly connected to the inner side of the lower end of the outer sleeve. A locking spring is provided between the locking spring seat and the lower conical sleeve.

[0012] The aforementioned locking mechanism may include a locking ring and a locking ring fixing seat. A first locking tooth is provided on the outer side of the flow pipe at the lower end of the shear pin seat. A locking ring is fitted on the outer side of the first locking tooth. A second locking tooth is provided on the inner side of the locking ring to engage with the first locking tooth for locking. The outer side of the locking ring is tapered, wider at the top and narrower at the bottom. The locking ring seat is located inside the locking ring fixing seat. The inner side of the upper end of the locking ring fixing seat is threadedly connected to the outer side of the lower end of the shear pin seat. The outer side of the lower end of the locking ring fixing seat is threadedly connected to the inner side of the upper end of the outer sleeve.

[0013] A sealing ring that fits onto the upper conical sleeve can be provided in the first groove corresponding to the upper and lower positions of the steel shear nail.

[0014] The present invention has a reasonable and compact structure and is easy to use. It uses a locking block to lock the oil pipe coupling. The locking boss is square, which has a better locking effect than the existing locking tooth structure. Furthermore, the upper conical sleeve contacts the upper conical surface of the locking block, which can prevent the locking block from bulging radially when the pipe string is descending, thus avoiding the problem of accidental shearing of the pin due to increased friction caused by the increased friction. Attached Figure Description

[0015] Appendix Figure 1 This is a schematic diagram of the front sectional view of the upper part of an embodiment of the present invention.

[0016] Appendix Figure 2 This is a schematic diagram of the front sectional view of the lower half of an embodiment of the present invention.

[0017] Appendix Figure 3 This is a partial sectional view of the cam located at the coupling of the present invention.

[0018] Appendix Figure 4 This is a schematic diagram of the main view of the cam and locking block after the copper shear nail is cut.

[0019] The codes in the attached diagram are as follows: 1 is the delivery device connecting pipe, 2 is the retrieval head, 3 is the set screw, 4 is the buffer spring seat, 5 is the buffer spring, 6 is the long bolt, 7 is the flow passage short pipe, 8 is the shear pin sleeve, 9 is the shear pin, 10 is the steel wire retaining ring, 11 is the shear pin seat, 12 is the locking ring, 13 is the locking ring fixing seat, 14 is the upper conical sleeve, 15 is the sealing ring, 16 is the steel shear pin, 17 is the copper shear pin, 18 is the screw, 19 is the leaf spring, 20 is the pin shaft, 21 is the cam, 22 is the outer sleeve, 23 is the locking block, 24 is the locking shaft, 25 is the lower conical sleeve, 26 is the locking spring, 27 is the locking spring seat, 28 is the adjusting spacer, 29 is the locking boss, 30 is the first flow passage hole, 31 is the second flow passage hole, 32 is the oil pipe, 33 is the coupling, 34 is the conical section, and 35 is the extension section. Detailed Implementation

[0020] The present invention is not limited to the following embodiments, and the specific implementation can be determined according to the technical solution of the present invention and the actual situation.

[0021] In this invention, for ease of description, the description of the relative positions of the components is based on the appendix to the specification. Figure 1 The layout is described using a diagrammatic method, such as front, back, top, bottom, left, right, etc. The positional relationships are determined based on the layout direction of the attached diagram in the instruction manual.

[0022] The present invention will be further described below with reference to embodiments and accompanying drawings:

[0023] Example 1: As shown in the attached document Figure 1 , 2As shown in Figures 3 and 4, the cam 21 type locking and unlocking buffer device for the plunger air lift operation includes a retrieval head 2, a buffer spring seat 4, a buffer spring 5, a long bolt 6, and a flow pipe. An inner ring platform is provided on the inner side of the upper end of the flow pipe. The lower part of the long bolt 6 is located below the inner ring platform, and the upper end of the long bolt 6 is located above the flow pipe. A shear pin seat 11 is fitted onto the outer side of the upper part of the flow pipe. The buffer spring seat 4 is fitted onto the outer side of the upper part of the long bolt 6. The retrieval head 2 is fixedly installed on the outer side of the upper end of the long bolt 6 by a set screw 3. The lower outer side of the buffer spring seat 4... A buffer spring 5 is provided between the upper end of the shear pin seat 11 and the long bolt 6 and the upper outer side of the flow tube. A locking mechanism that can restrict the movement direction of the flow tube is fixedly installed on the lower outer side of the shear pin seat 11. The outer side of the locking mechanism is threadedly connected to the outer sleeve 22. The lower part of the flow tube is provided with a first flow hole 30 that is open inside and out. The outer sleeve 22, which is located above the first flow hole 30, is provided with a second flow hole 31 that is open inside and out. The lower outer side of the flow tube is threadedly connected to an upper conical sleeve 14 located inside the outer cylinder. The outer side of the upper conical sleeve 14 has two sets of first and second sliding grooves spaced vertically along its circumference. Corresponding to the position of each set of first sliding grooves, the outer sleeve 22 is fitted with vertically spaced steel shear studs 16 and copper shear studs 17. The inner ends of each set of steel shear studs 16 and copper shear studs 17 are located at the upper and lower ends of the corresponding first sliding groove, respectively. The outer sleeve 22 corresponding to the upper position of each second sliding groove has through-hole mounting holes. Each mounting hole is connected to a cam assembly via a pin 20. The inner end of the cam assembly is located within the second sliding groove. The lower inner side of sleeve 14 is threadedly connected to a locking shaft 24 with its lower end located below it. At least two locking mechanisms are circumferentially spaced on the upper outer side of the locking shaft 24. The locking shaft 24 can push the locking mechanisms to lock. A booster component is provided at the lower part of the locking shaft 24. The booster component can push the locking shaft 24 to move upward and can release the locking mechanisms. An adjustment spacer 28 is fitted on the lower outer side of the booster component. The lower end of the outer sleeve 22 is located at the upper end of the adjustment spacer 28. The inner side of the lower end of the outer sleeve 22 is threadedly connected to the lower outer side of the booster component.

[0024] Before going down into the well, connect the delivery device connecting pipe 1 to the present invention. Specifically, the connection method is as follows: put the shear pin 9 sheath 8 and the wire retaining ring 10 on the delivery device connecting pipe 1, then put the delivery device connecting pipe 1 on the shear pin 9 fixing seat, push the shear pin 9 sheath 8 and the wire retaining ring 10 open, align the delivery device connecting pipe 1 with the small hole on the shear pin 9 fixing seat, insert the shear pin 9, push the shear pin 9 sheath 8 again to block the shear pin 9 and prevent it from falling out, and use the wire retaining ring 10 to restrict the movement of the shear pin 9 sheath 8.

[0025] Locking Process: During well entry, the wireline tool is connected to the upper end of the delivery pipe 1 via threads. As the tool string descends, the inner wall of the tubing 32 presses against the cam assembly, causing it to swing slightly at a certain angle. Simultaneously, the copper shear pin 17 prevents the upper conical sleeve 14 from moving upward. The outer conical surface of the upper end of the locking block 23 is positioned within the inner conical surface of the upper conical sleeve 14, and its radial movement is restricted by the upper conical sleeve 14, preventing the locking block 23 from extending outward and ensuring smooth well entry. When the tool string reaches below the tubing coupling 33 to be locked, the tool string is lifted. During the upward movement, the cam assembly, after passing the coupling 33, pushes the upper conical sleeve 14 upward, shearing the copper shear pin 17. The upper conical sleeve 14 and the lower booster assembly together drive the locking shaft 24 to move upward relative to the outer sleeve 22. 14. Gradually release the restriction on the extension of the locking mechanism. The locking shaft 24 pushes the locking mechanism to extend and lock. When the locking mechanism moves with the tool string to the annular groove in the middle of the coupling 33, the locking mechanism extends and locks in the annular groove at the coupling 33. The steel shear pin 16 restricts the upward movement of the upper cone sleeve 14, so that the locking shaft 24 can hold the locking block 23 when the locking mechanism is locked. The locking mechanism ensures that the flow pipe can only move upward and not fall, preventing the locking block from loosening and ensuring the locking mechanism is locked stably. After locking, remove the delivery device connecting pipe 1. The upward movement of the tool string is blocked. Through the action of the shocker, the delivery device shear pin 9 is cut off. The tool string connected to the delivery device connecting pipe 1 continues to move upward and is pulled out of the well. It can then enter the gas lift and liquid discharge working state.

[0026] Air-lift discharge operation: Because the long bolt 6 blocks the upper part of the pipe string, the first flow hole 30 and the second flow pipe ensure the internal and external communication of the pipe string, and the liquid has an internal and external communication channel to ensure the liquid discharge. When the plunger falls, the retrieval head 2 bears the impact force of the plunger, which is transmitted to the shear pin 9 fixing seat through the buffer spring 5, and then to the locking ring fixing seat 13 to the locking sleeve 22, and then to the locking block. At the same time, the long bolt 6 moves down along the inner hole of the flow short pipe 7 to prevent the buffer spring 5 from becoming unstable. The retrieval head 2 needs to withstand the impact force, so it is made of high-strength material and the head is quenched to a hardness of HRC55~60.

[0027] Retrieval process: The steel wire retrieval tool is lowered and grabs the retrieval head 2. Through the action of the shock absorber, the upper cone sleeve 14 cuts the steel shear nail 16, which drives the locking shaft 24 and the booster assembly to move upward. The locking shaft 24 passes through the locking mechanism, and the booster assembly moves upward to squeeze the locking mechanism to retract inward, realizing reliable release. The tool string can be smoothly lifted out, realizing the release function. The device is then removed from the wellbore.

[0028] The present invention adopts a segmented locking mechanism, which is stable under force. By setting a locking mechanism and steel shear nails 16 to restrict the position of the upper conical sleeve 14 and locking shaft 24, the locking shaft 24 is ensured to be located inside the locking mechanism when locking, thereby stably pushing the locking mechanism out and ensuring locking stability.

[0029] The cam-type locking and unlocking buffer device for the above-mentioned plunger air lift operation can be further optimized and / or improved according to actual needs:

[0030] Example 2: As shown in the attached document Figure 1 , 2 As shown in Figures 3 and 4, the cam assembly includes a cam 21, a pin 20, and a leaf spring 19. The cam 21 is smaller at the top and larger at the bottom. The cam 21 is rotatably connected to the inner side of the mounting hole of the outer sleeve 22 through the pin 20. The upper tapered sleeve 14 at the upper end of the cam 21 is fixedly installed with a leaf spring 19 that can expand outward by screws 18. The lower inner side of the leaf spring 19 abuts against the upper end of the cam 21, so that the cam 21 is kept tilted and has a tendency to rotate outward from the top.

[0031] As the tubing descends, cam 21 is tilted and held in place by leaf spring 19, which restricts the rotation direction of cam 21 and gives it a tendency to rotate outwards. The wall of oil pipe 32 generates an upward frictional force on the upper part of cam 21, causing cam 21 to oscillate slightly. When cam 21 passes coupling 33, the frictional force disappears, the outer diameter of oil pipe 32 expands, and cam 21 itself has a tendency to rotate outwards. The upper part of cam 21 rotates into the annular groove at coupling 33. As the tubing continues to descend, cam 21 returns to its original position. When the tubing ascends and passes coupling 33, the upper part of cam 21... When the tube string continues to move upward, the lower end of the oil pipe 32 pushes the upper small end of the cam 21 to rotate downward, and the lower large end of the cam 21 to rotate upward. The large end of the cam 21 pushes the upper cone sleeve 14 to move upward and cut the copper shear pin 17, thus releasing the restriction on the upward movement of the lower booster assembly. At the same time, the flow pipe moves upward. During the upward movement of the flow pipe, there is a gap between the inner ring platform on the inner side of the upper end and the lower part of the long bolt 6. Under the force of the extension of the buffer spring 5, the long bolt 6 is pulled upward, and the buffer spring 5 returns to its natural length, which facilitates the buffering effect when the plunger moves downward.

[0032] Example 3: As shown in the attached document Figure 2 , 4 As shown, the locking mechanism includes locking blocks 23 and locking bosses 29. Four locking blocks 23 are evenly distributed around the circumference of the upper outer side of the locking shaft 24. The upper outer side of the locking blocks 23 is tapered with a smaller upper end and a larger lower end, and the lower outer side of the locking blocks 23 is tapered with a larger upper end and a smaller lower end. The upper outer side of the locking blocks 23 matches the lower inner side of the upper tapered sleeve 14. Each locking block 23 has a locking boss 29 integrally provided on the middle outer side. The outer sleeve 22 corresponding to the position of each locking boss 29 has a square locking hole that runs through the inside and outside. The outer end of the locking boss 29 is located in the locking hole. The outer side of the locking shaft 24 corresponding to the lower end of the locking blocks 23 has a tapered section 34 and an extension section 35 integrally provided. The outer diameter of the tapered section 34 is smaller at the top and larger at the bottom, and the outer diameter of the extension section 35 is the same as the outer diameter of the lower end of the tapered section 34.

[0033] During the locking process, as the tool string is lifted, the upper conical sleeve 14 and the lower pusher assembly together move the locking shaft 24 upward relative to the outer sleeve 22. The upper conical sleeve 14 gradually releases the restriction on the extension of the locking block 23, and the outer conical surface of the conical section 34 on the locking shaft 24 forces the locking block 23 to extend outward. When the locking block 23 moves with the tool string to the annular groove in the middle of the coupling 33, the locking boss 29 extends out and locks into the annular groove at the coupling 33, while the steel shear pin 16 restricts the upper conical sleeve. The upward movement of the locking shaft 24 causes the extension 35 of the locking shaft 24 to press against the locking block 23, thus achieving locking, and then locking through the locking mechanism. The unlocking process involves the upper conical sleeve 14 shearing the steel shear nails 16 through the action of the shock absorber, causing the locking shaft 24 and the booster assembly to move upwards. The extension 35 of the locking shaft 24 passes through the locking block 23, and the upward movement of the booster assembly compresses the locking block 23, causing the locking protrusion 29 to retract inwards, achieving reliable unlocking. During downhole operation, the conical surface on the upper outer side of the locking block 23 is located inside the lower end of the upper conical sleeve 14, restricting the radial movement of the locking block 23. This prevents the locking block 23 from accidentally protruding and rubbing against the tubing wall 32, thus avoiding shear nail breakage and ensuring smooth operation.

[0034] Example 4: As shown in the appendix Figure 2 , 4 As shown, the booster assembly includes a lower conical sleeve 25, a locking spring 26, and a locking spring seat 27. The lower outer side of the locking shaft 24 is threadedly connected to the lower conical sleeve 25. The inner side of the upper end of the lower conical sleeve 25 is conical with a larger inner diameter at the top and a smaller inner diameter at the bottom. The lower outer side of the lower conical sleeve 25 is threadedly connected to the inner side of the lower end of the outer sleeve 22. A locking spring 26 is provided between the locking spring seat 27 and the lower conical sleeve 25.

[0035] After the copper shear pin 17 is cut, the locking spring 26 extends upward to push the locking shaft 24 and the upper conical sleeve 14 upward, causing the conical section 34 and the extension section 35 of the locking shaft 24 to push the locking block 23 outward to lock it. When it is necessary to remove the pipe string, when the pipe string is lifted, the outer conical surface of the lower end of the locking block 23 is inserted into the inner conical surface of the upper end of the lower conical sleeve 25. When the lower conical sleeve 25 is lifted, it will squeeze the locking block 23 inward to retract, thereby releasing the lock and removing the pipe string.

[0036] Example 5: As shown in the attached document Figure 1 As shown, the locking mechanism includes a locking ring 12 and a locking ring fixing seat 13. A first locking tooth is provided on the outer side of the flow pipe at the lower end of the shear pin seat 11. The locking ring 12 is fitted on the outer side of the first locking tooth. A second locking tooth is provided on the inner side of the locking ring 12 to lock with the first locking tooth. The outer side of the locking ring 12 is tapered, with a larger upper part and a smaller lower part. The locking ring 12 is seated in the locking ring fixing seat 13. The inner side of the upper end of the locking ring fixing seat 13 is threadedly connected to the outer side of the lower end of the shear pin seat 11. The outer side of the lower end of the locking ring fixing seat 13 is threadedly connected to the inner side of the upper end of the outer sleeve 22.

[0037] The locking ring 12 is made of spring steel and has a thin-walled sleeve with teeth on the outer conical surface. It holds the outer diameter annular groove teeth of the flow short pipe 7 tightly. The outer conical surface sits on the inner conical surface of the locking ring fixing seat 13 to prevent the flow short pipe 7 from moving downward and causing locking failure.

[0038] Example 6: As attached Figure 2 , 3 As shown in Figure 4, sealing rings 15 are provided in the first sliding grooves corresponding to the upper and lower positions of the steel scissors 16, which are fitted onto the upper conical sleeve 14. After the copper scissors 17 is cut, the locking spring 26 still has a certain amount of stored energy to generate an impact force, and the sealing rings 15 can buffer the impact and prevent the steel scissors 16 from being cut off at this time.

[0039] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Unnecessary technical features can be added or removed according to actual needs to meet the needs of different situations.

Claims

1. A cam-type locking and unlocking buffer device for plunger air lift operation, characterized in that... The system includes a retrieval head, a buffer spring seat, a buffer spring, a long bolt, and a flow tube. An inner ring platform is located on the inner side of the upper end of the flow tube. The lower part of the long bolt is located below the inner ring platform, and the upper end of the long bolt is located above the flow tube. A shear pin seat is fitted onto the outer side of the upper part of the flow tube, and a buffer spring seat is fitted onto the outer side of the upper part of the long bolt. The retrieval head is fixedly installed on the outer side of the upper end of the long bolt by a set screw. A buffer spring is located between the outer side of the lower part of the buffer spring seat and the upper end of the shear pin seat. The buffer spring is fitted onto the outer side of the upper part of the long bolt and the flow tube. A locking mechanism that restricts the movement direction of the flow tube is fixedly installed on the outer side of the lower end of the shear pin seat. An outer sleeve is threadedly connected to the outer side of the locking mechanism. A first flow hole, penetrating both the inner and outer sides, is located at the lower part of the flow tube. A second flow hole, penetrating both the inner and outer sides, is located on the outer sleeve above the first flow hole. An upper conical sleeve, located inside the outer cylinder, is threadedly connected to the outer side of the lower end of the flow tube. Two sets of... The first and second slides are spaced apart vertically. For each set of first slides, steel and copper scissors are installed on the outer sleeve at intervals. The inner ends of each steel and copper scissors are located at the upper and lower ends of the corresponding first slide. For each second slide, the outer sleeve at the upper position has through-holes. A cam assembly is connected to each mounting hole via a pin. The inner end of the cam assembly is located within the second slide. A locking shaft with its lower end located below is threaded onto the inner side of the lower part of the upper tapered sleeve. At least two locking mechanisms are circumferentially spaced on the outer side of the upper part of the locking shaft. The locking shaft can push the locking mechanisms to lock. A pusher assembly is located at the lower part of the locking shaft. The pusher assembly can push the locking shaft upwards and release the locking mechanisms. An adjusting sleeve is fitted on the outer side of the lower part of the pusher assembly. The lower end of the outer sleeve is located above the adjusting sleeve, and the inner side of the lower end of the outer sleeve is threadedly connected to the outer side of the lower part of the pusher assembly.

2. The cam-type locking and unlocking buffer device for plunger air lift operation according to claim 1, characterized in that... The cam assembly includes a cam, a pin, and a leaf spring. The cam is smaller at the top and larger at the bottom. The cam is rotatably connected to the inner side of the mounting hole of the outer sleeve through the pin. A leaf spring that can expand outward is fixedly installed on the outer side of the upper tapered sleeve at the upper end of the cam by screws. The lower side of the inner side of the leaf spring abuts against the upper end of the cam, so that the cam is kept tilted and has a tendency to rotate outward at the top.

3. The cam-type locking and unlocking buffer device for plunger air lift operation according to claim 1 or 2, characterized in that... The locking mechanism includes locking blocks and locking bosses. Four locking blocks are evenly distributed around the circumference of the upper outer side of the locking shaft. The upper outer side of the locking blocks is tapered, with the upper end being smaller than the lower end, and the lower outer side of the locking blocks is tapered, with the upper end being larger than the lower end. The upper outer side of the locking blocks matches the lower inner side of the upper tapered sleeve. Each locking block has a locking boss integrally provided on the middle outer side. A square locking hole is provided on the outer sleeve corresponding to the position of each locking boss, with the outer end of the locking boss located inside the locking hole. The locking shaft corresponding to the lower position of the locking block has an integrally provided tapered section and an extension section. The outer diameter of the tapered section is smaller at the top and larger at the bottom, and the outer diameter of the extension section is the same as the outer diameter of the lower end of the tapered section.

4. The cam-type locking and unlocking buffer device for plunger air lift operation according to claim 1 or 2, characterized in that... The booster assembly includes a lower conical sleeve, a locking spring, and a locking spring seat. The lower conical sleeve is threaded to the outer side of the lower end of the locking shaft. The inner side of the upper end of the lower conical sleeve is conical with a larger inner diameter at the top and a smaller inner diameter at the bottom. A locking spring seat is provided below the lower conical sleeve, with the lower outer side threaded to the inner side of the lower end of the outer sleeve. A locking spring is provided between the locking spring seat and the lower conical sleeve.

5. The cam-type locking and unlocking buffer device for plunger air lift operation according to claim 3, characterized in that... The booster assembly includes a lower conical sleeve, a locking spring, and a locking spring seat. The lower conical sleeve is threaded to the outer side of the lower end of the locking shaft. The inner side of the upper end of the lower conical sleeve is conical with a larger inner diameter at the top and a smaller inner diameter at the bottom. A locking spring seat is provided below the lower conical sleeve, with the lower outer side threaded to the inner side of the lower end of the outer sleeve. A locking spring is provided between the locking spring seat and the lower conical sleeve.

6. The cam-type locking and unlocking buffer device for plunger air lift operation according to claim 1, 2, or 5, characterized in that... The locking mechanism includes a locking ring and a locking ring fixing seat. The outer side of the flow pipe at the lower end of the shear pin seat is provided with a first locking tooth, and the locking ring is fitted on the outer side of the first locking tooth. The inner side of the locking ring is provided with a second locking tooth that cooperates with the first locking tooth to lock it. The outer side of the locking ring is tapered, with a larger upper part and a smaller lower part. The locking ring seat is inside the locking ring fixing seat. The inner side of the upper end of the locking ring fixing seat is threadedly connected to the outer side of the lower end of the shear pin seat. The outer side of the lower end of the locking ring fixing seat is threadedly connected to the inner side of the upper end of the outer sleeve.

7. The cam-type locking and unlocking buffer device for plunger air lift operation according to claim 3, characterized in that... The locking mechanism includes a locking ring and a locking ring fixing seat. The outer side of the flow pipe at the lower end of the shear pin seat is provided with a first locking tooth, and the locking ring is fitted on the outer side of the first locking tooth. The inner side of the locking ring is provided with a second locking tooth that cooperates with the first locking tooth to lock it. The outer side of the locking ring is tapered, with a larger upper part and a smaller lower part. The locking ring seat is inside the locking ring fixing seat. The inner side of the upper end of the locking ring fixing seat is threadedly connected to the outer side of the lower end of the shear pin seat. The outer side of the lower end of the locking ring fixing seat is threadedly connected to the inner side of the upper end of the outer sleeve.

8. The cam-type locking and unlocking buffer device for plunger air lift operation according to claim 4, characterized in that... The locking mechanism includes a locking ring and a locking ring fixing seat. The outer side of the flow pipe at the lower end of the shear pin seat is provided with a first locking tooth, and the locking ring is fitted on the outer side of the first locking tooth. The inner side of the locking ring is provided with a second locking tooth that cooperates with the first locking tooth to lock it. The outer side of the locking ring is tapered, with a larger upper part and a smaller lower part. The locking ring seat is inside the locking ring fixing seat. The inner side of the upper end of the locking ring fixing seat is threadedly connected to the outer side of the lower end of the shear pin seat. The outer side of the lower end of the locking ring fixing seat is threadedly connected to the inner side of the upper end of the outer sleeve.

9. The cam-type locking and unlocking buffer device for plunger air lift operation according to claim 1, 2, 5, 7, or 8, characterized in that... A sealing ring is provided in the first groove corresponding to the upper and lower positions of the steel shear nail, which is fitted onto the upper conical sleeve.

10. The cam-type locking and unlocking buffer device for plunger air lift operation according to claim 6, characterized in that... A sealing ring is provided in the first groove corresponding to the upper and lower positions of the steel shear nail, which is fitted onto the upper conical sleeve.

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