A wellhead clamping device for a pneumatic sucker rod slip

Abstract

The present invention relates to the field of oil and gas drilling and workover equipment, and provides a wellhead clamping device for a sucker rod pneumatic slip. The device includes a support base, a pneumatic assembly and a slip. The support base is composed of a support rod, a top plate and a base, with a communication hole in the middle, and the slips and the support rods are staggered inside. The upper movable plate is driven by a cylinder, and the opening and closing of the slips are realized by a connecting rod mechanism and a four-point parallel mechanism. The annular hoop below the slip can enhance the clamping effect and achieve gravity self-locking. Compared with the prior art, it has remarkable advantages. For example, the four-point parallel mechanism ensures synchronous and stable clamping of the slips, avoiding damage to the sucker rod; the double-stroke design improves the clamping reliability; the modular design of the slip blocks is convenient for replacement and maintenance; the arc-shaped groove increases the clamping force and reduces rod body damage; the design of the upper and lower slips can prevent failure or damage caused by the clamping and centralizing block, and is applicable to sucker rods of different diameters, effectively solving many problems of the existing wellhead clamping technology.

Description

Technical Field

[0001] The present invention relates to the field of oil and gas drilling and workover equipment, and particularly to a wellhead clamping device for a sucker rod pneumatic slip. Background Art

[0002] In oilfield exploitation operations, the wellhead device is crucial for the clamping operation of sucker rods. However, there are many problems in the existing wellhead clamping technologies. When dealing with sucker rods with centralizers (diameter about 62 mm) and a rod body diameter of 16 - 25 mm, it is difficult to meet the actual requirements.

[0003] On the one hand, the currently used clamping blocks have a large radial displacement problem during the clamping process. When performing radial movement, the slips are likely to clamp the centralizer, which may damage the device and the centralizer. On the other hand, when the slips move axially, once they encounter the centralizer, there is also a risk of damaging the device and the centralizer, seriously affecting the safety of wellhead operations and the reliability of the device.

[0004] In addition, the existing technologies cannot achieve effective selective avoidance according to the characteristics of different components of the sucker rod, and cannot flexibly handle different situations, resulting in low operation efficiency and easy occurrence of equipment failures. Therefore, in actual operations, there is an urgent need for a new wellhead clamping technology.

[0005] Therefore, it is necessary to provide a wellhead clamping device for a sucker rod pneumatic slip to solve the above technical problems. Summary of the Invention

[0006] In order to overcome the above problems, the present invention provides a wellhead clamping device for a sucker rod pneumatic slip.

[0007] The technical implementation solution of the present invention is a wellhead clamping device for a sucker rod pneumatic slip, which includes a support base, a pneumatic component, and a slip. The support base includes a support rod, a top plate, and a base, and a communication hole is provided in the middle of the support base; slips are provided in the support base and are distributed along the circumference with the communication hole as the center. At least two support rods are fixed to the inner circumference of the support base and are staggered with the slips. Springs are sleeved on the spaced support rods, and a lower movable plate is sleeved on the support rod at the upper end of the spring; an upper movable plate is installed in the support base above the lower movable plate, and a cylinder is installed in the support base. The power output end of the cylinder is connected to the upper movable plate and drives the upper movable plate to move up and down; the slip includes a slip end and a slip handle; the slip handle is horizontally fixed on the outer side of the upper end of the slip end; a hinge point I is provided at the inner end of the slip handle, and a triple plate is hinged on the hinge point I. The other ends of the triple plate are respectively provided with a main support hinge point and an inner push hinge point, and the inner push hinge point is located below and outside the main support hinge point; the main support hinge point is installed on the hinge seat on the inner side of the bottom of the lower movable plate through a pin shaft; a connecting rod II is hinged between the inner push hinge point and the upper movable plate; a hinge point II is provided at the outer end of the slip handle, and a connecting rod I is hinged on the hinge point II. The other end of the connecting rod I is provided with an auxiliary support hinge point, and the auxiliary support hinge point is installed on the hinge seat on the outer side of the bottom of the lower movable plate through a pin shaft; a four-point parallel mechanism is formed between the hinge point I, the main support hinge point, the hinge point II, and the auxiliary support hinge point.

[0008] Preferably, an annular hoop is provided below the slip. A circular through hole is provided at the center of the annular hoop. A chamfer is provided at the top end of the circular through hole of the annular hoop, and the annular hoop is fixedly connected to the center of the base.

[0009] Preferably, upper movable plate sleeves are evenly distributed on the circumference of the upper movable plate, and the upper movable plate sleeves are fixedly connected to the upper movable plate; lower movable plate sleeves are evenly distributed on the circumference of the lower movable plate, and the lower movable plate sleeves are fixedly connected to the lower movable plate; both the upper movable plate sleeves and the lower movable plate sleeves are sleeved on the support rod, and the bottom end of the upper movable plate sleeve passes through the lower movable plate, and the top end of the lower movable plate sleeve passes through the upper movable plate.

[0010] Preferably, the auxiliary support hinge point on the connecting rod I is fixedly hinged to the bottom of the lower movable plate, the connecting rod II passes through the lower movable plate and is fixedly hinged to the bottom of the upper movable plate, the hinge point II of the connecting rod I is fixedly hinged to the left end of the slip holder, the other end of the connecting rod II is hinged to the inner push hinge point of the triple plate, the main support hinge point of the triple plate is hinged to the lower movable plate, the hinge point I at the lower end of the triple plate is fixedly hinged to the right end of the slip holder, the slip holder is hollow, and a slip block is bolted to the rightmost end of the slip holder.

[0011] Preferably, the pneumatic component includes a cylinder and a cylinder fixing plate; the telescopic end of the cylinder is fixedly connected to the cylinder fixing plate, and the cylinder fixing plate is fixedly connected to the side of the upper movable plate close to the lower movable plate.

[0012] Preferably, the cylinder is located between the support rods in the support base.

[0013] Preferably, circular through holes with the same diameter as the circular through hole of the annular hoop are provided at the centers of the top plate, the base, the upper movable plate, and the lower movable plate.

[0014] Preferably, the side of the slip holder above the annular hoop, which is away from the slip block, is provided with an inclined surface inclined towards the slip block, the bottom of the slip block is provided with an upward inclined surface, and the surface of the slip block away from the triple plate is provided with an arc-shaped groove.

[0015] Preferably, the centers of the three slips above the annular hoop coincide exactly with the center of the annular hoop.

[0016] Preferably, a wellhead clamping device for a sucker rod pneumatic slip includes two sucker rod pneumatic slips. The two sucker rod pneumatic slips are installed up and down together, and the distance between the two sucker rod pneumatic slips is greater than or equal to the length of the upper centralizer on the sucker rod.

[0017] Compared with the prior art, the present invention has the following advantages:

[0018] 1. Sucker rod pneumatic slip

[0019] Through the four-point parallel mechanism formed by hinge point one, the main support hinge point, hinge point two, and the auxiliary support hinge point, the synchronism and stability of the slip during the clamping process are ensured. This design enables the slip to be evenly stressed, avoiding damage to the sucker rod caused by uneven stress; in the first stroke, the slip block fits with the sucker rod to complete the preliminary clamping; in the second stroke, the slip block is further pressed down, generating an inward component force through the chamfer inclined surface of the annular hoop, enhancing the clamping effect and achieving gravity self-locking. This double-stroke design improves the reliability and safety of clamping; the slip block is fixed to the slip holder by bolts, which is convenient for replacement and maintenance. This modular design reduces the maintenance cost and improves the durability of the device; the arc-shaped groove on the slip block increases the contact area with the sucker rod, improves the clamping force, and reduces the damage to the surface of the sucker rod during the clamping process.

[0020] 2. Wellhead clamping device

[0021] Two pneumatic slips for sucker rods are adopted, top and bottom, to ensure that at least one set of slips can avoid the centralizer on the sucker rod and directly clamp on the rod body. This design effectively prevents the clamping failure or equipment damage that may be caused when a single slip encounters a centralizer; the chamfered slope of the annular hoop generates an inward component force when the slip presses down, enhancing the clamping effect and achieving gravity self-locking, improving the stability and reliability of the clamping; the upper movable plate is driven by a cylinder, and the synchronous movement of the slips is achieved through a linkage mechanism. Pneumatic drive has the advantages of fast response speed and high control precision, and is suitable for the wellhead operation environment with frequent operations; the cylinder is located between the support rods, with a compact structure and space saving. At the same time, the design of the upper movable plate sleeve and the lower movable plate sleeve ensures that the upper and lower movable plates do not interfere with each other during the movement process, improving the stability and reliability of the device; circular through holes with the same diameter as the circular through hole of the annular hoop are opened at the centers of the top plate, the base, the upper movable plate and the lower movable plate, ensuring the passing of the sucker rod and being applicable to sucker rods of different diameters. Brief Description of the Drawings

[0022] Figure 1 This is the best structural schematic diagram of the present invention.

[0023] Figure 2 This is the schematic diagram of the internal part structure of the present invention.

[0024] Figure 3 This is the sectional structural schematic diagram of the present invention.

[0025] Figure 4 This is the structural schematic diagram of the slip of the present invention.

[0026] Figure 5 This is the structural schematic diagram of the slip clamping of the present invention.

[0027] Figure 6 This is the structural schematic diagram of the slip opening of the present invention.

[0028] Figure 7 This is the working schematic diagram of clamping the sucker rod of the present invention.

[0029] The meanings of the reference numerals in the drawings: 1. top plate; 2. upper movable plate; 3. lower movable plate; 401. connecting rod II; 402. triple plate; 403. slip block; 404. slip holder; 405. connecting rod I; 5. spring; 6. base; 7. cylinder; 8. support rod; 9. annular hoop; 10. upper movable plate sleeve; 11. lower movable plate sleeve; 12. cylinder fixing plate; 13. sucker rod; 41. hinge point I; 42. inner push hinge point; 43. main support hinge point; 44. hinge point II; 45. auxiliary support hinge point. Detailed Embodiment

[0030] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0031] The following is a detailed description of the specific implementation of the present invention in combination with specific embodiments:

[0032] Please refer to Figures 1 to 4 , a wellhead clamping device for a sucker rod pneumatic slip, comprising a support base, a pneumatic assembly and a slip. It is characterized in that the support base includes a support rod 8, a top plate 1 and a base 6, and a communication hole is provided in the middle of the support base; slips are arranged in the support base in a circumferential distribution centered on the communication hole, at least two support rods 8 are fixed on the inner circumference of the support base staggered with the slips, springs 5 are sleeved on the spaced support rods 8, and a lower movable plate 3 is sleeved on the support rod 8 at the upper end of the spring 5; an upper movable plate 2 is installed in the support base above the lower movable plate 3, and a cylinder 7 is installed in the support base. The power output end of the cylinder 7 is connected to the upper movable plate 2 and drives the upper movable plate 2 to move up and down; the slip includes a slip end and a slip handle; the slip handle is horizontally fixed on the outer side of the upper end of the slip end; a first hinge point 41 is provided at the inner end of the slip handle, a triple plate 402 is hinged on the first hinge point 41, and a main support hinge point 43 and an inner push hinge point 42 are respectively provided at the other end of the triple plate 402. The inner push hinge point 42 is located below the outer side of the main support hinge point 43; the main support hinge point 43 is installed on the hinge seat on the inner side of the bottom of the lower movable plate 3 through a pin shaft; a connecting rod II 401 is hinged between the inner push hinge point and the upper movable plate 2; a second hinge point 44 is provided at the outer end of the slip handle, a connecting rod I 405 is hinged on the second hinge point 44, and an auxiliary support hinge point 45 is provided at the other end of the connecting rod I 405. The auxiliary support hinge point 45 is installed on the hinge seat on the outer side of the bottom of the lower movable plate 3 through a pin shaft; a four-point parallel mechanism is formed among the first hinge point 41, the main support hinge point 43, the second hinge point 44 and the auxiliary support hinge point 45.

[0033] Among them, the slips distributed circumferentially around the communication hole in the support base can clamp the sucker rod 13, and make the sucker rod 13 be evenly stressed during the clamping process, avoiding damage to the sucker rod 13 caused by uneven stress during the clamping process; at least two support rods 8 fixed on the inner circumference of the support base are staggered with the slips, so that the slips will not be affected during the working process, thus ensuring the stability of the device; since springs 5 are sleeved on the spaced support rods 8, a lower movable plate 3 is sleeved on the support rod 8 at the upper end of the spring 5, and the spring 5 can make the lower movable plate 3 be evenly stressed during the working process, and the support rod 8 serves as a rigid guide rail for the upper movable plate 2, the lower movable plate 3 and the spring 5; a four-point parallel mechanism formed between the hinge point 41, the main support hinge point 43, the hinge point 44 and the auxiliary support hinge point 45 is connected to the upper movable plate 2 and the lower movable plate 3, and the power output end of the cylinder 7 is connected to the upper movable plate 2 and drives the upper movable plate 2 to move up and down. When the cylinder 7 drives the upper movable plate 2 to move downward and drives the slips to move horizontally until the slips are in contact with the sucker rod 13 to complete the action of the first stroke, under the action of the spring 5, the lower movable plate 3 does not move first until the upper movable plate 2 begins to squeeze the lower movable plate 3, and the cylinder 7 overcomes the elastic force of the spring to make the lower movable plate 3, the slips and the four-point parallel mechanism move downward to complete the action of the second stroke. The four-point parallel mechanism ensures the synchronism and stability of the slips during the clamping process, avoiding damage to the sucker rod caused by uneven stress.

[0034] Please refer to Figure 3 , a ring hoop 9 is provided below the slips, a circular through hole is opened at the center of the ring hoop 9, a chamfer is provided at the top of the circular through hole of the ring hoop 9, and the ring hoop 9 is fixedly connected to the center of the base 6.

[0035] Among them, a ring hoop 9 is provided below the slips and fixedly connected to the center of the base 6, which is convenient for the slips to move downward into the ring hoop 9, and the inclined surface of the chamfer at the top of the circular through hole of the ring hoop 9 will generate a vertical inward component force on the slips after the slips enter the ring hoop 9, causing the four-point parallel mechanism to move horizontally. When encountering the centralizer, it moves downward, the lower end of the slips contacts the ring hoop, and the action stops, thereby improving the clamping effect on the sucker rod 13 and completing gravity self-locking. During this process, due to the small internal force of the structure, the centralizer and the structure itself will not be damaged, and the clamping stability and reliability are improved.

[0036] Please refer to Figures 1 - 6 , upper movable plate sleeves 10 are evenly distributed on the circumference of the upper movable plate 2, and the upper movable plate sleeves 10 are fixedly connected to the upper movable plate 2; lower movable plate sleeves 11 are evenly distributed on the circumference of the lower movable plate 3, and the lower movable plate sleeves 11 are fixedly connected to the lower movable plate 3; both the upper movable plate sleeves 10 and the lower movable plate sleeves 11 are sleeved on the support rod 8, and the bottom end of the upper movable plate sleeve 10 passes through the lower movable plate 3, and the top end of the lower movable plate sleeve 11 passes through the upper movable plate 2.

[0037] Among them, upper movable plate sleeves 10 are evenly distributed in a circle on the upper movable plate 2, and the bottom ends of the upper movable plate sleeves 10 pass through the lower movable plate 3; lower movable plate sleeves 11 are evenly distributed in a circle on the lower movable plate 3, and the lower movable plate sleeves 11 are fixedly connected to the lower movable plate 3. The top ends of the lower movable plate sleeves 11 pass through the upper movable plate 2, so that the upper movable plate 2 and the lower movable plate 3 do not affect each other during the movement process, improving the stability and reliability of the device; both the upper movable plate sleeves 10 and the lower movable plate sleeves 11 are sleeved on the support rod 8, enabling the upper movable plate 2 and the lower movable plate 3 to slide smoothly under the drive of the upper movable plate sleeves 10 and the lower movable plate sleeves 11; the lower movable plate sleeves 11 are in contact with the top of the spring 5, making the acting force of the spring 5 more concentrated.

[0038] Please refer to Figure 3 and Figure 4 , the auxiliary support hinge point 45 on the connecting rod I405 is hinged and fixed to the bottom of the lower movable plate 3, the connecting rod II401 passes through the lower movable plate 3 and is hinged and fixed to the bottom of the upper movable plate 2, the hinge point two 44 of the connecting rod I405 is hinged and fixed to the left end of the slip holder 404, the other end of the connecting rod II401 is hinged and fixed to the inner push hinge point 42 of the triple plate 402, the main support hinge point 43 of the triple plate 402 is hinged and fixed to the lower movable plate 3, the hinge point one 41 at the lower end of the triple plate 402 is hinged and fixed to the right end of the slip holder 404, the slip holder 404 is hollow, and a slip block 403 is bolted to the rightmost end of the slip holder 404.

[0039] Among them, during the action process of the first stroke of the upper movable plate 2, when the upper movable plate 2 moves, the upper movable plate 2 moves downward, pushing the connecting rod II401, driving the triple plate 402 to rotate around the main support hinge point 43, driving the slip holder 404 through the hinge point one 41, and linking the connecting rod I405 to rotate around the auxiliary support hinge point 45, finally forming a synchronous closing movement of a four-point parallel mechanism to realize the clamping and positioning of the sucker rod 13 by the slip device; when the four-point parallel mechanism moves horizontally and encounters the centralizer, the lateral force is small, which will not damage the structure itself nor damage the centralizer; the slip block 403 bolted to the rightmost end of the slip holder 404 is convenient for replacement and maintenance during the working process. This modular design reduces the maintenance cost and improves the durability of the device.

[0040] Please refer to Figure 2 , the pneumatic assembly includes a cylinder 7 and a cylinder fixing plate 12; the telescopic end of the cylinder 7 is fixedly connected to the cylinder fixing plate 12, and the cylinder fixing plate 12 is fixedly connected to one side of the upper movable plate 2 close to the lower movable plate 3.

[0041] Among them, the telescopic end of the cylinder 7 is fixedly connected to the cylinder fixing plate 12, and the cylinder fixing plate 12 is fixedly connected to one side of the upper movable plate 2 close to the lower movable plate 3; the cylinder 7 transmits power to the upper movable plate 2, thereby providing a power source for the entire device.

[0042] Please refer to Figures 1 - 3 , the cylinder 7 is located between the support rods 8 in the support seat.

[0043] Among them, the cylinder 7 is located between the support rods 8 in the support seat, and the cylinders 7 are evenly distributed on the base 6, so that the acting force of the cylinder 7 on the upper movable plate 2 is evenly distributed, and the structure of the device is more compact.

[0044] Please refer to Figures 1 - 7 , circular through holes with the same diameter as the circular through hole of the annular hoop 9 are provided at the centers of the top plate 1, the base 6, the upper movable plate 2 and the lower movable plate 3.

[0045] Among them, circular through holes with the same diameter as the circular through hole of the annular hoop 9 are provided at the centers of the top plate 1, the base 6, the upper movable plate 2 and the lower movable plate 3, which ensures the passing of the sucker rod 13 and is applicable to sucker rods 13 of different diameters.

[0046] Please refer to Figures 3 - 4 , on the side of the slip holder 404 above the annular hoop 9 away from the slip block 403, there is an inclined surface inclined towards the slip block 403, at the bottom of the slip block 403 there is an inclined surface inclined upwards, and on the surface of the slip block 403 away from the triple plate 402 there is an arc-shaped groove.

[0047] Among them, on the side of the slip holder 404 above the annular hoop 9 away from the slip block 403, there is an inclined surface inclined towards the slip block 403, and at the bottom of the slip block 403 there is an inclined surface inclined upwards, which provides necessary conditions for the slip block 403 to smoothly enter the annular hoop 9, while the arc-shaped groove on the surface of the slip block 403 away from the triple plate 402 increases the contact area between the slip block 403 and the sucker rod 13, increases the clamping force of the sucker rod 13, and at the same time reduces the damage to the surface of the sucker rod during the clamping process.

[0048] Please refer to Figure 5 , the centers of the three groups of slips above the annular hoop 9 just coincide with the center of the annular hoop 9.

[0049] Among them, the centers of the three groups of slips above the annular hoop 9 just coincide with the center of the annular hoop 9, which ensures that when the sucker rod 13 is clamped and falls, the sucker rod 13 is always on a straight line and the sucker rod will not be damaged.

[0050] Please refer to Figure 7A wellhead clamping device for a sucker rod pneumatic slip comprises two sucker rod pneumatic slips, which are installed together up and down and the distance between the two sucker rod pneumatic slips is greater than or equal to the length of the straightening block on the sucker rod, and the two pneumatic slips act simultaneously.

[0051] Among them, the two sucker rod pneumatic slips are installed together up and down and the distance between the two sucker rod pneumatic slips is greater than or equal to the length of the straightening block on the sucker rod, which ensures that at least one group of slips can avoid the straightening block on the sucker rod 13. The two pneumatic slips act at the same time to ensure that there is a slip that can lock the sucker rod so that the slip can be stuck on the rod body of the sucker rod 13, preventing the clamping failure or equipment damage caused by a single slip when encountering the straightening block and the problem of a single sucker rod pneumatic slip causing the sucker rod 13 to fall into the well during operation.

[0052] During operation, firstly set two sucker rod pneumatic slips up and down, and ensure that the distance between the two sucker rod pneumatic slips is greater than the length of the sucker rod straightening block, and the two pneumatic slips act at the same time to ensure that one slip can lock the sucker rod, and then put the sucker rod into the device. Since the upper movable plate 2 is hinged and fixed to the connecting rod II401, and the lower movable connecting plate 3 is hinged and fixed to the auxiliary support hinge point 45 on the connecting rod I405, when the cylinder 7 pushes the upper movable plate 2 to move, the lower movable plate 3 is kept stationary due to the force of the spring 5, and the upper movable plate 2 moves downward, pushing the connecting rod II401, driving the triple plate 402 to rotate around the main support hinge point 43, and driving the slip frame 404 through the hinge point 141, linking the connecting rod I405 around the auxiliary support hinge point 45. Rotate to make the four-point parallel mechanism close synchronously, the cava block 403 and the sucker rod 13 fit together to complete the first stroke action, and then the cylinder 7 in the pneumatic cava of the two sucker rods continues to contract. During the contraction process, the cylinder 7 drives the upper movable plate 2 to move downward to the lower movable plate 3, and the cylinder 7 overcomes the elastic force of the spring to make the lower movable plate 3, the cava and the four-point parallel mechanism move downward to perform the second stroke action until the outer side of the cava block 403 abuts against the annular hoop 9. At this time, the second stroke action is completed and the sucker rod can be locked and fixed by its own gravity.

[0053] When the pneumatic slips are released, the above action is repeated in reverse.

[0054] The above description is only an embodiment of the present invention, and does not limit the scope of the present invention. In the present invention, for the convenience of description, the relative position relationship of each component is described according to the attached specification. Figure 1 The layout is described in detail, such as the positional relationship of front, back, top, bottom, left, right, etc., which is based on the attached manual. Figure 1It is determined by the layout direction. Any equivalent structural or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall similarly be included within the scope of patent protection of the present invention.

Claims

1. A wellhead clamping device for a sucker rod pneumatic slip, comprising a support seat, a pneumatic assembly and a slip, characterized in that: The support seat comprises a support rod (8), a top plate (1) and a base (6), wherein a connecting hole is provided in the middle of the support seat; a slip is provided in the support seat along the circumference with the connecting hole as the center, at least two support rods (8) are fixed to the inner circumference of the support seat staggered with the slips, springs (5) are sleeved on the separated support rods (8), and a lower movable plate (3) is sleeved on the support rod (8) at the upper end of the spring (5); an upper movable plate (2) is installed in the support seat above the lower movable plate (3), and a cylinder (7) is installed in the support seat, and the power output end of the cylinder (7) is connected to the upper movable plate (2) and drives the upper movable plate (2) to move up and down; the slip comprises a slip end and a slip handle; the slip handle is horizontally fixed to the outer side of the upper end of the slip end; a hinge point (41) is provided at the inner end of the slip handle, and a triple plate (40) is hingedly connected to the hinge point (41) 2), the other end of the triple plate (402) is respectively provided with a main support hinge point (43) and an inner push hinge point (42), the inner push hinge point (42) is located below the outer side of the main support hinge point (43); the main support hinge point (43) is installed on the hinge seat on the inner side of the bottom of the lower movable plate (3) through a pin shaft; the inner push hinge point and the upper movable plate (2) are hinged by a connecting rod II (401); the outer end of the cava handle is provided with a hinge point II (44), the hinge point II (44) is hinged with a connecting rod I (405), the other end of the connecting rod I (405) is provided with an auxiliary support hinge point (45), the auxiliary support hinge point (45) is installed on the hinge seat on the outer side of the bottom of the lower movable plate (3) through a pin shaft; a four-point parallel mechanism is formed between the hinge point I (41), the main support hinge point (43), the hinge point II (44) and the auxiliary support hinge point (45); An annular hoop (9) is provided below the slip, a circular through hole is provided at the center of the annular hoop (9), a top end of the circular through hole of the annular hoop (9) is chamfered, and the annular hoop (9) is fixedly connected to the center of the base (6); The utility model comprises two sucker rod pneumatic slips, which are installed together up and down, and the distance between the two sucker rod pneumatic slips is greater than or equal to the length of the straightening block on the sucker rod.

2. The wellhead clamping device of the sucker rod pneumatic slip according to claim 1, characterized in that: The upper movable plate (2) is evenly distributed with upper movable plate sleeves (10) on its upper circumference, and the upper movable plate sleeves (10) are fixedly connected to the upper movable plate (2); the lower movable plate sleeves (11) are evenly distributed with lower movable plate sleeves (11) on its upper circumference, and the lower movable plate sleeves (11) are fixedly connected to the lower movable plate (3); the upper movable plate sleeves (10) and the lower movable plate sleeves (11) are both sleeved on the support rod (8), and the bottom end of the upper movable plate sleeves (10) passes through the lower movable plate (3), and the top end of the lower movable plate sleeves (11) passes through the upper movable plate (2).

3. The wellhead clamping device of the sucker rod pneumatic slip according to claim 2, characterized in that: The auxiliary support hinge point (45) on the connecting rod I (405) is hinged and fixed to the bottom of the lower movable plate (3), the connecting rod II (401) passes through the lower movable plate (3) and is hinged and fixed to the bottom of the upper movable plate (2), the hinge point II (44) of the connecting rod I (405) is hinged and fixed to the left end of the slip frame (404), the other end of the connecting rod II (401) is hinged and fixed to the inner push hinge point (42) of the triple-jointed plate (402), the main support hinge point (43) of the triple-jointed plate (402) is hinged and fixed to the lower movable plate (3), the hinge point I (41) at the lower end of the triple-jointed plate (402) is hinged and fixed to the right end of the slip frame (404), the slip frame (404) is hollow, and a slip block (403) is bolted to the rightmost end of the slip frame (404).

4. The wellhead clamping device of the sucker rod pneumatic slip according to claim 3 is characterized in that: The pneumatic assembly comprises a cylinder (7) and a cylinder fixing plate (12); the telescopic end of the cylinder (7) is fixedly connected to the cylinder fixing plate (12), and the cylinder fixing plate (12) is fixedly connected to a surface of the upper movable plate (2) close to the lower movable plate (3).

5. The wellhead clamping device of the sucker rod pneumatic slip according to claim 4, characterized in that: The cylinder (7) is located between the support rods (8) in the support seat.

6. The wellhead clamping device of the sucker rod pneumatic slip according to claim 5, characterized in that: A circular through hole having the same diameter as the circular through hole of the annular hoop (9) is provided at the center of the top plate (1), the base (6), the upper movable plate (2) and the lower movable plate (3).

7. The wellhead clamping device of the sucker rod pneumatic slip according to claim 6, characterized in that: A side of the slip frame (404) above the annular hoop (9) away from the slip block (403) is provided with an inclined surface inclined toward the slip block (403), a bottom of the slip block (403) is provided with an inclined surface inclined upward, and a surface of the slip block (403) away from the triple plate (402) is provided with an arc-shaped groove.

8. The wellhead clamping device of the sucker rod pneumatic slip according to claim 7, characterized in that: The centers of the three groups of slips above the annular hoop (9) coincide with the center of the annular hoop (9).

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