Annular rubber core and blowout preventer

Abstract

The present invention discloses an annular rubber core and a blowout preventer, and relates to the technical field of oil drilling and production. The annular rubber core includes a rubber ring and a steel ring arranged on its bottom surface, and the two are bonded into one by vulcanization, and the bonding surface sizes of the two are consistent. The blowout preventer includes: the blowout preventer body includes a top cover, an outer shell, and a plurality of pistons arranged inside the blowout preventer body. A through groove running through the upper and lower parts is arranged at the center of the blowout preventer body, and the through groove is used to insert a drill pipe, and the top cover covers the outer shell; the first wear-resistant plate is arranged at the bottom of the top cover; the plurality of rubber cores have the same thickness and different outer diameters, and are sequentially sleeved from the inside to the outside, the annular rubber core located in the outermost circle is close to the inner wall of the outer shell, and the rubber ring on the top surface of the annular rubber core is close to the first wear-resistant plate, and the plurality of pistons are respectively connected to the steel rings of the corresponding annular rubber cores, and are used to move the steel rings upward so that the rubber ring of the innermost circle is close to the drill pipe. When an annular rubber core is damaged and affects the sealing effect, it is not necessary to replace all the annular rubber cores.

Description

Technical Field

[0001] The invention relates to the technical field of oil drilling and production, in particular to an annular rubber core and a blowout preventer. Background Art

[0002] BOP is used to close the wellhead during oil testing, well repair, well completion and other operations to prevent blowout accidents. It combines the functions of full sealing and semi-sealing into one, and has the characteristics of simple structure, easy operation, high pressure resistance, etc. It is a safety sealing wellhead device commonly used in oil fields to prevent blowouts. Hydraulic BOP mainly includes gate BOP and annular BOP. The structure of annular BOP is mainly composed of four parts: shell, top cover, rubber core and piston. The shape of the rubber core is generally spherical or conical.

[0003] CN114396241B discloses a double-layer sealed spherical rubber core and annular blowout preventer. The solution is provided with a spherical rubber core with a double-layer sealing structure. The rubber teeth and support ribs on the top are gathered as the first layer of sealing, and the sealing head at the bottom of the spherical rubber core is gathered as the second layer of sealing. The double-layer sealing structure can effectively solve the problem that the rubber teeth and support ribs cannot be sealed, or the sealing effect is poor. CN115898319B discloses a double-rubber core composite annular blowout preventer. The solution arranges the spherical rubber core and the conical rubber core in a blowout preventer at the same time, and realizes their respective functions through double pistons. It can perform single-layer sealing independently or double-layer sealing, so as to meet the sealing requirements of low-pressure wells and high-pressure wells. However, there is a problem in both of the above two solutions: when a component or part of the rubber core is damaged and affects the sealing effect, the entire rubber core needs to be replaced. Summary of the invention

[0004] In order to solve the deficiencies of the prior art, the present invention provides an annular rubber core and a blowout preventer, improves the structure of the rubber core and the blowout preventer, and when a part of the rubber core is damaged and affects the sealing effect, there is no need to replace all the rubber cores.

[0005] In order to achieve the purpose of the present invention, the following scheme is proposed:

[0006] The utility model relates to an annular rubber core, comprising a rubber ring and a steel ring arranged on the bottom surface thereof, the two are bonded into one body by vulcanization, and the bonding surfaces of the two have the same size.

[0007] Furthermore, the material of the rubber ring is rubber, and the material of the steel ring is 45# or Q345.

[0008] A blowout preventer comprises a blowout preventer body, a first wear-resistant plate and a plurality of annular rubber cores.

[0009] The BOP body includes a top cover, an outer shell, and a plurality of pistons arranged inside the BOP body. A through slot is provided at the center of the BOP body, which runs through the center and into which the drill pipe is inserted. The top cover covers the outer shell.

[0010] The first wear-resistant plate is arranged at the bottom of the top cover;

[0011] The multiple annular rubber cores have the same thickness and different outer diameters and are sequentially mounted from the inside to the outside. The annular rubber core located at the outermost circle is in close contact with the inner wall of the outer shell, and the rubber ring on the top surface of the annular rubber core is in close contact with the first wear-resistant plate. The multiple pistons are respectively connected to the steel rings of the corresponding annular rubber cores and are used to move the steel rings upward so that the rubber ring of the innermost circle is in close contact with the drill pipe.

[0012] Furthermore, it also includes multiple fan-shaped second wear-resistant plates and two third wear-resistant plates. The radial cross-section of the third wear-resistant plate is Z-shaped, and the two corners of the Z-shape are right angles. From top to bottom, it includes a first horizontal plate, a vertical plate and a second horizontal plate. The two third wear-resistant plates are symmetrically arranged on the top of the through groove. The first horizontal plate is supported on the top surface of the top cover, and the vertical plate and the second horizontal plate are located in the through groove. An annular groove is provided on the top of the inner wall of the first wear-resistant plate, and multiple second wear-resistant plates are arranged in a circular array in the annular groove. The second wear-resistant plate is slidably arranged under the action of a power source. When the multiple second wear-resistant plates move toward the drill pipe and form a complete ring, they are used to make the inner wall of the second horizontal plate close to the drill pipe.

[0013] Furthermore, an annular slot is provided at the bottom or middle section of the outer wall of the second transverse plate. When the plurality of second wear-resistant plates move toward the drill pipe and form a complete ring, the second wear-resistant plates are inserted into the slot and closely adhere to the second transverse plate.

[0014] Furthermore, a T-shaped block is provided on the top of the second wear-resistant plate, and a T-shaped slot is provided at a corresponding position of the top cover, and the T-shaped block is slidably matched in the T-shaped slot.

[0015] Furthermore, the second transverse plate is connected to the vertical plate through a plurality of bolts.

[0016] Furthermore, the first wear-resistant plate is fixedly connected to the top cover by a plurality of bolts.

[0017] Furthermore, it also includes two first rubber baffle plates and an annular second rubber baffle plate, the second rubber baffle plate is arranged at the bottom of the innermost steel ring, the inner diameter of the second rubber baffle plate is smaller than the diameter of the through groove, a plurality of vertical bars are arranged at the bottom of the second horizontal plate, and the inner spacing between the vertical bars and the drill rod is less than 20 mm, the first rubber baffle plate is provided with a plurality of through holes, the vertical bars pass through the corresponding through holes, and a block larger than the vertical bar is arranged at the bottom of the vertical bar, the first rubber baffle plate is supported on the second rubber baffle plate, the inner diameter of the first rubber baffle plate is consistent with the outer diameter of the drill rod, the outer diameter is consistent with the diameter of the through groove, and the thickness is less than the thickness of the steel ring.

[0018] Furthermore, the vertical bars are elastic.

[0019] The beneficial effects of the present invention are as follows: the existing rubber core is improved in shape and structure, and the present invention provides an annular rubber core, in which the rubber ring and the steel ring are distributed in upper and lower layers, the material of the steel ring is relatively hard, and is used to squeeze the rubber upward under the action of the piston, and the material of the rubber is relatively soft, and is easily deformed when squeezed, thereby sealing the drill pipe; when applied to the blowout preventer, multiple annular rubber cores are sequentially sleeved from the inside to the outside, one annular rubber core corresponds to one piston, and the corresponding number of pistons can be selected to start according to the specifications of the drill pipe, thereby reducing the loss of the annular rubber core; when any annular rubber core is damaged and affects the sealing effect, only the damaged annular rubber core needs to be replaced, and there is no need to replace all the annular rubber cores. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The structure diagram of the annular rubber core is shown;

[0021] Figure 2 A schematic diagram showing a partial structure of a blowout preventer is shown;

[0022] Figure 3 A schematic diagram of the top cover and three wear plates is shown;

[0023] Figure 4 A first schematic diagram showing the second wear plate being inserted into the slot;

[0024] Figure 5 A second schematic diagram showing the insertion of the second wear plate into the slot;

[0025] Figure 6 A schematic diagram of the third wear-resistant plate and two rubber baffle plates is shown;

[0026] Figure 7 A schematic diagram showing a rubber ring sealing a drill pipe;

[0027] Figure 8 A schematic diagram showing the rubber ring squeezing the vertical bar and sealing the drill pipe;

[0028] Fig. 9 An external view showing a portion of the blowout preventer structure;

[0029] Fig.10 A diagram showing four second wear plate sections within the annular groove;

[0030] Fig.11 The structure diagram of the third wear-resistant plate and the first rubber baffle plate is shown;

[0031] Fig.12 A third wear plate structure diagram is shown;

[0032] Fig.13 A top view of the first baffle plate is shown;

[0033] Markings in the figure: rubber ring-11, steel ring-12, blowout preventer body-2, top cover-21, T-slot-211, shell-22, piston-23, through slot-24, first wear-resistant plate-31, annular groove-311, second wear-resistant plate-32, T-block-321, third wear-resistant plate-33, slot-331, drill pipe-4, first rubber baffle plate-51, through hole-511, second rubber baffle plate-52, vertical bar-53, block-531. DETAILED DESCRIPTION

[0034] Example 1

[0035] like Figure 1 As shown, this embodiment provides an annular rubber core, including a rubber ring 11 and a steel ring 12. The steel ring 12 is arranged on the bottom surface of the rubber ring 11. The two are bonded together by vulcanization, and the bonding surface size of the rubber ring 11 and the steel ring 12 is consistent. The rubber ring 11 and the steel ring 12 are both annular, the material of the rubber ring 11 is rubber, and the material of the steel ring 12 is 45# or Q345.

[0036] In terms of shape, common shapes of the rubber core in the prior art are spherical and conical, while the shape of the rubber core provided in this embodiment is annular.

[0037] Structurally, in the spherical rubber core disclosed in CN114396241B, there is a gap between two adjacent rubber teeth, and a metal support rib is spaced between the two rubber teeth; in the rubber core disclosed in CN115898319B, a first metal support rib is evenly distributed in the spherical rubber core, and a second metal support rib is evenly distributed in the conical rubber core; in the annular rubber core provided in this embodiment, the rubber ring 11 and the steel ring 12 are distributed in the upper and lower layers.

[0038] Example 2

[0039] like Figure 2 , Fig. 9 As shown, this embodiment provides a blowout preventer, including a blowout preventer body 2, a first wear-resistant plate 31 and three annular rubber cores described in Embodiment 1.

[0040] Specifically, the BOP body 2 includes a top cover 21, an outer shell 22 and three pistons 23 arranged inside the BOP body 2. A through groove 24 running through the center of the BOP body 2 is provided, and the through groove 24 is used to insert the drill pipe 4. The top cover 21 covers the top of the outer shell 22.

[0041] The three annular rubber cores have the same thickness and different outer diameters, and are sequentially sleeved from the inside to the outside, that is, the outer wall of the innermost annular rubber core is in close contact with the inner wall of the middle annular rubber core, the outer wall of the middle annular rubber core is in close contact with the inner wall of the outermost annular rubber core, and the outer wall of the outermost annular rubber core is in close contact with the inner wall of the shell 22. The first wear-resistant plate 31 is annular, and the first wear-resistant plate 31 is fixed to the bottom of the top cover 21. The rubber ring 11 on the top surface of the annular rubber core is in close contact with the first wear-resistant plate 31. The three pistons 23 are respectively connected to the steel rings 12 of the corresponding annular rubber cores. The pistons 23 can move upward under the action of the hydraulic cylinder. The function of the pistons 23 is to move the steel rings 12 upward. Figure 7 As shown, the rubber ring 11 of the innermost annular rubber core is squeezed and deformed, and then closely adheres to the drill rod 4, thereby achieving a sealing effect.

[0042] A piston 23 acts on an annular rubber core. When a larger drill pipe 4 needs to be sealed, a small amount of rubber can complete the seal, so it is sufficient to start a piston 23. Figure 7 When a smaller drill pipe 4 needs to be sealed, more rubber is needed to complete the seal, so two or three pistons 23 need to be started simultaneously. The above structural design and use method can reduce the loss of the annular rubber core and extend the service life.

[0043] Function of the first wear-resistant plate 31: When the annular rubber core is working, the annular rubber core pushes upward without directly contacting the top cover 21 of the blowout preventer, and the first wear-resistant plate 31 plays a role in protecting the top cover 21. The first wear-resistant plate 31 will be worn out after being used for a period of time. In order to facilitate the replacement of the first wear-resistant plate 31, the first wear-resistant plate 31 of this embodiment is fixedly connected to the top cover 21 by multiple bolts.

[0044] When any one of the three annular rubber cores is damaged and affects the sealing effect, only the damaged annular rubber core needs to be replaced, and there is no need to replace all three annular rubber cores.

[0045] When the rubber contacts and seals the drill pipe 4, the excess rubber will inevitably flow upward and downward along the gap between the drill pipe 4 and the blowout preventer. In order to solve this problem, this embodiment is further optimized on the basis of the above solution, as follows:

[0046] like Figure 3 , Fig. 9 , Fig.10 , Fig.12As shown, the blowout preventer also includes four fan-shaped second wear-resistant plates 32 and two third wear-resistant plates 33. The radial cross-section of the third wear-resistant plate 33 is Z-shaped, and the two corners of the Z-shaped are both right angles. The third wear-resistant plate 33 includes a first horizontal plate, a vertical plate, and a second horizontal plate from top to bottom. The two third wear-resistant plates 33 are symmetrically arranged on the top of the through groove 24. When the two first horizontal plates are butt-jointed, when the two vertical plates are butt-jointed, when the two second horizontal plates are butt-jointed, they can form a complete ring respectively. The first horizontal plate is supported on the top surface of the top cover 21, and the vertical plate and the second horizontal plate are located in the through groove 24. The first wear-resistant plate An annular groove 311 is provided at the top of the inner wall of the plate 31, and four second wear-resistant plates 32 are arranged in a circular array in the annular groove 311. The bottom surface and the top surface of the second wear-resistant plate 32 are respectively close to the first wear-resistant plate 31 and the top cover 21. The second wear-resistant plate 32 is slidably arranged under the action of the hydraulic cylinder, and the sliding direction of the second wear-resistant plate 32 is perpendicular to the central axis of the drill rod 4. When the four second wear-resistant plates 32 move toward the drill rod 4 and form a complete circle, at this time, the second cross plate of the third wear-resistant plate 33 is squeezed by the second wear-resistant plate 32 and is close to the drill rod 4, and the inner wall of the second cross plate is close to the outer wall of the drill rod 4.

[0047] The second wear-resistant plate 32 and the third wear-resistant plate 33 can not only restrict the upward flow of rubber, but also play a sealing role.

[0048] More specifically, in order to ensure that the second wear-resistant plate 32 slides along a predetermined straight line and improves the stability during the sliding process, as Figure 3 , Fig.10 As shown, a T-block 321 is provided on the top of the second wear-resistant plate 32 of this embodiment, and a T-slot 211 is provided at a corresponding position of the top cover 21 , and the T-block 321 is slidably matched in the T-slot 211 .

[0049] More specifically, in order to further improve the stability and sealing performance of the third wear-resistant plate 33, in the first case: Figure 4 , Fig.12 As shown, an annular slot 331 is provided at the bottom of the outer wall of the second horizontal plate. When the four second wear-resistant plates 32 move toward the drill rod 4 and form a complete ring, the second wear-resistant plates 32 are inserted into the slot 331 and close to the second horizontal plate; the second case: as Figure 5 As shown, an annular slot 331 is provided in the middle section of the outer wall of the second horizontal plate. When the four second wear-resistant plates 32 move toward the drill rod 4 and form a complete ring, the second wear-resistant plate 32 is inserted into the slot 331 and fits tightly against the second horizontal plate. The purpose of this design is: first, to ensure the sealing between the second wear-resistant plate 32 and the third wear-resistant plate 33, and also to ensure the sealing between the third wear-resistant plate 33 and the drill rod 4.

[0050] When sealing drill rods 4 of different specifications, it is necessary to select a third wear-resistant plate 33 of corresponding size, or more precisely, to select a second horizontal plate of corresponding size, to ensure that the inner diameter of the second horizontal plate is consistent with the outer diameter of the drill rod 4. The first method: use the handle to extract the entire third wear-resistant plate 33 from the through slot 24, and then replace it with another third wear-resistant plate 33 that matches the size of the drill rod 4; the second method: the second horizontal plate is connected to the vertical plate through multiple bolts, and the handle is used to extract the entire third wear-resistant plate 33 from the through slot 24, and then the bolts are removed and replaced with another second horizontal plate that matches the size of the drill rod 4.

[0051] The above solution solves the problem of rubber flowing upwards, and the following solution solves the problem of rubber flowing downwards:

[0052] like Figure 6 , Fig.11 , Fig.13 As shown, the blowout preventer also includes two semicircular first rubber baffles 51 and an annular second rubber baffle 52, the second rubber baffle 52 is fixedly connected to the bottom of the steel ring 12 of the innermost annular rubber core, the inner diameter of the second rubber baffle 52 is smaller than the diameter of the through groove 24, three vertical bars 53 are provided at the bottom of the second cross plate, and the inner spacing between the vertical bars 53 and the drill pipe 4 is less than 20 mm, the first rubber baffle 51 is provided with three through holes 511, the vertical bars 53 pass through the corresponding through holes 511, and a stopper 531 larger than the vertical bar 53 is provided at the bottom of the vertical bar 53, the first rubber baffle 51 is supported on the second rubber baffle 52, the inner diameter of the first rubber baffle 51 is consistent with the outer diameter of the drill pipe 4, the outer diameter of the first rubber baffle 51 is consistent with the diameter of the through groove 24, and the thickness of the first rubber baffle 51 is less than the thickness of the steel ring 12.

[0053] When it is necessary to seal the drill pipe 4, Figure 8 As shown, the third wear-resistant plate 33 is squeezed by the second wear-resistant plate 32 and is close to the drill rod 4; the piston 23 of the innermost annular rubber core moves upward, and on the one hand, the rubber ring 11 is squeezed and deformed, and then closely adheres to the vertical bar 53 and the drill rod 4, and on the other hand, the second rubber baffle plate 52 will move upward with the steel ring 12, and the first rubber baffle plate 51 will also move upward along the vertical bar 53 under the action of the second rubber baffle plate 52. The function of the first rubber baffle plate 51 is to prevent the rubber from flowing downward and to achieve a sealing effect.

[0054] Regarding the role of the vertical bars 53: First, the vertical bars 53 can make the first rubber baffle plate 51 suspended below the third wear-resistant plate 33, so that the first rubber baffle plate 51 and the third wear-resistant plate 33 can be extracted from the through groove 24 for replacement, and it is also convenient to put the first rubber baffle plate 51 and the third wear-resistant plate 33 into the through groove 24 together. It should be noted here that when it is necessary to seal drill rods 4 of different specifications, the first rubber baffle plate 51 should also be replaced accordingly to ensure that the inner diameter of the first rubber baffle plate 51 is consistent with the outer diameter of the drill rod 4; second, the internal spacing between the vertical bars 53 and the drill rod 4 is less than 20 mm, and the vertical bars 53 have a certain elasticity. This design is to ensure that the rubber can squeeze the vertical bars 53 and make the vertical bars 53 close to the drill rod 4, so as to achieve sealing. It should be noted here that if the vertical bars 53 are not elastic, when the rubber seals the drill rod 4, part of the rubber will fill the gap between the vertical bars 53 and the drill rod 4, which can also achieve a better sealing effect.

[0055] Instructions for use: According to the specifications of the drill rod 4, select the first rubber baffle plate 51 and the second horizontal plate of corresponding sizes, and fix the second horizontal plate to the vertical plate through multiple bolts to complete the assembly of the third wear-resistant plate 33 and the first rubber baffle plate 51; use the handle to put the third wear-resistant plate 33 and the first rubber baffle plate 51 into the through groove 24 as a whole, and the first rubber baffle plate 51 is supported on the second rubber baffle plate 52, and the first horizontal plate is supported on the top surface of the top cover 21; the four second wear-resistant plates 32 move toward the drill rod 4 under the action of the hydraulic cylinder and form a complete The round ring makes the inner wall of the second horizontal plate close to the drill rod 4; according to the specifications of the drill rod 4, the corresponding number of pistons 23 are started, and the pistons 23 move the steel ring 12 upward and squeeze the rubber. On the one hand, the rubber is squeezed and deformed, so that it is close to the vertical bar 53 and the drill rod 4. On the other hand, the second rubber baffle plate 52 will move up with the steel ring 12, and the first rubber baffle plate 51 will also move up along the vertical bar 53 under the action of the second rubber baffle plate 52. The second horizontal plate and the first rubber baffle plate 51 are used to limit the upward or downward flow of rubber, and can also improve the sealing performance of the blowout preventer.

[0056] The above embodiments are only used to illustrate the technical ideas and features of the present invention, and are not intended to be the only or limit the present invention. It should be understood by those skilled in the art that various changes or equivalent substitutions made to the present invention without departing from the scope of the present invention all fall within the scope of protection of the present invention.

Claims

1. A blowout preventer, It is characterized in that It comprises a blowout preventer body (2), a first wear-resistant plate (31) and a plurality of annular rubber cores; The blowout preventer body (2) comprises a top cover (21), an outer shell (22) and a plurality of pistons (23) arranged inside the blowout preventer body (2). A through groove (24) penetrating from top to bottom is provided at the center of the blowout preventer body (2). The through groove (24) is used to insert a drill pipe (4). The top cover (21) covers the outer shell (22). The first wear-resistant plate (31) is arranged at the bottom of the top cover (21); The annular rubber core comprises a rubber ring (11) and a steel ring (12) arranged on the bottom surface thereof, the two are bonded into one body by vulcanization, and the bonding surfaces of the two are of the same size. The plurality of annular rubber cores have the same thickness and different outer diameters, and are sequentially sleeved from the inside to the outside. The annular rubber core located at the outermost ring is in close contact with the inner wall of the outer shell (22), and the rubber ring (11) on the top surface of the annular rubber core is in close contact with the first wear-resistant plate (31). The plurality of pistons (23) are respectively connected to the steel rings (12) of the corresponding annular rubber cores, and are used to move the steel rings (12) upwards so that the rubber ring (11) at the innermost ring is in close contact with the drill pipe (4).

2. The blowout preventer according to claim 1, It is characterized in that The material of the steel ring (12) is 45# or Q345.

3. The blowout preventer according to claim 1, It is characterized in that It also includes a plurality of fan-shaped second wear-resistant plates (32) and two third wear-resistant plates (33), the radial cross-section of the third wear-resistant plate (33) is Z-shaped, and the two corners of the Z-shaped are both right angles. From top to bottom, it includes a first horizontal plate, a vertical plate, and a second horizontal plate. The two third wear-resistant plates (33) are symmetrically arranged on the top of the through groove (24), the first horizontal plate is supported on the top surface of the top cover (21), and the vertical plate and the second horizontal plate are located in the through groove (24). The top of the inner wall of the first wear-resistant plate (31) is provided with an annular groove (311), and the plurality of second wear-resistant plates (32) are arranged in a circumferential array in the annular groove (311). The second wear-resistant plates (32) are slidably arranged under the action of a power source, and when the plurality of second wear-resistant plates (32) move toward the drill rod (4) and form a complete ring, the inner wall of the second horizontal plate is used to make it close to the drill rod (4).

4. The blowout preventer according to claim 3, It is characterized in that An annular slot (331) is provided at the bottom or middle section of the outer wall of the second transverse plate. When the plurality of second wear-resistant plates (32) move toward the drill rod (4) and form a complete ring, the second wear-resistant plates (32) are inserted into the slot (331) and closely adhere to the second transverse plate.

5. The blowout preventer according to claim 3, It is characterized in that A T-shaped block (321) is provided on the top of the second wear-resistant plate (32), a T-shaped slot (211) is provided at a corresponding position of the top cover (21), and the T-shaped block (321) is slidably matched in the T-shaped slot (211).

6. The blowout preventer according to claim 3, It is characterized in that The second transverse plate is connected to the vertical plate through a plurality of bolts.

7. The blowout preventer according to claim 1, It is characterized in that The first wear-resistant plate (31) is fixedly connected to the top cover (21) via a plurality of bolts.

8. The blowout preventer according to claim 3, It is characterized in that It also comprises two first rubber baffle plates (51) and an annular second rubber baffle plate (52), the second rubber baffle plate (52) being arranged at the bottom of the innermost steel ring (12), the inner diameter of the second rubber baffle plate (52) being smaller than the diameter of the through groove (24), a plurality of vertical bars (53) being arranged at the bottom of the second horizontal plate, and the inner spacing between the vertical bars (53) and the drill rod (4) being smaller than 20 mm, the first rubber baffle plate (51) being provided with a plurality of through holes (511), the vertical bars (53) penetrating corresponding through holes (511), and a stopper (531) having a size larger than the vertical bar (53) being arranged at the bottom of the vertical bar (53), the first rubber baffle plate (51) being supported on the second rubber baffle plate (52), the inner diameter of the first rubber baffle plate (51) being consistent with the outer diameter of the drill rod (4), the outer diameter being consistent with the diameter of the through groove (24), and the thickness being smaller than the thickness of the steel ring (12).

9. The blowout preventer according to claim 8, It is characterized in that The vertical strips (53) are elastic.

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