Spherical rubber core structure and blowout preventer thereof

Abstract

The invention discloses a spherical rubber core structure and a blowout preventer thereof, and belongs to the technical field of petroleum drilling equipment. The skeleton structure comprises a plurality of inner skeletons and a plurality of outer skeletons, one outer skeleton is located at a gap between every two adjacent inner skeletons, the stop block structure comprises a stop block and a sliding piece, and the stop block is in sliding connection with the sliding piece; according to the spherical rubber core structure disclosed by the invention, by adopting an inner-outer double-layer framework structure, when a well is sealed, a gap between adjacent inner frameworks or adjacent outer frameworks is greatly reduced compared with a gap between traditional spherical rubber core frameworks, and more reliable performance is provided for bearing a high-temperature and high-pressure ring shape; meanwhile, the stop block structure is arranged at the bottom of the rubber core main body, and a sliding piece and a stop block of the stop block structure can be matched with the rubber core main body to do telescopic motion and swing motion, so that the flowing of rubber at the bottom of the rubber core main body can be controlled, the use of available rubber is greatly increased, and the service life of the spherical rubber core structure can be greatly prolonged.

Description

Technical Field

[0001] The invention belongs to the technical field of petroleum drilling equipment, and in particular relates to a spherical rubber core structure and a blowout preventer thereof. Background Art

[0002] In recent years, with the development of China's oil drilling technology and the development of 10,000-meter deep wells in the oil industry, the oil drilling environment has also undergone great changes, requiring well control equipment to be resistant to high pressure and high temperature, adapt to new drilling media, and have a long service life.

[0003] For the development of 10,000-meter deep wells, due to deeper drilling, the fluid pressure and temperature in the well are higher; at the same time, major oil fields promote the use of oil-based mud instead of water-based mud in the drilling process. These factors have put forward new requirements for the rubber core of the blowout preventer.

[0004] In the oilfield drilling process, the well control equipment, i.e. the wellhead pressure control equipment, is mainly composed of gate blowout preventers and annular blowout preventers. There are two main types of annular blowout preventers: spherical structure rubber core and conical structure rubber core.

[0005] The traditional spherical rubber core is made of nitrile rubber. Figure 1 As shown, several skeletons are evenly embedded inside for support. When the blowout preventer is closed, the piston moves upward to push the skeleton in the spherical rubber core to move along the inner spherical surface of the top cover toward the center. At the same time, the volume of the top cover decreases, and the rubber of the spherical rubber core moves into the diameter under the joint action of the piston and the skeleton, thus sealing the drilling string or wellbore, that is, sealing the empty well.

[0006] The skeleton is a separate entity, shaped like a partial arc cone. When it is in the initial state of the spherical rubber core, there is a large gap between the skeletons. When it seals the pipe string or seals an empty well, the skeletons cannot fit completely together, and there is still a gap between them. This structure is very likely to cause the rubber to break and age when sealing high pressure, especially when sealing high-temperature well fluid, causing the sealing failure of the spherical rubber core.

[0007] In the process of closing the BOP, the conventional spherical rubber core of the prior art solution has a large amount of rubber stored in it, so a part of the rubber will be squeezed and deformed into the inside of the BOP. This part of the rubber has the largest deformation, and its corresponding tensile stress is the largest. After the long-term opening and closing operation of the BOP, the rubber at the bottom of the spherical rubber core is prone to fatigue fracture, causing its function to fail.

[0008] Furthermore, major oil fields are now promoting oil-based mud instead of water-based mud. Although oil-based mud has better lubrication performance and better gravel and rock carrying capacity than water-based mud, it is more likely to be similar to rubber molecules, destroying the rubber molecular structure, causing the spherical rubber core to age and fail, and reducing the service life of the spherical rubber core.

[0009] There is an urgent need to propose a spherical rubber core structure and its blowout preventer to solve the above technical problems. Summary of the Invention

[0010] The object of the present invention is to provide a spherical rubber core structure and its blowout preventer to solve the above problems. The spherical rubber core structure disclosed by the present invention adopts an inner and outer double-layer skeleton structure. When sealing the well, the gap between adjacent inner skeletons or adjacent outer skeletons is greatly reduced compared with the gap between the skeletons of the traditional spherical rubber core, providing more reliable performance for withstanding high-temperature and high-pressure annulus; at the same time, a stop block structure is arranged at the bottom of the rubber core body. The sliding part and the stop block of the stop block structure can cooperate with the rubber core body to perform telescopic movement and swinging movement, so as to control the flow of the rubber at the bottom of the rubber core body, greatly increasing the use of available rubber and greatly increasing the service life of the spherical rubber core structure; under the cooperation of the inner and outer double-layer skeleton structure and the stop block structure, when the wellbore string in the well or the well is in an empty well state, the rubber can be tightly wrapped. This can ensure that on the premise of realizing its sealing, less rubber is in contact with the drilling fluid, that is, oil-based mud, thereby reducing the rubber aging caused by the principle of like dissolves like and improving the service life of the spherical rubber core structure.

[0011] To achieve the above object, the present invention provides the following solutions: The present invention discloses a spherical rubber core structure, including:

[0012] A rubber core body;

[0013] A skeleton structure, the skeleton structure and the rubber core body are integrally formed structures, including a plurality of inner skeletons and a plurality of outer skeletons. One outer skeleton is located at the gap between two adjacent inner skeletons, and the inner skeletons are located inside the outer skeletons. The number of the inner skeletons is the same as that of the outer skeletons. When sealing the well, the oil pushes the piston to move upward, so that the inner skeletons and the outer skeletons move toward the center position. The gap between one inner skeleton and another adjacent inner skeleton or the gap between one outer skeleton and another adjacent outer skeleton gradually becomes smaller until they overlap at the top to form a circle;

[0014] A stop block structure, including a stop block and a sliding part. The stop block and the rubber core body are integrally formed structures. The sliding parts are respectively arranged at the bottom of one inner skeleton or one outer skeleton, and there is a swinging space for the sliding part on one inner skeleton or one outer skeleton close to the center position of the rubber core body. The stop block is slidably connected with the sliding part. When sealing the well, the stop block moves in the sliding part along the first direction until the top of the skeleton structure overlaps to form a circle; when opening, the stop block moves in the sliding part along the second direction until the blowout preventer is in an open state. The moving directions of the first direction and the second direction are opposite.

[0015] Preferably, the stop block includes:

[0016] A stopper body vulcanized and formed at the bottom of the rubber core body;

[0017] A guide rod, the stopper and the guide rod are integrally formed, and the guide rod is slidably connected within the slider.

[0018] Preferably, the slider includes:

[0019] A sliding sleeve, one end of the sliding sleeve is embedded at the bottom of one of the inner skeletons or the outer skeletons, the other end of the sliding sleeve is slidably connected within the guide rod, and the end connected to the guide rod is located within the swing space;

[0020] A plugging member, the plugging member enters from the outside of one of the inner skeletons or the outer skeletons to the outside, and is detachably connected to the sliding sleeve.

[0021] Preferably, a screw is threadedly connected to the end of the guide rod away from the stopper, the screw is located within the sliding sleeve, when the guide rod moves within the sliding sleeve, the screw defines the movement stroke of the guide rod, and thus defines the movement stroke of the stopper.

[0022] Preferably, one of the inner skeletons or the outer skeletons is respectively provided with a mounting hole Ⅰ, a mounting hole Ⅱ and a mounting hole Ⅲ at the bottom, and the centers of the mounting hole Ⅰ, the mounting hole Ⅱ and the mounting hole Ⅲ are on the same center line, the sliding sleeve is located within the mounting hole Ⅱ and the mounting hole Ⅲ, the plugging member is located within the mounting hole Ⅰ, the mounting hole Ⅲ is the swing space of the sliding sleeve, and the aperture of the mounting hole Ⅲ is larger than the aperture of the mounting hole Ⅱ, and the aperture of the mounting hole Ⅲ is larger than the outer diameter of the sliding sleeve, ensuring that the sliding sleeve can perform up-and-down swing movement within the mounting hole Ⅲ.

[0023] Preferably, the sliding sleeve is a ball head sleeve, the plugging member is a ball head screw plug, the ball head screw plug is threadedly connected within the inner skeleton or the outer skeleton, and is adapted to the ball head of the ball head sleeve.

[0024] Preferably, the cross-sectional shape of the stopper body is a triangular-like structure.

[0025] Preferably, the stopper structure is a rigid structure.

[0026] Preferably, a plurality of grooves are provided at the bottom of the rubber core body, and the positions of the grooves are between the gaps of two adjacent inner skeletons.

[0027] To achieve the above object, the present invention also provides the following solution: The present invention also discloses a blowout preventer, including a cover body, a housing, a piston and the above-mentioned spherical rubber core structure located within the cover body and the housing, and the spherical rubber core structure is located above the piston.

[0028] Compared with the prior art, the present invention has the following advantages and technical effects: The spherical rubber core structure disclosed by the present invention adopts an inner and outer double-layer skeleton structure. When sealing the well, the gap between adjacent inner skeletons or adjacent outer skeletons is greatly reduced compared with the gap between the traditional spherical rubber core skeletons, providing more reliable performance for withstanding high-temperature and high-pressure annuli; at the same time, a stop block structure is provided at the bottom of the rubber core body. The sliding part and the stop block of the stop block structure can cooperate with the rubber core body to perform telescopic movement and swinging movement, so as to control the flow of the rubber at the bottom of the rubber core body, greatly increasing the use of available rubber and greatly increasing the service life of the spherical rubber core structure; with the cooperation of the inner and outer double-layer skeleton structure and the stop block structure, when the wellbore string or the well is in an empty well state, the rubber can be tightly wrapped. This can ensure that on the premise of achieving its sealing, less rubber comes into contact with the drilling fluid, i.e., oil-based mud, thereby reducing the aging of the rubber caused by the principle of similar solubility and improving the service life of the spherical rubber core structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings:

[0030] Figure 1 is a schematic structural diagram of a spherical rubber core structure in the prior art;

[0031] Figure 2 is a schematic structural diagram of the spherical rubber core structure disclosed by the present invention;

[0032] Figure 3 is Figure 2 a cross-sectional view taken along the C-C direction in

[0033] Figure 4 is Figure 2 a partial cross-sectional view of the spherical rubber core structure in

[0034] Figure 5 is a schematic structural diagram of the skeleton structure;

[0035] Figure 6 is a bottom view of the spherical rubber core structure disclosed by the present invention;

[0036] Figure 7 is a top view of the spherical rubber core structure disclosed by the present invention;

[0037] Figure 8 is Figure 7 a cross-sectional view taken along the D-D direction in

[0038] Figure 9 is Figure 8 a partial enlarged view of A in

[0039] Figure 10 a schematic structural view of the final state of the deformation of the skeleton structure in the present invention;

[0040] Figure 11 a schematic structural view of the open state of the blowout preventer in the present invention;

[0041] Figure 12 a schematic structural view of the closed state of the blowout preventer in the present invention;

[0042] Wherein, 1, rubber core body; 2, skeleton structure; 21, inner skeleton; 22, outer skeleton; 3, stopper structure; 31, stopper; 311, stopper body; 312, guide rod; 32, sliding member; 321, sliding sleeve; 322, screw; 323, ball head plug; 324, mounting hole Ⅰ; 325, mounting hole Ⅱ; 326, mounting hole Ⅲ; 4, groove; 5, cover body; 6, housing; 7, piston; 8, through hole. Specific embodiments

[0043] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with 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. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0044] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0045] As Figures 1-12 shown, the present invention discloses a spherical rubber core structure, including:

[0046] rubber core body 1;

[0047] skeleton structure 2, the skeleton structure 2 and the rubber core body 1 are integrally formed structures, including a plurality of inner skeletons 21 and a plurality of outer skeletons 22. One outer skeleton 22 is located at the gap between two adjacent inner skeletons 21, and the inner skeleton 21 is located inside the outer skeleton 22. The number of the inner skeletons 21 is the same as that of the outer skeletons 22. When sealing the well, the oil fluid pushes the piston upward, causing the inner skeletons 21 and the outer skeletons 22 to move towards the center position. The gap between one inner skeleton 21 and another adjacent inner skeleton 21 or the gap between one outer skeleton 22 and another adjacent outer skeleton 22 gradually becomes smaller until they overlap into a circle at the top;

[0048] The stopper structure 3 includes a stopper 31 and a sliding member 32. The stopper 31 and the rubber core body 1 are of an integrally formed structure. The sliding member 32 is respectively arranged at the bottom of one of the inner skeletons 21 or one of the outer skeletons 22, and there is a swinging space for the sliding member 32 on one of the inner skeletons 21 or one of the outer skeletons 22 close to the center position of the rubber core body 1. The stopper 31 is in sliding connection with the sliding member 32. When sealing the well, the stopper 31 moves in the sliding member 32 along the first direction until the tops of the skeleton structures 2 overlap to form a circle; when opening, the stopper 31 moves in the sliding member 32 along the second direction until the blowout preventer is in an open state, and the moving directions of the first direction and the second direction are opposite.

[0049] Specifically, as Figure 3 shown, wherein the rubber core body 1 is made of vulcanized sealing rubber; as Figure 4 shown, wherein the inner skeleton 21 and the outer skeleton 22 are arranged in a laminated manner, that is, the inner skeleton 21 is located inside the outer skeleton 22, and each inner skeleton 21 and outer skeleton 22 is a small fan-shaped surface. When several inner skeletons 21 overlap, a complete circle is formed. Similarly, when several outer skeletons 22 overlap, a complete circle can also be formed. The inner skeleton 21 is used for the inner support when the rubber core body 1 deforms, squeezing the rubber core body 1 to deform, and the outer skeleton 22 is used for the outer support when the rubber core body 1 deforms, squeezing the rubber core body 1 to deform; at the same time, the fan-shaped surface of each outer skeleton 22 is located at the gap between two adjacent inner skeletons 21. When the rubber core body 1 is squeezed and deformed, the gap between adjacent inner skeletons 21 becomes smaller. At the same time, the gap between two adjacent outer skeletons 22 also becomes smaller, and at the same time, the outer skeleton 22 closely adheres to the gap between the two inner skeletons 21, which further ensures the sealing performance of the entire skeleton structure 2, and thus ensures that the entire spherical rubber core structure can operate in an environment with higher pressure and higher temperature; in addition, the inner skeletons 21 and the outer skeletons 22 are evenly distributed in the rubber core body 1; due to the control of the rubber movement by the skeleton structure 2, the maximum deformation of the rubber can be greatly reduced. Therefore, the design application range of the rubber core body 1 can be increased, that is, rubber raw materials with lower tensile strength and lower elongation rate can be used to produce the rubber core body 1.

[0050] As Figure 3 and Figure 4As shown in the figure, in order to further ensure the sealing performance and stability, the stop block structure 3 is a rigid structure and can be made of metal. When the blowout preventer seals the well, the stop block 31 moves towards the center with the rubber core body 1. The stop block 31 slides within the sliding member 32 until a circle is formed at the top of the inner and outer double-layer skeleton structure 2 and a circle is formed at the bottom of the rubber core body 1 and tightly adheres to the well tubular column, thus ensuring the sealing performance at the bottom of the rubber core body 1. Moreover, the stop block structure 3 can control the flow of the rubber at the bottom of the spherical rubber core structure, greatly increasing the utilization of the available rubber, and further greatly increasing the service life of the spherical rubber core structure. The settings of the inner and outer double-layer skeleton structure 2 and the stop block structure 3 can ensure the double sealing of the well tubular column, and thus the entire structure can withstand well fluids at higher temperatures and higher pressures in an oil-based mud environment and ensure long-term stable operation.

[0051] For a further optimized solution, the stop block 31 includes:

[0052] A stop block body 311, which is vulcanized and formed at the bottom of the rubber core body 1;

[0053] A guide rod 312, the stop block 31 and the guide rod 312 are integrally formed structures, and the guide rod 312 is slidably connected within the sliding member 32.

[0054] Furthermore, the sliding member 32 includes:

[0055] A sliding sleeve 321, one end of the sliding sleeve 321 is embedded at the bottom of one of the inner skeletons 21 or one of the outer skeletons 22, the other end of the sliding sleeve 321 is slidably connected within the guide rod 312, and the end slidably connected to the guide rod 312 is located within the swing space;

[0056] A plugging member, the plugging member enters from the outside of one of the inner skeletons 21 or one of the outer skeletons 22 to the outside and is detachably connected to the sliding sleeve 321.

[0057] Still further, a screw 322 is threadedly connected to the end of the guide rod 312 away from the stop block 31. The screw 322 is located within the sliding sleeve 321. When the guide rod 312 moves within the sliding sleeve 321, the screw 322 limits the movement stroke of the guide rod 312, and thus limits the movement stroke of the stop block 31.

[0058] Specifically, as Figure 5As shown, the cross-sectional shape of the stopper body 311 is a triangular-like structure. The triangular structure can not only ensure stability but also further ensure the clamping of the pipe string in the well. When the blowout preventer is closed, the piston moves upward. At this time, the piston pushes the rubber core body 1 upward. Since the inner and outer double-layer skeleton structure 2 and the rubber core body 1 are integrally vulcanized, the inner skeleton 21 and the outer skeleton 22 swing along the swing space. In this way, the gaps between adjacent inner skeletons 21 and the gaps between adjacent outer skeletons 22 gradually become smaller until the tops of several inner skeletons 21 and outer skeletons 22 form a circle. At the same time, the stopper body 311 will move towards its center along with the rubber core body 1, and the guide rod 312 slides in the sliding sleeve 321 until several stopper bodies 311 clamp the pipe string in the well, thereby ensuring the sealing performance. The setting of the stopper 31 can not only effectively control the movement of the rubber inside the spherical rubber core, improve its service life, but also prevent cracks from appearing in the rubber core body 1 under high pressure and contact and blend with the oil-based mud to reduce its life. Such a setting can form a spherical rubber core structure that can operate stably in the oil-based mud for a long time. In addition, the number of stopper bodies 311 is the same as the number of inner and outer skeletons 22. There is a step at the front end of the stopper body 311, and there are several through holes 8 on the bottom surface. The setting of the through holes 8 enables the stopper body 311 and the rubber core body 1 to be integrally vulcanized, so that the stopper body 31 will move together with the rubber core body 1. The stopper body 311 moves along with the rubber core body 1 and moves closer to each other.

[0059] In a further optimized solution, an installation hole I 324, an installation hole II 325, and an installation hole III 326 are respectively formed at the bottom of one of the inner skeletons 21 or one of the outer skeletons 22, and the centers of the installation hole I 324, the installation hole II 325, and the installation hole III 326 are on the same center line. The sliding sleeve 321 is located in the installation hole II 325 and the installation hole III 326, the plugging member is located in the installation hole I 324, the installation hole III 326 is the swing space of the sliding sleeve 321, and the aperture of the installation hole III 326 is larger than the aperture of the installation hole II 325, and the aperture of the installation hole III 326 is larger than the outer diameter of the sliding sleeve 321, ensuring that the sliding sleeve 321 can perform up and down swing movement in the installation hole III 326.

[0060] In a further optimized solution, the sliding sleeve 321 is a ball head sleeve, the plugging member is a ball head screw plug 323, the ball head screw plug 323 is threadedly connected in the inner skeleton 21 or the outer skeleton 22, and is adapted to the ball head of the ball head sleeve.

[0061] Specifically, as Figure 8 and Figure 9As shown in the figure, in order to ensure the swinging movement of the inner framework 21 and the outer framework 22, the aperture of the mounting hole Ⅲ326 is larger than that of the mounting hole Ⅱ325, so that the inner framework 21 and the outer framework 22 can move within them when contracting and expanding. The cross-section of the mounting hole Ⅲ326 is a sector structure.

[0062] In a further optimized solution, a plurality of grooves 4 are provided at the bottom of the rubber core body 1, and the positions of the grooves 4 are between the gaps of two adjacent inner frameworks 21.

[0063] Specifically, as Figure 4 shown in the figure, in order to ensure that when the inner framework 21 and the outer framework 22 are closed, they cannot be completely closed, a plurality of grooves 4 are provided at the bottom of the rubber core body 1, and the positions of the grooves 4 are between the gaps of two adjacent inner frameworks 21, so that when the inner framework 21 and the outer framework 22 are closed, they will not turn up.

[0064] As Figures 10-12 shown in the figure, the present invention also discloses a blowout preventer, which includes a cover body 5, a housing 6, a piston 7 and the above-mentioned spherical rubber core structure located in the cover body 5 and the housing 6, and the spherical rubber core structure is located above the piston 7.

[0065] Specifically, the outer dimension of the spherical rubber core structure is the same as that of the traditional spherical rubber core, and it can be universal with the blowout preventers on the market. As Figure 11 shown in the figure, initial state: The spherical rubber core structure is installed in the blowout preventer, that is, installed in the cover body 5 and the housing 6, and located above the piston 7. The blowout preventer is opened and closed through a hydraulic control system. In the initial state, the blowout preventer is in the open state, and the piston 7 is at the bottommost position. The spherical rubber core structure is installed inside the blowout preventer, above the piston 7. In the initial state, the spherical rubber core is in a relaxed state, the bottom of the spherical rubber core structure is in contact with the upper end surface of the piston 7. The outer spherical surface of the spherical rubber core structure is in contact with the inner spherical surface of the top cover. The inner framework 21 and the outer framework 22 of the spherical rubber core structure are both in the initial state.

[0066] As Figure 12As shown in the figure, in the closed state: the blowout preventer is in the closed state. The piston moves upward under the action of high-pressure hydraulic fluid, squeezing the spherical rubber core structure. The outer skeleton 22 and the inner skeleton 21 of the spherical rubber core structure are in contact with the spherical surface of the top cover and move towards the middle along the spherical surface. The inner and outer skeletons 22 contract, and the rubber core body 1 moves towards the center due to the extrusion of the inner and outer skeletons 22, which can achieve the sealing of the internal pipe string or directly seal the wellhead. During use, the inner skeleton 21 and the outer skeleton 22 are overlapped. When moving towards the center of the rubber core body 1, the overlapping surface becomes larger and larger, and the top seal of the spherical rubber core structure becomes better and better. When the blowout preventer is completely closed, the inner and outer skeletons 22 will completely coincide, leaving only a very small hole in the middle. At the same time, due to the flow of the rubber core body 1, the block 31 at the bottom of the rubber core body 1 is driven to move. The block 31 can perform telescopic movement and up-and-down swing through the ball head sleeve, and there are gaps in the hole. This can well control the flow of the rubber. At the same time, the block 31 is a triangular structure. When the ball core is completely closed, this structure can better seal the rubber, making the rubber completely in the space surrounded by the skeleton. Therefore, the rubber can better seal the pipe string, seal higher pressures, and withstand higher well fluid temperatures.

[0067] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0068] The embodiments described above are only for describing the preferred mode of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention should fall within the protection scope determined by the claims of the present invention.

Claims

1. A spherical rubber core structure, characterized in that: include: Rubber core body (1); A skeleton structure (2), wherein the skeleton structure (2) and the rubber core body (1) are an integrally formed structure, comprising a plurality of inner skeletons (21) and a plurality of outer skeletons (22), wherein one outer skeleton (22) is located at a gap between two adjacent inner skeletons (21), and the inner skeleton (21) is located on the inner side of the outer skeleton (22), and the number of the inner skeletons (21) and the outer skeletons (22) is the same. When sealing the well, the oil pushes the piston upward, so that the inner skeleton (21) and the outer skeleton (22) move toward the center position, and the gap between one inner skeleton (21) and another adjacent inner skeleton (21) or one outer skeleton (22) and another adjacent outer skeleton (22) gradually decreases until the tops overlap to form a circle; The block structure (3) comprises a block (31) and a sliding member (32). The block (31) and the rubber core body (1) are integrally formed structures. The sliding member (32) is respectively arranged at the bottom of an inner frame (21) or an outer frame (22), and a swinging space for the sliding member (32) is reserved on an inner frame (21) or an outer frame (22) close to the center of the rubber core body (1). The block (31) and the sliding member (32) are in sliding connection. When sealing the well, the block (31) moves in the sliding member (32) along a first direction until the top of the frame structure (2) overlaps to form a circle; when opening, the block (31) moves in the sliding member (32) along a second direction until the blowout preventer is in an open state. The moving directions of the first direction and the second direction are opposite.

2. The spherical rubber core structure according to claim 1, characterized in that: The stopper (31) comprises: A block body (311), wherein the block body (311) is vulcanized and formed at the bottom of the rubber core body (1); The guide rod (312), the stopper (31) and the guide rod (312) are an integrally formed structure, and the guide rod (312) is slidably connected in the sliding member (32).

3. The spherical rubber core structure according to claim 2, characterized in that: The sliding member (32) comprises: A sliding sleeve (321), one end of the sliding sleeve (321) is embedded in the bottom of one of the inner skeletons (21) or one of the outer skeletons (22), the other end of the sliding sleeve (321) is slidably connected in the guide rod (312), and the end slidably connected with the guide rod (312) is located in the swing space; A blocking piece is inserted from the outside of an inner frame (21) or an outer frame (22) toward the outside thereof, and is detachably connected to the sliding sleeve (321).

4. The spherical rubber core structure according to claim 3, characterized in that: One end of the guide rod (312) away from the stopper (31) is threadedly connected with a screw (322), and the screw (322) is located in the sliding sleeve (321). When the guide rod (312) moves in the sliding sleeve (321), the screw (322) limits the movement stroke of the guide rod (312), thereby limiting the movement stroke of the stopper (31).

5. The spherical rubber core structure according to claim 3, characterized in that: An inner frame (21) or an outer frame (22) is provided with a mounting hole I (324), a mounting hole II (325) and a mounting hole III (326) at the bottom thereof, and the centers of the mounting holes I (324), II (325) and III (326) are located on the same center line; the sliding sleeve (321) is located in the mounting hole II (325) and the mounting hole III (326); the blocking member is located in the mounting hole I (324); the mounting hole III (326) is a swinging space for the sliding sleeve (321); and the aperture of the mounting hole III (326) is larger than the aperture of the mounting hole II (325); the aperture of the mounting hole III (326) is larger than the outer diameter of the sliding sleeve (321), thereby ensuring that the sliding sleeve (321) can realize up and down swinging motion in the mounting hole III (326).

6. The spherical rubber core structure according to claim 3, characterized in that: The sliding sleeve (321) is a ball head sleeve, and the sealing member is a ball head screw plug (323). The ball head screw plug (323) is threadedly connected in the inner frame (21) or the outer frame (22) and is adapted to the ball head of the ball head sleeve.

7. The spherical rubber core structure according to claim 2, characterized in that: The cross-sectional shape of the block body (311) is a triangular structure.

8. The spherical rubber core structure according to claim 1, characterized in that: The stopper structure (3) is a rigid structure.

9. The spherical rubber core structure according to claim 1, characterized in that: A plurality of grooves (4) are provided at the bottom of the rubber core body (1), and the grooves (4) are located between the gaps of two adjacent inner skeletons (21).

10. A blowout preventer, characterized in that: It comprises a cover body (5), a shell (6), a piston (7), and the spherical rubber core structure according to claim 1 located inside the cover body (5) and the shell (6), wherein the spherical rubber core structure is located above the piston (7).

Images