A well drilling blowout preventer

Abstract

The application discloses a drilling blowout preventer, which comprises a base pipe, two fixed plates arranged on the two sides of the outer wall of the base pipe, a lower base plate fixedly arranged on the top of the base pipe, a gate valve device arranged above the lower base plate and comprising a first gate valve plate and a second gate valve plate arranged transversely, recesses arranged on the inner walls of the first gate valve plate and the second gate valve plate, and a same sealing ring arranged in the two recesses, a gland arranged above the gate valve device, and a second threaded fixing assembly comprising a screw rod and a first fixing nut, one side of the screw rod being respectively arranged through the fixed plates, the lower base plate and the gland and one side of the first gate valve plate and the second gate valve plate, and the other side of the screw rod being respectively arranged through the fixed plates, the lower base plate and the gland, and the first fixing nut being arranged on the screw rod. The structure is relatively simple, the manufacturing cost can be reduced, the sealing can be realized through manual operation, the matching requirements for the well site are reduced, the use cost can be reduced, and thus the overall cost can be effectively reduced by using the blowout preventer.

Description

Technical Field

[0001] This invention relates to the field of shale gas drilling equipment technology, and in particular to a drilling blowout preventer. Background Technology

[0002] During shale gas drilling, small amounts of toxic and harmful gases are produced. To prevent or reduce the spread of these gases at the well site, blowout preventers (BOPs) are required to avoid leakage from the wellhead. Common BOPs include universal BOPs, rotary BOPs, and annular BOPs. While there are many types of BOPs available on the market, most are designed for boreholes with high formation pressure. Therefore, their structures are relatively complex, and they require specialized hydraulic stations, power transmission, and electrical control systems to operate properly, resulting in higher overall operating costs.

[0003] For boreholes with low formation pressure, the pressure at which a blowout occurs is relatively small. Using a high-pressure blowout preventer (BOP) would be too costly, and its application in such boreholes would result in significant performance waste. Therefore, it is necessary to design a BOP suitable for boreholes with low formation pressure to reduce costs and effectively prevent or minimize the occurrence of blowout events. Summary of the Invention

[0004] The purpose of this invention is to provide a drilling blowout preventer that can reduce costs and prevent or reduce the occurrence of blowout events.

[0005] To achieve the above objectives, a drilling blowout preventer is provided, comprising:

[0006] The base tube has threads on its inner wall and fixing plates on both sides of its outer wall.

[0007] The lower pad is fixed to the top of the base tube and has a first through hole that runs vertically through it. The outer side wall of the lower pad is provided with a spray hole that connects to the first through hole.

[0008] The gate valve device, located above the lower pad, includes a first gate valve plate and a second gate valve plate arranged laterally. The longitudinal projections of one side of the first gate valve plate and the second gate valve plate overlap, and the other side is detachably connected by a first threaded fixing assembly. The first gate valve plate and the second gate valve plate form a second through hole that runs vertically through the bottom. The inner walls of the first gate valve plate and the second gate valve plate are provided with grooves, and the same sealing ring is provided in the two grooves.

[0009] A pressure cap is installed above the gate valve device and has a third through hole that runs vertically through the valve. The first through hole, the second through hole, and the third through hole are connected in sequence.

[0010] The second threaded fixing assembly includes a screw rod and a first fixing nut. The screw rod is configured as two and is respectively disposed on both sides of the base tube. The screw rod on one side passes through the fixing plate, the lower pad plate and the pressure cap, and passes through one side of the first gate valve plate and the second gate valve plate. The screw rod on the other side passes through the fixing plate, the lower pad plate and the pressure cap, and is located between the first gate valve plate and the second gate valve plate. The first fixing nut is fitted on the screw rod above the pressure cap and below the fixing plate.

[0011] According to the aforementioned drilling blowout preventer, rubber gaskets are provided between the lower pad and the gate valve device, and between the gate valve device and the pressure cap.

[0012] According to the aforementioned drilling blowout preventer, the inner wall of the blowout hole has threads.

[0013] According to the aforementioned drilling blowout preventer, the first gate valve plate and the second gate valve plate have opposing semicircular openings on their other sides, and the screw member on the other side is located inside the two semicircular openings.

[0014] According to the aforementioned drilling blowout preventer, the bottom surface of the lower pad has a stepped groove arranged around the first through hole, and the upper end of the base tube is inserted into the stepped groove.

[0015] According to the aforementioned drilling blowout preventer, the first threaded fixing assembly includes a fixing bolt, a second fixing nut, a sleeve, and a third fixing nut. Both the first and second gate valve plates have transverse notches on their other sides. The fixing bolt is vertically arranged and passes through the second gate valve plate and the notch on the second gate valve plate. The second fixing nut is sleeved on the fixing bolt above the second gate valve plate. The sleeve is horizontally arranged and sleeved on the fixing bolt within the notch on the second gate valve plate. The sleeve passes through the notch on the first gate valve plate and has external threads. The third fixing nut is fitted onto the sleeve.

[0016] According to the aforementioned drilling blowout preventer, it further includes two expansion mechanisms arranged opposite to each other. Each expansion mechanism includes an expansion plate, a top cover, a guide post, a spring member, and a locking assembly. The expansion plate is arc-shaped and vertically inserted into the third and second through holes, with its lower end located inside the sealing ring. The top cover is located above the pressure cap and is fixedly connected to the expansion plate. The top cover is sleeved on the screw member. The guide post is located at the bottom of the top cover. The guide post is configured as two of different lengths and arranged at intervals. The shorter guide post is inserted into the pressure cap, and the longer guide post passes through the pressure cap and extends below the pressure cap. The bottom side wall of the longer guide post has a limiting hole. The spring member is sleeved on the guide post above the pressure cap and connected to the top cover.

[0017] The top surfaces of the first gate valve plate and the second gate valve plate are each provided with a first receiving groove. The width of the first receiving groove is greater than the width of the guide post. The limiting holes of the two expansion mechanisms are each located in a first receiving groove. The first gate valve plate and the second gate valve plate are each provided with a locking component.

[0018] According to the aforementioned drilling blowout preventer, the locking assembly includes a second receiving groove, a limiting rod, a piston head, a threaded rod, a limiting plate, and a handle;

[0019] In the locking assembly on the second gate valve plate, the second receiving groove is opened on the outer side wall of the second gate valve plate, the limiting rod is slidably inserted into the second gate valve plate, and one end of the limiting rod is located in the first receiving groove and inserted into the limiting hole, and the other end is located in the second receiving groove. The width of the other end of the limiting rod is smaller than the width of the limiting hole. The piston head is slidably disposed in the second receiving groove. One end of the threaded rod is rotatably connected to the piston head, and the other end extends out of the second receiving groove. The limiting plate is fixedly disposed in the second receiving groove and is fitted onto the threaded rod. The handle is disposed at the end of the threaded rod away from the piston head.

[0020] According to the aforementioned drilling blowout preventer, the second gate valve plate has an air passage that connects the groove and the second receiving groove.

[0021] Beneficial effects:

[0022] As described above, during use, the blowout preventer is assembled on top of the casing, and the base tube can be fitted onto the top of the casing at the borehole head. The base tube is connected to the casing thread through the thread inside the base tube, making the blowout preventer easy to install and remove. When gas or other fluids are ejected, a seal is formed between the blowout preventer and the drill pipe, and the ejected fluid can be discharged through the vent hole to prevent it from overflowing uncontrollably at the well site, thereby effectively preventing or reducing the occurrence of blowout events.

[0023] The above structure is relatively simple, which can reduce manufacturing costs. It can also achieve sealing through manual operation, reducing the supporting requirements for the well site and thus reducing operating costs. Therefore, using the above blowout preventer can effectively reduce the overall cost.

[0024] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0025] The present invention will be further described below with reference to the accompanying drawings and embodiments;

[0026] Figure 1 This is a front view of the first embodiment of the present invention;

[0027] Figure 2 for Figure 1 A top view of the pressure cap shown;

[0028] Figure 3 for Figure 1 A top view of the lower pad shown;

[0029] Figure 4 This is a top view of the first gate valve plate;

[0030] Figure 5 This is a front view of the first gate valve plate;

[0031] Figure 6 This is a top view of the second gate valve plate;

[0032] Figure 7 This is a front view of the second gate valve plate;

[0033] Figure 8 for Figure 1 AA section view;

[0034] Figure 9 This is a front view of the second embodiment of the present invention;

[0035] Figure 10 Top view of the expansion plate and top cover;

[0036] Figure 11 for Figure 10 BB cross-sectional view;

[0037] Figure 12 This is a cross-sectional view of the second gate valve plate in the second embodiment of the present invention. Detailed Implementation

[0038] This section will describe in detail specific embodiments of the present invention. Preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the drawings is to supplement the textual description with graphics, so that people can intuitively and vividly understand each technical feature and overall technical solution of the present invention, but they should not be construed as limiting the scope of protection of the present invention.

[0039] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0040] In the description of this invention, terms such as greater than, less than, and exceeding are understood to exclude the stated number, while terms such as above, below, and within are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0041] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0042] Reference Figure 1-8 A drilling blowout preventer includes a base tube 10, a lower pad 20, a gate valve device 30, a pressure cap 40, and a second threaded fixing assembly 50. The inner wall of the base tube 10 is threaded, and fixing plates 11 are fixed on both sides of the outer wall. The lower pad 20 is fixed to the top of the base tube 10. The lower pad 20 has a first through hole 21 that runs vertically through it, and the outer wall of the lower pad 20 has a blowout hole 22 that communicates with the first through hole 21. The gate valve device 30 is located above the lower pad 20 and includes a first gate valve plate 31 and a second gate valve plate 32 arranged laterally. The longitudinal projections of one side of the first gate valve plate 31 and the second gate valve plate 32 overlap or completely overlap, and the other side is detachably connected by a first threaded fixing assembly 34. The first gate valve plate 31 and the second gate valve plate 32 form a second through hole 33 that runs vertically through the center. The inner walls of the first gate valve plate 31 and the second gate valve plate 32 are provided with grooves 311. The same sealing ring (not shown in the figure) is provided in the two grooves 311, that is, one side of the sealing ring is located in the groove 311 inside the first gate valve plate 31, and the other side of the sealing ring is located in the groove 311 inside the second gate valve plate 32. The pressure cap 40 is located above the gate valve device 30 and has a third through hole 41 that runs vertically through the center. The first through hole 21, the second through hole 33 and the third through hole 41 are connected in sequence.

[0043] The second threaded fixing assembly 50 includes a screw member 51 and a first fixing nut 52. The screw members 51 are configured as two and are respectively disposed on both sides of the base tube 10. The screw member 51 on one side passes through the fixing plate 11, the lower pad 20 and the pressure cap 40 respectively, and the screw member 51 also passes through one side of the first gate valve plate 31 and the second gate valve plate 32. The screw member 51 on the other side passes through the fixing plate 11, the lower pad 20 and the pressure cap 40 respectively, and the screw member 51 on the other side is located between the first gate valve plate 31 and the second gate valve plate 32. The first fixing nut 52 is fitted on the screw member 51 above the pressure cap 40 and below the fixing plate 11.

[0044] As described above, during use, the blowout preventer (BOP) is assembled on top of the casing. The base tube 10 can be fitted onto the top of the casing at the borehole head and connected to the casing threaded through the internal threads of the base tube 10, facilitating easy assembly and disassembly of the BOP. The drill pipe passes through the BOP and casing for construction, and the diameter of the drill pipe is smaller than the diameters of the first perforation 21, the second perforation 33, and the third perforation 41. In the event of gas or other fluid ejection, a seal is formed between the BOP and the drill pipe, and the ejected fluid can be discharged through the vent hole 22, preventing uncontrolled overflow at the well site and effectively preventing or reducing blowout events. The above structure is relatively simple, reducing manufacturing costs, and the ability to achieve sealing through manual operation reduces the requirements for well site support, thereby reducing operating costs. Thus, using the above-described BOP can effectively reduce costs.

[0045] The structure of this invention is suitable for use in drilling applications with low formation pressure, where the pressure at which a blowout occurs is relatively small, and the blowout preventer of this invention can effectively seal the well.

[0046] When assembling the blowout preventer (BOP) onto the top of the casing, the first threaded fixing assembly 34 and the second threaded fixing assembly 50 are not fully tightened initially to allow for movement between the components. This allows for fine-tuning during sealing and reduces wear on the sealing ring caused by contact with the drill pipe. When BOP is required, the positions of the components are fine-tuned before tightening the first threaded fixing assembly 34 and the second threaded fixing assembly 50 to ensure a good seal. Furthermore, when the casing sinks, the fixing plate 11 can support it at the wellhead to prevent further sinking.

[0047] In this embodiment, rubber gaskets (not shown in the figure) are provided between the lower pad 20 and the gate valve device 30, and between the gate valve device 30 and the pressure cap 40, to ensure the anti-spray sealing effect.

[0048] The inner wall of the vent 22 is threaded so that a pipe fitting can be installed to guide the ejected fluid to a set position.

[0049] In this embodiment, a screw 51 is inserted through the first gate valve plate 31 and the second gate valve plate 32, allowing one side of the first gate valve plate 31 and the second gate valve plate 32 to be rotatably connected. The other side of the first gate valve plate 31 and the second gate valve plate 32 has opposing semi-circular openings 312, and the screw 51 on the other side is located within the two semi-circular openings 312, so that the other sides of the first gate valve plate 31 and the second gate valve plate 32 can be in contact.

[0050] The bottom surface of the lower pad 20 has a stepped groove 23 arranged around the first through hole 21. The upper end of the base tube 10 is inserted into the stepped groove 23 so that the base tube 10 and the lower pad 20 can be aligned and positioned during processing.

[0051] In this embodiment, the first threaded fixing assembly 34 includes a fixing bolt 341, a second fixing nut 342, a sleeve 343, and a third fixing nut 344. The other side of the first gate valve plate 31 and the second gate valve plate 32 both have a transverse notch 313. The fixing bolt 341 is arranged vertically and passes through the notch 313 on the second gate valve plate 32. The second fixing nut 342 is sleeved on the fixing bolt 341 above the second gate valve plate 32. The sleeve 343 is arranged transversely and is sleeved on the fixing bolt 341 within the notch 313 on the second gate valve plate 32. The sleeve 343 passes through the notch 313 on the first gate valve plate 31 and has an external thread. The third fixing nut 344 is fitted onto the sleeve 343. By tightening the third fixing nut 344, the other side of the first gate valve plate 31 and the second gate valve plate 32 can be fixedly connected, and the screw member 51 on the other side is located between the first gate valve plate 31 and the second gate valve plate 32, which can restrict the transverse movement of the gate valve device 30.

[0052] In some embodiments, for the first threaded fixing assembly 34, a through hole can be provided laterally on the other side of the first gate valve plate 31 and the second gate valve plate 32, the fixing bolt 341 passes through the two through holes, the second fixing nut 342 is sleeved on the fixing bolt 341, and the diameter of the through hole is 1-4 mm larger than the diameter of the fixing bolt 341.

[0053] Reference Figure 9-12 In some embodiments, the blowout preventer also includes two oppositely arranged expansion mechanisms 60. When the blowout preventer seal is not required, the expansion mechanisms 60 can separate the sealing ring from the drill rod, avoiding contact wear between the sealing ring and the drill rod, and also preventing the sealing ring from dislodging from the groove 311 due to the twisting of the drill rod.

[0054] Specifically, each expansion mechanism 60 includes an expansion plate 61, a top cover 62, a guide post 63, a spring member 64, and a locking assembly 65. The expansion plate 61 is arc-shaped and vertically inserted into the third through hole 41 and the second through hole 33, with its lower end located inside the sealing ring. The top cover 62 is located above the pressure cover 40 and is fixedly connected to the expansion plate 61, and is sleeved on the screw member 51. The guide post 63 is located at the bottom of the top cover 62, and there are two guide posts 63 of different lengths arranged at intervals. The pressure cover 40 has insertion holes for the guide posts 63. The shorter guide post 63 is inserted into the pressure cover 40, and its bottom does not protrude from the bottom surface of the pressure cover 40. The longer guide post 63 passes through the pressure cover 40 and extends below the pressure cover 40, and its bottom side wall has a limiting hole 631. The spring member 64 is sleeved on the guide post 63 above the pressure cover 40 and connected to the top cover 62. The top surfaces of the first gate valve plate 31 and the second gate valve plate 32 are each provided with a first receiving groove 321. The width of the first receiving groove 321 is greater than the width of the guide post 63. The limiting holes 631 of the two expansion mechanisms 60 are each located in a first receiving groove 321. The first gate valve plate 31 and the second gate valve plate 32 are each provided with a locking component 65.

[0055] The locking assembly 65 includes a second receiving groove 651, a limiting rod 652, a piston head 653, a threaded rod 654, a limiting plate 655, and a handle 656. Taking the locking assembly 65 on the second gate valve plate 32 as an example, its second receiving groove 651 is opened on the outer side wall of the second gate valve plate 32, the limiting rod 652 is slidably inserted into the second gate valve plate 32, one end of the limiting rod 652 is located in the first receiving groove 321 and inserted into the limiting hole 631, the other end of the limiting rod 652 is located in the second receiving groove 651, the width of the other end of the limiting rod 652 is smaller than the width of the limiting hole 631, the piston head 653 is slidably disposed in the second receiving groove 651, one end of the threaded rod 654 is rotatably connected to the piston head 653, the other end extends out of the second receiving groove 651, the limiting plate 655 is fixedly disposed in the second receiving groove 651 and is fitted onto the threaded rod 654, and the handle 656 is disposed at the end of the threaded rod 654 away from the piston head 653.

[0056] The second receiving groove 65 of the locking component 65 on the first gate valve plate 31 is opened on the outer side wall of the first gate valve plate 31. The rest of the structure is the same as that on the second gate valve plate 32, and will not be described again here.

[0057] As described above, the width of the first receiving groove 321 is greater than the width of the guide post 63, and the width of the other end of the limiting rod 652 is less than the width of the limiting hole 631, so as to accommodate the fine-tuning movement of the gate valve device 30 and the pressure cap 40 before the blowout seal; and before the blowout seal, the expansion plate 61 separates the sealing ring from the drill rod to prevent it from contacting the drill rod and being worn.

[0058] When a blowout seal is required, turn handle 656 to move limit rod 652 out of limit hole 631. Spring 64 assists in pushing top cover 62 upward to indicate to the operator that limit rod 652 has moved out of limit hole 631. At this time, expansion plate 61 and top cover 62 can be pulled upward, sealing ring contacts drill rod, and first fixing nut 52 is exposed upward, which can be tightened. The requirement to pull out top cover 62 to expose first fixing nut 52 serves as a foolproof mechanism, preventing operators from tightening first fixing nut 52 before releasing expansion mechanism 60.

[0059] Furthermore, the second gate valve plate 32 has an air passage 322 that connects the groove 311 and the second receiving groove 651. When the expansion plate 61 is located inside the sealing ring, it squeezes the sealing ring, and the sealing ring is pressed against the inner wall surface of the groove 311. When the handle 656 is turned, the piston head 653 can also be driven to move, so that a negative pressure is formed in the air passage 322, which adsorbs and positions the sealing ring, preventing the sealing ring from moving with the expansion plate 61 and detaching from the groove 311 when the expansion plate 61 is pulled out.

[0060] The air passage 322 has multiple openings arranged along the groove 311 to ensure good adsorption and positioning of the sealing ring. Additionally, air holes may be provided on the limiting plate 655 to balance the internal and external air pressures.

[0061] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A drilling blowout preventer, characterized in that, include: The base tube has threads on its inner wall and fixing plates on both sides of its outer wall. The lower pad is fixed to the top of the base tube and has a first through hole that runs vertically through it. The outer side wall of the lower pad is provided with a spray hole that connects to the first through hole. The gate valve device, located above the lower pad, includes a first gate valve plate and a second gate valve plate arranged laterally. The longitudinal projections of one side of the first gate valve plate and the second gate valve plate overlap, and the other side is detachably connected by a first threaded fixing assembly. The first gate valve plate and the second gate valve plate form a second through hole that runs vertically through the bottom. The inner walls of the first gate valve plate and the second gate valve plate are provided with grooves, and the same sealing ring is provided in the two grooves. A pressure cap is installed above the gate valve device and has a third through hole that runs vertically through the valve. The first through hole, the second through hole, and the third through hole are connected in sequence. The second threaded fixing assembly includes a screw rod and a first fixing nut. The screw rod is configured as two and is respectively disposed on both sides of the base tube. The screw rod on one side passes through the fixing plate, the lower pad plate and the pressure cap, and passes through one side of the first gate valve plate and the second gate valve plate. The screw rod on the other side passes through the fixing plate, the lower pad plate and the pressure cap, and is located between the first gate valve plate and the second gate valve plate. The first fixing nut is fitted on the screw rod above the pressure cap and below the fixing plate. It also includes two expansion mechanisms arranged opposite to each other. Each expansion mechanism includes an expansion plate, a top cover, guide posts, spring members, and a locking assembly. The expansion plate is arc-shaped and vertically inserted into the third and second through holes, with the lower end of the expansion plate located inside the sealing ring. The top cover is located above the pressure cap and is fixedly connected to the expansion plate. The top cover is sleeved on the screw member. The guide posts are located at the bottom of the top cover. The guide posts are configured as two with different lengths and are arranged at intervals. The shorter guide post is inserted into the pressure cap, and the longer guide post passes through the pressure cap and extends to the bottom of the pressure cap. The bottom side wall of the longer guide post has a limiting hole. The spring member is sleeved on the guide post above the pressure cap and connected to the top cover. The top surfaces of the first gate valve plate and the second gate valve plate are each provided with a first receiving groove. The width of the first receiving groove is greater than the width of the guide post. The limiting holes of the two expansion mechanisms are each located in a first receiving groove. The first gate valve plate and the second gate valve plate are each provided with a locking component.

2. A drilling blowout preventer according to claim 1, characterized in that, Rubber gaskets are provided between the lower pad and the gate valve device, and between the gate valve device and the pressure cap.

3. A drilling blowout preventer according to claim 1, characterized in that, The inner wall of the vent hole has threads.

4. A drilling blowout preventer according to claim 1, characterized in that, The first gate valve plate and the second gate valve plate have oppositely arranged semi-circular openings on their other sides, and the screw member on the other side is located inside the two semi-circular openings.

5. A drilling blowout preventer according to claim 1, characterized in that, The bottom surface of the lower pad has a stepped groove arranged around the first through hole, and the upper end of the base tube is inserted into the stepped groove.

6. A drilling blowout preventer according to claim 1, characterized in that, The first threaded fixing assembly includes a fixing bolt, a second fixing nut, a sleeve, and a third fixing nut. The first gate valve plate and the second gate valve plate each have a transverse notch on their other side. The fixing bolt is arranged vertically and passes through the second gate valve plate and the notch on the second gate valve plate. The second fixing nut is sleeved on the fixing bolt above the second gate valve plate. The sleeve is arranged transversely and is sleeved on the fixing bolt within the notch on the second gate valve plate. The sleeve passes through the notch on the first gate valve plate and has external threads. The third fixing nut is fitted onto the sleeve.

7. A drilling blowout preventer according to claim 1, characterized in that, The locking assembly includes a second receiving groove, a limiting rod, a piston head, a threaded rod, a limiting plate, and a handle; In the locking assembly on the second gate valve plate, the second receiving groove is opened on the outer side wall of the second gate valve plate, the limiting rod is slidably inserted into the second gate valve plate, and one end of the limiting rod is located in the first receiving groove and inserted into the limiting hole, and the other end is located in the second receiving groove. The width of the other end of the limiting rod is smaller than the width of the limiting hole. The piston head is slidably disposed in the second receiving groove. One end of the threaded rod is rotatably connected to the piston head, and the other end extends out of the second receiving groove. The limiting plate is fixedly disposed in the second receiving groove and is fitted onto the threaded rod. The handle is disposed at the end of the threaded rod away from the piston head.

8. A drilling blowout preventer according to claim 7, characterized in that, The second gate valve plate has an air passage that connects the groove and the second receiving groove.

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