A rapid pressure relief device for a perforating gun used in oil and gas wells

Abstract

This application discloses a rapid pressure relief device for a perforating gun used in oil and gas wells, relating to the technical field of oil and gas well perforation. The device includes: a cartridge and end caps threaded onto both ends of the cartridge. The pressure relief device further includes: multiple pressure relief holes formed on the wall of the end caps, with plugs hingedly installed within each pressure relief hole. A pressure piston is also slidably disposed within the end caps. A connecting rod is hinged between the pressure piston and each plug. When the detonation gas pressure pushes the pressure piston to slide, the connecting rod converts the axial movement into an outward flipping motion of the plug around a flipping axis, causing the pressure relief holes to open rapidly, achieving high-flow-rate rapid pressure relief. After pressure relief is completed, the pressure block on the reset block, driven by a reset spring, pushes the plugs to flip back and reset via a locking foot, forming a reliable seal with the annular sealing gasket between the cap and the outer opening of the pressure relief hole. This allows for repeated use, greatly saving on operating costs.

Description

Technical Field

[0001] This application relates to the technical field of oil and gas well perforation, and more specifically, to a rapid pressure relief device for a perforation gun used in oil and gas wells. Background Technology

[0002] Perforation is a key process in oil and gas well completion engineering. Its basic principle is to use the high-speed metal jet generated by the explosion of the perforation bullet in the perforation gun to penetrate the casing, cement sheath and enter the formation, and establish a flow channel between the wellbore and the oil and gas layer. The perforation gun is usually composed of gun body (bullet rack), perforation bullet, detonation device and two end connectors. During operation, it is lowered to the predetermined depth and then ignited.

[0003] The detonation of a perforating projectile generates enormous high-pressure gas inside the gun body, with peak pressures reaching 100-200 MPa and temperatures reaching thousands of degrees Celsius. If this high-pressure gas cannot be released from the gun body in a timely and effective manner, the following technical problems will occur: Firstly, there is a risk of damage to the gun body structure. If the high-pressure gas cannot be discharged in time, it will cause uncontrollable radial expansion (diameter expansion) of the gun body. In severe cases, it will cause the gun body to burst. When the perforating gun with expanded diameter is pulled out of the well, it is prone to jamming. At best, it will increase the time and cost of the retrieval operation, and at worst, it will lead to the scrapping of the well.

[0004] Secondly, secondary damage to the casing and formation: the residual high-pressure gas continues to expand after perforation, which may cause unexpected secondary impacts on the formed perforation channel, destroying the integrity of the channel and affecting the efficiency of oil and gas flow.

[0005] Third, the special challenges of deep-sea operation environment: In deep-sea (water depth exceeding 1000 meters) and ultra-deep-water (water depth exceeding 3000 meters) drilling, the perforating gun needs to withstand external hydrostatic pressure of several megapascals to tens of megapascals. The sealing structure of the existing pressure relief device is prone to leakage under such high pressure. Seawater entering the gun body will cause the perforating bullet to become damp and fail. At the same time, the low temperature environment of deep sea will affect the performance of elastic seals and shear elements, causing the pressure relief response threshold to drift and the reliability to decrease significantly.

[0006] Existing perforation gun pressure relief technologies, such as the oil and gas well enhancement perforation gun disclosed in Chinese patent CN99221047.X, involve machining blind holes in the gun barrel wall and covering the bottom of the blind holes with rubber plugs. During perforation detonation, high-pressure gas forces open the rubber plugs to relieve pressure. Another example is a composite perforation gun disclosed in Chinese patent CN2811558Y, which uses a composite countersunk hole structure composed of two or more intersecting circular countersunk holes to expand the pressure relief area. However, the inventors recognized that while such solutions are simple in structure and have a fast response speed, they have significant drawbacks. The rubber plugs are prone to aging in the high-pressure environment of the deep sea, and relying solely on rubber plugs for sealing makes leakage very easy. Furthermore, the remaining wall thickness of the blind holes needs to be precisely calculated, requiring high manufacturing precision. Moreover, the structure is irreversible after pressure relief and cannot be reused, significantly increasing operating costs in deep-sea operations.

[0007] To address the aforementioned issues, we provide a rapid pressure relief device for a perforating gun used in oil and gas wells. Summary of the Invention

[0008] To address the problems mentioned in the background art, this application provides a rapid pressure relief device for a perforating gun used in oil and gas wells.

[0009] The rapid pressure relief device for a perforating gun in oil and gas wells provided in this application adopts the following technical solution: A rapid pressure relief device for a perforating gun used in oil and gas wells includes: a cartridge holder and end caps threadedly mounted at both ends of the cartridge holder. The cartridge holder consists of an outer cylinder and an inner tube. The pressure relief device further includes: Ammunition carriers are fixed inside the tube at a predetermined angle. The tube walls of the tube body and the tube are respectively provided with embedding holes corresponding to the positions of each ammunition carrier. The same perforation tube is installed in the corresponding embedding holes on the tube body and the tube, and each ammunition carrier corresponds to one perforation tube. A buffer element is disposed in the gap between the cylinder body and the tube. When the internal air pressure of the cartridge expands after ignition, it directly compresses the volume of the buffer element. Multiple pressure relief holes are formed on the end tube wall, and a stopper is hinged in each pressure relief hole. A pressure piston is also slidably arranged inside the end. An inclined connecting rod is hinged between the pressure piston and each stopper. When the air pressure inside the cartridge expands after ignition, it pushes the pressure piston to slide inward into the end, thereby pushing the stopper to flip outward through the inclined connecting rod and opening the pressure relief hole.

[0010] In some embodiments, the stopper consists of a cap for sealing the outer opening of the pressure relief hole and a piston block connected to the inclined connecting rod, wherein an annular sealing gasket is provided at the joint between the cap and the piston block; The piston block is hinged to the inclined connecting rod on the side facing the inside of the cartridge, and a flipping shaft is installed on the other side of the piston block facing the inside of the cartridge. The flipping shaft is rotatably connected to the inner wall of the corresponding pressure relief hole.

[0011] In some embodiments, a reset block is also provided inside the end, and a plurality of pressure blocks that slide and limit within the pressure relief hole are provided on the reset block. A locking foot that cooperates with the pressure block is also installed on the other side of the piston block facing the inside of the cartridge. Multiple reset springs are provided between the side of the reset block and the inner wall of the end.

[0012] In some embodiments, the inner wall of the end has a stepped hole with an increased diameter along the axial direction. When the pressure piston slides past the stepped hole, the high-pressure gas in the cartridge can enter the interior of the end and be released through the pressure relief hole.

[0013] In some embodiments, an axially oriented guide rod is installed at the center of the inner wall of the end, and the reset block and the pressure piston are both slidably disposed on the guide rod. The reset block and the pressure piston are respectively provided with sealing rings for maintaining a sliding seal with the guide rod.

[0014] In some embodiments, the buffer element is an elongated airbag arranged along the axial direction of the cartridge, and the end of the airbag is connected to a perforation tube at a corresponding position through a connecting pipe. A one-way valve is installed on the connecting pipe, and the one-way valve is configured to open from the airbag to the perforation tube. The tube is also provided with multiple impact holes, which are offset from the positions of the airbags.

[0015] In some embodiments, the opening at one end of the perforation tube facing the outside of the cartridge case is sealed with a ruptureable thin cap, and a conical plate is also provided inside the perforation tube, with the tip of the conical plate facing the thin cap.

[0016] In some embodiments, the inner wall of the perforating tube has a reduced variable cross-sectional inner diameter at one end near the thin cap, the conical plate is placed on the variable cross-sectional inner diameter, and the outer diameter of the conical plate is larger than the minimum diameter of the variable cross-sectional inner diameter.

[0017] In summary, in the technical solution of this application embodiment, when the detonation gas pressure pushes the pressure piston to slide, the inclined connecting rod converts the axial movement into the outward flipping movement of the stopper around the flipping axis, so that the pressure relief hole opens quickly and achieves a large flow of rapid pressure relief; after the pressure relief is completed, the pressure block on the reset block is driven by the reset spring to push the stopper to flip back and reset through the locking foot, and forms a reliable seal with the annular sealing gasket between the cover and the outer opening of the pressure relief hole, so that it can be reused and greatly saves the cost of use; In the technical solution of this application embodiment, the elongated airbag set in the gap between the cylinder body and the cylinder tube serves as a buffer element. During detonation, it is compressed and absorbs the impact energy, reducing the impact on the cylinder tube. The end of the airbag is connected to the perforation tube through a connecting pipe and a one-way valve. After seawater backflows, the compressed gas in the airbag is released to the perforation tube through the one-way valve, which can realize delayed exhaust and energy management, and can ensure the balance of pressure inside and outside the launcher after perforation, increasing the pressure resistance. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the pressure relief device in this application; Figure 2 This is a cross-sectional schematic diagram of the overall pressure relief device of this application; Figure 3 This is a cross-sectional schematic diagram of the end structure of this application; Figure 4 This is a cross-sectional schematic diagram of the pressure relief hole in the end of this application; Figure 5 This is a schematic diagram of the internal structure of the end of this application; Figure 6 This is a schematic diagram of the retainer and pressure piston in this application; Figure 7 This is a cross-sectional schematic diagram of the pressure piston and reset block of this application; Figure 8 This is a cross-sectional schematic diagram of the cylinder body and tube of this application; Figure 9 This is a schematic diagram of the fit between the perforation tube and the buffer element in this application; Figure 10 This is a cross-sectional schematic diagram of the perforation tube of this application; Figure 11 This application Figure 5 Enlarged schematic diagram of section A of the structure; Figure 12 This application Figure 9 An enlarged schematic diagram of the structure of part B in the middle section.

[0019] Explanation of reference numerals in the attached figures: 1. Ammunition rack; 11. Barrel body; 12. Tube; 13. Ammunition loading carrier; 14. Perforation tube; 15. Buffer element; 16. Impact hole; 1401. Thin cap; 1402. Conical plate; 1501, Connecting pipe; 1502, Check valve; 2. End; 201. Pressure relief hole; 203. Plug; 204. Pressure piston; 205. Diagonal connecting rod; 206. Reset block; 207. Guide rod; 2031. Cap; 2032. Piston block; 2033. Annular sealing gasket; 2034. Tilting shaft; 2035. Clamping foot; 2061, Pressure block; 2062, Return spring. Detailed Implementation

[0020] The following is in conjunction with the appendix Figures 1 to 12 The present invention will be described in further detail below.

[0021] In the description of this application, it should be understood that the terms "thickness," "upper," "top," "bottom," "inner," "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are used only for the convenience of describing this application 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, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0022] It should be noted that the accompanying drawings are schematic and not to scale. For clarity and convenience, the relative dimensions and proportions of the parts shown are exaggerated or reduced in size; all dimensions are merely illustrative and not limiting. Furthermore, the same reference numerals are used for the same structures, elements, or fittings appearing in more than two drawings to indicate similar features.

[0023] In related technologies, blind holes are machined on the barrel wall, and the bottom of the blind holes is covered with rubber plugs. When the perforation hole detonates, the high-pressure gas blows open the rubber plugs to release pressure. Alternatively, a composite countersunk hole structure is used, which consists of two or more intersecting circular countersunk holes to expand the pressure relief area. However, there are obvious drawbacks. The rubber plugs are prone to aging in the high-pressure environment of the deep sea. Using only rubber plugs for sealing is very easy to leak. Moreover, the remaining wall thickness of the blind hole needs to be calculated accurately, which requires high manufacturing precision. Furthermore, the structure is irreversible after pressure relief and cannot be reused, which greatly increases the operating cost in deep-sea operations. Reference Figure 1 , Figure 2 , Figure 8 As shown, a rapid pressure relief device for a perforating gun for oil and gas wells according to this application includes a cartridge 1 and end heads 2 threadedly assembled at both ends of the cartridge 1. The cartridge 1 is composed of an outer cylinder 11 and an inner tube 12, with an annular gap formed between the cylinder 11 and the tube 12. In this device, ammunition carriers 13 are fixed in the tube 12 at predetermined angles (e.g., circumferential intervals of 60° or 90°, depending on the perforation phase requirements). The tube walls of the tube body 11 and the tube 12 are respectively provided with embedded holes corresponding to the positions of each ammunition carrier 13. The same perforation tube 14 is installed in the corresponding embedded holes on the tube body 11 and the tube 12, and each ammunition carrier 13 corresponds to one perforation tube 14, ensuring that the jet generated after the perforation shell explodes can accurately pass through the perforation tube 14 and be directed toward the stratum.

[0024] Reference Figure 3 , Figure 4 , Figure 6 As shown, multiple pressure relief holes 201 are provided on the tube wall of end 2. These pressure relief holes 201 are evenly distributed in the circumference to ensure that the gun body is subjected to uniform force when pressure is released. A stopper 203 is hinged in each pressure relief hole 201 through a flip shaft 2034. A pressure piston 204 is also slidably provided in end 2. The outer diameter of the pressure piston 204 is slidably sealed with the inner diameter of end 2. A diagonal connecting rod 205 is hinged between the pressure piston 204 and each stopper 203. One end of the diagonal connecting rod 205 is hinged to the end face of the pressure piston 204, and the other end is hinged to the side of the stopper 203 facing the inside of the cartridge 1. After ignition, when the gas pressure inside the cartridge 1 expands, the high-pressure gas first enters the inside of the end 2, pushing the pressure piston 204 to slide into the inside of the end 2 (i.e. away from the cartridge 1). The movement of the pressure piston 204 is converted into a thrust on the stopper 203 through the diagonal connecting rod 205. Since the hinge point between the diagonal connecting rod 205 and the stopper 203 is off from the rotation axis of the stopper 203, this thrust will generate a torque, forcing the stopper 203 to rotate outward, thereby quickly opening the pressure relief hole 201 and realizing the rapid discharge of high-pressure gas. Furthermore, the stopper 203 consists of a cover 2031 for sealing the outer opening of the pressure relief hole 201 and a piston block 2032 connected to the inclined connecting rod 205. The shape of the cover 2031 matches the shape of the outer opening of the pressure relief hole 201, thereby ensuring that the pressure relief hole 201 can be completely covered when closed. An annular sealing gasket 2033 is provided at the joint between the cover 2031 and the piston block 2032. Specifically, the piston block 2032 is provided with a hinge seat on the side facing the inside of the cartridge 1 and is hinged to the inclined connecting rod 205, while the piston block 2032 is provided with a flip shaft 2034 on the other side facing the inside of the cartridge 1 (i.e. the side opposite to the hinge seat), and the two ends of the flip shaft 2034 are rotatably connected to the inner wall of the corresponding pressure relief hole 201. During operation, when the inclined connecting rod 205 pushes the piston block 2032, the piston block 2032 rotates outward around the flipping shaft 2034, causing the cover 2031 to leave the outer opening of the pressure relief hole 201, thus opening it. When the pressure is released, the cover 2031, under the action of the reset block 206, presses the pressure relief hole 201 again, and the annular sealing gasket 2033 is compressed, which can withstand the reverse pressure of external high-pressure seawater, prevent seawater backflow, and form a reliable seal.

[0025] Reference Figure 4 , Figure 5 , Figure 7 , Figure 11 As shown, a reset block 206 is also provided inside the end 2. The reset block 206 is provided with a plurality of pressure blocks 2061 that slide and limit in the pressure relief hole 201. Correspondingly, the piston block 2032 is also provided with a locking foot 2035 that cooperates with the pressure block 2061 on the other side of the inner side of the cartridge 1 (that is, the same side as the flip shaft 2034 but near the edge). Furthermore, a plurality of reset springs 2062 are provided between the side of the reset block 206 and the inner wall of the end 2. These reset springs 2062 are evenly distributed in the circumferential direction and are used to pull the reset block 206 to reset and slide. During operation, when the stopper 203 flips outward to open, the locking foot 2035 rotates with the piston block 2032, pushing the pressure block 2061 and causing the reset block 206 to overcome the elastic force of the reset spring 2062 and move towards the magazine 1. When the pressure relief is completed and the internal pressure of the gun drops, the reset spring 2062 will pull the reset block 206 to reset away from the magazine 1. At this time, the pressure block 2061 can cooperate with the locking foot 2035 to push the stopper 203 inward to re-close the pressure relief hole 201. Therefore, the reset block 206 can realize the automatic closing of the stopper 203 and can be reused, which greatly saves the cost of use.

[0026] Based on the above, in order to facilitate the smooth passage of airflow in the cartridge 1 through the pressure piston 204 and out through the pressure relief hole 201, a stepped hole with an increased diameter is provided on the inner wall of the end 2 along the axial direction. Specifically, the step hole is designed such that when the pressure piston 204 is in the initial position, the outer wall of the pressure piston 204 is sealed to the inner wall of the small diameter section of the end 2. At this time, the airflow in the cartridge 1 cannot pass through the pressure piston 204 to enter the pressure relief hole 201. After ignition, the pressure piston 204 is pushed and slid past the step hole by the high-pressure gas, and an annular gap appears between the outer wall of the pressure piston 204 and the inner wall of the end 2. The high-pressure gas in the cartridge 1 can then enter the interior of the end 2 through this gap and be further released through the already opened pressure relief hole 201. Furthermore, an axially oriented guide rod 207 is installed at the center of the inner wall of end 2 (i.e., at a position coaxial with the axis of the cartridge 1); Specifically, one end of the guide rod 207 is fixed to the bottom wall of the end 2, and the other end extends toward the spring holder 1. The center of the reset block 206 and the pressure piston 204 are both provided with guide holes, and both slide through the guide rod 207, so that the pressure piston 204 and the reset block 206 can still maintain coaxial movement under high pressure impact, avoiding deviation and jamming. To ensure sealing, sealing rings (such as Glyd rings or Step seals) are respectively provided in the inner walls of the guide holes of the reset block 206 and the pressure piston 204 to maintain sliding seal with the guide rod 207. In addition, a sealing ring is also provided on the outer circumferential surface of the pressure piston 204 to seal with the inner wall of the end 2.

[0027] Reference Figure 8 , Figure 9 , Figure 12 As shown, a buffer element 15 is also provided in the gap between the cylinder body 11 and the cylinder tube 12. After ignition, when the internal air pressure of the ejector 1 expands, the high-pressure gas directly compresses the volume of the buffer element 15. The buffer element 15 absorbs a large amount of impact energy during the compression process, thereby significantly reducing the direct impact of the high-pressure gas on the cylinder tube 12 and preventing the cylinder tube 12 from undergoing plastic deformation or rupture. In this embodiment of the application, the buffer element 15 is a long strip-shaped airbag arranged along the axial direction of the cartridge 1. The airbag can be made of multi-layer composite material (such as aramid reinforced rubber) to withstand high pressure impact, and multiple airbags are arranged in parallel. Specifically, the end of the airbag is connected to the corresponding perforation tube 14 through the connecting tube 1501. At least one end of each airbag is connected to the side wall of the nearest perforation tube 14 through a connecting tube 1501. A one-way valve 1502 is installed on the connecting tube 1501. The direction of the one-way valve 1502 is set from the airbag to the perforation tube 14. That is to say, the gas can only flow from the airbag to the perforation tube 14 and cannot flow in the opposite direction. Furthermore, multiple impact holes 16 are provided on the tube 12. The impact holes 16 are staggered from the positions of each airbag. Their function is to allow high-pressure gas to enter the interlayer compression airbag after detonation. Based on this, the specific workflow is as follows: Airbag compression stage: After the perforating projectile detonates, the pressure inside the tube 12 rises sharply. The high-pressure gas is ejected outward through the perforating tube 14 (perforating operation) and enters the gap through the impact hole 16, compressing the airbag. The airbag volume shrinks and absorbs a large amount of impact energy. One-way valve 1502 closing stage: During the airbag compression process, the pressure inside the airbag gradually increases. When the pressure inside the airbag is not greater than the pressure inside the perforation tube 14, the one-way valve 1502 remains closed to prevent high-pressure gas from flowing back into the airbag. Seawater backflow stage: After the firing port is completed, the pressure inside the gun drops, and external seawater will backflow into the firing tube 14. The gas bag is still in a compressed state, and its internal pressure will be higher than the internal pressure of the firing tube 14. At this time, the one-way valve 1502 will open, and the internal pressure of the gas bag will be released into the firing tube 14. As the seawater gradually fills the ammunition carrier 13 through the firing tube 14, the internal pressure of the firing tube 14 is the same as the seawater pressure. After the gas in the gas bag is released for a period of time, its internal pressure will be balanced with the seawater pressure. At this time, the one-way valve 1502 will close again. In this process, the residual pressure in the ammunition carrier 1 is further reduced by the "delayed exhaust" of the gas bag, and the internal pressure can be balanced with the seawater pressure, thereby increasing the pressure resistance of the ammunition carrier 1 in seawater.

[0028] Reference Figure 9 , Figure 10 As shown, a ruptureable thin cap 1401 is sealed at the opening of the perforation tube 14 facing the outside of the cartridge 1. The thin cap 1401 can be made of metal film (such as copper foil or aluminum foil) or brittle plastic film, and its thickness is determined according to the preset rupture pressure. The function of the thin cap 1401 is to seal the perforation tube 14 before the perforation to prevent external liquids or impurities from entering the interior of the cartridge 1. In this embodiment of the application, a cone plate 1402 is also provided inside the perforation tube 14. The cone of the cone plate 1402 is positioned toward the thin cover 1401. The cone plate 1402 is made of high-strength metal. In addition, the inner wall of the perforating tube 14 has a reduced cross-sectional inner diameter (i.e., the inner diameter suddenly decreases to form an annular step) at one end near the thin cover 1401. The outer diameter of the cone plate 1402 is larger than the minimum diameter of the variable cross-sectional inner diameter, but smaller than the main body inner diameter of the perforating tube 14. The cone plate 1402 is initially placed on the step surface of the variable cross-sectional inner diameter, and the pointed cone faces the thin cover 1401. Based on this, the cone plate 1402 has two functions during operation: Active puncture function (normal working condition): When the perforating projectile detonates and generates high-pressure gas, the gas pushes the cone plate 1402 to move at high speed toward the thin cover 1401. The cone punctures the thin cover 1401, opening a channel for the jet and high-pressure gas. This design can ensure that the thin cover 1401 ruptures reliably under a predetermined pressure. Anti-backflow sealing function (abnormal working conditions): If the thin cover 1401 breaks prematurely before the perforation due to an accident such as transportation vibration or pressure fluctuation, external seawater will backflow into the perforation tube 14. At this time, the seawater pressure will push the cone plate 1402 to move inward towards the inside of the cartridge 1. The cone surface of the cone plate 1402 will form a seal with the variable cross-section inner diameter of the inner wall of the perforation tube 14, preventing seawater from further entering the inside of the cartridge 1 and protecting the perforated projectile from moisture.

[0029] All standard parts used in this application can be purchased from the market, and irregular parts can be customized according to the description and drawings. The specific connection methods of each part adopt conventional methods such as bolts, rivets, and welding that are mature in the prior art. The machinery, parts and equipment adopt conventional models in the prior art. In addition, the circuit connection adopts conventional connection methods in the prior art, which will not be described in detail here.

[0030] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from the spirit and scope of this application, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A rapid pressure relief device for a perforating gun used in oil and gas wells, comprising a cartridge holder (1) and end caps (2) threadedly fitted to both ends of the cartridge holder (1), characterized in that, The cartridge holder (1) consists of an outer cylinder (11) and an inner tube (12), and the pressure relief device further includes: Ammunition carriers (13) are fixed inside the tube (12) at a predetermined angle. The tube walls of the tube body (11) and the tube (12) are respectively provided with embedding holes corresponding to the positions of each ammunition carrier (13). The same perforating tube (14) is installed in the corresponding embedding holes on the tube body (11) and the tube (12). Each ammunition carrier (13) corresponds to one perforating tube (14). The buffer element (15) is located in the gap between the cylinder body (11) and the tube (12). When the air pressure inside the cartridge (1) expands after ignition, it directly compresses the volume of the buffer element (15). Multiple pressure relief holes (201) are opened on the pipe wall of the end (2). A stopper (203) is hinged in the pressure relief hole (201). A pressure piston (204) is also slidably arranged in the end (2). An inclined connecting rod (205) is hinged between the pressure piston (204) and each stopper (203). When the air pressure inside the cartridge (1) expands after ignition, it pushes the pressure piston (204) to slide into the end (2), thereby pushing the stopper (203) to flip outward through the inclined connecting rod (205) and opening the pressure relief hole (201).

2. The rapid pressure relief device for a perforating gun in an oil and gas well according to claim 1, characterized in that: The stopper (203) consists of a cap (2031) for sealing the outer opening of the pressure relief hole (201) and a piston block (2032) connected to the inclined connecting rod (205). An annular sealing gasket (2033) is provided at the joint between the cap (2031) and the piston block (2032). The piston block (2032) is hinged to the inclined connecting rod (205) on the side facing the inside of the cartridge (1), and a flip shaft (2034) is installed on the other side of the piston block (2032) facing the inside of the cartridge (1). The flip shaft (2034) is rotatably connected to the inner wall of the corresponding pressure relief hole (201).

3. The rapid pressure relief device for a perforating gun in an oil and gas well according to claim 1, characterized in that: The end (2) is also provided with a reset block (206), and the reset block (206) is provided with a plurality of pressure blocks (2061) that slide and limit in the pressure relief hole (201). The piston block (2032) is also provided with a locking foot (2035) that cooperates with the pressure block (2061) on the other side facing the inside of the cartridge (1). Multiple reset springs (2062) are provided between the side of the reset block (206) and the inner wall of the end (2).

4. The rapid pressure relief device for a perforating gun in an oil and gas well according to claim 3, characterized in that: The inner wall of the end (2) is provided with a stepped hole with an increased diameter along the axial direction. When the pressure piston (204) slides past the stepped hole, the high pressure gas in the cartridge (1) can enter the interior of the end (2) and be released through the pressure relief hole (201).

5. A rapid pressure relief device for a perforating gun in an oil and gas well according to claim 4, characterized in that: A guide rod (207) is installed at the center of the inner wall of the end (2) along the axis. The reset block (206) and the pressure piston (204) are both slidably mounted on the guide rod (207). The reset block (206) and the pressure piston (204) are respectively provided with sealing rings to maintain a sliding seal with the guide rod (207).

6. The rapid pressure relief device for a perforating gun in an oil and gas well according to claim 1, characterized in that: The buffer element (15) is a long strip-shaped airbag arranged along the axial direction of the cartridge (1), and the end of the airbag is connected to the perforation tube (14) at the corresponding position through the connecting pipe (1501). A one-way valve (1502) is installed on the connecting pipe (1501), and the one-way valve (1502) is configured to conduct from the airbag to the perforation tube (14). The tube (12) is also provided with a plurality of impact holes (16), which are offset from the positions of each airbag.

7. A rapid pressure relief device for a perforating gun in an oil and gas well according to claim 6, characterized in that: The opening of the perforating tube (14) facing the outside of the cartridge (1) is sealed with a ruptureable thin cover (1401). A cone plate (1402) is also provided inside the perforating tube (14), with the pointed tip of the cone plate (1402) facing the thin cover (1401).

8. A rapid pressure relief device for a perforating gun in an oil and gas well according to claim 6, characterized in that: The inner wall of the perforating tube (14) near the end of the thin cover (1401) has a reduced variable cross-section inner diameter. The cone plate (1402) is placed on the variable cross-section inner diameter, and the outer diameter of the cone plate (1402) is larger than the minimum diameter of the variable cross-section inner diameter.

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