High-temperature-resistant and high-pressure-resistant oil field underground perforating gun

Abstract

The invention relates to the technical field of oil field development, and discloses a high-temperature and high-pressure resistant oil field underground perforating gun which comprises a gun body assembly, a gun rack pipe assembly is arranged in the gun body assembly, a buffer assembly is fixedly connected to the top end of the gun rack pipe assembly and comprises a base plate, a connecting block is fixedly connected to the upper surface of the base plate, and the connecting block is fixedly connected to the upper surface of the base plate. A bottom plate is fixedly connected to the outer wall of the connecting block, a side plate is fixedly connected to the upper surface of the bottom plate, a top plate is fixedly connected to the upper surface of the side plate, a supporting block is slidably connected to the interior of the top plate, a pressure reducing shaft is fixedly connected to the upper surface of the connecting block, and a first spring is fixedly connected to the top end of the pressure reducing shaft; the top end of the first spring is fixedly connected with a supporting shaft, and the outer wall of the pressure reducing shaft is slidably connected with a sleeve. By relieving the first pressure pulse, the impact force can be reduced, disturbance to the well wall stratum is reduced, and therefore the risks of well leakage and well collapse are reduced, and the continuity and safety of operation are guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of oilfield development, in particular to an oilfield downhole perforating gun resistant to high temperature and high pressure. Background Art

[0002] Downhole perforating guns in oil fields are widely used in the completion of oil and gas wells to provide a good channel for oil and gas extraction. In the complex environment of deep wells, high temperature and high pressure, perforating operations need to withstand huge impact force and high pressure.

[0003] First, when a traditional perforating gun is perforating underground, the explosion of the perforating bullet generates an instantaneous huge pressure pulse, resulting in a huge impact force. This impact force not only causes huge stress on the perforating gun itself, but also causes serious disturbance to the well wall and the formation around the wellbore, which can easily lead to the risk of well wall collapse and even well leakage. Especially in softer and more fragile formations, the direct effect of the impact force can cause damage to the formation structure and lead to well wall instability. The occurrence of problems such as well leakage and well collapse seriously affects the safety of operations and poses a great challenge to the continuity of underground operations. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a downhole perforating gun for oil fields that is resistant to high temperature and pressure, and solves the problem that when a traditional perforating gun is perforating downhole, the explosion of the perforating bullet generates an instantaneous huge pressure pulse, resulting in a huge impact force.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions: a high temperature and high pressure resistant oil field downhole perforating gun, comprising a gun body assembly, a bomb rack tube assembly is arranged inside the gun body assembly, a buffer assembly is fixedly connected to the top of the bomb rack tube assembly, the buffer assembly comprises a chassis, a connecting block is fixedly connected to the upper surface of the chassis, a bottom plate is fixedly connected to the outer wall of the connecting block, a side plate is fixedly connected to the upper surface of the bottom plate, a top plate is fixedly connected to the upper surface of the side plate, a support block is slidably connected to the inside of the top plate, a decompression shaft is fixedly connected to the upper surface of the connecting block, a spring 1 is fixedly connected to the top of the spring 1, a support shaft is fixedly connected to the upper surface of the decompression shaft, a sleeve is slidably connected to the outer wall of the decompression shaft, and a mitigation assembly is fixedly connected to the upper surface of the chassis.

[0006] Preferably, the deceleration assembly includes four groups of buffer shafts with upper and lower sides respectively, the bottom end of the lower buffer shaft is fixedly connected to the upper surface of the chassis, the top end of the lower buffer shaft is fixedly connected to spring 2, the top end of spring 2 is fixedly connected to the bottom end of the upper buffer shaft, and the top end of the upper buffer shaft is fixedly connected to the lower surface of the gun head.

[0007] Preferably, the mitigation assembly also includes a sleeve, the lower interior of the sleeve is fixedly connected to the outer wall of the lower buffer shaft, the upper interior of the sleeve is slidably connected to the outer wall of the upper buffer shaft, and the outer wall of the second spring is slidably connected to the interior of the sleeve.

[0008] Preferably, the gun body assembly includes a gun body, the interior of the gun body is arranged outside the bullet rack tube assembly, the lower side of the gun body is fixedly connected to the inside with a gun tail, the top of the gun body is fixedly connected to the gun head, and the gun body is provided with a plurality of blind holes.

[0009] Preferably, the bullet rack tube assembly comprises a shell, the outer wall of the shell is arranged inside the gun body, a plurality of perforating bullets are passed through the interior of the shell, and the positions of the perforating bullets correspond one-to-one to the blind holes.

[0010] Preferably, an opening and closing assembly is provided inside the gun tail.

[0011] Preferably, the opening and closing assembly includes a motor, the top end of the motor is fixedly connected to the inside of the gun butt, the output end of the motor is fixedly provided with a support plate, the upper surface of the support plate is rotatably connected to a rotating arm, the lower surface of the rotating arm is rotatably connected to a baffle, the upper surface of the baffle is rotatably connected to a connecting plate, and the lower surface of the support plate is fixedly connected to the inside of the gun butt.

[0012] Preferably, the upper surface of the support block is fixedly connected to the lower surface of the gun head, and the top end of the support shaft is fixedly connected to the lower surface of the support block.

[0013] Preferably, the inner wall of the sleeve is fixedly connected to the outer wall of the support shaft, and the outer wall of the spring 1 is slidably connected to the inside of the sleeve.

[0014] Preferably, the gun body and the shell are made of titanium alloy or carbon fiber material.

[0015] Working principle: When the shell is moved by the first pressure pulse, it will push the chassis to move, and when the chassis moves, it will drive the connecting block to move, and when the connecting block moves, it will drive the bottom plate, side plate and top plate to slide, and when the inside of the top plate slides on the outer wall of the support block, the connecting block will push the outer wall of the decompression shaft to slide inside the sleeve, and when the outer wall of the decompression shaft slides inside the sleeve, it will push the spring 1 to compress, and when the spring 1 is compressed inside the sleeve under the support of the support shaft, it will absorb the pressure brought to the shell by the first pressure pulse, so as to achieve the effect of alleviating impact force and resisting high pressure; When the second pressure pulse is generated inside the perforating gun, it will push the slide and compress it to prevent it from breaking due to excessive pressure and absorb the unbearable impact force, thus achieving a double effect of alleviating the impact force; When the perforating gun is not in use, the motor is turned on. When the motor starts running, it drives the rotating arm to rotate. When the lower surface of the rotating arm rotates under the support of the support plate, it drives the baffle at the other end of the rotating arm to rotate and close, so that the baffle can be opened when the perforating gun is used and closed when the perforating gun is not used.

[0016] The present invention provides a downhole perforating gun for oil fields that is resistant to high temperature and high pressure. It has the following beneficial effects: 1. The present invention absorbs the pressure brought to the shell by the first pressure pulse when the spring 1 is compressed inside the sleeve under the support of the support shaft, thereby achieving the effect of alleviating impact force and resisting high pressure. By alleviating the first pressure pulse, the impact force can be reduced, and the disturbance to the well wall formation can be reduced, thereby reducing the risk of well leakage and well collapse, and ensuring the continuity and safety of the operation.

[0017] 2. The second spring of the present invention absorbs the impact force that the first spring cannot withstand, thereby achieving a double effect of alleviating the impact force. By alleviating the second pressure pulse, the repeated load effect of the sleeve can be reduced, thereby extending the service life of the sleeve.

[0018] 3. The baffle of the perforating gun of the present invention can be closed when the perforating gun is not in use. In certain circumstances, closing the hole at the tail of the perforating gun can prevent well fluid, mud or other impurities from entering the inside of the perforating gun, thereby reducing the risk of blockage and equipment damage. For example, when the perforating operation has not been completed and some additional operations are required, closing the tail hole can prevent the complex well fluid environment downhole from having an adverse effect on the perforator, thereby ensuring the safety of the operation.

[0019] 4. The gun body and shell of the present invention are made of titanium alloy or carbon fiber material, which has extremely high strength and performs well under high temperature and high pressure conditions. At the same time, its corrosion resistance is also very excellent. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the three-dimensional structure of a downhole perforating gun in an oil field that is resistant to high temperature and high pressure according to the present invention; Figure 2 It is a bottom view schematic diagram of the three-dimensional structure of a downhole perforating gun in an oil field that is resistant to high temperature and high pressure according to the present invention; Figure 3 It is a schematic cross-sectional view of the internal structure of the gun body of the present invention; Figure 4 It is a schematic cross-sectional view of the internal structure of the housing of the present invention; Figure 5 It is a schematic diagram of the local structure of the connection block of the present invention; Figure 6 It is a schematic cross-sectional view of the interior of the casing of the present invention; Figure 7 It is a schematic diagram of the local structure of the baffle of the present invention.

[0021] Among them, 1. gun body assembly; 11. gun body; 12. gun tail; 13. gun head; 14. blind hole; 2. bullet rack tube assembly; 21. shell; 22. perforating bullet; 3. buffer assembly; 31. chassis; 32. connecting block; 33. bottom plate; 34. side plate; 35. decompression shaft; 36. spring one; 37. support shaft; 38. sleeve; 39. top plate; 310. support block; 4. deceleration assembly; 41. sleeve; 42. buffer shaft; 43. spring two; 5. opening and closing assembly; 51. motor; 52. rotating arm; 53. support plate; 54. baffle; 55. connecting plate. DETAILED DESCRIPTION

[0022] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] Please refer to the attached Figure 1 -Attached Figure 5 The embodiment of the present invention provides a high temperature and high pressure resistant oil field downhole perforating gun, including a gun body assembly 1, a bomb rack tube assembly 2 is arranged inside the gun body assembly 1, a buffer assembly 3 is fixedly connected to the top of the bomb rack tube assembly 2, the buffer assembly 3 includes a chassis 31, a connecting block 32 is fixedly connected to the upper surface of the chassis 31, a bottom plate 33 is fixedly connected to the outer wall of the connecting block 32, a side plate 34 is fixedly connected to the upper surface of the bottom plate 33, a top plate 39 is fixedly connected to the upper surface of the side plate 34, a support block 310 is slidably connected to the inside of the top plate 39, a decompression shaft 35 is fixedly connected to the upper surface of the connecting block 32, a spring 36 is fixedly connected to the top of the spring 36, a support shaft 37 is fixedly connected to the top of the spring 36, a sleeve 38 is slidably connected to the outer wall of the decompression shaft 35, and a mitigation assembly 4 is fixedly connected to the upper surface of the chassis 31. The gun body assembly 1 includes a gun body 11, the interior of the gun body 11 is arranged outside the bullet rack tube assembly 2, a gun tail 12 is fixedly connected to the interior of the lower side of the gun body 11, a gun head 13 is fixedly connected to the top of the gun body 11, and the gun body 11 is provided with a plurality of blind holes 14. The bullet rack tube assembly 2 includes a shell 21, the outer wall of the shell 21 is arranged inside the gun body 11, and a plurality of perforating bullets 22 are penetrated inside the shell 21, and the positions of the perforating bullets 22 correspond to the blind holes 14 one by one.

[0024] Specifically, when the perforating gun is needed, the perforating gun is firstly inserted vertically into the underground stratum, and then the detonating cord on the outer wall of the bomb rack tube assembly 2 is detonated, and the detonating cord ignites multiple perforating bullets 22 in sequence, and the perforating bullets 22 generate high-pressure jets, which are ejected from the blind hole 14 and punch out a deep hole in the stratum to facilitate the inflow of underground oil; at the same time, a first pressure pulse is generated inside the perforating gun, and the first pressure pulse drives the shell 21 to move in the direction of the gun head 13. When the shell 21 is moved by the first pressure pulse, it will push the chassis 31 to move, and when the chassis 31 moves, it will drive the connecting block 32 to move, and when the connecting block 32 moves, it will drive the bottom The plate 33, the side plate 34 and the top plate 39 slide. When the inside of the top plate 39 slides on the outer wall of the support block 310, the connecting block 32 pushes the outer wall of the pressure reducing shaft 35 to slide inside the sleeve 38. When the outer wall of the pressure reducing shaft 35 slides inside the sleeve 38, it pushes the spring 1 36 to be compressed. When the spring 1 36 is compressed inside the sleeve 38 under the support of the support shaft 37, it absorbs the pressure brought to the shell 21 by the first pressure pulse, thereby achieving the effect of alleviating the impact force and resisting high pressure. The high-intensity initial pressure pulse is easy to cause the formation structure around the well wall to be damaged, especially for softer and more fragile formations, which are easy to cause problems such as leakage and well collapse. By alleviating the first pressure pulse, the impact force can be reduced, the disturbance to the well wall formation can be reduced, thereby reducing the risk of leakage and well collapse, and ensuring the continuity and safety of the operation.

[0025] Please refer to the attached Figure 6 The deceleration assembly 4 includes four groups of upper and lower buffer shafts 42, the bottom end of the lower buffer shaft 42 is fixedly connected to the upper surface of the chassis 31, the top of the lower buffer shaft 42 is fixedly connected to a spring 2 43, the top of the spring 2 43 is fixedly connected to the bottom end of the upper buffer shaft 42, and the top of the upper buffer shaft 42 is fixedly connected to the lower surface of the gun head 13. The deceleration assembly 4 also includes a casing 41, the lower inner part of the casing 41 is fixedly connected to the outer wall of the lower buffer shaft 42, the upper inner part of the casing 41 is slidably connected to the outer wall of the upper buffer shaft 42, and the outer wall of the spring 2 43 is slidably connected to the inside of the casing 41.

[0026] Specifically, when the second pressure pulse is generated inside the perforating gun, the chassis 31 will push the buffer shaft 42 to slide and compress the spring 2 43. The casing 41 is used to protect the spring 2 43 to prevent it from breaking due to excessive pressure. The spring 2 43 will absorb the impact force that the spring 1 36 cannot withstand, thereby achieving a double effect of alleviating the impact force. The second pressure pulse is often caused by the reflection wave or shock wave after perforating, which has a long-term impact on the downhole casing and equipment. If this pulse is large, it will aggravate the fatigue damage of the casing, especially under long-term repeated action, which may cause microcracks and metal fatigue problems. By alleviating the second pressure pulse, the repeated load of the casing can be reduced and the service life of the casing can be extended.

[0027] Please refer to the attached Figure 7 , an opening and closing assembly 5 is arranged inside the gun tail 12. The opening and closing assembly 5 comprises a motor 51, the top end of the motor 51 is fixedly connected inside the gun tail 12, a support plate 53 is fixedly arranged at the output end of the motor 51, a rotating arm 52 is rotatably connected to the upper surface of the support plate 53, a baffle 54 is rotatably connected to the lower surface of the rotating arm 52, a connecting plate 55 is rotatably connected to the upper surface of the baffle 54, and the lower surface of the support plate 53 is fixedly connected to the inside of the gun tail 12. The upper surface of the support block 310 is fixedly connected to the lower surface of the gun head 13, and the top end of the support shaft 37 is fixedly connected to the lower surface of the support block 310. The inner wall of the sleeve 38 is fixedly connected to the outer wall of the support shaft 37, and the outer wall of the spring 1 36 is slidably connected to the inside of the sleeve 38.

[0028] Specifically, when the perforating gun is not in use, the motor 51 is turned on. When the motor 51 starts to run, it drives the arm 52 to rotate. When the lower surface of the arm 52 rotates under the support of the support plate 53, it drives the baffle 54 at the other end of the arm 52 to rotate and close, so that the baffle 54 can be opened when the perforating gun is in use and closed when the perforating gun is not in use. In certain cases, closing the hole at the tail of the perforating gun can prevent well fluid, mud or other impurities from entering the perforating gun, reducing the risk of blockage and equipment damage. For example, when the perforating operation has not been completed and some additional operations are required, closing the tail hole can prevent the complex well fluid environment downhole from adversely affecting the perforator, thereby ensuring the safety of the operation.

[0029] Please refer to the attached Figure 1 The gun body 11 and the shell 21 are made of titanium alloy or carbon fiber material.

[0030] Specifically, titanium alloy has extremely high strength and performs well under high temperature and high pressure conditions. It also has excellent corrosion resistance, especially in corrosive media such as hydrogen sulfide and carbon dioxide, and can resist corrosion from complex fluids underground. This can effectively extend the service life of perforating guns in harsh underground environments, reduce the risk of equipment damage and the cost of repairs and replacements during operations.

[0031] Carbon fiber materials also have extremely high strength and excellent corrosion resistance, especially for common downhole chemical corrosive substances. The high strength-to-weight ratio of carbon fiber makes the perforating gun lighter while maintaining strength, making it easier to operate and carry.

[0032] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A downhole perforating gun for oil fields resistant to high temperature and high pressure, comprising a gun body assembly (1), characterized in that: The gun body assembly (1) is provided with a bomb rack tube assembly (2) inside, the top end of the bomb rack tube assembly (2) is fixedly connected to a buffer assembly (3), the buffer assembly (3) comprises a chassis (31), the upper surface of the chassis (31) is fixedly connected to a connection block (32), the outer wall of the connection block (32) is fixedly connected to a bottom plate (33), the upper surface of the bottom plate (33) is fixedly connected to a side plate (34), the upper surface of the side plate (34) is fixedly connected to a top plate (39), the interior of the top plate (39) is slidably connected to a support block (310), the upper surface of the connection block (32) is fixedly connected to a decompression shaft (35), the top end of the decompression shaft (35) is fixedly connected to a spring 1 (36), the top end of the spring 1 (36) is fixedly connected to a support shaft (37), the outer wall of the decompression shaft (35) is slidably connected to a sleeve (38), and the upper surface of the chassis (31) is fixedly connected to a decompression assembly (4).

2. The oil field downhole perforating gun resistant to high temperature and high pressure according to claim 1, characterized in that: The deceleration assembly (4) comprises four groups of buffer shafts (42) on the upper and lower sides, respectively. The bottom end of the buffer shaft (42) on the lower side is fixedly connected to the upper surface of the chassis (31), the top end of the buffer shaft (42) on the lower side is fixedly connected to a spring 2 (43), the top end of the spring 2 (43) is fixedly connected to the bottom end of the buffer shaft (42) on the upper side, and the top end of the buffer shaft (42) on the upper side is fixedly connected to the lower surface of the gun head (13).

3. The oil field downhole perforating gun resistant to high temperature and high pressure according to claim 2, characterized in that: The mitigation assembly (4) further comprises a sleeve (41), wherein the lower interior of the sleeve (41) is fixedly connected to the outer wall of the lower buffer shaft (42), the upper interior of the sleeve (41) is slidably connected to the outer wall of the upper buffer shaft (42), and the outer wall of the second spring (43) is slidably connected to the interior of the sleeve (41).

4. The oil field downhole perforating gun resistant to high temperature and high pressure according to claim 1, characterized in that: The gun body assembly (1) comprises a gun body (11), the interior of the gun body (11) being arranged outside the ammunition rack tube assembly (2), a gun tail (12) being fixedly connected to the interior of the lower side of the gun body (11), a gun head (13) being fixedly connected to the top of the gun body (11), and a plurality of blind holes (14) being formed in the gun body (11).

5. The oil field downhole perforating gun resistant to high temperature and high pressure according to claim 4, characterized in that: The bullet rack tube assembly (2) comprises a shell (21), the outer wall of the shell (21) being arranged inside the gun body (11), a plurality of perforating bullets (22) being arranged inside the shell (21), and the positions of the perforating bullets (22) corresponding one-to-one to the blind holes (14).

6. The oil field downhole perforating gun resistant to high temperature and high pressure according to claim 4, characterized in that: An opening and closing assembly (5) is arranged inside the gun tail (12).

7. The oil field downhole perforating gun resistant to high temperature and high pressure according to claim 6, characterized in that: The opening and closing assembly (5) comprises a motor (51), the top end of the motor (51) is fixedly connected to the inside of the gun butt (12), the output end of the motor (51) is fixedly provided with a support plate (53), the upper surface of the support plate (53) is rotatably connected to a rotating arm (52), the lower surface of the rotating arm (52) is rotatably connected to a baffle (54), the upper surface of the baffle (54) is rotatably connected to a connecting plate (55), and the lower surface of the support plate (53) is fixedly connected to the inside of the gun butt (12).

8. The high temperature and high pressure resistant oil field downhole perforating gun according to claim 1, characterized in that: The upper surface of the support block (310) is fixedly connected to the lower surface of the gun head (13), and the top end of the support shaft (37) is fixedly connected to the lower surface of the support block (310).

9. The oil field downhole perforating gun resistant to high temperature and high pressure according to claim 1, characterized in that: The inner wall of the sleeve (38) is fixedly connected to the outer wall of the support shaft (37), and the outer wall of the spring 1 (36) is slidably connected to the inside of the sleeve (38).

10. The oil field downhole perforating gun resistant to high temperature and high pressure according to claim 7, characterized in that: The gun body (11) and the shell (21) are made of titanium alloy or carbon fiber material.

Images