Perforating gun

Abstract

The invention relates to the technical field of perforating guns, in particular to a perforating gun. Comprising a connecting pipe, a plurality of perforating units which are detachably connected, perforating bullet sets which are arranged in the perforating units in a spiral gradient mode, a control module which is arranged on the connecting pipe and the perforating units and used for controlling detonation of the perforating bullet sets, and pressure relief holes which are formed in the perforating units and used for high-pressure pressure relief. A metal baffle is inserted into a detonating cord path, delay is achieved through energy loss generated when detonation waves penetrate through the baffle, meanwhile, each perforating bullet is provided with an independent electronic detonator, the detonation time sequence is accurately controlled through a microprocessor, and flow resistance, turbulence and stress concentration are reduced through smooth transition by means of a conical gradually-expanded hole. Graded pressure relief is achieved through the multi-stage stepped holes, so that energy is dispersed, pressure sudden rising is avoided, graded filtering is achieved through the coarse filter screen and the fine filter screen, the service life of the fine filter screen is prolonged, and the maintenance frequency is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of perforating guns, and in particular to a perforating gun. Background Art

[0002] A tool used for well completion or cementing at the oil field. A perforating gun is a combination of equipment and its supporting parts used for perforating oil and gas wells.

[0003] The existing perforating guns have the following defects in actual use:

[0004] The pressure relief holes of traditional perforating guns usually have a uniform diameter and are evenly distributed circumferentially or axially. The nonlinear propagation characteristics of the explosion pressure wave are not taken into account, resulting in local pressure accumulation. In addition, the pressure relief holes are mostly concentrated at the tail of the gun body or are symmetrically distributed, which does not match the explosion position of the perforating bullet, resulting in a too long pressure release path, causing the middle part of the gun body to bulge and deform due to pressure retention, and even weld cracking. Summary of the invention

[0005] The purpose of the present invention is to solve the problem in the prior art that the pressure relief hole is not designed reasonably, the internal pressure is released slowly after the explosion, and the gun body is deformed or damaged again, and a perforating gun is proposed.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A perforating gun comprises a connecting pipe, a plurality of detachably connected perforating units, a spiral gradient arranged perforating charge group arranged inside the perforating unit, a control module arranged on the connecting pipe and the perforating unit and used for controlling the detonation of the perforating charge group, and a pressure relief hole installed on the perforating unit for high pressure relief.

[0008] Preferably, there are two connecting tubes in total, one of which is arranged at the gun head position, and the other of which is arranged at the gun tail position, a fluororubber O-ring is used at the connecting tube interface, an expanded graphite tape is pre-embedded inside the fluororubber O-ring, an installation groove is opened on the outer wall of the connecting tube, a first electromagnet is fixedly installed in the installation groove, a second electromagnet matched with the first electromagnet is slidably installed in the installation groove, a spring and a telescopic sleeve are fixedly connected between the first electromagnet and the second electromagnet, the spring is located in the installation groove, the telescopic sleeve is used to close the installation groove, a movable rod is installed with a pin on the first electromagnet, a slider is slidably installed on the movable rod through the groove, a connecting rod is installed with a pin between the slider and the second electromagnet, and a resistance wheel is rotatably installed at the end of the movable rod away from the first electromagnet.

[0009] Preferably, two adjacent perforating units are connected by threads, and each of the perforating units comprises:

[0010] A gun body threadedly connected to the connecting pipe;

[0011] The ammunition rack is bolted to the connecting pipe and is located in the gun body, and the centers of the bottom surfaces of the gun body and the ammunition rack coincide with each other and their axes completely coincide with each other.

[0012] Preferably, the perforating charge group includes at least four perforating charges, the perforating charges are distributed in a spiral line along the axis of the gun body, the phase angle θ of the perforating charge group ranges from 45° to 60°, the circumferential phase angle difference between two adjacent perforating charges increases by 5° to 15° along the forward direction of the gun body, the ammunition rack fixes the perforating charges through a retaining ring groove, and a bionic guide groove is provided on the surface of the perforating charge shell.

[0013] Preferably, the control module comprises:

[0014] A detonator fixedly mounted in a connecting tube at the rear of the gun, wherein the detonator is equipped with a pressure sensor and a microprocessor, and the microprocessor is configured to dynamically adjust the detonation timing according to pressure changes;

[0015] A detonating joint matched with the perforating charge group;

[0016] A detonating cord connected between the detonation connector and the detonator.

[0017] Preferably, the main explosive package of the perforating bullet is located at the center of the detonating joint, the auxiliary explosive packages of the perforating bullet are distributed in a ring around the main explosive package, a metal baffle fixedly connected to the ammunition rack is inserted into the detonating cord path, and each perforating bullet is equipped with an independent electronic detonator.

[0018] Preferably, the pressure relief holes are symmetrically distributed on the same cross-section of the gun body, and at least six pressure relief holes are arranged in each circle. The pressure relief holes are arranged on the middle and rear part of the gun body and the tail part of the gun body. The pressure relief holes located at the middle and rear part of the gun body have an aperture diameter of 2-3mm, and the pressure relief holes located at the tail part of the gun body have an aperture diameter of 4-6mm.

[0019] Preferably, the pressure relief hole is equipped with an embedded PZT ceramic piece and a micro solenoid valve for real-time monitoring of pressure fluctuations in the hole, the embedded PZT ceramic piece has a size of 5×5mm, the front end of the pressure relief hole is a tapered gradually expanding hole, the length of the tapered gradually expanding hole is 20mm, the taper of the tapered gradually expanding hole is 0.15, the inlet diameter of the tapered gradually expanding hole is 3mm, the outlet diameter of the tapered gradually expanding hole is 5mm, the rear end of the pressure relief hole is a multi-step hole, the length of the multi-step hole is 15mm, the length of each step of the multi-step hole is 5mm, and the height of each step of the multi-step hole is 0.5mm.

[0020] Preferably, the inner wall of the pressure relief hole is provided with shark skin V-shaped grooves, the spacing between the shark skin V-shaped grooves is 200-500μm, the depth of the shark skin V-shaped grooves is 10-30μm, the inclination angle of the shark skin V-shaped grooves is 30°, and a lotus leaf effect micro-protrusion array is embedded in the shark skin V-shaped groove, the height of the lotus leaf effect micro-protrusion array is 20-50μm, the spacing between the lotus leaf effect micro-protrusion arrays is 50-100μm, and the contact angle of the lotus leaf effect micro-protrusion array is greater than 150°.

[0021] Preferably, a coarse filter is provided at one end of the pressure relief hole close to the ammunition rack, and the pore size of the coarse filter is 3 mm. A fine filter is provided at one end of the pressure relief hole away from the ammunition rack, and the pore size of the fine filter is 0.3 mm.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] 1. The fluororubber O-ring of the present invention provides basic elasticity and sealing, and uses expanded graphite tape to compensate for the gap caused by rubber hardening at high temperature, forming a double sealing barrier, so that the sealing performance of the fluororubber O-ring at high temperature is significantly improved.

[0024] 2. The perforating units in the present invention can be freely combined to adapt to different well depths and formation conditions. Users can adjust the perforating density according to their needs. When a single perforating unit is damaged, only the corresponding perforating unit needs to be replaced without scrapping the entire unit, which helps to reduce maintenance costs. At the same time, the perforating bullets are distributed along the spiral line to avoid energy superposition, thereby reducing casing damage, and the spiral gradient arrangement is used to further disperse the explosion impact, so that the perforation coverage is uniform. The spiral arrangement ensures that the perforating channels are evenly distributed in the circumferential and axial directions, thereby improving the formation conductivity and increasing oil and gas production.

[0025] 3. The present invention inserts a metal baffle in the detonating cord path to achieve delay by utilizing the energy loss of the detonation wave penetrating the baffle. At the same time, each perforating bullet is equipped with an independent electronic detonator. The detonation timing is accurately controlled by a microprocessor. Delayed detonation staggers the peak values ​​of stress waves generated by the explosions of adjacent perforating bullets, and delayed detonation avoids mutual interference of jets.

[0026] 4. The present invention utilizes tapered gradually expanding holes to reduce flow resistance through smooth transition, reduce turbulence, reduce stress concentration, and help extend fatigue life. It also utilizes multi-stage stepped holes to achieve graded pressure relief, thereby dispersing energy to avoid sudden pressure rise. At the same time, it reduces local stress peaks by dispersing explosion shock waves, and achieves graded filtration through coarse and fine filters, which helps to extend the service life of the fine filter and reduce maintenance frequency. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1A schematic diagram of the overall structure of a perforating gun proposed by the present invention;

[0028] Figure 2 A cross-sectional view of a perforating unit and a perforating bullet assembly of a perforating gun proposed by the present invention;

[0029] Figure 3 A cross-sectional view of a gun body of a perforating gun proposed by the present invention;

[0030] Figure 4 A schematic diagram of a connecting pipe structure of a perforating gun proposed by the present invention;

[0031] Figure 5 A perforating gun according to the present invention Figure 4 A cross-sectional view of

[0032] Figure 6 A schematic diagram of a pressure relief hole structure of a perforating gun proposed by the present invention;

[0033] Figure 7 A perforating gun according to the present invention Figure 6 Center section view.

[0034] In the figure:

[0035] 1. Connecting pipe; 101. Fluorine rubber O-ring; 102. Mounting slide; 103. First electromagnet; 104. Second electromagnet; 105. Spring; 106. Telescopic sleeve; 107. Movable rod; 108. Sliding block; 109. Connecting rod; 110. Contact wheel;

[0036] 2. Perforating unit; 201. Gun body; 202. Ammunition rack;

[0037] 3. Perforating bullet group; 301. Perforating bullet;

[0038] 4. Control module; 401. Detonator; 402. Detonation connector; 403. Detonating cord; 4031. Metal baffle; 4032. Independent electronic detonator;

[0039] 5. Pressure relief hole; 501. Conical gradually expanding hole; 502. Multi-stage stepped hole; 503. Coarse filter screen; 504. Fine filter screen. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0041] Reference Figure 1-Figure 7A perforating gun includes a connecting pipe 1, a plurality of detachably connected perforating units 2, a spiral gradient arranged perforating charge group 3 arranged inside the perforating unit 2, a control module 4 arranged on the connecting pipe 1 and the perforating unit 2 and used for controlling the detonation of the perforating charge group 3, and a pressure relief hole 5 installed on the perforating unit 2 for high pressure relief. The components are arranged as follows:

[0042] There are two connecting tubes 1, one connecting tube 1 is arranged at the gun head position, and the other connecting tube 1 is arranged at the gun tail position. A fluororubber O-ring 101 is used at the interface of the connecting tube 1. An expanded graphite tape is pre-embedded inside the fluororubber O-ring 101. The expanded graphite tape has self-lubricating properties. The width of the expanded graphite tape is 2-5mm, and the thickness of the expanded graphite tape is 0.5-1mm. In a high temperature environment, the expanded graphite tape expands to fill the gap, which helps to avoid the sealing failure of the fluororubber O-ring 101 due to thermal aging or permanent deformation.

[0043] An installation slot 102 is provided on the outer wall of the connecting pipe 1, a first electromagnet 103 is fixedly installed in the installation slot 102, a second electromagnet 104 matched with the first electromagnet 103 is slidably installed in the installation slot 102, a spring 105 and a telescopic sleeve 106 are fixedly connected between the first electromagnet 103 and the second electromagnet 104, it should be noted that the telescopic sleeve 106 is formed by slidingly assembling a hollow rectangular plate and a solid rectangular plate, the telescopic sleeve 106 is used to close the installation slot 102, and prevent impurities in the well from invading the installation slot 102, the spring 105 is located in the installation slot 102, and the spring 105 serves as the second electromagnet 104 closing The reset element in the closed state is that a movable rod 107 is installed on the pin on the first electromagnet 103, and a slider 108 is installed on the movable rod 107 through a sliding groove. A connecting rod 109 is installed on the pin between the slider 108 and the second electromagnet 104. A resistance wheel 110 is rotatably installed on the end of the movable rod 107 away from the first electromagnet 103. The slider 108 provides a movable space for the connecting rod 109. At the same time, the connecting rod 109 will perform linear movement under the influence of the second electromagnet 104. At this time, the connecting rod 109 drives the movable rod 107 to deflect through the slider 108, thereby driving the resistance wheel 110 to resist the well wall, so as to ensure the stability of the perforating gun when it is located in the well.

[0044] Two adjacent perforating units 2 are connected by threads. Each perforating unit 2 includes a gun body 201 and an ammunition rack 202. The components are arranged as follows:

[0045] The gun body 201 is threadedly connected to the connecting pipe 1, the ammunition rack 202 is bolted to the connecting pipe 1 and is located in the gun body 201, the center of the bottom surface of the gun body 201 and the ammunition rack 202 coincide with each other and the axis completely coincides, the perforating bullet group 3 includes at least four perforating bullets 301, the perforating bullets 301 are distributed in a spiral line along the axis of the gun body 201, the phase angle θ of the perforating bullet group 3 ranges from 45° to 60°, the circumferential phase angle difference of adjacent perforating bullets 301 is Δθ, the axial spacing is ΔL, and Δθ and ΔL satisfy the relationship:

[0046] △L=k·△θ (k is the formation permeability adaptation coefficient, k=0.1-0.3mm / °)

[0047] The circumferential phase angle difference between two adjacent perforating bullets 301 increases by 5° to 15° along the forward direction of the gun body 201, wherein the mathematical constraints are:

[0048] (n is the number of perforating bullets 301 in a single circle, n≥4)

[0049] The charge Q of the perforating bullet 301 is negatively correlated with the phase angle Δθ, and the following conditions need to be met:

[0050] Q=Q0·e -λΔθ (λ is the attenuation coefficient, λ=0.05-0.1° -1 )

[0051] The ammunition rack 202 is fixedly mounted with the perforating bullet 301 through the retaining spring groove. The surface of the shell of the perforating bullet 301 is provided with a bionic guide groove. The depth h of the bionic guide groove and the bullet diameter D satisfy the following relationship:

[0052] h=0.05D~0.1D(D=20-40mm)

[0053] The inclination angle γ of the guide groove matches the phase angle Δθ:

[0054]

[0055] The bionic guide groove guides the gas flow generated by the explosion, reduces turbulence and energy dissipation, and makes the metal jet more concentrated. At the same time, the bionic guide groove is used to guide the jet to diffuse more evenly, reduce local stress concentration in the casing, and generate shear force when high-speed airflow passes through the groove, thereby removing attached debris and preventing jet deflection.

[0056] In a further implementation method, the control module 4 includes a detonator 401, a detonating connector 402, and a detonating cord 403, and each component is arranged as follows:

[0057] A detonator 401 fixedly mounted in the connecting tube 1 at the rear of the gun, wherein the detonator 401 is equipped with a pressure sensor and a microprocessor, and the microprocessor is configured to dynamically adjust the detonation timing according to pressure changes;

[0058] A detonating joint 402 provided in a matching manner in the perforating bullet group 3;

[0059] A detonating cord 403 is connected between the detonation connector 402 and the detonator 401 .

[0060] The main explosive package of the perforating bullet 301 is located at the center of the detonating joint 402, and the auxiliary explosive package of the perforating bullet 301 is distributed in a ring around the main explosive package, and the energy interference is prevented by the isolation layer. The auxiliary explosive packaging is HNS, and the mass accounts for 30%-50% of the main explosive. It should be noted that the perforating bullet 301 is equipped with a pressure sensor and an optical fiber sensor. If the pressure at the joint outlet does not reach the threshold value (such as 5kpsi) after the main explosive is detonated, it is judged to be interrupted. At the same time, the optical signal transmission interruption exceeds the set time (such as 10μs), triggering the supplementary explosion, and the detonation wave generated by the supplementary explosion must be consistent with the original Wavefront phase matching prevents energy cancellation. A metal baffle 4031 fixedly connected to the ammunition rack 202 is inserted into the path of the detonating cord 403. The energy loss of the detonation wave penetrating the baffle is used to achieve delay. The titanium alloy (thickness 0.1-0.3mm) has a penetration delay of about 2-5μs / layer. Each perforating bullet 301 is equipped with an independent electronic detonator 4032. It should be noted that the independent electronic detonator 4032 is equipped with a corresponding microprocessor, and the detonation timing is accurately controlled by the microprocessor. When the resistivity is greater than 50Ω·m, the delay time is automatically increased from 5μs to 15μs.

[0061] The pressure relief holes 5 are symmetrically distributed on the same cross section of the gun body 201. There are at least six pressure relief holes 5 in each circle. The pressure relief holes 5 are arranged on the middle and rear part of the gun body 201 and the tail part of the gun body 201. The pressure relief holes 5 located at the middle and rear part of the gun body 201 have an aperture of 2-3mm, so as to quickly release the initial pressure. The pressure relief holes 5 located at the tail part of the gun body 201 have an aperture of 4-6mm, so as to achieve continuous pressure relief and back pressure prevention. The pressure relief holes 5 are equipped with embedded PZT ceramic pieces and micro solenoid valves for real-time monitoring of pressure fluctuations in the holes. The size of the embedded PZT ceramic piece is 5×5mm, and the pressure relief holes 5 are provided with a plurality of pressure relief holes. The front end of the hole 5 is a tapered gradually expanding hole 501, the length of the tapered gradually expanding hole 501 is 20mm, the taper of the tapered gradually expanding hole 501 is 0.15, the inlet diameter of the tapered gradually expanding hole 501 is 3mm, the outlet diameter of the tapered gradually expanding hole 501 is 5mm, the rear end of the pressure relief hole 5 is a multi-stepped hole 502, the length of the multi-stepped hole 502 is 15mm, the length of each step of the multi-stepped hole 502 is 5mm, and the height of each step of the multi-stepped hole 502 is 0.5mm. The inner wall of the pressure relief hole 5 is provided with shark skin V-shaped grooves, and the spacing between the shark skin V-shaped grooves is 200-500μ m, the depth of the shark skin V-shaped groove is 10-30μm, the inclination angle of the shark skin V-shaped groove is 30°, and the lotus leaf effect micro-protrusion array is embedded in the shark skin V-shaped groove to reduce particle attachment through the super-hydrophobicity of the lotus leaf effect micro-protrusion array, and at the same time, the shark skin V-shaped groove is used to inhibit turbulence generation, and jointly reduce flow energy loss. At high flow speeds, the shark skin V-shaped groove dominates drag reduction. At low flow speeds, the super-hydrophobic effect of the lotus leaf effect micro-protrusion array inhibits static deposition. The height of the lotus leaf effect micro-protrusion array is 20-50μm, and the spacing between the lotus leaf effect micro-protrusion arrays is 50-1 00μm, the contact angle of the lotus leaf effect micro-protrusion array is greater than 150°, a coarse filter 503 is arranged at the end of the pressure relief hole 5 close to the ammunition rack 202, and the pore size of the coarse filter 503 is 3mm to intercept large debris, and the material of the coarse filter 503 is tungsten carbide coated steel mesh, and a fine filter 504 is arranged at the end of the pressure relief hole 5 away from the ammunition rack 202, and the pore size of the fine filter 504 is 0.3mm, and the material of the fine filter 504 is Ti6Al4V titanium alloy. The pressure relief efficiency and the risk of clogging are balanced through graded filtration, which helps to extend the life of the fine filter 504 and thus reduce the maintenance frequency.

[0062] The present invention can be explained by the following operation mode:

[0063] Use non-woven cloth dipped in isopropyl alcohol to wipe the inner wall of the gun body 201 to remove oil stains and metal debris, and confirm that the thread of the perforating unit 2 is not damaged and the depth error of the retaining ring groove is less than ±0.1mm;

[0064] Mark the installation angle on the outer wall of the gun body 201 according to the design drawing, and use a laser locator to project the reference line, with a deviation of <±0.5°. Use a positioning spacer to determine the spacing between adjacent perforating bullets 301. Hold the perforating bullet 301 shell and push it into the ammunition rack 202 along the card slot. A "click" sound indicates that the retaining spring is locked (the retaining spring preload must be ≥50N);

[0065] Starting from the end of the detonator 401, the detonating cord 403 is embedded into the explosive hole on the perforating bullet 301. At the same time, the tension of the straight section of the detonating cord 403 is 5-10N, and the bending radius is greater than 50mm (to prevent energy attenuation at the corner). The detonating connector 402 is inserted between the perforating bullets 301 to ensure that the insertion depth of the detonating cord 403 is ≥15mm. Conductive grease is applied to ensure that the circuit is conductive (contact resistance <0.1Ω);

[0066] Start the first electromagnet 103 and the second electromagnet 104. The second electromagnet 104 moves toward the first electromagnet 103 under the influence of magnetic force, so that the spring 105 and the telescopic sleeve 106 are structurally contracted. The second electromagnet 104 drives one end of the movable rod 107 to perform linear movement. The other end of the movable rod 107 drives the connecting rod 109 to perform horizontal movement through the slider 108. The connecting rod 109 drives the movable rod 107 to deflect toward the well wall. The movable rod 107 drives the abutment wheel 110 to abut against the well wall.

[0067] According to the well depth and formation conditions, the corresponding number of perforating units 2 are assembled and installed. When the detonator 401 detects the pressure change in the well through the pressure sensor, the microprocessor receives the signal of the downhole pressure sensor. If an abnormal pressure fluctuation is detected, the metal baffle 4031 and the independent electronic detonator 4032 automatically delay the detonation for 0.5 seconds, and execute the secondary ignition command after the wellbore fluid is stable.

[0068] After the explosion, the embedded PZT ceramic piece is used to monitor the pressure fluctuation in the hole in real time, and the pressure relief hole 5 is opened by a micro solenoid valve to quickly release the high-pressure gas in the gun body 201 (the peak pressure can reach 200-300MPa). The super-hydrophobicity of the lotus leaf effect micro-protrusion array reduces particle adhesion, and the shark skin V-groove is used to suppress turbulence, thereby jointly reducing flow energy loss. At the same time, large debris is intercepted by the coarse filter 503, and small particle debris is intercepted by the fine filter 504.

[0069] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A perforating gun, characterized in that: The invention comprises a connecting pipe (1), a plurality of detachably connected perforating units (2), a spiral gradient arranged perforating charge group (3) arranged inside the perforating unit (2), a control module (4) arranged on the connecting pipe (1) and the perforating unit (2) and used for controlling the detonation of the perforating charge group (3), and a pressure relief hole (5) installed on the perforating unit (2) for high pressure relief.

2. A perforating gun according to claim 1, characterized in that: There are two connecting tubes 1, one of which is arranged at the gun head position, and the other of which is arranged at the gun tail position. A fluororubber O-ring (101) is used at the interface of the connecting tube (1), and an expanded graphite tape is pre-buried inside the fluororubber O-ring (101). An installation groove (102) is provided on the outer wall of the connecting tube (1), and a first electromagnet (103) is fixedly installed in the installation groove (102). A second electromagnet (104) matched with the first electromagnet (103) is slidably installed in the installation groove (102). The first electromagnet (103) and the second electromagnet (104) are arranged to be matched with each other. A spring (105) and a telescopic sleeve (106) are fixedly connected between the magnets (104), the spring (105) is located in the installation slide groove (102), the telescopic sleeve (106) is used to close the installation slide groove (102), a movable rod (107) is installed on a pin shaft on the first electromagnet (103), a slider (108) is installed on the movable rod (107) through the slide groove, a connecting rod (109) is installed on a pin shaft between the slider (108) and the second electromagnet (104), and a resistance wheel (110) is rotatably installed on the end of the movable rod (107) away from the first electromagnet (103).

3. A perforating gun according to claim 1, characterized in that: Two adjacent perforating units (2) are connected via threads, and each perforating unit (2) comprises: A gun body (201) threadedly connected to the connecting pipe (1); An ammunition rack (202) is bolted to the connecting pipe (1) and is located in the gun body (201); the centers of the bottom surfaces of the gun body (201) and the ammunition rack (202) coincide with each other, and their axes completely coincide with each other.

4. A perforating gun according to claim 3, characterized in that: The perforating bullet group (3) comprises at least four perforating bullets (301), the perforating bullets (301) are distributed in a spiral line along the axis of the gun body (201), the phase angle θ of the perforating bullet group (3) ranges from 45° to 60°, the circumferential phase angle difference between two adjacent perforating bullets (301) increases by 5° to 15° along the forward direction of the gun body (201), the ammunition rack (202) fixes the perforating bullets (301) via a retaining ring groove, and a bionic guide groove is provided on the surface of the shell of the perforating bullet (301).

5. A perforating gun according to claim 3, characterized in that: The control module (4) comprises: A detonator (401) fixedly mounted in a connecting tube (1) at the rear of the gun, wherein the detonator (401) is equipped with a pressure sensor and a microprocessor, and the microprocessor is configured to dynamically adjust the detonation timing according to pressure changes; A detonating joint (402) matched with the perforating charge group (3); A detonating cord (403) connected between the detonation joint (402) and the detonator (401).

6. A perforating gun according to claim 5, characterized in that: The main explosive package of the perforating bullet (301) is located at the center of the detonating joint (402), and the auxiliary explosive packages of the perforating bullet (301) are distributed in a ring around the main explosive package. A metal baffle (4031) fixedly connected to the ammunition rack (202) is inserted into the path of the detonating cord (403), and each perforating bullet (301) is equipped with an independent electronic detonator (4032).

7. A perforating gun according to claim 5, characterized in that: The pressure relief holes (5) are symmetrically distributed on the same cross section of the gun body (201), and at least six pressure relief holes (5) are arranged in each circle. The pressure relief holes (5) are arranged on the middle and rear part of the gun body (201) and the tail part of the gun body (201). The diameter of the pressure relief holes (5) located at the middle and rear part of the gun body (201) is 2-3 mm, and the diameter of the pressure relief holes (5) located at the tail part of the gun body (201) is 4-6 mm.

8. A perforating gun according to claim 1, characterized in that: The pressure relief hole (5) is equipped with an embedded PZT ceramic sheet and a micro electromagnetic valve for real-time monitoring of pressure fluctuations in the hole. The size of the embedded PZT ceramic sheet is 5×5 mm. The front end of the pressure relief hole (5) is a tapered gradually expanding hole (501). The length of the tapered gradually expanding hole (501) is 20 mm. The taper of the tapered gradually expanding hole (501) is 0.

15. The inlet diameter of the tapered gradually expanding hole (501) is 3 mm. The outlet diameter of the tapered gradually expanding hole (501) is 5 mm. The rear end of the pressure relief hole (5) is a multi-step stepped hole (502). The length of the multi-step stepped hole (502) is 15 mm. The length of each step of the multi-step stepped hole (502) is 5 mm. The height of each step of the multi-step stepped hole (502) is 0.5 mm.

9. A perforating gun according to claim 1, characterized in that: The inner wall of the pressure relief hole (5) is provided with a shark skin V-shaped groove, the spacing between the shark skin V-shaped grooves is 200-500 μm, the depth of the shark skin V-shaped groove is 10-30 μm, the inclination angle of the shark skin V-shaped groove is 30°, a lotus leaf effect micro-protrusion array is embedded in the shark skin V-shaped groove, the height of the lotus leaf effect micro-protrusion array is 20-50 μm, the spacing between the lotus leaf effect micro-protrusion array is 50-100 μm, and the contact angle of the lotus leaf effect micro-protrusion array is greater than 150°.

10. A perforating gun according to claim 3, characterized in that: A coarse filter (503) is arranged at one end of the pressure relief hole (5) close to the ammunition rack (202), and the pore size of the coarse filter (503) is 3 mm. A fine filter (504) is arranged at one end of the pressure relief hole (5) away from the ammunition rack (202), and the pore size of the fine filter (504) is 0.3 mm.

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