Perforating gun suitable for ultra-deep well and detonation control method thereof

Abstract

The embodiment of the invention discloses a perforating gun suitable for an ultra-deep well and a detonation control method of the perforating gun, and relates to the technical field of oil and gas ultra-deep well perforating bullets. The perforating gun comprises a perforating gun barrel, a perforating gun body and a driving device, wherein the perforating gun barrel is of a hollow ring-shaped structure; the multiple bidirectional perforating bullet units are arranged in the axis direction of the perforating gun barrel, and the axis of each bidirectional perforating bullet unit is perpendicular to the axis of the perforating gun barrel; wherein each two-way perforating bullet unit comprises two perforating bullets which are symmetrically arranged on the two sides of the axis of the perforating gun barrel body, and openings of the two perforating bullets face the radial direction of the perforating gun barrel body outwards, so that recoil force vectors of jet flow generated by the two perforating bullets are mutually counteracted. The embodiment of the invention is suitable for an oil gas ultra-deep well perforation scene.

Description

Technical Field

[0001] This application relates to the field of perforation projectile technology for ultra-deep oil and gas wells, and particularly to a perforation gun suitable for ultra-deep wells and its detonation control method. Background Technology

[0002] Conventional perforating projectiles generally employ a unidirectional jet structure, meaning one projectile corresponds to one perforation. This design results in a limited charge and a single direction of energy release, generating a large number of ineffective rarefaction waves, which is not conducive to forming an effective perforation channel. Furthermore, excessive ineffective energy may cause unnecessary damage to the wellbore structure, increasing operational risks. The strong recoil force generated by the unidirectional jet structure during perforation makes the long, continuous tubing string, which can extend for thousands of meters, prone to severe vibration in ultra-deep well perforation operations. This vibration not only affects perforation accuracy but may also lead to serious consequences such as failure of the continuous tubing string. Traditional vibration reduction measures have limited effectiveness in ultra-deep well environments and are difficult to effectively suppress such large-amplitude vibrations. Summary of the Invention

[0003] In view of this, embodiments of this application provide a perforating gun suitable for ultra-deep wells and its detonation control method, which facilitates the solution of the pipe string vibration problem in ultra-deep wells.

[0004] In a first aspect, embodiments of this application provide a perforating gun suitable for ultra-deep wells, comprising: a perforating gun barrel body, which is a hollow annular structure; and a plurality of bidirectional perforating projectile units, wherein the plurality of bidirectional perforating projectile units are arranged along the axial direction of the perforating gun barrel body, and the axis of each bidirectional perforating projectile unit is perpendicular to the axis of the perforating gun barrel body; wherein each bidirectional perforating projectile unit includes two perforating projectiles symmetrically arranged on both sides of the axis of the perforating gun barrel body, and the openings of the two perforating projectiles face radially outward from the perforating gun barrel body, so that the recoil force vectors of the jets generated by the two perforating projectiles cancel each other out.

[0005] Optionally, the perforating projectile includes: a main cavity for the perforating projectile; a shaped charge liner, which is conical in shape, disposed inside the main cavity for the perforating projectile, and a sealed cavity is formed between the shaped charge liner and the main cavity for the perforating projectile; the sealed cavity is filled with explosives.

[0006] Optionally, it also includes a perforation projectile support, which is a hollow annular structure; the bidirectional perforation projectile unit is disposed inside the perforation projectile support; the space inside the perforation projectile support, except for the solid space intersecting with the solid space of the bidirectional perforation projectile unit, is a cavity structure to accommodate the detonation controller; the detonation controller is connected to the perforation projectile.

[0007] Optionally, it also includes a detonating cord, which has a flexible cylindrical structure, an outer layer covered with waterproof material, and an inner core filled with explosive; the detonating cord is provided with a joint; the perforation projectile support is provided with a module that is sealed and fixedly connected to the joint; the module is connected to the detonation controller.

[0008] Optionally, the detonation controller is disposed in the cavity structure; the detonation controller includes: a sensing and detection module for detecting the detonation wave signal of the detonating cord; a timing control module for controlling the detonation sequence of the perforating projectile; a detonation drive module for generating a detonation current; and an anti-interference protection module for shielding electromagnetic interference.

[0009] Optionally, the perforation projectile support includes multiple supports, which are arranged along the axial direction of the perforation gun barrel, and the axis of the perforation projectile support is perpendicular to the axis of the perforation gun barrel.

[0010] Optionally, a through hole with the same diameter as the outer diameter of the perforating projectile unit is provided at the contact point between the perforating gun barrel and the bidirectional perforating projectile unit.

[0011] Optionally, the barrel of the perforating gun has an opening that penetrates the barrel wall and is adjacent to the through hole.

[0012] Secondly, this application provides a method for controlling the detonation of a perforating gun in ultra-deep wells, comprising the steps of: setting a delay time for a first bidirectional perforating projectile unit of the perforating gun as a first delay time, setting a delay time for a second bidirectional perforating projectile unit of the perforating gun as a second delay time, wherein the second delay time is greater than the first delay time; activating a detonating cord, using the detonating cord to sequentially transmit detonation waves to the detonation controllers of the first bidirectional perforating projectile unit and the second bidirectional perforating projectile unit; after detecting the detonation wave of the detonating cord, the detonation controller of the first bidirectional perforating projectile unit waits for the first delay time, and then simultaneously detonates the first bidirectional perforating projectile unit. A first and a second perforating projectile are symmetrically arranged. A first metal jet is formed in the first perforating projectile, and a second metal jet is formed in the second perforating projectile. The first and second metal jets are generated simultaneously and are symmetrical along the axis of the perforating gun. The recoil vector of the first metal jet on the first perforating projectile and the recoil vector of the second metal jet on the second perforating projectile cancel each other out in real time along the axis of the first bidirectional perforating projectile unit. After detecting the detonation wave of the detonating cord, the detonation controller of the second bidirectional perforating projectile unit waits for the second delay time and then simultaneously detonates the symmetrically arranged third and fourth perforating projectiles of the second bidirectional perforating projectile unit.

[0013] Optionally, the barrel of the perforating gun has a through hole for installing the first bidirectional perforating projectile unit and the second bidirectional perforating projectile unit, and the barrel wall of the perforating gun has an opening adjacent to the through hole that penetrates the barrel wall; after the first metal jet contacts the well wall, the process further includes the following steps: the rock fragments generated by the impact of the first metal jet on the well wall fall off the well wall; the rock fragments falling off the well wall enter the cavity inside the perforating gun through the opening; a new inner wall is exposed at the well wall, and the new inner wall is exposed within the impact range of the first metal jet; the first metal jet continues to impact the new inner wall until it forces the well wall through the perforation hole.

[0014] This application provides a perforating gun suitable for ultra-deep wells and its detonation control method. The bidirectional perforating projectile unit includes two perforating projectiles symmetrically arranged on both sides of the axis of the perforating gun barrel. The openings of the perforating projectiles face radially outwards towards the perforating gun barrel. The tails of the two symmetrically arranged perforating projectiles are fixedly connected, so that the recoil forces of the jets generated by the two symmetrically arranged perforating projectiles cancel each other out. This helps to solve the problem of tubing vibration caused by recoil force in traditional unidirectional jet structures in ultra-deep wells. At the same time, multiple bidirectional perforating projectile units can be arranged in the perforating gun at one time, which can improve the efficiency of downhole perforation operations. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of a perforating gun structure according to an embodiment of this application; Figure 2 This is a schematic diagram of the perforation projectile structure according to an embodiment of this application; Figure 3 This is a schematic diagram of the cross-sectional structure of a perforating projectile according to an embodiment of this application; Figure 4 This is a schematic diagram of a bidirectional perforation projectile unit and a perforation projectile support structure according to an embodiment of this application; Figure 5 This is a schematic cross-sectional view of a bidirectional perforation projectile unit and a perforation projectile support according to an embodiment of this application; Figure 6 This is a schematic diagram of a perforation gun detonation control method applicable to ultra-deep wells according to an embodiment of this application; In the picture: 100 - Perforation gun; 1-Perforating gun barrel; 2-Two-way perforating projectile unit; 3-Perforating projectile; 4-Perforating projectile support; 5-Detonating cord; 6-Detonation controller; 31-Perforation projectile main body cavity; 32-Cream liner; 33-Extension section; 41-Cavity structure; 42-Module; Detailed Implementation

[0017] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0018] It should be understood that the described embodiments are merely some, not all, of the embodiments in this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0019] Example 1: See Figure 1 ,like Figure 1 As shown, this application embodiment provides a perforating gun 100 suitable for ultra-deep wells, comprising: a perforating gun barrel 1, which is a hollow annular structure; a plurality of bidirectional perforating projectile units 2, wherein the plurality of bidirectional perforating projectile units 2 are arranged along the axial direction of the perforating gun barrel 1, and the axis of each bidirectional perforating projectile unit 2 is perpendicular to the axis of the perforating gun barrel 1; wherein each bidirectional perforating projectile unit 2 includes two perforating projectiles 3 symmetrically arranged on both sides of the axis of the perforating gun barrel 1, and the openings of the two perforating projectiles 3 face radially outward from the perforating gun barrel 1, so that the recoil force vectors of the jets generated by the two perforating projectiles 3 cancel each other out.

[0020] In this embodiment, the perforating gun barrel 1 is designed as a hollow annular structure, which reduces the weight of the perforating gun 100 and facilitates the processing of the perforating gun barrel 1, making it easier to install the bidirectional perforating projectile unit 2 in the perforating gun barrel 1. Each bidirectional perforating projectile unit 2 includes two perforating projectiles 3, the openings of which face radially outward towards the perforating gun barrel 1 to perforate the well wall adjacent to the perforating gun barrel 1. The two perforating projectiles 3 are symmetrically arranged on both sides of the axis of the perforating gun barrel 1, and the central axis of the two perforating projectiles 3 is... The two perforating projectiles 3 are collinear so that the recoil force vectors of the jets generated by the two perforating projectiles 3 cancel each other out, reducing the impact on the connecting tubing and reducing the vibration of the connecting tubing. This makes it easier to solve the problem of tubing vibration caused by recoil force in traditional unidirectional jet structures in ultra-deep wells. Multiple bidirectional perforating projectile units 2 are installed in a perforating gun 100. The multiple bidirectional perforating projectile units 2 are arranged along the axial direction of the perforating gun barrel 1. Multiple bidirectional perforating projectile units 2 can be arranged in the perforating gun 100 at one time to perforate the well wall, thereby improving the efficiency of downhole perforation operations.

[0021] In some embodiments, the tail ends of the two symmetrically arranged perforating projectiles 3 are fixedly connected, that is, the ends of the perforating projectiles 3 near the axis of the perforating gun barrel 1 are fixedly connected. When the two perforating projectiles 3 generate jets, they support each other so that the recoil force vectors of the jets generated by the two perforating projectiles 3 cancel each other out; thus, excessive ineffective energy will not cause unnecessary damage to the wellbore structure, improving the energy transfer efficiency and energy utilization rate of the perforating projectiles 3. Since the jet energy loss of the symmetrically arranged perforating projectiles 3 is small and the penetration is strong, it can improve the perforation quality and increase the perforation depth, making it suitable for perforation operations in complex environments of ultra-deep wells. At the same time, it can make the jet of the perforating projectiles 3 form a regular perforation channel on the well wall, which is beneficial to subsequent oil and gas extraction. It also reduces the vibration of the working tubing caused by the impact of the explosion energy of the perforating projectiles 3 on the downhole tubing during the perforation process, improving the safety and reliability of the perforation operation.

[0022] In some embodiments, the perforating gun barrel 1 is made of a high-strength alloy material to utilize its excellent temperature resistance of 300°C and pressure resistance of 200MPa to reduce the impact of high temperature, high pressure and / or high humidity environment on the detonation and / or explosion of the bidirectional perforating projectile unit 2 in ultra-deep wells; at the same time, the perforating projectile 3 is disposed on the outer periphery of the perforating gun barrel 1 so that the opening of the perforating projectile 3 is as close as possible to the well wall, and when the perforating projectile 3 explodes, the jet of the perforating projectile 3 can reach the well wall at the fastest speed and impact the well wall to form a perforation.

[0023] In some embodiments, to avoid the sympathetic detonation effect of the bidirectional perforating projectile unit 2 during detonation affecting adjacent bidirectional perforating projectile units 2, the distance between two adjacent bidirectional perforating projectile units 2 is greater than the sympathetic detonation distance of the perforating projectile 3 in adjacent directions.

[0024] In some embodiments, the spacing between the perforating projectiles 3 is specifically set to 300-500mm, and the arrangement density of the perforating projectiles 3 is 12-16 per m, which is higher than the arrangement density of conventional unidirectional perforating projectiles. The same distance interval generates more perforations on the well wall, which is beneficial to enhance reservoir communication capacity and increase drainage area. The delay interval between the perforating projectiles and the symmetrical bidirectional perforating projectiles is 0.5-1ms, and the detonation interval between adjacent bidirectional perforating projectile units 2 is 1-2ms. The detonation time control ensures that the jet quality formed by the perforating projectiles 3 of adjacent bidirectional perforating projectile units 2 is optimal and reduces mutual interference. The synergistic effect of the bidirectional perforations formed by the symmetrical perforating projectiles of the bidirectional perforating projectile unit 2 on the well wall and the high-density arrangement of the perforating projectiles 3 can transform the reservoir over a larger area, forming a complex fracture network, thereby significantly improving oil and gas production.

[0025] See Figure 2 and Figure 3 ,like Figure 2 and Figure 3As shown, in some embodiments, the perforating projectile 3 includes: a perforating projectile main body cavity 31; a shaped charge liner 32, which is a conical structure, disposed inside the perforating projectile main body cavity 31, and a sealed cavity is formed between the shaped charge liner 32 and the perforating projectile main body cavity 31; the sealed cavity is filled with explosives.

[0026] In this embodiment, the main cavity 31 of the perforating projectile is a funnel-shaped structure, and at the larger diameter end of the funnel-shaped structure, it extends a distance in the opposite direction to the smaller diameter end to form an extension 33, so as to form a cavity space sufficient to accommodate the explosive and the shaped charge liner 32. The main cavity 31 of the perforating projectile is used to ensure the stability and penetration capability of the jet. The cone-shaped shaped charge liner 32 is made of metal material and is located inside the main cavity 31 of the perforating projectile. It is a structure arranged in a 360° circumferential direction along the axis of the bidirectional perforating projectile unit 2, and forms a sealed cavity with the main cavity 31 of the perforating projectile. After the explosive is filled inside the main cavity 31 of the perforating projectile, the shaped charge liner 32 is installed into the main cavity 31 of the perforating projectile with adhesive to seal the explosive, so that the explosive of the final perforating projectile 3 is in the sealed cavity.

[0027] In some embodiments, the inner wall of the perforating projectile body cavity 31 is made of a smooth curved surface to facilitate the installation of the shaped charge liner 32 and to prevent the detonation energy from being partially converted into thermal energy instead of kinetic energy due to the rough inner wall of the perforating projectile body cavity 31 when the perforating projectile 3 explodes, thus causing energy loss, and / or to avoid asymmetric flow effects that could cause the jet of the shaped charge liner 32 to deflect and reduce the perforation effect, and / or to avoid the rough inner wall increasing the friction between the jet particles and the rough inner wall, thereby consuming the kinetic energy of the jet and reducing the impact effect of the jet on the well wall.

[0028] In some embodiments, the shaped charge liner 32 of the perforating projectile 3 is made of copper, with a cone angle of 60°, and is filled with RDX-based high-energy explosive with a charge density of 1.6-1.8 g / cm³. The bidirectional perforating projectile unit 2 adopts a symmetrical arrangement on both sides, with the central axes of the two perforating projectiles 3 of the bidirectional perforating projectile unit 2 being collinear. The conical cavity of the shaped charge liner 32 of the perforating projectile 3 is symmetrically arranged on both sides of the axis of the perforating gun barrel 1 to ensure that the recoil force vectors of the high-speed jet when the perforating projectile 3 detonates cancel each other out. The symmetrically arranged perforating projectiles 3 can form a perforation channel with a diameter of 1.2-1.35 times the outer diameter of the perforating projectile 3. The explosion of the perforating projectile 3 will form an annular slit with a depth of 15-20 cm on the well wall. This slit can change the stress distribution of the deep formation, release the formation structural stress, provide a favorable stress environment for the initiation and propagation of fractures in subsequent hydraulic fracturing operations, increase the reservoir stimulation volume, and improve the oil and gas permeability and well productivity.

[0029] In some embodiments, when the two perforating projectiles 3 of the bidirectional perforating projectile unit 2 explode, the wall of the perforating projectile main cavity 31 ruptures, and the two perforating projectiles 3 form a high-pressure convergence zone in the region of the center of gravity axis of the perforating gun barrel 1. The pressure field intensity of this convergence zone is 40% to 60% higher than that generated by the unidirectional jet structure, which generates a higher driving force on the jet generated by the perforating projectile 3 and improves the penetration ability of the jet into the rock strata of the well wall of the ultra-deep well.

[0030] See Figure 4 and Figure 5 ,like Figure 4 and Figure 5 As shown, in some embodiments, the perforating gun 100 further includes a perforating projectile support 4, which is a hollow annular structure; the bidirectional perforating projectile unit 2 is disposed inside the perforating projectile support 4; the space inside the perforating projectile support 4, except for the solid space of the bidirectional perforating projectile unit 2, is a cavity structure 41 to accommodate the detonation controller 6; the detonation controller 6 is connected to the perforating projectile 3.

[0031] In this embodiment, the perforating gun 100 also includes a perforating projectile support 4. The hollow annular structure of the perforating projectile support 4 allows the bidirectional perforating projectile unit 2 to be accommodated within the perforating projectile support 4 to support the bidirectional perforating projectile unit 2. The extension 33 of the perforating projectile 3 of the bidirectional perforating projectile unit 2 is sealed at the contact point with the perforating projectile support 4. Furthermore, the space within the perforating projectile support 4, excluding the intersection of the solid space of the perforating projectile support 4 and the bidirectional perforating projectile unit 2, is a cavity structure 41, i.e., the cavity structure 41 is a sealed structure. This sealed structure provides a space for the detonation controller 6 and provides a sealed environment for the connection between the bidirectional perforating projectile unit 2 and the detonation controller 6, thereby reducing to some extent the impact of the high temperature, high pressure, and / or high humidity environment in ultra-deep wells on the detonation triggering, control, and / or detonation circuit of the detonation controller 6 within the cavity structure 41.

[0032] In some embodiments, the perforating gun 100 further includes a detonating cord 5, which has a flexible cylindrical structure, is covered with a waterproof material on the outside, and is filled with explosive in the inside; the detonating cord 5 is provided with a connector; the perforating projectile support 4 is provided with a module 42 that is sealed and fixedly connected to the connector; the module 42 is connected to the detonation controller 6.

[0033] In this embodiment, the waterproof material covering the outer layer of the detonating cord 5 avoids the influence of the humid environment in ultra-deep wells, and the explosive filled in the inner core is used to transmit the detonation wave to detonate the perforating projectile 3; the perforating projectile support 4 is provided with a module 42 connected to the detonation controller 6. This module 42 is located inside the support wall of the perforating projectile support 4, does not protrude from the outer surface of the support wall of the perforating projectile support 4, and is sealed to the support wall of the perforating projectile support 4, thereby reducing the high temperature, high pressure and / or high humidity environment in ultra-deep wells to a certain extent. The impact on the detonation controller 6 inside the cavity structure 41; and before the perforating gun 100 is delivered to the ultra-deep well, the joint on the detonating cord 5 is sealed and fixedly connected to the module 42, which can avoid the impact of the high temperature and high humidity environment in the ultra-deep well on the detonation wave transmitted at the joint of the detonating cord 5; when the detonating cord 5 transmits the detonation wave to the joint of the detonating cord 5, the module 42 at the joint of the detonating cord 5 transmits the detonation wave to the detonation controller 6 inside the perforating projectile support 4, triggering the detonation controller 6 to detonate the perforating projectile 3.

[0034] In some embodiments, the detonation controller 6 is disposed in the cavity structure 41; the detonation controller 6 includes: a sensing and detection module for detecting the detonation wave signal of the detonating cord 5; a timing control module for controlling the detonation sequence of the perforating projectile 3; a detonation drive module for generating a detonation current; and an anti-interference protection module for shielding electromagnetic interference.

[0035] In this embodiment, the detonation controller 6 is housed within the cavity structure 41 to physically isolate it from the ultra-deep well space, thereby reducing the impact of the high temperature, high pressure, and / or high humidity environment in the ultra-deep well to a certain extent. The anti-interference protection module employs multiple electromagnetic shielding circuits, operating continuously throughout the entire detonation control process to ensure that the timing control and detonation drive are not affected by external electromagnetic interference. The sensing and detection module uses piezoelectric and / or fiber optic strain principle to detect the detonation wave of the detonating cord 5. When the sensing and detection module detects the detonation wave of the detonating cord 5, under the continuous protection of the anti-interference protection module, it immediately triggers the timing control module to start timing according to a preset sequence. After the timing ends, it triggers the detonation drive module to detonate the perforating projectile 3. It can be understood that, depending on the different ultra-deep wells and... The arrangement of the downhole perforating projectile 3 varies, as do the requirements for perforation in the wellbore, resulting in different preset timing sequences. The timing control module uses a high-precision clock chip to achieve a delay accuracy of less than 1ms and supports delayed triggering to accurately control the detonation sequence of the perforating projectile 3 according to the design sequence. The detonation drive module is also equipped with overcurrent protection and automatic short-circuit recovery current. The anti-interference protection module adopts a multi-layer electromagnetic shielding structure to ensure reliable operation in the high-temperature and high-pressure environment of deep wells. The timing control module, detonation drive module, and anti-interference protection module of the detonation controller 6 are reliably and fixedly connected to ensure accurate detonation control. The circuit wiring in the detonation controller 6 strictly follows the layout rules, separating high and low voltage, strong and weak signals, and maintaining sufficient creepage distance and electrical clearance.

[0036] In some embodiments, the timing control module, detonation drive module, and anti-interference protection module of the detonation controller 6 are designed in a modular and independent manner, and the modules are reliably connected through a standard interface, which facilitates maintenance and replacement of module components.

[0037] In some embodiments, the detonation controller 6 includes: a sensing module for detecting the detonation wave signal of the detonating cord 5; a detonation drive module for generating a detonation current; an electronic detonator for controlling the detonation timing of the perforating projectile 3 and detonating the perforating projectile 3; and an anti-interference protection module for shielding electromagnetic interference. Before installing the perforating gun 100 in an ultra-deep well, the delay parameters of the electronic detonator are set separately, with the delay time of the electronic detonator ranging from 1ms to 10000ms. When the sensing module detects the detonation wave of the detonating cord 5, under the continuous protection of the anti-interference protection module, the detonation drive module is immediately triggered to generate a stable detonation current and deliver it to the electronic detonator to reach the current threshold of the electronic detonator, activating the electronic detonator to start timing. After the electronic detonator finishes timing, the perforating projectile 3 is detonated.

[0038] In some embodiments, the perforation projectile support 4 includes multiple supports, which are arranged along the axial direction of the perforation gun barrel 1, and the axis of the perforation projectile support 4 is perpendicular to the axis of the perforation gun barrel 1.

[0039] In this embodiment, the perforation projectile support 4 includes multiple units to support each bidirectional perforation projectile unit 2 in the perforation gun barrel 1 and to provide a space for the detonation controller 6 corresponding to each bidirectional perforation projectile unit 2. The bidirectional perforation projectile unit 2 is housed in the hollow annular structure of the perforation projectile support 4 and is arranged along the axial direction of the perforation gun barrel 1, just like the bidirectional perforation projectile unit 2. The axis of the perforation projectile support 4 is perpendicular to the axis of the perforation gun barrel 1, and it supports the symmetrically arranged perforation projectiles 3 of the bidirectional perforation projectile unit 2. When the perforation projectile 3 explodes, it provides support for the recoil vector of the metal jet generated by the symmetrically arranged perforation projectile 3 on the perforation projectile 3.

[0040] In some embodiments, adjacent perforation projectile supports 4 are staggered or arranged in the same direction. Traditionally, the unidirectional and / or asymmetrical arrangement of the perforation projectiles 3 can easily cause deformation of the connecting column between two adjacent perforation gun barrels 1 and the column formed by multiple perforation gun barrels 1, due to the cumulative vibration in the same direction from multiple perforation projectiles 3 within the perforation gun 100. In the embodiments of this application, the staggered or unidirectional arrangement of adjacent perforation projectile supports 4, combined with the symmetrical arrangement of the perforation projectiles 3 in the bidirectional perforation projectile unit 2, allows the recoil force vectors generated by the jets of the symmetrically arranged perforation projectiles 3 to cancel each other out, reducing the vibration of the column. It also weakens the deformation of the connecting column caused by the cumulative vibration in the same direction generated by the traditional unidirectional perforation projectiles 3, making the perforation projectiles more stable. The jet of the perforating projectile 3 provides more uniform rock breaking on the well wall. When adjacent perforating projectile supports 4 are staggered, the perforating projectile 3 of the bidirectional perforating projectile unit 2 within the adjacent perforating projectile support 4 can, to a certain extent, avoid the direct impact of fragments generated by the sympathetic detonation of the perforating projectile main cavity 31 and the rock fragments generated by the well wall on the adjacent perforating projectile supports 4. When the fragments and rock fragments are in contact with each other on the perforating projectile supports 4, the velocity of the fragments and rock fragments has been relatively reduced, avoiding vibration of the adjacent perforating projectile supports 4, thereby avoiding vibration of the perforating projectile 3 cylinder and the connecting pipe string. When adjacent perforating projectile supports 4 are arranged in the same direction, it is convenient to process through holes in the same direction on the perforating gun cylinder 1, ensuring processing accuracy and improving processing efficiency.

[0041] In some embodiments, the phase angle between adjacent perforation projectile supports 4 is 90°. The 90° orthogonal staggered arrangement facilitates the manufacturing process and ensures the processing accuracy, avoiding the irregular vibration and deformation of the tube column caused by the uneven stress wave generated when the perforation projectile 3 explodes due to processing errors. On the other hand, when the perforation projectiles 3 explode simultaneously or in a time-delayed manner, regular superimposed harmonics can be generated in the orthogonal direction, causing the tube column to vibrate regularly without causing the tube column to bend or deform.

[0042] In some embodiments, a through hole with the same diameter as the outer diameter of the perforating bullet 3 unit is provided at the contact point between the perforating gun barrel 1 and the bidirectional perforating bullet unit 2.

[0043] In this embodiment, the bidirectional perforating projectile unit 2 is arranged along the axial direction of the perforating gun barrel 1, and the axial direction of the bidirectional perforating projectile unit 2 is perpendicular to the axial direction of the perforating gun barrel 1. A through hole with the same diameter as the outer diameter of the perforating projectile unit 3 is opened at the contact point between the perforating gun barrel 1 and the bidirectional perforating projectile unit 2. The through hole penetrates the barrel walls on both sides of the perforating gun barrel 1 so that the bidirectional perforating projectile unit 2 can be installed into the perforating gun barrel 1 through the through hole on the perforating gun barrel 1. The barrel wall of the perforating gun barrel 1 is used to support the bidirectional perforating projectile unit 2 to fix the position of the bidirectional perforating projectile unit 2 relative to the perforating gun barrel 1.

[0044] In some embodiments, it is understood that when the bidirectional perforating projectile unit 2 is installed in the perforating projectile bracket 4, when the bidirectional perforating projectile unit 2 and the perforating projectile bracket 4 are installed together in the perforating gun barrel 1, the diameter of the through hole opened on the perforating gun barrel 1 should be the same as the outer diameter of the perforating projectile bracket 4 outside the bidirectional perforating projectile unit 2.

[0045] In some embodiments, the barrel wall of the perforating gun body 1 has an opening that penetrates the barrel wall adjacent to the through hole. Due to the limited space between the outer wall of the perforating gun body 1 and the well wall in ultra-deep wells, when the jet of the perforating projectile 3 impacts the well wall, the explosively broken rock generated on the well wall cannot detach from the well wall within the limited space. Therefore, the continuous jet of the perforating projectile 3 will continuously impact the broken rock fragments that still exist in the original well wall space, failing to effectively impact the well wall after the rock fragmentation, resulting in low efficiency in perforating the well wall. Without affecting the support of the barrel wall of the perforating gun body 1 for the bidirectional perforating projectile unit 2, an opening penetrating the barrel wall of the perforating gun body 1 is opened adjacent to the through hole, and the opening intersects with the edge of the through hole. The opening forms a space between the external space of the perforating gun body 1 and the internal space of the perforating gun body 1 excluding the bidirectional perforating projectile unit 2. The interconnected cavity allows the jet generated when the perforating projectile 3 explodes to impact the well wall, causing rock fragments to detach from the wall at the impact point. These fragments can then enter the cavity at the opening, exposing the previously obscured inner well wall to the impact range of the jet from the perforating projectile 3. This allows the jet from the perforating projectile 3 to continuously impact the well wall, increasing the impact efficiency of the jet on the well wall and improving the efficiency of the perforations created by the jet on the well wall. Preferably, there can be multiple openings, and these openings are evenly distributed circumferentially along the center of the through hole, so that the rock fragments generated by the jet from the perforating projectile 3 can enter the cavity evenly, reducing the vibration of the perforating gun barrel 1 caused by uneven impacts from the jet from the perforating projectile 3 and the rock fragments. It is understood that the openings adjacent to the through holes symmetrically positioned on both sides of the axis of the perforating gun barrel 1 are also symmetrical.

[0046] In some embodiments, the outer side of the shaped charge liner 32 of the perforating projectile 3 is provided with spherical steel balls covering the inner surface of the shaped charge liner 32. The steel balls have the same diameter, and the diameter of the steel balls is designed to be 5% to 10% of the inner diameter of the extension 33 of the main cavity 31 of the perforating projectile. Under the impact of the jet generated by the explosion of the perforating projectile 3 shattering the shaped charge liner 32 on the well wall, a perforation is generated on the well wall. Due to the high temperature, high pressure and / or high humidity environment of ultra-deep wells, the perforation generated on the well wall may close. When the jet of the perforating projectile 3 impacts the well wall, some fragments of the shaped charge liner 32 detach from the well wall along with the broken rock after impact. After a perforation is formed on the well wall, some fragments of the shaped charge liner 32 will be embedded in the perforation. These fragments of the shaped charge liner 32 can provide a certain degree of support for the perforation. When the perforating projectile 3 explodes, the explosive energy generated by the explosive in the perforating projectile 3 makes... Steel balls, positioned on the inner side of the shaped charge liner 32, enter the perforation after the liner 32 and embed themselves in the inner wall of the perforation. This provides support to the inner wall of the perforation, preventing the perforation from closing due to the impact of the perforating projectile 3 on the well wall, thus improving perforation efficiency and facilitating subsequent oil and gas extraction. The steel balls also have evenly distributed through-holes to reduce mass, allowing for greater acceleration during the explosive detonation, reducing the contact area with the inner wall of the perforation, and increasing the pressure at the contact surface, thus facilitating embedding. Simultaneously, the through-holes on the steel balls support the inner wall of the perforation without hindering oil and gas collection. The diameter of the through-holes is designed to be 10%–20% of the steel ball's diameter, with 3–8 through-holes evenly distributed on the spherical surface of the steel ball. This reduces the mass of the steel ball while facilitating oil and gas collection after embedding it in the inner wall of the perforation.

[0047] Example 2: See Figure 6 ,like Figure 6 As shown, this application provides a method for controlling the detonation of a perforating gun suitable for ultra-deep wells, including the following steps: S100. Set the delay time of the first bidirectional perforating bullet unit of the perforating gun to a first delay time, set the delay time of the second bidirectional perforating bullet unit of the perforating gun to a second delay time, and the second delay time is greater than the first delay time.

[0048] In this step, the first bidirectional perforating projectile unit is not necessarily located above the second bidirectional perforating projectile unit. The detonating cord can be connected to the first bidirectional perforating projectile unit and the second bidirectional perforating projectile unit in different connection sequences according to the blasting sequence. Then, the first delay time and the second delay time are set according to the blasting sequence. In this step, the second delay time is greater than the first delay time, that is, the second bidirectional perforating projectile unit explodes later than the first bidirectional perforating projectile unit.

[0049] S101. Activate the detonating cord and use the detonating cord to sequentially transmit the detonation wave to the detonation controllers of the first bidirectional perforation projectile unit and the second bidirectional perforation projectile unit.

[0050] In this step, the detonation wave is sequentially transmitted to the detonation controllers of the first and second bidirectional perforating projectile units according to the connection order of the detonating cord to the first and second bidirectional perforating projectile units. The detonation controllers of the first and second bidirectional perforating projectile units are triggered sequentially to detonate the perforating projectiles of the first and second bidirectional perforating projectile units.

[0051] S102. After detecting the detonation wave of the detonating cord, the detonation controller of the first bidirectional perforating projectile unit waits for the first delay time and then simultaneously detonates the first and second perforating projectiles symmetrically arranged in the first bidirectional perforating projectile unit. A first metal jet is formed in the first perforating projectile and a second metal jet is formed in the second perforating projectile. The first metal jet and the second metal jet are generated simultaneously and are symmetrical along the axis of the perforating gun.

[0052] In this step, after the detonation controller of the first bidirectional perforating projectile unit detects the detonation wave of the detonating cord, it waits for a first delay time and then simultaneously detonates the first and second perforating projectiles. After the explosive in the first perforating projectile detonates, it ruptures the shaped charge liner of the first perforating projectile, forming a first metal jet. After the explosive in the second perforating projectile detonates, it ruptures the shaped charge liner of the second perforating projectile, forming a second metal jet. The shaped charge liners of the first and second perforating projectiles collapse and fission simultaneously, generating the first and second metal jets at the same time. The first and second metal jets are symmetrical along the axis of the perforating gun. The jets generated by the perforating projectiles symmetrically arranged on both sides of the axis of the perforating gun barrel simultaneously reach the symmetrical points on the well wall, forming the first and second perforations at the symmetrical positions on the well wall. The first metal jet impacts the well wall to form the first perforation, and the second metal jet impacts the well wall to form the second perforation.

[0053] S103, the recoil vector of the first metal jet on the first perforating projectile and the recoil vector of the second metal jet on the second perforating projectile cancel each other out in real time along the axial direction of the first bidirectional perforating projectile unit.

[0054] In this step, by utilizing the strictly symmetrical arrangement of the first and second perforating projectiles in the first bidirectional perforating projectile unit, during the process of the first and second perforating projectiles impacting the well wall after their explosion to generate the first and second perforations, the recoil vector of the first metal jet on the first perforating projectile and the recoil vector of the second metal jet on the second perforating projectile are symmetrical and collinear along the axis of the first bidirectional perforating projectile unit. This achieves real-time mutual cancellation of the recoil vectors of the first metal jet on the first perforating projectile and the recoil vectors of the second metal jet on the second perforating projectile, reducing the uneven vibration of the connecting tubing string.

[0055] S104. After detecting the detonation wave of the detonating cord, the detonation controller of the second bidirectional perforation projectile unit waits for the second delay time and then simultaneously detonates the symmetrically arranged third and fourth perforation projectiles of the second bidirectional perforation projectile unit.

[0056] In this step, since the detonation cord delay is determined by physical distance, the detonation controllers of adjacent first and second bidirectional perforation projectile units may successively detect the detonation wave of the detonation cord within a microsecond delay difference. It is difficult to control the delay between adjacent first and second bidirectional perforation projectile units using the detonation cord. Therefore, the second delay time of the detonation controller of the second bidirectional perforation projectile unit is made greater than the first delay time of the detonation controller of the first bidirectional perforation projectile unit. The time difference between the second delay time and the first delay time is the controlled delay difference between adjacent first and second bidirectional perforation projectile units. After detecting the detonation wave of the detonation cord and waiting for the second delay time, the second bidirectional perforation projectile unit detonates the third and fourth perforation projectiles simultaneously. The steps after the explosives in the third and fourth perforation projectiles explode are similar to those after the explosives in the first and second perforation projectiles explode, and will not be described again.

[0057] In some embodiments, during the formation of the first and second perforations, when the instantaneous impact force generated by the first or second metal jet deviates, the recoil vector of the metal jet on the symmetrical side of the axis of the perforating gun is compensated and adjusted to suppress the vibration of the coupling column; when the direction of the instantaneous impact force generated by the first or second metal jet deviates from the direction parallel to the axis of the first bidirectional perforating projectile unit, the recoil vector of the metal jet generated by the perforating projectile on the symmetrical side of the axis of the perforating gun is compensated and adjusted through the fixed connection structure between the first and second perforating projectiles to improve the symmetry of the first and second metal jets, thereby suppressing the vibration of the coupling column caused by the asymmetry of the first and second metal jets.

[0058] In some embodiments, depending on the required delay time for the perforation projectile explosion, the difference between the first delay time and the second delay time can be set to be greater than the time required for the two perforation projectiles in a two-way perforation projectile unit to fully explode or the time required for the wave peak to dissipate after the explosion.

[0059] In some embodiments, the barrel of the perforating gun has a through hole for mounting the first bidirectional perforating projectile unit and the second bidirectional perforating projectile unit, and the barrel wall of the perforating gun has an opening adjacent to the through hole that penetrates the barrel wall; after the first metal jet contacts the well wall, the method further includes the steps of: the rock fragments generated by the impact of the first metal jet on the well wall falling off the well wall; the rock fragments falling off the well wall entering the cavity inside the perforating gun through the opening; a new inner wall being exposed at the well wall, the new inner wall being exposed within the impact range of the first metal jet; and the first metal jet continuously impacting the new inner wall until the well wall is forced through the perforation hole.

[0060] In this step, when the barrel of the perforating gun is close to the well wall and there is no space nearby to accommodate the rock fragments generated by the metal jet impacting the well wall, preventing the rock fragments from falling off the well wall, the rock fragments that are broken by the metal jet impact but still remain in the original space of the well wall will block the subsequent jet impact on the well wall after the broken rock fragments, reducing perforation efficiency. In this step, the rock fragments generated by the first metal jet impacting the well wall fall off the well wall and can enter the cavity inside the perforating gun through the opening in the barrel wall. At the original well wall location, the new inner wall that was not broken by the first metal jet impact but was previously obscured by the falling rock fragments is exposed within the impact range of the first metal jet. This allows the rock fragments to pass through the cavity inside the perforating gun. The cavity's ability to contain the broken rock allows it to fall into the cavity after the well wall is impacted by the first metal jet. This allows the first metal jet to continuously impact the new inner wall, causing new broken rock fragments to continue to detach from the well wall and enter the cavity inside the perforating gun through the opening. This enhances the impact effect of the first metal jet on the well wall and improves perforation efficiency. The above steps are repeated continuously during the duration of the first metal jet until the well wall is perforated through the perforation hole. The impact process of the metal jets generated by the second, third, and fourth perforating projectiles on the well wall is similar to that of the first metal jet and will not be described in detail here.

[0061] In some embodiments, after the first and second perforating projectiles of the first bidirectional perforating projectile unit explode, the process further includes the following steps: the walls of the main perforating projectile bodies of the first and second perforating projectiles rupture, and the space where the main perforating projectile bodies of the first and second perforating projectiles are located communicates with the cavity inside the perforating gun; after the third and fourth perforating projectiles of the second bidirectional perforating projectile unit are detonated, the third perforating projectile generates a third metal jet, and the fourth perforating projectile generates a fourth metal jet; the rock fragments generated by the impact of the third and fourth metal jets on the well wall enter the cavity inside the perforating gun from the opening, and can also enter the cavity where the main perforating projectile bodies of the first and second perforating projectiles are located from the ruptured walls of the main perforating projectile bodies, thus accommodating more rock fragments generated by the well wall and improving perforation efficiency.

[0062] In some embodiments, before activating the detonating cord, the control method further includes the steps of: selecting perforating projectiles and selecting at least two perforating projectiles; selecting a pipe fitting and machining a through hole perpendicular to the axis of the pipe fitting and penetrating the pipe fitting according to the outer diameter of the perforating projectile to form a perforating gun barrel; selecting a metal tube of appropriate length according to the diameter of the perforating gun barrel and the length of the two perforating projectiles, and fixing the tail ends of the two perforating projectiles together so that the length of the bidirectional perforating projectile unit formed by the two perforating projectiles is the same as the diameter of the perforating gun barrel; fixing the detonation wire of the detonation controller to the detonation hole at the tail end of the two perforating projectiles, and fixing the detonation controller in the middle space of the bidirectional perforating projectile unit; installing the bidirectional perforating projectile unit into the perforating gun barrel from the through hole so that the bidirectional perforating projectile unit is symmetrical along the axis of the perforating gun barrel; and deploying the perforating gun barrel to a designated position in the ultra-deep well.

[0063] In some embodiments, the method may further include the following steps: selecting a pipe fitting whose inner diameter matches the outer diameter of the perforating projectile, based on the outer diameter of the projectile and the diameter of the perforating gun barrel, as a perforating projectile support; machining a through hole on the side wall of the perforating gun barrel, having the same outer diameter as the perforating projectile support, perpendicular to the axis of the perforating gun barrel, and penetrating the perforating gun barrel; fixing the detonation wire of the detonation controller to the detonation holes at the tails of the two projectiles, and fixing the detonation controller in the middle space of the bidirectional perforating projectile unit; symmetrically installing the two projectiles into the inner diameter holes at both ends of the perforating projectile support, thus forming a symmetrically arranged bidirectional perforating projectile unit within the perforating projectile support; the tight fit between the inner diameter of the perforating projectile support and the outer diameter of the projectile allows the perforating projectile support to real-time cancel and compensate for the recoil force vector generated by the metal jet of the projectile on the projectile during the explosion of the projectile; and installing the perforating projectile support and the bidirectional perforating projectile unit into the perforating gun barrel through the through hole.

[0064] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0065] The above description is merely a specific implementation of the embodiments of this application, but the protection scope of the embodiments of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the embodiments of this application should be included within the protection scope of the embodiments of this application. Therefore, the protection scope of the embodiments of this application should be determined by the protection scope of the claims.

Claims

1. A perforating gun suitable for ultra-deep wells, characterized in that, include: The barrel of the perforating gun is a hollow, ring-shaped structure; Multiple bidirectional perforating projectile units are arranged along the axial direction of the perforating gun barrel, and the axis of each bidirectional perforating projectile unit is perpendicular to the axis of the perforating gun barrel. Each of the bidirectional perforating projectile units includes two perforating projectiles symmetrically arranged on both sides of the axis of the perforating gun barrel, and the openings of the two perforating projectiles face radially outward from the perforating gun barrel, so that the recoil force vectors of the jets generated by the two perforating projectiles cancel each other out.

2. The perforating gun according to claim 1, characterized in that, The perforating projectile includes: The main cavity of the perforating projectile; The shaped charge liner has a conical structure and is located inside the main cavity of the perforated projectile, forming a sealed cavity between the shaped charge liner and the main cavity of the perforated projectile. The sealed cavity is filled with explosives.

3. The perforating gun according to claim 1, characterized in that, It also includes a perforation projectile support, which is a hollow annular structure; the bidirectional perforation projectile unit is disposed inside the perforation projectile support; the space inside the perforation projectile support, except for the solid space of the bidirectional perforation projectile unit, is a cavity structure to accommodate the detonation controller; the detonation controller is connected to the perforation projectile.

4. The perforating gun according to claim 3, characterized in that, It also includes a detonating cord, which has a flexible cylindrical structure, an outer layer covered with waterproof material, and an inner core filled with explosive; the detonating cord is provided with a joint; the perforation projectile support is provided with a module that is sealed and fixedly connected to the joint; the module is connected to the detonation controller.

5. The perforating gun according to claim 4, characterized in that, The detonation controller is disposed within the cavity structure; The detonation controller includes: A sensing and detection module is used to detect the detonation wave signal of the detonating cord; A timing control module is used to control the detonation sequence of the perforating projectile; The detonation drive module is used to generate the detonation current; Anti-interference protection module, used to shield against electromagnetic interference.

6. The perforating gun according to claim 3, characterized in that, The perforation projectile support includes multiple supports, which are arranged along the axial direction of the perforation gun barrel, and the axis of the perforation projectile support is perpendicular to the axis of the perforation gun barrel.

7. The perforating gun according to claim 1, characterized in that, The perforating gun barrel has a through hole with the same diameter as the outer diameter of the perforating projectile unit at the contact point with the bidirectional perforating projectile unit.

8. The perforating gun according to claim 7, characterized in that, The barrel of the perforating gun has an opening that penetrates the barrel wall and is adjacent to the through hole.

9. A method for controlling the detonation of a perforating gun suitable for ultra-deep wells, characterized in that, Including the following steps: The delay time of the first bidirectional perforating projectile unit of the perforating gun is set as the first delay time, and the delay time of the second bidirectional perforating projectile unit of the perforating gun is set as the second delay time, and the second delay time is greater than the first delay time; The detonating cord is activated, and the detonating cord is used to sequentially transmit the detonation wave to the detonation controllers of the first bidirectional perforation projectile unit and the second bidirectional perforation projectile unit; After detecting the detonation wave of the detonating cord, the detonation controller of the first bidirectional perforating projectile unit waits for the first delay time and then simultaneously detonates the first and second perforating projectiles symmetrically arranged in the first bidirectional perforating projectile unit. A first metal jet is formed in the first perforating projectile and a second metal jet is formed in the second perforating projectile. The first metal jet and the second metal jet are generated simultaneously and are symmetrical along the axis of the perforating gun. The recoil vector of the first metal jet against the first perforating projectile and the recoil vector of the second metal jet against the second perforating projectile cancel each other out in real time along the axial direction of the first bidirectional perforating projectile unit. After detecting the detonation wave of the detonating cord, the detonation controller of the second bidirectional perforation projectile unit waits for the second delay time and then simultaneously detonates the symmetrically arranged third and fourth perforation projectiles of the second bidirectional perforation projectile unit.

10. The control method according to claim 9, characterized in that, The barrel of the perforating gun has a through hole for mounting the first bidirectional perforating projectile unit and the second bidirectional perforating projectile unit, and the barrel wall of the perforating gun has an opening adjacent to the through hole that penetrates the barrel wall; after the first metal jet contacts the well wall, the process further includes the following steps: The rock fragments generated by the impact of the first metal jet on the well wall detach from the well wall; The rock fragments that broke off from the well wall entered the cavity inside the perforating gun through the opening; A new inner wall is exposed at the well wall, and the new inner wall is exposed within the impact range of the first metal jet; The first metal jet continues to impact the new inner wall until it forces the well wall out of the perforation.

Images