A vortex coaxial fracturing enhancement perforating bullet

Abstract

The invention belongs to the technical field of oil field perforating, and discloses a vortex coaxial follow-up fracturing enhancement perforating bullet, comprising a perforating bullet, a sealing fixing device and a fracturing medicine box arranged from top to bottom; the perforating bullet comprises a detonating groove, a detonating cord, a shell slope, high-energy explosives, an outer charge liner, a metal charge liner and an inner charge liner, the detonating groove is arranged above the shell slope, the upper half of the shell slope is inclined outward from top to bottom, and the lower half of the shell slope is cylindrical; the charge liner of the invention is a double-layer double-cone charge liner, and the structure and blasting height of the charge liner are optimized, and the penetration depth and hole expansion diameter are taken into consideration through the cooperation of a small cone angle upper cone and a large cone angle lower cone and the effect of the inner and outer materials of the charge liner, so as to ensure the jet penetration speed and improve the hole expansion capacity of the jet, so that the fracturing explosive acts at a deeper place and plays the functions of cleaning and hole expansion.

Description

Technical Field

[0001] The invention relates to the technical field of oil field perforation, and more particularly to a vortex coaxial follow-up fracturing enhancement type perforating bullet. Background Art

[0002] In the production process of oil fields, perforation channels are generated after focused perforation, and perforation compaction zones are formed at the same time. The compaction zone is the most important component of perforation damage and seriously affects the productivity of oil wells. Over the years, with the development of low-porosity and low-permeability oil and gas reservoirs in oil fields, under the existing process technology conditions, most of them cannot achieve the ideal negative pressure effect and cannot completely eliminate the compaction zone around the perforation channels. Therefore, it is necessary to design a vortex coaxial follow-up compaction zone fracturing perforating bullet to solve the problem that the existing perforating bullets cannot effectively remove the perforation compaction zone of the rock formation.

[0003] After searching and comparing, a gunless coaxial follow-up perforator with patent number CN101566056A was found. The device includes a gunless perforator cartridge rack and a gunless perforating bullet mounted on the cartridge rack. The gunless perforating bullet includes a cartridge case, a charge liner arranged inside the cartridge case, and a high-energy explosive pressed between the cartridge case and the charge liner. This application has a simple structure and reliable installation. While the charge liner forms a high-speed jet for perforating, the special fracturing agent is detonated and pulse fracturing is directly performed on the formation.

[0004] After searching and comparing, a coaxial follow-up perforating bullet and a self-eliminating compaction belt perforating process thereof with patent number CN104169521A were found. The equipment includes a shaped-energy perforating bullet and a breaking and compacting medicine box with a breaking and compacting medicine cake inside. This application provides a coaxial follow-up perforating bullet with a simple structure, easy processing and operation, good use effect, and the perforating compaction belt can be automatically removed during perforation.

[0005] However, when the above-mentioned perforating bullet is used for perforating, the detonation time and detonation conditions of the compaction-breaking charge are unstable. In the actual perforating process, it is difficult to ensure that most of the compaction-breaking charge can enter the perforating channel. Instead, it explodes when the focused jet is formed, and the purpose of eliminating the compaction zone cannot be achieved.

[0006] In order to solve the above problems, the present invention provides a vortex coaxial follow-up fracturing enhancement type perforating bullet. Summary of the invention

[0007] The eddy current coaxial fracturing enhancement type perforating bullet provided by the present invention adopts the following technical solution:

[0008] A vortex coaxial follow-up fracturing enhancement type perforating bullet, comprising a perforating bullet, a sealing fixing device and a fracturing medicine box arranged from top to bottom;

[0009] The perforating bullet comprises a detonating groove, a detonating cord, a cartridge case slope, a high-energy explosive, an outer charge liner, a metal charge liner, and an inner charge liner. The detonating groove is arranged above the cartridge case slope, the upper half of the cartridge case slope is inclined outward from top to bottom, and the lower half of the cartridge case slope is cylindrical in design, the high-energy explosive is arranged between the cartridge case slope and the metal charge liner, the outer charge liner is arranged at the outer end of the metal charge liner, and the inner charge liner is arranged at the inner end of the metal charge liner, the detonating cord is arranged at the lower end of the inner side of the detonating groove, and the detonating cord is embedded in the upper end of the cartridge case slope.

[0010] Furthermore, the outer liner is made of energetic material, and the inner liner is made of high-tungsten formula material.

[0011] Through the above technical solution, both the outer layer liner and the inner layer liner can play the role of cleaning the channel and expanding the hole.

[0012] Furthermore, the outer liner, the metal liner and the inner liner together form a liner structure, and the liner structure is a double-cone liner with an upper cone angle of 60° and a lower cone angle of 100°.

[0013] Through the above technical solution, the cooperation of the upper cone with a small cone angle and the lower cone with a large cone angle is utilized to take into account both the penetration depth and the hole expansion diameter, thereby ensuring the penetration speed of the jet and improving the hole expansion capacity of the jet, thereby allowing the fracturing explosives to act at deeper places.

[0014] Furthermore, the fracturing medicine box includes a medicine box shell, a partition, a fracturing medicine cake, and a jet channel. The medicine box shell is a cylindrical box body, and the partition is arranged in the middle of the inner side of the medicine box shell. The fracturing medicine cake is compressed between the partition and the medicine box shell by a medicine pressing device, and is divided into an upper and lower part. A jet channel is left in the middle of the partition. The jet channel is in a diabolo shape relying on the partition and the fracturing medicine cake, and the upper and lower ends are bowl-shaped and the middle is a cylindrical channel.

[0015] Furthermore, the fracturing medicine cake material is an auxiliary fuel with low temperature resistance, and the particles of the oxidant and the fuel are coated and matched with different particle sizes at the same time.

[0016] Furthermore, the sealing and fixing device is arranged between the fracturing cartridge and the perforating bullet, and comprises a limit frame, a fixing ring, an adjusting ring, a supporting ring, and a sealing ring. The supporting ring is installed inside the bottom end of the inclined surface of the cartridge case, and the supporting ring supports the bottom end of the metal charge cap. The adjusting ring, the limit frame, and the fixing ring are mounted from top to bottom above the fracturing cartridge and below the outer side of the inclined surface of the cartridge case. The adjusting ring is vertically movably installed in the middle of the inner cavity of the limit frame, and a supporting spring is installed at the inner top of the limit frame.

[0017] Furthermore, an annular groove is provided on the outer surface of the bottom end of the inclined surface of the cartridge case, and a sealing ring is arranged on the inner wall of the annular groove.

[0018] Through the above technical solution, the sealing ring achieves a sealing effect between the perforating bullet shell and the fracturing cartridge.

[0019] In summary, the present invention includes the following beneficial technical effects:

[0020] (1) The charge liner of the present invention is a double-layer double-cone charge liner, and the structure and blasting height of the charge liner are optimized. Through the cooperation of the upper cone with a small cone angle and the lower cone with a large cone angle and the effect of the inner and outer materials of the charge liner, the penetration depth and the hole expansion diameter are taken into account, the jet penetration speed is guaranteed, and the hole expansion ability of the jet is improved, so that the fracturing explosive can act at a deeper place and play the role of cleaning and hole expansion;

[0021] (2) Compared with traditional synergists, the fracturing agent in the fracturing agent box of the present invention has changed the type of oxidant in the formula, replaced other auxiliary materials with low temperature resistance, so that it can meet the temperature resistance of 220°C, adjusted the solid content, optimized the ratio of oxidant to fuel, and made it suitable for the production process of coaxial follow-up perforating bullets. At the same time, the energy level is improved. Through the coating treatment and particle size matching of the oxidant and fuel particles, the deflagration speed of the synergist is adjusted, so that the matching of the jet action time difference of the perforating bullet is optimized;

[0022] (3) Compared with the traditional fracturing box, the fracturing box structure of the present invention can effectively increase the loading amount of fracturing medicine. The jet channel is arranged in a diabolo shape, which can form a vortex with the partition, thereby increasing the utilization rate of the fracturing medicine, preventing the fracturing box from exploding in the first place, and increasing the jet penetration speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0024] Figure 2 It is a schematic diagram of the perforating bullet of the present invention.

[0025] Figure 3 It is a schematic diagram of the fracturing kit of the present invention.

[0026] Figure 4 It is a schematic diagram of the sealing and fixing device of the present invention.

[0027] Description of the numbers in the figure:

[0028] 1. Perforating bullet; 101. Detonating groove; 102. Detonating cord; 103. Sloped surface of cartridge case; 104. High-energy explosive; 105. Outer charge liner; 106. Metal charge liner; 107. Inner charge liner; 2. Sealing and fixing device; 201. Limiting frame; 202. Fixing ring; 203. Adjusting ring; 204. Supporting ring; 205. Sealing ring; 3. Fracturing cartridge; 301. Cartridge shell; 302. Fracturing pill; 303. Partition; 304. Jet channel. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments, and all other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making creative work are within the scope of protection of the present invention.

[0030] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "top / bottom" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0031] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "mounted / connected", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] Example:

[0033] The embodiment of the present invention discloses a vortex coaxial fracturing enhancement type perforating bullet, please refer to Figure 1 and Figure 2 , including three parts arranged from top to bottom: a perforating bullet 1, a sealing fixing device 2, and a fracturing medicine box 3;

[0034] The perforating bullet 1 comprises a detonating groove 101, a detonating cord 102, a cartridge case slope 103, a high-energy explosive 104, an outer charge liner 105, a metal charge liner 106, and an inner charge liner 107. The detonating groove 101 is arranged above the cartridge case slope 103. The upper half of the cartridge case slope 103 is inclined outward from top to bottom, and the lower half of the cartridge case slope 103 is cylindrical in design. The high-energy explosive 104 is arranged between the cartridge case slope 103 and the metal charge liner 106. The outer charge liner 105 is arranged at the outer end of the metal charge liner 106, and the inner charge liner 107 is arranged at the inner end of the metal charge liner 106. The detonating cord 102 is arranged at the lower end of the inner side of the detonating groove 101, and the detonating cord 102 is embedded in the upper end of the cartridge case slope 103.

[0035] The outer charge liner 105 is an energetic material and forms a pestle. A high-temperature and high-pressure gas is formed through chemical reaction inside the channel, which has the effect of cleaning and expanding the hole. The inner charge liner 107 is a high-tungsten formula material. When the jet is formed, it ensures the penetration performance while providing the channel cleaning agent and hole expansion function. The outer charge liner 105, the metal charge liner 106, and the inner charge liner 107 together form a charge liner structure. The charge liner structure is a double-cone charge liner with an upper cone angle of 60° and a lower cone angle of 100°.

[0036] See also Figure 1 and Figure 3 The fracturing medicine box 3 includes a medicine box shell 301, a partition 303, a fracturing medicine cake 302, and a jet channel 304. The medicine box shell 301 is a cylindrical box body. The partition 303 is arranged in the middle of the inner side of the medicine box shell 301. The fracturing medicine cake 302 is compressed between the partition 303 and the medicine box shell 301 by a medicine pressing device, and is divided into an upper and lower part. A jet channel 304 is left in the middle of the partition 303. The jet channel 304 is in a diabolo shape relying on the partition 303 and the fracturing medicine cake 302, and the upper and lower ends are bowl-shaped and the middle is a cylindrical channel. The material of the fracturing medicine cake 302 is an auxiliary fuel with low temperature resistance, and the particles of the oxidant and the fuel are coated and the particle size is matched at the same time.

[0037] See also Figure 1 and Figure 4The sealing and fixing device 2 is arranged between the fracturing medicine box 3 and the perforating bullet 1, and comprises a limit frame 201, a fixing ring 202, an adjusting ring 203, a supporting ring 204, and a sealing ring 205. The supporting ring 204 is installed inside the bottom end of the shell inclined surface 103, and the supporting ring 204 supports the bottom end of the metal charge cap 106. The adjusting ring 203, the limit frame 201, and the fixing ring 202 are mounted from top to bottom on the top of the fracturing medicine box 3 and the bottom of the outer side of the shell inclined surface 103. The adjusting ring 203 is vertically movably installed on the limit frame The middle part of the inner cavity of 201, and a supporting spring is installed on the inner top of the limit frame 201. When working, the adjusting ring 203 is pushed downward by the supporting spring to fix the fixing ring 202 to prevent the fracturing cartridge 3 and the shell inclined surface 103 from sliding. At the same time, the fixation between the fracturing cartridge 3 and the perforating bullet 1 can be released by releasing the supporting spring. An annular groove is provided on the outer surface of the bottom end of the shell inclined surface 103, and a sealing ring 205 is arranged on the inner wall of the annular groove to ensure the sealing effect between the perforating bullet 1 and the fracturing cartridge 3.

[0038] The implementation principle of this embodiment is as follows: when the whole is perforating, the detonating cord 102 in the detonating groove 101 is first detonated, and then the high-energy explosive 104 set in the perforating bullet 1 is detonated. After the high-energy explosive 104 is detonated, the shaped jet explodes in the vertical direction, and the bowl-shaped jet channel 304 at the upper end of the fracturing medicine cake 302 generates a part of horizontal movement around the rotating column where the negative pressure center is located. Due to the cyclic rotation, centrifugal force will be generated, thereby forming a vortex. The vortex gathers the fracturing medicine cake 302 above the partition 303 into the shaped jet through the centripetal force, and the partition 303 3 is composed of energy-gathering fibers, which temporarily block a part of the energy-gathering jet. The lower end of the fracturing medicine cake 302 will not explode immediately under the action of the partition 303. After the upper medicine cake forms a vortex, the partition 303 breaks, and the lower medicine cake is also gathered into the energy-gathering jet by the centripetal force. When the perforation hole is formed, as the energy-gathering jet enters the perforation wellbore, multiple explosions occur in the perforation hole under the combined action of the pressure and temperature in the perforation hole, so that cracks are generated around the perforation hole, and the perforation hole is completely connected with the surrounding formation, so as to achieve the effect of automatically eliminating the compaction zone.

[0039] The above are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A vortex coaxial fracturing enhancement perforating bullet, characterized in that: It comprises three parts arranged from top to bottom: a perforating bullet (1), a sealing fixing device (2), and a fracturing medicine box (3); The perforating bullet (1) comprises a detonating groove (101), a detonating cord (102), a shell slope (103), a high-energy explosive (104), an outer charge liner (105), a metal charge liner (106), and an inner charge liner (107). The detonating groove (101) is arranged above the shell slope (103). The upper part of the shell slope (103) is inclined outward from top to bottom, and the lower part of the shell slope (103) is cylindrical. The high-energy explosive (104) is arranged between the shell inclined surface (103) and the metal charge liner (106), the outer charge liner (105) is arranged at the outer end of the metal charge liner (106), and the inner charge liner (107) is arranged at the inner end of the metal charge liner (106), the detonating cord (102) is arranged at the lower end of the inner side of the detonating groove (101), and the detonating cord (102) is embedded in the upper end of the shell inclined surface (103); The fracturing medicine box (3) comprises a medicine box shell (301), a partition (303), a fracturing medicine cake (302), and a jet channel (304); the medicine box shell (301) is a cylindrical box body; the partition (303) is arranged at the middle part of the inner side of the medicine box shell (301); the fracturing medicine cake (302) is compressed between the partition (303) and the medicine box shell (301) by a medicine pressing device, and is divided into an upper and lower part; a jet channel (304) is left in the middle part of the partition (303); the jet channel (304) is in a diabolo shape by relying on the partition (303) and the fracturing medicine cake (302); the upper end and the lower end are bowl-shaped, and the middle is a cylindrical channel; the partition (303) is composed of energy-gathering fibers; The sealing and fixing device (2) is arranged between the fracturing cartridge (3) and the perforating bullet (1), and comprises a limiting frame (201), a fixing ring (202), an adjusting ring (203), a supporting ring (204), and a sealing ring (205); the supporting ring (204) is installed inside the bottom end of the cartridge case inclined surface (103), and the supporting ring (204) supports the bottom end of the metal charge cap (106); the adjusting ring (203), the limiting frame (201), and the fixing ring (202) are mounted from top to bottom above the fracturing cartridge (3) and below the outer side of the cartridge case inclined surface (103); the adjusting ring (203) is vertically movably installed in the middle of the inner cavity of the limiting frame (201), and a supporting spring is installed at the inner top of the limiting frame (201).

2. The eddy current coaxial fracturing enhancement perforating bullet according to claim 1, characterized in that: The outer liner (105) is made of energetic material, and the inner liner (107) is made of high-tungsten formula material.

3. The eddy current coaxial fracturing enhancement perforating bullet according to claim 1, characterized in that: The outer liner (105), the metal liner (106), and the inner liner (107) together form a liner structure, and the liner structure is a double-cone liner, and the upper cone angle is 60° and the lower cone angle is 100°.

4. The eddy current coaxial fracturing enhancement perforating bullet according to claim 1, characterized in that: An annular groove is formed on the outer surface of the bottom end of the cartridge case inclined surface (103), and a sealing ring (205) is arranged on the inner wall of the annular groove.

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