Modularized dense cluster plane perforating device

Abstract

The modularized dense cluster plane perforating device comprises a shell, a bullet carrier assembly, perforating bullets and contact type digital detonators, multiple sets of perforating devices are connected in the axial direction, and contacts of the contact type digital detonators of the previous set of perforating device are flexibly connected with contacts of the bullet carrier assembly of the next set of perforating device. A plurality of devices are connected through elastic soft contacts, assembly is simple, and front-back connection is reliable. When the modularized dense cluster plane perforating device is used on site, only four parts are assembled through press fitting and screwing, operations such as wiring and booster tube detonating cord assembling which are prone to causing human errors are omitted, the process is simple, and efficiency and safety are high; a plurality of devices are connected through elastic soft contacts, assembly is simple, and front-back connection is reliable.

Description

Modular dense-cluster planar perforation device Technical Field

[0001] This invention relates to the field of oil and natural gas production and development, and in particular to a modular dense cluster planar perforation device. Background Technology

[0002] In the existing technology, the multi-stage cluster perforation operation string mainly includes an ignition device and a perforator. The ignition device includes an electric detonator, a firing selector module, a wire guide, a straightener, a gun-to-gun connector, etc., and the perforator includes a gun barrel, upper and lower positioning plates, a contact, a pin assembly, a wire, a cartridge holder, a detonating cord, a perforating cartridge, a detonating tube, etc. All of the above parts need to be assembled on-site, which is numerous, labor-intensive, and complex.

[0003] Shale gas development involves staged fracturing, with each stage consisting of clustered perforations. Each detonator and its associated perforator constitute a cluster. During fracturing operations, to ensure uniform fracture development, the optimal distribution of perforations in each cluster within each stage is equidistant. Currently, the minimum length of a single cluster is approximately 0.6m. Given a fixed height for the blowout preventer and wellhead lifting device, the number of clusters that can be deployed in a single well operation is limited by the length of each cluster. The maximum number of clusters deployed in a single well operation is currently around 20, and it is impossible to increase the number of clusters further.

[0004] Meanwhile, improving gun loading efficiency, reducing the risk of human error, and enhancing the reliability of downhole operations have become the focus of the perforation industry. With technological advancements, the industry believes that borehole diameter is more critical than penetration depth in fracturing operations, and planar perforation can increase the perforation flow area per unit length; in addition, planar perforation avoids the competition for fracturing between perforation channels caused by conventional spiral perforation, which is more conducive to improving fracturing efficiency.

[0005] As mentioned above, multi-stage clustered perforations currently have the following problems:

[0006] 1. The work involves a large number of tools and complex assembly;

[0007] 2. The spacing between each cluster is relatively long, limiting the maximum number of clusters and making it difficult to evenly distribute perforations downhole;

[0008] 3. The spiral distribution of the pores easily leads to competition for pore fracturing, resulting in a higher fracturing initiation pressure. Summary of the Invention

[0009] To address the aforementioned technical problems, this invention proposes a modular dense-cluster planar perforation device.

[0010] The modular dense-cluster planar perforation device of the present invention includes a housing, a cartridge assembly, a perforating bullet, and a contact-type digital detonator. Multiple perforation devices are connected axially, and the contacts of the contact-type digital detonator of the previous perforation device are flexibly connected to the contacts of the cartridge assembly of the next perforation device.

[0011] In one embodiment, the cartridge assembly is fixed inside the housing, the perforated cartridge is fixed inside the cartridge assembly, one end of the contact-type digital detonator extends into the housing and is fixed on the small end of the housing, and the contact-type digital detonator cooperates with the hole shaft of the cartridge assembly; wherein, the cartridge assembly has multiple cartridge slots arranged on the same plane along its axial normal.

[0012] In one embodiment, the cartridge assembly includes a contact, a wire bonding spring, a pressure ring, and a cartridge. The contact is fixed to one end of the wire bonding spring and is interference-fitted with the wire bonding spring. The other end of the wire bonding spring is fixed to the cartridge via the pressure ring. The cartridge has an eccentric through hole along its axial direction. A cable is disposed in the eccentric through hole. One end of the cable is connected to the wire bonding spring, and the other end is connected to a conductive ring fixed to the cartridge. The cartridge has a central through hole along its axial direction. The contact-type digital detonator is disposed in the central through hole. The cartridge groove is disposed on the same plane along the axial direction normal to the cartridge.

[0013] In one embodiment, the outer circumferential surface of the housing is provided with a plurality of flat-bottomed countersunk holes corresponding to the spring groove.

[0014] In one embodiment, the cartridge case is further provided with a positioning step and a limiting buckle, and the small end of the outer shell of the perforating cartridge is provided with a step structure that cooperates with the positioning step to realize the assembly and positioning of the perforating cartridge.

[0015] In one embodiment, the cable is provided with heat shrink tubing for insulation protection.

[0016] In one embodiment, the contact-type digital detonator includes a detonator, a conductive spring, a plastic housing, and a metal housing with contacts. The detonator has a built-in firing selection module. One end of the detonator is disposed inside the plastic housing, and the other end protrudes to connect with the perforating cartridge after assembly. The conductive spring is disposed outside the plastic housing and is interference-fitted with the plastic housing. The metal housing with contacts is threadedly connected to the housing. The metal housing with contacts has contacts disposed inside, and the contacts are softly connected to the contacts of the cartridge holder assembly of another perforating device.

[0017] In one embodiment, the small end of the housing is provided with an internal thread for connecting a contact-type digital detonator; the small end of the housing is provided with an external thread and a sealing groove, the external thread being used to connect to the internal thread of the large end of the housing of another perforation device.

[0018] In one embodiment, the large end of the housing is provided with a screw groove, and the outer circle of the cartridge is provided with a screw hole that mates with the screw groove, so as to achieve circumferential positioning of the cartridge.

[0019] In one embodiment, the number of spring grooves is three, and the number of flat-bottomed countersunk holes is three.

[0020] Compared with the prior art, the modular dense-cluster planar perforation device of the present invention has the following advantages:

[0021] In field use, only four parts are assembled by pressing and screwing, eliminating operations that are prone to human error, such as wiring and assembling detonating cords and fuses. The process is simple, efficient, and safe. The minimalist structure, with each set only 0.19m in length, far shorter than the 0.6m of existing technologies, allows for three times the number of perforation clusters (approximately 60 clusters) per well, achieving high-density clustered perforation. Three perforations on the same plane increase the perforation density compared to conventional spiral perforation, which is beneficial for fracturing operations. Multiple units are connected by flexible soft contacts, simplifying assembly and ensuring reliable connections.

[0022] The above-mentioned technical features can be combined in various technically feasible ways to produce new implementation schemes, as long as the purpose of the present invention can be achieved. Attached Figure Description

[0023] The invention will now be described in more detail based on embodiments that are merely non-limiting and with reference to the accompanying drawings. Wherein:

[0024] Figure 1 shows a cross-sectional view of the modular dense cluster planar perforation device according to the present invention;

[0025] Figure 2A is a detailed sectional view of the shell portion of Figure 1;

[0026] Figure 2B is a detailed sectional view of the ammunition rack assembly in Figure 1;

[0027] Figure 2C is a detailed view of the perforation projectile in Figure 1;

[0028] Figure 2D is a detailed view of the contact-type digital detonator section of Figure 1;

[0029] Figure 3 is an isometric view of the magazine portion of the magazine assembly in Figure 2B.

[0030] In the figures, identical components are labeled with the same reference numerals. The figures are not drawn to scale.

[0031] The attached figures are labeled as follows:

[0032] 1. Housing; 2. Carrier assembly; 3. Perforated cartridge; 4. Contact-type digital detonator; 11. Internal thread; 12. Screw slot; 13. Flat-bottomed countersunk hole; 14. Sealing groove; 15. External thread; 21. Contact; 22. Welded wire spring; 23. Pressure ring; 24. Carrier; 25. Conductive ring; 26. Cable; 27. Heat shrink tubing; 28. Screw; 41. Detonator; 42. Conductive spring; 43. Plastic housing; 44. Metal housing with contact; 45. Contact; 241. Positioning step; 242. Limiting buckle; 441. Contact; 442. Sealing ring. Detailed Implementation

[0033] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, as long as there is no conflict, the various embodiments and features in each embodiment of the present invention can be combined with each other, and the resulting technical solutions are all within the protection scope of the present invention.

[0034] For any parts not mentioned in this invention, existing technologies can be used or referenced.

[0035] Currently, multi-stage clustered perforation operation strings mainly include an ignition device and a perforator. The ignition device includes multiple parts such as an electric detonator, a firing selector module, a wire guide, a straightener, and a gun-to-gun connector. The perforator includes multiple parts such as a gun barrel, upper and lower positioning plates, a contact, a pin assembly, a wire, a cartridge holder, a detonating cord, a perforating cartridge, and a detonation tube. All of these parts need to be assembled on-site, which involves a large number of parts, a large workload, and complex assembly.

[0036] Furthermore, in the staged fracturing of shale gas development, each stage is perforated in clusters, with each detonator and its matching perforator forming a cluster. During perforation fracturing operations, to ensure the uniform development of fracturing fractures, the optimal distribution of perforation positions for each cluster in each stage is equidistant. Currently, the minimum length of a single cluster is approximately 0.6m. Under the condition that the height of the blowout preventer and the wellhead lifting device is fixed, the number of clusters that can be run into the well in a single operation is limited by the length of each cluster. Currently, the maximum number of clusters that can be run into the well in a single operation is approximately 20, and it is impossible to increase the number of clusters further.

[0037] To address the aforementioned problems, this invention proposes a modular, densely clustered planar perforation device to achieve high-density clustered perforation while simplifying the assembly process. Specifically, the small end of the shell refers to the end with the smaller outer diameter, and the outer end of the shell extends to the end with the larger outer diameter; the small end of the perforating projectile refers to the end with the smaller outer diameter, and the large end of the perforating projectile refers to the end with the larger outer diameter.

[0038] As shown in Figure 1, the modular dense cluster planar perforation device of the present invention includes a housing 1, a cartridge assembly 2, a perforating bullet 3, and a contact-type digital detonator 4. Multiple perforation devices are connected axially, and the contacts of the contact-type digital detonator 4 of the previous perforation device are flexibly connected to the contacts of the cartridge assembly 2 of the next perforation device.

[0039] When used in the field, the perforation device of the present invention only requires pressing and screwing to assemble four parts, eliminating operations that are prone to human error, such as wiring and assembling detonating cords and detonating tubes. The process is simple, efficient and safe. Multiple devices are connected by flexible soft contacts, which makes assembly simple and the connection between front and back is reliable.

[0040] Referring again to Figure 1, in an optional embodiment, the cartridge assembly 2 is fixed inside the housing 1, the perforated cartridge 3 is fixed inside the cartridge assembly 2, one end of the contact-type digital detonator 4 extends into the housing 1 and is fixed on the small end of the housing 1, and the contact-type digital detonator 4 cooperates with the hole shaft of the cartridge assembly 2; wherein, the cartridge assembly 2 has multiple cartridge slots arranged on the same plane along its axial direction.

[0041] The perforation device of the present invention has multiple perforation grooves on the same plane of the perforation frame. Compared with conventional spiral perforation, it increases the perforation density on the same plane, which is beneficial to fracturing operations.

[0042] Optionally, the contact-type digital detonator 4 is threadedly connected to the housing 1.

[0043] In an optional embodiment, as shown in FIG2B, the cartridge assembly 2 includes a contact 21, a wire-welding spring 22, a pressure ring 23, and a cartridge 24. The contact 21 is fixed to one end of the wire-welding spring 22 and is interference-fitted with the wire-welding spring 22. The other end of the wire-welding spring 22 is fixed to the cartridge 24 by the pressure ring 23. The cartridge 24 has an eccentric through hole along its axial direction. A cable 26 is disposed in the eccentric through hole. One end of the cable 26 is connected to the wire-welding spring 22, and the other end is connected to a conductive ring 25 fixed to the other end of the cartridge 24. The cartridge 24 has a central through hole along its axial direction. A contact-type digital detonator 4 is disposed in the central through hole. Multiple cartridge slots are arranged on the same plane along the axial direction normal to the cartridge 24.

[0044] Furthermore, heat shrink tubing 27 can be installed on the outside of the cable 26 to provide insulation protection for the cable 26.

[0045] As shown in Figures 1, 2A and 2B, in one embodiment, the outer circumferential surface of the housing 1 is provided with a plurality of flat-bottomed countersunk holes 13 corresponding to the bullet groove, in order to reduce the energy loss when the perforating bullet penetrates.

[0046] Referring again to Figures 1 and 2B, in an optional embodiment, the perforating bullet 3 is fixed on the cartridge holder 24, which is provided with a positioning step 241 and a limiting buckle 242. The perforating bullet 3 is fixed by the positioning step 241 and the limiting buckle 242. At the same time, the small end of the outer shell of the perforating bullet 3 is provided with a step structure that cooperates with the positioning step 241 to realize the assembly and positioning of the perforating bullet 3.

[0047] The limiting buckle 242 is located at the large end of the firing hole 3 on the ammunition rack.

[0048] As shown in Figures 1 and 2D, in an optional embodiment, the contact-type digital detonator 4 includes a detonator 41, a conductive spring 42, a plastic housing 43, and a metal housing 44 with contacts connected in sequence. The detonator 41 has a built-in firing selection module. One end of the detonator 41 is disposed inside the plastic housing 43, and the other end protrudes to connect with the perforating cartridge 3 after assembly. The conductive spring 42 is disposed on the outside of the plastic housing 43, at the end where the detonator 41 is installed, and is interference-fitted with the plastic housing 43. After assembly, the conductive spring 42 cooperates with the conductive ring 25. The metal housing 44 with contacts is disposed at the other end of the plastic housing 43 and is threadedly connected to the housing 1. The metal housing 44 with contacts has contacts 441 disposed inside, and the contacts 441 are softly connected to the contacts 21 of the cartridge holder assembly 2 of another perforating device. The conductive spring 42 and the contacts 441 are connected inside the contact-type digital detonator 4 to conduct and transmit signals. A sealing ring 442 is disposed on the outer circumference of the metal housing 44 with contacts, which forms a seal after cooperating with the housing 1.

[0049] As shown in Figures 1 and 2A, the small end of the housing 1 is provided with an internal thread 11 for connecting to the contact point digital detonator 4; the small end of the housing is provided with an external thread 15 and a sealing groove 14. The external thread 15 is used to connect to the internal thread 11 of the large end of the housing 1 of another perforation device. A sealing ring (such as an O-ring) is provided in the sealing groove 14 to achieve a seal between the housings.

[0050] Furthermore, the large end of the housing 1 is provided with a screw groove 12, and the outer edge of the cartridge 24 is provided with a screw hole that mates with the screw groove 12. The circumferential positioning of the cartridge 24 is achieved by passing a screw through the screw groove 12 and the screw hole.

[0051] In one optional embodiment, the number of spring grooves is 3, and the number of flat-bottomed countersunk holes is 3.

[0052] The modular dense-cluster planar perforation device of this invention requires only four parts to be assembled in the field through pressing and screwing, eliminating operations prone to human error such as wiring and assembling detonating cords and fuses. The process is simple, efficient, and safe. The structure is simple, with each set only 0.19m in length, far shorter than the 0.6m of existing technologies. It can achieve approximately 60 perforation clusters in a single well run, three times that of existing technologies, realizing high-density clustered perforation. With three perforations on the same plane, compared to conventional spiral perforation, the perforation density is increased, which is beneficial for fracturing operations. Furthermore, multiple devices are connected by flexible soft contacts, simplifying assembly and ensuring reliable connections.

[0053] The following describes the method of using the perforation device of the present invention using a specific embodiment:

[0054] When the perforating device is used in the field, the perforating bullet 3 is first pressed into the bullet holder assembly 2. The bullet holder assembly 2 is inserted from the large end of the housing 1, and the contact-type digital detonator 4 is screwed into the small end of the housing, thus completing the assembly of one cluster. Repeat the above steps, and then connect the external thread 15 of the small end of the housing 1 of the previous perforating device to the internal thread 11 of the large end of the housing 1 of the other perforating device, so that they are connected back and forth along the axial direction to form a multi-stage clustered perforating tube string.

[0055] In use, the device is lowered into the well to a predetermined position by a cable. When an electrical signal is transmitted, the contact 21, welding spring 22, cable 26, conductive ring 25, conductive spring 42, and contact 441 of the cartridge assembly 2 form a conductive path, selectively detonating the contact-type digital detonator 4, thereby detonating the perforating shell to perform a cluster of perforations. Then, the cartridge is dragged to the next position, selectively detonating the contact-type digital detonator 4, thereby detonating the perforating shell to complete the next cluster of perforations. By repeating the above steps, multi-stage cluster perforation operations can be completed.

[0056] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "comprising" or "including," and similar words used in this invention, mean that the element or object preceding the word encompasses the element or object listed following the word and its equivalents, without excluding other elements or objects. The terms "connected" or "linked," and similar words, are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. In the description of this invention, the terms "vertical," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. When the absolute position of the described object changes, the relative positional relationship may also change accordingly, and therefore should not be construed as a limitation of the invention.

[0057] Therefore, those skilled in the art should recognize that although the present invention has been described with reference to preferred embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the invention. In particular, the technical features mentioned in the various embodiments can be combined in any manner as long as there is no structural conflict. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A modular dense-cluster planar perforation device, characterized in that, The perforation device includes a housing, a cartridge assembly, a perforating cartridge, and a contact-type digital detonator. Multiple perforation devices are connected axially, and the contacts of the contact-type digital detonator of the previous perforation device are flexibly connected to the contacts of the cartridge assembly of the next perforation device.

2. The modular dense-cluster planar perforation device according to claim 1, characterized in that, The cartridge holder assembly is fixed inside the housing, the perforated cartridge is fixed inside the cartridge holder assembly, one end of the contact-type digital detonator extends into the housing and is fixed to the small end of the housing, and the contact-type digital detonator cooperates with the hole shaft of the cartridge holder assembly; wherein, the cartridge holder assembly has multiple cartridge slots arranged on the same plane along its axial normal.

3. The modular dense-cluster planar perforation device according to claim 2, characterized in that, The cartridge assembly includes a contact, a wire bonding spring, a pressure ring, and a cartridge. The contact is fixed to one end of the wire bonding spring and is interference-fitted with the wire bonding spring. The other end of the wire bonding spring is fixed to the cartridge via the pressure ring. The cartridge has an eccentric through hole along its axial direction. A cable is disposed in the eccentric through hole. One end of the cable is connected to the wire bonding spring, and the other end is connected to a conductive ring fixed to the cartridge. The cartridge has a central through hole along its axial direction. The contact-type digital detonator is disposed in the central through hole. The cartridge groove is disposed on the same plane along the axial direction normal to the cartridge.

4. The modular dense-cluster planar perforation device according to claim 3, characterized in that, The outer circumferential surface of the housing is provided with multiple flat-bottomed countersunk holes corresponding to the spring groove.

5. The modular dense-cluster planar perforation device according to claim 4, characterized in that, The cartridge case is also equipped with a positioning step and a limiting buckle. The small end of the outer shell of the perforating projectile is provided with a step structure that cooperates with the positioning step to realize the assembly and positioning of the perforating projectile.

6. The modular dense-cluster planar perforation device according to claim 5, characterized in that, The cable is insulated and protected by heat shrink tubing.

7. The modular dense-cluster planar perforation device according to claim 5, characterized in that, The contact-type digital detonator includes a detonator, a conductive spring, a plastic housing, and a metal housing with contacts. The detonator has a built-in firing selection module. One end of the detonator is located inside the plastic housing, and the other end protrudes to connect with the perforating cartridge after assembly. The conductive spring is located at the end of the plastic housing where the detonator is installed and is interference-fitted with the plastic housing. The metal housing with contacts is threaded to the housing. The metal housing with contacts has contacts inside, and the contacts are softly connected to the contacts of the cartridge holder assembly of another perforating device.

8. The modular dense-cluster planar perforation device according to claim 7, characterized in that, The small end of the housing is provided with an internal thread for connecting a contact-type digital detonator; the small end of the housing is provided with an external thread and a sealing groove, the external thread being used to connect to the internal thread of the large end of the housing of another perforation device.

9. The modular dense-cluster planar perforation device according to claim 5, characterized in that, The large end of the housing is provided with a screw groove, and the outer circle of the cartridge is provided with a screw hole that mates with the screw groove, so as to achieve circumferential positioning of the cartridge.

10. The modular dense-cluster planar perforation device according to claim 4, characterized in that, The number of spring grooves is 3, and the number of flat-bottomed countersunk holes is 3.

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