Directional clustering perforating gun

Abstract

The directional clustering perforating gun comprises a dynamic conductive structure, and a circuit transmission line of the dynamic conductive structure comprises a spring, a dynamic conductive ring, a bearing and a lower positioning rod; the bearing comprises a ball bearing and a thrust bearing; the ball bearing and the thrust bearing form a parallel circuit assembly which is connected to the circuit transmission line. The problem that electric signal transmission of existing similar perforating guns is not stable enough is effectively solved.

Description

Technical Field

[0001] The present disclosure relates to perforating equipment used in oilfield completion operations in oilfield production enhancement measures, in particular to a directional clustered perforating gun. Background Art

[0002] like Figure 1 As shown in the figure, the current directional cluster perforating gun string adopts gravity orientation by counterweight blocks, the cable plug connector assembly in the barrel and the barrel wall form a transmission circuit as the positive and negative electrodes, and the electronic selective firing switch controls the detonator and perforating bullet of the perforating gun to detonate and perforate in sequence. The conductive sealing structure of the unperforated barrel withstands the high pressure generated by the combined action of the perforating shock wave and the downhole oil, and maintains the normal sealing, conductive and signal transmission state, so as to proceed with the selective firing and perforation of the next gun.

[0003] However, the perforating gun of this structure currently has the following problems: First, the transmission of electrical signals is not stable enough: the perforating bullet frame assembly rotates randomly during the process of going down the well. When it rotates, it needs to realize the conductive function with relatively static parts such as detonators and lower joints. Therefore, a dynamic conductive structure is adopted, and its circuit transmission line consists of a spring-dynamic conductive ring-ball bearing-lower positioning rod. The ball bearing rotates and conducts electricity, but due to the small gap between the inner and outer rings of the bearing, its conductivity is unstable, and there will be a virtual connection phenomenon, and the electrical signal transmission is unstable, which affects the detonation perforation. Second, the problem of unstable structure of the sealing conductive component: the joints between clusters of the directional cluster perforating gun adopt the sealing method of the sealing conductive component, which is required to withstand the impact of the underground formation high pressure and the perforation blast wave. The sealing conductive component is formed by injection molding between two metal parts, that is, plastic is injected between the two metal parts of the sealing conductive component. Due to the strong impact force of the perforation blast wave, the sealing conductive component will break, resulting in the interruption of the detonation electrical signal. The third is the problem of gravity orientation accuracy: the reason is that the space inside the tube is small and there are few counterweights that can be installed, resulting in low orientation accuracy. Fourth, the safety and reliability are not strong: before use, the pyrotechnic perforating bullet is assembled in the gun body together with the detonator. They are connected through the selective firing switch. The two coexist for a long time, and there is a possibility of accidental explosion. Summary of the invention

[0004] In view of this, the present disclosure provides a directional clustered perforating gun, which at least solves the problem of unstable electrical signal transmission of existing similar perforating guns.

[0005] To achieve the above-mentioned purpose of the invention, the directional cluster perforating gun comprises a dynamic conductive structure, wherein the circuit transmission line of the dynamic conductive structure is a spring, a dynamic conductive ring, a bearing and a lower positioning rod; wherein: The bearings include ball bearings and thrust bearings; The ball bearing and the thrust bearing form a parallel circuit component connected to the circuit transmission line.

[0006] In the present disclosure and possible embodiments, a thrust spring is connected between the thrust bearing and the lower positioning rod.

[0007] In the present disclosure and possible embodiments, the perforating gun further comprises: Sealing conductive components; The sealed conductive component is formed by injecting plastic between the first metal component and the second metal component; a labyrinth sealing structure is used between the plastic and the first metal component and the second metal component to seal the shaft end.

[0008] In the present disclosure and possible embodiments, the plastic is PEEK material.

[0009] In the present disclosure and possible embodiments, the labyrinth sealing structure is a labyrinth groove provided on the contact end surfaces of the first metal member and the second metal member with the plastic respectively.

[0010] In the present disclosure and possible embodiments, the perforating gun further comprises: Directional bomb rack assembly; An eccentric distance is set between the centroid and the center of gravity of the directional bomb rack assembly.

[0011] In the present disclosure and possible embodiments, the bomb rack body of the directional bomb rack assembly is positioned in the gun barrel using insulating eccentric disks respectively connected to both ends thereof.

[0012] In the present disclosure and possible embodiments, the insulating eccentric disk is fixed in the gun barrel via a rotating support bearing.

[0013] In the present disclosure and possible embodiments, a counterweight is disposed on the outer side of the bomb rack body.

[0014] Beneficial effects of the present invention: The directional clustered perforating gun disclosed in the present invention has a dynamic conductive structure that adds a circuit structure connected in parallel with the ball bearing: thrust bearing + thrust spring. The single conductive circuit of the current directional clustered perforating gun, namely, spring-dynamic conductive ring-ball bearing-lower positioning rod, is changed into a double-circuit structure. The thrust bearing and the ball bearing under the action of spring force adopt multi-point dynamic contact conduction, which prevents the single conductive circuit of the ball bearing from having insufficient contact force and fewer contact points, thus avoiding the occurrence of false connection phenomenon in electrical signal transmission. The upper and lower rings and balls of the thrust bearing can stably conduct electricity without affecting the flexible rotation of the ball bearing, thereby ensuring reliable conduction between the dynamic conductive ring and the lower positioning rod, further ensuring the stability of electrical signal transmission of the directional clustered perforating gun, reducing the number of inspections and adjustments for raising and lowering the perforating gun into the well, and alleviating the labor intensity of workers. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above and other objects, features and advantages of the present disclosure will become more apparent through the following description of the embodiments of the present disclosure with reference to the accompanying drawings, in which: Figure 1 It is a schematic diagram of the structure of a directional clustered perforating gun of the background technology of the present disclosure; Figure 2 is a structural assembly diagram of a directional clustered perforating gun according to an embodiment of the present disclosure; Figure 3 is a schematic structural diagram of a directional bomb rack assembly according to an embodiment of the present disclosure; Figure 3A is a schematic diagram of gravity orientation of perforation of a directional bomb rack assembly according to an embodiment of the present disclosure; Figure 4 is a schematic diagram of a dynamic conductive structure according to an embodiment of the present disclosure; Figure 5 is a schematic diagram of a dynamic conductive structure according to an embodiment of the present disclosure; Figure 6 This is the installation position diagram of the perforating bullet before use; Figure 7 This is the installation location diagram of the electronic detonator selected before use. Implementation

[0016] The present disclosure is described below based on embodiments, but it is worth noting that the present disclosure is not limited to these embodiments. In the detailed description of the present disclosure below, some specific details are described in detail. However, for the parts that are not described in detail, those skilled in the art can also fully understand the present disclosure.

[0017] In addition, it should be understood by those skilled in the art that the drawings provided are only for illustrating the purpose, features and advantages of the present disclosure, and the drawings are not actually drawn to scale. The serial numbers assigned to the components herein, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning. The "connection" and "coupling" mentioned in this application. Unless otherwise specified, both direct and indirect connections (couplings) are included. In the description of this application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", etc. is based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore, cannot be understood as a limitation on the present application.

[0018] At the same time, unless the context clearly requires otherwise, the words "include", "comprises" and similar words throughout the specification and claims should be interpreted as inclusive rather than exclusive or exhaustive; that is, the meaning of "including but not limited to".

[0019] Figure 2 is a structural assembly diagram of a directional clustered perforating gun according to an embodiment of the present disclosure; Figure 2 As shown, the directional cluster perforating gun of this embodiment has a structure of a two-stage perforating gun, specifically including an upper joint 1, a sealing conductive component 2, a directional bomb rack assembly 3, an intermediate joint 4, a selective detonator integrated unit 5, a barrel 6, a dynamic conductive structure 7 and a lower joint 8; wherein the barrel 6 is connected to the upper joint 1, the intermediate joint 4 and the lower joint 8 by a trapezoidal thread.

[0020] Among them, the upper joint 1, the sealed conductive component 2, the gun barrel 6, the middle joint 4 and the selective detonator integrated unit 5 constitute a closed cavity, and the directional bomb rack assembly 3 is equipped with a perforating bullet. Using the positive and negative circuits formed by the surface of the gun barrel 6 and the internal through-wire 11, under the control of the electronic selective detonator integrated unit 5, the pulse response technology is used to activate the electronic selective detonator 50, thereby detonating the perforating bullet and performing the perforating operation. Compared with the directional cluster perforating gun described in the background technology, the present disclosure improves the sealed conductive component 2, the directional bomb rack assembly 3 and the dynamic conductive structure 7 therein to solve the problems described in the background technology; specifically as follows: like Figure 3 As shown in the figure, the directional bullet rack assembly 3 of the embodiment of the present disclosure has a base body 30 for mounting a perforating bullet 33, and both ends of the bullet rack body 30 are connected to an insulating eccentric disk 32. The bullet rack body 30 is fixed in the gun barrel 6 through the insulating eccentric disk 32, the rotation support bearing 31 and the positioning sleeve 37, and the counterweight 36 is arranged on the outside of the bullet rack body 30. The present disclosure designs an eccentric structure of the bullet rack body 30 similar to a "crankshaft", so that the center of gravity line 34 and the centroid line 35 of the directional bullet rack assembly do not overlap, and there is a certain eccentric distance e between the two. Because of the eccentric structure design of the directional bullet rack assembly, each component assembled on the entire directional bullet rack assembly 3 becomes a counterweight capable of generating rotational orientation. In the limited narrow space of the inner cavity of the gun barrel 6, the total weight of the counterweight can be increased by 40%, thereby increasing the reset orientation capability of the bullet rack body 30, and the gun orientation accuracy is improved from ±5 to 8° to ±3 to 5°.

[0021] like Figure 3AAs shown: According to the directional perforating operation requirements proposed by the user, the angle between the center of gravity 34 of the directional bomb rack assembly 3 and the perforating direction is clarified, and insulating eccentric disks 32 are installed at both ends of the bomb rack body 30. The relative positions between them should meet the following requirements: first, the eccentric direction of the insulating eccentric disk 32 is arranged up and down along the center of gravity 34, and second, the perforating bullet 33 is installed in the middle of the bomb rack body 30, and the angle between the perforating direction and the center of gravity 34 is the technical index required by the user. The relative assembly position of the counterweight 36 and the bomb rack body 30 is adjusted and fixed, so that the centroid position of the directional bomb rack assembly (including the counterweight) is in the vertical plane of the center of gravity 34 (as shown in the figure). At this time, the angle between the center of gravity 34 and the perforating direction is the direction required by the user, thereby ensuring that no matter how the perforating gun barrel rotates in the horizontal well, the jet orientation remains unchanged.

[0022] The size of the eccentric distance e of the directional bomb frame assembly is determined by the eccentricity of the insulating eccentric disc 32 installed on the bearings at both ends. The eccentricity of the insulating eccentric disc 32 is processed according to the design requirements.

[0023] like Figure 4 As shown, the circuit transmission line of the dynamic conductive structure 7 of the embodiment of the present disclosure is composed of a spring 74, a dynamic conductive ring 75, a bearing and a lower positioning rod 13, wherein the bearing is composed of a ball bearing 73 and a thrust bearing 72. The circuit transmission line of the current dynamic conductive structure of the directional cluster perforating gun is a single conductive line composed of a spring, a dynamic conductive ring, a ball bearing and a lower positioning rod. The ball of the ball bearing not only rotates but also conducts electricity. Since there is a small gap between the inner and outer rings of the bearing, only a single point of contact conduction is generated between the ball of the ball bearing and the inner and outer rings, resulting in unstable conduction. The dynamic conductive structure 7 of the present disclosure adds a circuit structure in parallel with the ball bearing: thrust bearing 72+thrust spring 71. The ball bearing and the thrust bearing form a parallel circuit assembly connected to the circuit transmission line, that is, the single conductive line of the spring, dynamic conductive ring, ball bearing and lower positioning rod of the current directional cluster perforating gun is changed into a double-line structure. Under the action of the thrust spring 71, there is no gap between the upper and lower rings of the thrust bearing and the ball, realizing multi-point contact conduction. Because the upper and lower rings of the thrust bearing and the ball bearing can stably conduct electricity without affecting the flexible rotation of the ball bearing 73, reliable conduction between the dynamic conductive ring 75 and the lower positioning rod 13 is ensured, further ensuring the stability of the electrical signal transmission of the 89-type cluster perforating gun, reducing the number of inspections and adjustments of the perforating gun when it is lifted and lowered into the well, and reducing the labor intensity of the workers. The thrust bearing 72 is connected to the lower positioning rod 13 through the thrust spring 71.

[0024] like Figure 5As shown: the sealed conductive component 2 of the embodiment of the present disclosure is composed of a first metal part 21, a second metal part 22 and a component formed by injecting plastic 23 therebetween, wherein the plastic 23 is respectively sealed with the first metal part 21 and the second metal part 22 using a labyrinth sealing structure for axial end sealing, and the labyrinth sealing structure is a labyrinth groove arranged on the contact end surface of the plastic 23 and the first metal part 21 and the second metal part 22; in addition, the plastic 23 is made of high-strength, high-temperature resistant PEEK special plastic material.

[0025] The design of the labyrinth seal structure increases the injection bonding strength between the first metal part 21 and the second metal part 22, ensuring that it can work reliably under the high pressure of the underground formation and the impact vibration of the perforation explosion wave. At the same time, the temperature resistance of the perforating gun is increased from 170°C to 210°C, and the pressure resistance is increased from 105 MPa to 100 MPa. a Increased to 140MP a The improved sealing and conducting assembly disclosed above can ensure that after a cluster of perforated guns is perforated in a high-temperature and high-pressure oil well, another cluster of unperforated guns can withstand the impact of the detonation wave, thereby achieving reliable sealing and conduction of the guns under higher temperature and pressure environments.

[0026] The assembly of the components of the directional cluster perforating gun of the embodiment of the present disclosure is further described. The entire assembly process is divided into the following steps: first, the assembly of the perforating gun barrel component; second, the assembly of the upper joint component; third, the assembly of the middle joint component; and fourth, the general assembly of the perforating gun. The specific process is as follows: (1) Assembly of perforating gun barrel components: According to the perforating operation requirements, the eccentric direction and counterweight of the bomb rack are arranged, insulating eccentric disks 32 are installed at both ends of the bomb rack body 30, and the perforating bullet 33 is installed in the middle of the bomb rack body 30 to control the direction of the perforating bullet jet emission, so as to ensure that the jet orientation remains unchanged regardless of how the perforating gun barrel rotates in the horizontal well. The through wire 11 is connected with the upper positioning rod 10, the lower positioning rod 13, and the dynamic conductive ring 75 of the dynamic conductive structure 7 with an elastic mechanism to maintain smooth conduction, complete the assembly of the directional bomb rack assembly, insert the bomb rack components into the barrel 6 of the perforating gun, and position the bomb rack body 30 by relying on the limiting step in the barrel to complete the assembly of the perforating gun barrel components.

[0027] (2) Assembly of upper joint components: The upper joint 1 is fixed with a tool. First, the O-ring is installed into the sealing groove of the upper joint. Then, the sealing conductive component 2 is installed into the inner cavity of the upper joint with a special tool and tightened with a nut to position it. The conductive rod 9 and the conductive spring 12 are inserted into the insulating plastic tube, and then put into the inner cavity on the left side of the upper joint together and tightened with a nut to position it. The conductive rod 9 maintains smooth conduction with the dynamic conductive structure and maintains good insulation with the outer surface of the upper joint, thus completing the assembly of the upper joint components.

[0028] (3) Assembly of intermediate joint components: The middle joint 4 is fixed, and the O-ring 51 is first installed into the sealing groove of the middle joint 4, and then the O-ring 51 is installed into the sealing groove of the selective electronic detonator 50. Then, the selective detonator integrated unit 5 is screwed into the inner cavity of the middle joint 4 using a special tool. The center contact at the right end of the selective electronic detonator 50 is well insulated from the outer surface of the middle joint 4, thus completing the assembly of the middle joint components.

[0029] (4) Perforating gun assembly: The assembled perforating gun barrel components are fixed with a tool, and the assembled upper joint components are screwed into the upper end of the gun barrel 6 to connect the conductive rod 9 with the upper positioning rod 10 in the gun barrel 6. Then, the assembled middle joint components are screwed into the lower end of the gun barrel 6 to keep the dynamic conductive ring 75 and the selective detonator integrated unit 5 conductive and unobstructed. In this way, the final assembly of one cluster of perforating guns is completed. The perforating gun barrel components are continuously connected with the assembled middle joint components to complete the final assembly of multiple clusters of perforating guns.

[0030] Depend on Figure 6 and Figure 7 As shown, the perforating bullet 33 and the optional electronic detonator 50 are assembled on different components before use and are physically separated from each other, which is more in line with the national management requirements for the use of pyrotechnics and has no safety hazards.

[0031] From the above description, it can be seen that the perforating gun of the present invention is easy and quick to operate, which greatly reduces the workload of on-site assembly. Since the total amount of counterweight is large in a limited space, the directional reset accuracy is high; and the electrical signal transmission is stable, which reduces the number of inspections and adjustments of the perforating gun when it is raised and lowered into the well, improves work efficiency, and reduces labor intensity; at the same time, the perforating bullet and the selective electronic detonator are assembled on different components before use, and are physically separated from each other, so that the safety is significantly improved.

[0032] The above-described embodiments are only embodiments of the present disclosure, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the present disclosure. It should be noted that, for a person of ordinary skill in the art, without departing from the concept of the present disclosure, several variations, equivalent substitutions, improvements, etc. may be made, all of which fall within the scope of protection of the present disclosure. Therefore, the scope of protection of the present disclosure shall be subject to the attached claims.

Claims

1. A directional cluster perforating gun, comprising a dynamic conductive structure, wherein the circuit transmission line of the dynamic conductive structure is a spring, a dynamic conductive ring, a bearing and a lower positioning rod; characterized in that: The bearings include ball bearings and thrust bearings; The ball bearing and the thrust bearing form a parallel circuit component connected to the circuit transmission line.

2. The perforating gun according to claim 1, characterized in that: A thrust spring is connected between the thrust bearing and the lower positioning rod.

3. The perforating gun according to claim 1 or 2, characterized in that: The perforating gun also includes: Sealing conductive components; The sealed conductive component is formed by injecting plastic between the first metal component and the second metal component; a labyrinth sealing structure is used between the plastic and the first metal component and the second metal component to seal the shaft end.

4. The perforating gun according to claim 3, characterized in that: The plastic is PEEK material.

5. The perforating gun according to claim 4, characterized in that: The labyrinth sealing structure is a labyrinth groove provided on the contact end surfaces of the first metal member and the second metal member with the plastic respectively.

6. The perforating gun according to any one of claims 1, 2, 4 or 5, characterized in that: The perforating gun also includes: Directional bomb rack assembly; An eccentric distance is set between the centroid and the center of gravity of the directional bomb rack assembly.

7. The perforating gun according to claim 6, characterized in that: The bomb rack body of the directional bomb rack assembly is positioned in the gun barrel by using insulating eccentric disks respectively connected to both ends of the bomb rack body.

8. The perforating gun according to claim 7, characterized in that: The insulating eccentric disc is fixed in the gun barrel via a rotating support bearing.

9. The perforating gun according to claim 8, characterized in that: A counterweight is arranged on the outer side of the bomb rack body.

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