Automatic pressure relief device
By setting a pressure relief chamber and a one-way valve in the perforation string conveying tool, the problem of accidental detonation of the perforation gun caused by the pressure difference is solved by automatically releasing pressure and reducing pressure, thus achieving the safety and reliability of perforation operations.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SINOPEC OILFIELD SERVICE CORPORATION
- Filing Date
- 2025-06-04
- Publication Date
- 2026-04-28
AI Technical Summary
In pressurized operations and testing of perforation, the formation of a confined space due to defects in the tubing structure design and human error can cause a surge in pressure at high downhole temperatures, potentially leading to accidental detonation of the perforation gun. Existing technologies cannot effectively prevent this.
Design an automatic pressure relief device, including a pressure relief chamber, a valve seat and a one-way valve, to automatically relieve pressure and reduce pressure through pressure difference, thereby preventing pressure surges in confined spaces and ensuring safe operation of the perforating gun.
It enables automatic depressurization of the perforation string conveyor during the lowering process to prevent accidental detonation of the perforation gun, while also enabling reliable pressurized detonation to ensure the safety of perforation operations.
Smart Images
Figure CN224174599U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of petroleum engineering technology, and more specifically, to an automatic pressure relief device. Background Technology
[0002] With the increasing complexity of perforation string structures in tubing and coiled tubing, especially in pressurized operations and test perforations, design flaws in the string structure and human error can lead to the formation of a closed space between the pressure initiation device and the internal release tool of the coiled tubing. Under the influence of high downhole temperatures, the internal pressure of this closed space can surge, potentially causing accidental detonation of the perforation gun.
[0003] Currently, a 3mm hole is usually made at the tubing coupling to prevent the formation of a confined space. However, the increased annular pressure during the lowering of the continuous tubing may also cause the perforating gun to detonate accidentally.
[0004] Therefore, how to avoid the problem of accidental detonation of the perforating gun caused by the confined space of the pipeline perforation hole is a technical problem that needs to be solved by those skilled in the art. Utility Model Content
[0005] This application provides an automatic pressure relief device that can automatically reduce pressure during the perforation operation of the perforation string conveyor, thereby preventing accidental detonation, while ensuring that the perforation string conveyor is pressurized and detonated.
[0006] This application provides an automatic pressure relief device for perforation operations of a perforation string conveying tool, comprising:
[0007] The device body encloses and forms a pressure relief chamber, and a first installation chamber that connects the pressure relief chamber to the downhole environment. The device body is provided with an initiator connection part and a conveying component connection part.
[0008] A valve seat is used for sealing installation in the first mounting cavity. The valve seat encloses and forms an opening structure and a second mounting cavity. The second mounting cavity is connected to the pressure relief cavity, and the second mounting cavity is connected to the downhole environment through the opening structure.
[0009] A one-way valve is used for sealing installation in the second mounting cavity. The one-way valve includes a valve body and a resilient connecting assembly. The valve body internally encloses a third mounting cavity, which communicates with the pressure relief cavity and the opening structure. The resilient connecting assembly is used for sealing installation in the third mounting cavity. The one-way valve is configured such that: when the pressure difference applied to the resilient connecting assembly is less than the pre-compression force of the resilient connecting assembly, the resilient connecting assembly blocks the opening structure; and when the pressure difference is greater than or equal to the pre-compression force, the resilient connecting assembly opens the opening structure to automatically release pressure.
[0010] In some embodiments, the pressure difference includes the difference between the internal pressure value between the blowout preventer and the pressure initiation device inside the perforation string delivery tool and the annular pressure value in the wellbore.
[0011] In some embodiments, the resilient connection assembly includes: a plug, a stopper, a preload spring, and a first sealing ring; wherein the first sealing ring is sealed and installed on the outer peripheral surface of the valve body, the plug is used to block the opening structure, a first end of the preload spring facing the opening structure is connected to the plug, and a second end of the preload spring away from the opening structure is connected to the stopper.
[0012] In some embodiments, the third mounting cavity includes a third mounting sub-cavity and a third communicating cavity, the third communicating cavity being connected to the pressure relief cavity and the third mounting sub-cavity, the third mounting sub-cavity being connected to the opening structure, the elastic connection assembly being disposed in the third mounting sub-cavity, and the plug being used to seal the third communicating cavity.
[0013] In some embodiments, the opening structure includes a first opening and a second opening, the first opening communicating with the downhole environment, the second opening communicating with the second opening and the third mounting cavity, and the diameter of the second opening being smaller than the diameter of the first opening.
[0014] In some embodiments, the third communicating cavity is provided with a ball seat structure, and the ball seat structure has a step on the side facing the third mounting sub-cavity, and the plug is sealed to the step.
[0015] In some embodiments, the plug is a spherical structure.
[0016] In some embodiments, the detonator connection portion and the conveyor connection portion are disposed at two ends of the device body along a first direction, the detonator connection portion is provided with a first external thread, and the conveyor connection portion is provided with a second external thread.
[0017] In some embodiments, a nut is also provided on the first external thread and the second external thread.
[0018] In some embodiments, the perforation string delivery tool includes tubing, or continuous tubing, or drill pipe.
[0019] In this embodiment, the safe lowering of the perforating string conveyor can be achieved, preventing accidental detonation of the perforating gun due to increased pressure caused by temperature rise in the sealed space between the pressure initiation device and the internal discharge tool of the perforating string conveyor during the lowering process. Furthermore, the one-way valve in this application has the function of forward pressure bearing and reliable reverse pressure relief. It achieves unidirectional flow and automatic unidirectional pressure relief, utilizing the intermittent flow principle to achieve pressurized detonation within the perforating string conveyor, while simultaneously isolating annular pressure from entering the perforating string conveyor. Attached Figure Description
[0020] 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 embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.
[0021] Figure 1 Schematic diagram of an automatic pressure relief device provided in some embodiments of this application;
[0022] Figure 2 This is a schematic diagram of a check valve in an automatic pressure relief device provided in some embodiments of this application.
[0023] The attached figures are labeled as follows:
[0024] 1-Device body; 2-Valve seat; 3-Check valve; 4-Nut;
[0025] 11-Pressure relief chamber; 12-First mounting chamber; 13-Initiator connection; 14-Conveying component connection; 21-Opening structure; 22-Second mounting chamber; 31-Valve body; 32-Elastic connection assembly;
[0026] 211-First opening; 212-Second opening; 311-Third mounting cavity; 321-Plug; 322-Plug; 323-Preload spring; 324-First sealing ring;
[0027] 3111 - Third mounting cavity; 3112 - Third connecting cavity; 3113 - Ball seat structure;
[0028] X - First direction. Detailed Implementation
[0029] The automatic pressure relief device provided in this application solves the problem of accidental detonation of the perforating gun caused by the possible formation of a confined space during the perforation operation of the perforation string conveyor, thus ensuring safe perforation operation.
[0030] In traditional perforation operations, a specialized perforating gun is placed inside the perforation string delivery vehicle (PSV) for rock blasting. During the lowering of the PSV, a confined space can easily form between the PSV and the perforating gun. Combined with the high-temperature environment downhole, which reduces sealing, the pressure difference within this confined space increases. When the pressure difference reaches a certain level, the pressure within the confined space will surge, potentially causing the perforating gun to explode unexpectedly, leading to an accident.
[0031] To prevent the perforating gun from accidentally detonating due to high pressure generated in the confined space during the lowering of the perforating tube string conveyor, the current solution is to open a small hole of about 3mm at the coupling of the perforating tube string conveyor to relieve pressure. However, this can only relieve pressure during the lowering of the tubing and cannot fundamentally solve the problem of accidental detonation of the perforating gun when the annular pressure increases.
[0032] In view of this, this application provides an automatic pressure relief device, which sets a pressure relief chamber and an installation chamber in the device body, and seals a valve seat and a one-way valve in the installation chamber. The cooperation of the valve seat and the one-way valve allows oil and gas to flow in one direction, and automatically relieves pressure according to the pressure difference. When the pressure is too high, the pressure is automatically released to avoid accidental detonation of the perforating gun, while achieving the purpose of reliable pressurization and detonation in the oil pipe or drill pipe.
[0033] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0034] Please refer to Figure 1 and Figure 2 , Figure 1 Schematic diagram of an automatic pressure relief device provided in some embodiments of this application; Figure 2 This is a schematic diagram of a check valve in an automatic pressure relief device provided in some embodiments of this application.
[0035] This application provides an automatic pressure relief device for perforation operations of a perforation string conveying tool, which mainly includes: a device body 1, a valve seat 2, and a one-way valve 3. The device body 1 encloses a pressure relief chamber and a first mounting chamber 12, both located inside the device body 1. The first mounting chamber 12 connects the pressure relief chamber to the downhole environment. The device body 1 is provided with an initiator connection part 13 and a conveying component connection part 14.
[0036] Both the detonator connection part 13 and the conveyor connection part 14 can be provided on the outside, inside or on the end face of the device body 1. The device body 1 is connected to the pressure opening detonator through the detonator connection part 13 and to the perforation string conveying tool through the conveyor connection part 14.
[0037] The valve seat 2 is sealed and installed in the first mounting cavity 12. The valve seat 2 encloses and forms an opening structure and a second mounting cavity. The second mounting cavity is connected to the pressure relief cavity. The opening structure is located on the side of the valve seat 2 that is close to the downhole environment. The opening structure and the second mounting cavity can be coaxially arranged, vertically distributed, or obliquely distributed at an angle. The opening structure is connected to the second mounting cavity, and the second mounting cavity is connected to the downhole environment through the opening structure.
[0038] The one-way valve 3 is sealed and installed in the second mounting cavity. The one-way valve 3 includes a valve body 31 and an elastic connecting assembly 32. The valve body 31 encloses a third mounting cavity 311, which is connected to the pressure relief cavity and the opening structure. The elastic connecting assembly 32 is sealed and installed in the third mounting cavity 311. The elastic connecting assembly 32 has elastic compression and reset functions. When the pressure difference acting on the elastic connecting assembly 32 is less than the pre-compression force of the elastic connecting assembly 32, the elastic connecting assembly 32 can block the opening structure. When the pressure difference is greater than or equal to the pre-compression force, the elastic connecting assembly 32 can open the opening structure under pressure, thereby achieving automatic pressure relief.
[0039] When installing this automatic pressure relief device, install and secure the device body 1 onto the pressure opening or pressure opening delayed detonation device; connect the perforation string delivery tool to the device body 1 and lower it into the wellbore sequentially. During drilling, the pressure is reduced by unidirectional fluid drainage based on the internal and external pressure difference of the sealed space. After the perforation string delivery tool is in place, adjust the depth and the perforation string delivery tool, and detonate the perforating gun by applying pressure from inside the perforation string delivery tool.
[0040] In the automatic pressure relief device of this application, during the lowering of the perforated string delivery tool, there is a large pressure difference between the device body 1 and the annulus pressure of the wellbore. The device automatically relieves pressure based on the pressure difference using a one-way valve 3. When the pressure is higher than the annulus pressure of the wellbore (e.g., 1 MPa), the device discharges fluid in one direction into the confined space to reduce the pressure to a safe range. At the same time, the one-way valve 3 can prevent reverse pressure and prevent the annulus pressure from entering the perforated string delivery tool.
[0041] It should be noted that the perforation string conveying tool in this application includes, but is not limited to, tubing, coiled tubing, or drill pipe.
[0042] In addition, the pressure difference in this application includes the difference between the internal pressure value between the blowout preventer and the pressure initiation device inside the perforation string delivery tool and the annular pressure value in the wellbore.
[0043] Regarding the connection method between the automatic pressure relief device, the pressure initiation device, and the perforated string conveying tool, in one optional embodiment, the initiator connection portion 13 of the device body 1 is provided with a first external thread, and the conveying component connection portion 14 of the device body 1 is provided with a second external thread. Correspondingly, the pressure initiation device is provided with an internal thread, and the perforated string conveying tool is provided with an internal thread. The pressure initiation device, the perforated string conveying tool, and the device body 1 are connected by threads. This design can improve adaptability and make connection convenient and quick.
[0044] In addition, a nut can be connected to the first external thread of the detonator connection 13 and to the second external thread of the conveyor connection 14 to protect the device body 1 and prevent dust and other impurities from entering the pressure relief chamber of the device body 1.
[0045] like Figure 1 As shown. Exemplarily, the pressure relief chamber is located at the center of the device body 1, and the pressure relief chamber is along the first direction X, that is... Figure 1 The pressure relief chamber is vertically positioned within the device body 1, extending along its extension direction. The first mounting cavity 12 is vertically connected to the pressure relief chamber and the external downhole environment. This configuration allows the pressure relief chamber to form a structure that is vertically connected along the first direction X. The external liquid acts horizontally on the pressure relief chamber, reducing flow loss.
[0046] like Figure 2 As shown, in one specific embodiment, the elastic connection assembly 32 includes: a plug 321, a plug 322, a preload spring 323, and a first sealing ring 324. The first sealing ring 324 is sleeved on the outer peripheral surface of the valve body 31 and is sealed to the second mounting cavity of the valve seat 2. The plug 321 is used to block the opening structure. The first end of the preload spring 323 facing the opening structure is connected to the plug 321, and the second end facing away from the opening structure is connected to the plug 322. The plug 321 is threaded to the valve body 31. The preload force of the preload spring 323 is adjusted by adjusting the screw-in depth. When the product of the pressure difference ΔP and the cross-sectional area S of the ball seat is greater than the preload force, automatic pressure relief is achieved.
[0047] In one specific embodiment, the third mounting cavity 311 includes a third mounting sub-cavity 3111 and a third connecting cavity 3112. The third connecting cavity 3112 is connected to the pressure relief cavity and the third mounting sub-cavity 3111. The third mounting sub-cavity 3111 is connected to the open structure. The elastic connecting component 32 is disposed in the third mounting sub-cavity 3111, and the plug 322 is sealed in the third connecting cavity 3112.
[0048] Optionally, both the third mounting sub-cavity 3111 and the third connecting cavity 3112 are equal-diameter cavities, and the size of the third connecting cavity 3112 is smaller than that of the third mounting sub-cavity 3111, so as to form a pre-pressure and increase the thrust.
[0049] Furthermore, the opening structure in this application includes a first opening 211 and a second opening 212. The first opening 211 is connected to the downhole environment, and the second opening 212 is connected to the third mounting cavity 311. The diameter of the second opening 212 is smaller than the diameter of the first opening 211.
[0050] Optionally, both the first opening 211 and the second opening 212 are equal-diameter openings, and the size of the second opening 212 is smaller than the size of the first opening 211, so that the oil and gas entering the valve seat 2 form a pre-pressure, further increasing the thrust.
[0051] Furthermore, a ball seat structure 3113 is provided inside the valve body 31. This ball seat structure 3113 is located in the third communicating cavity 3112. A step is provided on the side of the ball seat structure 3113 facing the third mounting cavity 3111, and the plug 322 is sealed to the step. Specifically, the preload spring 323 and the plug 322 are installed in the ball seat structure 3113. The step provided in the ball seat structure 3113 is a variable diameter step, and the size of the step matches that of the plug 322. Under the action of the preload spring 323, the plug 322 is sealed to the variable diameter step, thus achieving a sealing function.
[0052] The plug 322 may be, but is not limited to, a spherical structure. For example, it may be a steel ball with a step that matches the diameter of the steel ball and is smaller than the diameter of the steel ball. The step is sealed by machining a sealing structure, such as a sealing protrusion, a sealing groove, or setting a sealing sleeve on its surface.
[0053] The automatic pressure relief device provided in this application has the following specific installation steps:
[0054] Step 1: Place the plug 322 into the ball seat structure 3113 inside the valve body 31;
[0055] Step 2: Install the preload spring 323 onto the plug 322;
[0056] Step 3: Screw the plug 321 into the threaded opening of the valve body 31;
[0057] Step four: Install the first sealing ring 324 onto the valve body 31.
[0058] The specific installation steps for assembling the automatic pressure relief device are as follows:
[0059] Step 1: Screw the assembled check valve 3 into the threaded opening of the valve seat 2;
[0060] Step 2: Install the second sealing ring onto valve seat 2;
[0061] Step 3: Screw the assembled valve seat 2 into the threaded opening of the device body 1;
[0062] After the automatic pressure relief device is installed, it is connected to the pressure opening perforation pipe string. The specific installation steps are as follows:
[0063] Step 1: Install and tighten the automatic pressure relief device on the pressure opening or pressure opening delayed detonation device;
[0064] Step 2: Connect a perforating pipe or drill pipe and other perforating pipe string delivery tool to the main body 1 of the device, and lower them into the wellbore in sequence. During the drilling process, the pressure difference between the inside and outside of the sealed space is used to achieve unidirectional fluid drainage and pressure reduction.
[0065] Step 3: After the perforation string conveyor is lowered into place, the depth is checked and the perforation string conveyor is adjusted. The perforation gun is detonated by applying pressure from inside the perforation string conveyor.
[0066] Therefore, the core of this application is to provide an automatic pressure relief device for perforation operations of a perforation string conveying tool, which can achieve unidirectional fluid drainage and pressure reduction by relying on the internal and external pressure difference of the sealed space during the process of lowering the perforation string conveying tool, thereby avoiding accidental detonation, while at the same time achieving the purpose of reliable pressurization and detonation in the tubing or drill pipe.
[0067] It should be noted that the detonator connection part 13 and the conveyor connection part 14 are disposed at the two ends of the device body 1 along the first direction. The detonator connection part 13 is provided with a first external thread, and the conveyor connection part 14 is provided with a second external thread.
[0068] The automatic pressure relief device provided in this application has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this application. It should be noted that those skilled in the art can make several improvements and modifications to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of this application.
Claims
1. An automatic pressure relief device for perforation operations of a perforation string conveying tool, characterized in that, include: The device body (1) is enclosed to form a pressure relief chamber (11) and a first installation chamber (12) connected to the pressure relief chamber and the downhole environment. The device body (1) is provided with a detonator connection part (13) and a conveyor connection part (14). A valve seat (2) is used to seal and install in the first mounting cavity (12). The valve seat (2) encloses and forms an opening structure (21) and a second mounting cavity (22). The second mounting cavity is connected to the pressure relief cavity, and the second mounting cavity is connected to the downhole environment through the opening structure. A one-way valve (3) is used for sealing installation in the second mounting cavity. The one-way valve (3) includes a valve body (31) and an elastic connection assembly (32). The valve body (31) is internally enclosed to form a third mounting cavity (311). The third mounting cavity (311) is connected to the pressure relief cavity and the opening structure. The elastic connection assembly (32) is used for sealing installation in the third mounting cavity (311). The one-way valve (3) is configured such that when the pressure difference applied to the elastic connection assembly (32) is less than the pre-compression force value of the elastic connection assembly (32), the elastic connection assembly (32) blocks the opening structure, and when the pressure difference is greater than or equal to the pre-compression force value, the elastic connection assembly (32) opens the opening structure to automatically release pressure.
2. The automatic pressure relief device according to claim 1, characterized in that, The pressure difference includes the difference between the internal pressure value between the blowout preventer and the pressure initiation device inside the perforation string delivery tool and the annular pressure value in the wellbore.
3. The automatic pressure relief device according to claim 2, characterized in that, The elastic connection assembly (32) includes: a plug (321), a plug element (322), a preload spring (323), and a first sealing ring (324); wherein, The first sealing ring (324) is sealed and installed on the outer peripheral surface of the valve body (31). The plug (321) is used to block the opening structure. The first end of the preload spring (323) facing the opening structure is connected to the plug (321), and the second end of the preload spring (323) away from the opening structure is connected to the plug (322).
4. The automatic pressure relief device according to claim 3, characterized in that, The third mounting cavity (311) includes a third mounting sub-cavity (3111) and a third connecting cavity (3112). The third connecting cavity (3112) is connected to the pressure relief cavity and the third mounting sub-cavity (3111). The third mounting sub-cavity (3111) is connected to the opening structure. The elastic connecting component (32) is disposed in the third mounting sub-cavity (3111). The plug (322) is used to block the third connecting cavity (3112).
5. The automatic pressure relief device according to claim 3, characterized in that, The opening structure includes a first opening (211) and a second opening (212). The first opening (211) is connected to the downhole environment, and the second opening (212) is connected to the third mounting cavity (311). The diameter of the second opening (212) is smaller than the diameter of the first opening (211).
6. The automatic pressure relief device according to claim 4, characterized in that, The third connecting cavity (3112) is provided with a ball seat structure (3113), and the ball seat structure (3113) has a step on the side facing the third mounting sub-cavity (3111), and the plug (322) is sealed to the step.
7. The automatic pressure relief device according to claim 6, characterized in that, The plug (322) has a spherical structure.
8. The automatic pressure relief device according to claim 1, characterized in that, The detonator connection part (13) and the conveyor connection part (14) are disposed at two ends of the device body (1) along the first direction. The detonator connection part (13) is provided with a first external thread, and the conveyor connection part (14) is provided with a second external thread.
9. The automatic pressure relief device according to claim 8, characterized in that, It also includes nuts disposed on the first external thread and the second external thread.
10. The automatic pressure relief device according to claim 1, characterized in that, The perforation string conveying tool includes tubing, or continuous tubing, or drill pipe.