A safety pressure transmission device for oil and gas well perforation

Abstract

The present invention is applicable to the technical field of oil and gas wells, and provides a safety pressure transmission device for oil and gas well perforation, including a device body, a piston hole and a mounting hole are provided in the device body, the mounting hole is connected to a pressure detonation device, and also includes: a screen cup, one end of the screen cup is threadedly installed at the outer end of the piston hole; a pressure differential piston, one end of the pressure differential piston is set as a step cylinder, one end of the step cylinder of the pressure differential piston is inwardly installed in the piston hole, and liquid inlet holes are provided on the side walls at both ends of the piston hole, and both groups of liquid inlet holes cooperate with the pressure differential piston. A safety pressure transmission device for oil and gas well perforation in the present invention can effectively prevent the device from being mis-detonated and mis-perforated due to water hammer effect and falling objects in the well, ensure the safety and reliability of the pipe string and the detonation process, and through the design of the pressure differential piston, it can effectively block accidental falling objects in the well, has higher safety, and improves the safety of the oil and gas well perforation operation site and the success rate of perforation construction.

Description

Technical Field

[0001] The invention belongs to the technical field of oil and gas wells, and in particular relates to a safety pressure transmission device for perforating oil and gas wells. Background Art

[0002] In the perforating operation of oil and gas wells, the pressure detonator is a widely used perforating equipment. At present, there are many types of pressure detonators in China, all of which use a method of shearing the pin under a certain pressure to make the piston move downward, and then the striker hits the firing pin and acts on the fire workpiece to detonate the perforating gun. However, this method has obvious defects and has very high requirements for the accuracy of the pin shear value.

[0003] An analysis of the misfire accidents caused by misfires using pressure detonation devices in recent years shows that in the process of lowering the pipe string in actual construction, abnormal operation modes such as emergency stop and emergency release, upsetting and drilling may occur, causing pressure fluctuations; once the agitated pressure in the well exceeds the safety pressure set by the pressure detonation device, misfire accidents will occur. The differential pressure detonation device (CN103147725A) uses an intermediate joint with a pressure channel to ensure the pressure balance of the piston assembly when the pipe string is lowered, thereby ensuring safety and reliability during construction; however, the piston assembly of the device is composed of many parts and is complex to install. The pressure channel set by the intermediate joint is easy to cause the piston assembly to be blocked under complex well conditions, affecting the normal detonation of the device.

[0004] Therefore, in view of the above situation, it is urgent to develop a safe pressure transmission device for oil and gas well perforation to overcome the shortcomings in current practical applications. Summary of the invention

[0005] In view of the deficiencies in the prior art, an object of the embodiments of the present invention is to provide a safe pressure transmission device for oil and gas well perforation to solve the problems in the above-mentioned background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A safety pressure transmission device for oil and gas well perforation, comprising a device body, a piston hole and a mounting hole are provided in the device body, and an oil pipe buckle for connecting with an oil pipe is provided at one end of the device body, and the mounting hole is connected to a pressure detonation device, and further comprising:

[0008] A sieve cup, one end of which is threadedly mounted on the outer end of the piston hole, and a through hole is provided in the sieve cup, the through hole is communicated with the piston hole, and the sieve cup is used to limit the movement of the pressure difference piston;

[0009] A pressure differential piston, one end of which is arranged as a stepped cylinder, one end of which is installed inwardly in the piston hole, and liquid inlet holes are provided on the side walls at both ends of the piston hole, and two groups of liquid inlet holes cooperate with the pressure differential piston, and the pressure differential piston is used to control the connectivity between the two groups of liquid inlet holes.

[0010] As a further technical solution of the present invention, the two groups of liquid inlet holes are respectively connected to the oil pipe buckle and the mounting hole, and the diameter of the liquid inlet hole connected to the oil pipe buckle is larger than the diameter of the liquid inlet hole connected to the mounting hole.

[0011] As a further technical solution of the present invention, the lower part of the pressure differential piston is a rotating body with a needle-like structure, a countersunk hole is opened on the top of the pressure differential piston, and five groups of sealing grooves are opened in the middle position of the pressure differential piston, and sealing rings are installed in the sealing grooves.

[0012] As a further technical solution of the present invention, the diameter of the liquid inlet hole is consistent with the step height of the pressure difference piston step column.

[0013] As a further technical solution of the present invention, a thread groove is provided on the inner wall of the mounting hole, and the thread groove cooperates with the outer wall thread of the pressure detonator.

[0014] As a further technical solution of the present invention, the pressure detonating device includes a pressure detonating body, in which a piston, a striker rod and a firing component are installed, one end of the piston is connected to the striker rod, and a piston sleeve is installed on the other end of the piston, and a buffer cover is installed on the piston sleeve. One end of the pressure detonating body close to the buffer cover is threadedly installed in the mounting hole, and the striker rod cooperates with the firing component.

[0015] As a further technical solution of the present invention, the device body and the sieve cup are both of a cylindrical structure.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. The device body adopts a non-full-bore structural design and is equipped with a differential pressure piston. When the tubing is lowered, the pressure at both ends of the differential pressure piston is consistent. Under a certain range of fluctuating pressure, the differential pressure piston does not move upward, and the safety pin is not under pressure at this time. When the device is lowered to the expected position and the pressurized pressure is greater than the external pressure of the differential pressure piston, the differential pressure piston moves upward, and when the pressurized pressure is greater than the shear value of the safety pin, the pin is sheared and the device is detonated normally, which can effectively avoid the occurrence of accidental detonation caused by fluctuating pressure and construction errors.

[0018] 2. Through the design of the pressure difference piston, the input and output ends of the device body are isolated, and the liquid inlet pressure channel is opened only when the designed detonation conditions are met. Since the diameter of the liquid inlet hole is designed to be small, the possibility of the detonator being accidentally detonated by objects falling from the wellhead is fundamentally eliminated, and it has the function of preventing objects falling from the wellhead;

[0019] 3. The present invention is flexible to use. The safety pressure transmission device can be adapted to various pressure detonating devices only by designing the buckle type of the output end of the device body, and has good universal adaptability.

[0020] In order to more clearly illustrate the structural features and effects of the present invention, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A structural cross-sectional view of a safety pressure transmission device for oil and gas well perforation provided in an embodiment of the present invention.

[0022] Figure 2 for Figure 1 Structural cross-section of the medium pressure piston.

[0023] Figure 3 for Figure 1 Structural cross-section view of the middle sieve cup.

[0024] Figure 4 A cross-sectional view of the connection between a safety pressure transmission device for oil and gas well perforation and a pressure detonation device provided by an embodiment of the present invention.

[0025] Figure 5 for Figure 4 Structural cross-section view of the medium-pressure detonator.

[0026] Figure numerals: 1 - device body, 2 - sieve cup, 3 - pressure piston, 5 - pressure detonating device, 6 - buffer cover, 7 - piston sleeve, 8 - piston, 10 - pressure detonating body, 10 - striker, 11 - firing member, 12 - piston hole, 13 - mounting hole, 14 - oil pipe buckle, 15 - through hole, 16 - sealing ring, 17 - liquid inlet hole, 18 - sealing groove. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0028] The specific implementation of the present invention is described in detail below in conjunction with specific embodiments.

[0029] like Figures 1 to 4As shown, as an embodiment of the present invention, a safety pressure transmission device for oil and gas well perforation is provided, comprising a device body 1, wherein a piston hole 12 and a mounting hole 13 are provided in the device body 1, and an oil pipe buckle 14 for connecting with an oil pipe is provided at one end of the device body 1, wherein the mounting hole 13 is connected to a pressure detonation device 5, and further comprising:

[0030] A sieve cup 2, one end of which is threadedly mounted on the outer end of the piston hole 12, and a through hole 15 is provided in the sieve cup 2, the through hole 15 is communicated with the piston hole 12, and the sieve cup 2 is used to limit the movement of the differential pressure piston 3;

[0031] The pressure differential piston 3 has one end configured as a stepped cylinder, one end of the stepped cylinder of the pressure differential piston 3 is inwardly installed in the piston hole 12, and liquid inlet holes 17 are provided on the side walls at both ends of the piston hole 12, and the two groups of liquid inlet holes 17 are both matched with the pressure differential piston 3, and the pressure differential piston 3 is used to control the connectivity of the two groups of liquid inlet holes 17.

[0032] In this embodiment, the present invention can effectively prevent the pressure detonation device from causing mis-detonation and mis-perforation due to the water hammer effect and fallen objects in the well, ensuring the safety and reliability of the pipe string and the detonation process. Moreover, through the design of the pressure difference piston, it can effectively block accidental fallen objects in the well, with higher safety, improving the safety of the oil and gas well perforating operation site and the success rate of the perforating construction.

[0033] like Figure 1 As shown, as a preferred embodiment of the present invention, the two groups of liquid inlet holes 17 are respectively connected to the oil pipe buckle 14 and the mounting hole 13, and the diameter of the liquid inlet hole 17 connected to the oil pipe buckle 14 is larger than the diameter of the liquid inlet hole 17 connected to the mounting hole 13.

[0034] like Figure 2 As shown, as a preferred embodiment of the present invention, the lower part of the pressure differential piston 3 is a rotating body with a needle-like structure, a countersunk hole is provided on the top of the pressure differential piston 3, and five groups of sealing grooves 18 are provided in the middle position of the pressure differential piston 3, and a sealing ring 16 is installed in the sealing groove 18.

[0035] In this embodiment, the diameter of the liquid inlet hole 17 connected to the oil pipe buckle 14 is larger than the diameter of the liquid inlet hole 17 connected to the mounting hole 13, so that the pressure difference piston 3 can have the pressurized unlocking and sending function.

[0036] like Figure 1 As shown, as a preferred embodiment of the present invention, the diameter of the liquid inlet hole 17 is consistent with the step height of the step column of the pressure difference piston 3.

[0037] like Figure 1 and 4As shown, as a preferred embodiment of the present invention, a thread groove is provided on the inner wall of the mounting hole 13 , and the thread groove is matched with the outer wall thread of the pressure detonator 5 .

[0038] In this embodiment, the present invention is combined with the pressure detonator 5 for oil and gas well perforation to form a new type of safety pressure detonator for oil and gas well perforation, so as to realize its safety function of preventing the pressure detonator from accidentally detonating due to excessive pressure and objects falling from the wellhead.

[0039] like Figure 4 and 5 As shown, as a preferred embodiment of the present invention, the pressure detonating device 5 includes a pressure detonating body 9, in which a piston 8, a striker rod 10 and a firing component 11 are installed, one end of the piston 8 is connected to the striker rod 10, and a piston sleeve 7 is installed on the other end of the piston 8, and a buffer cover 6 is installed on the piston sleeve 7, one end of the pressure detonating body 9 close to the buffer cover 6 is threadedly installed in the mounting hole 13, and the striker rod 10 cooperates with the firing component 11.

[0040] like Figure 1 As shown, as a preferred embodiment of the present invention, the device body 1 and the sieve cup 2 are both a cylindrical structure.

[0041] The working principle of the present invention is:

[0042] During construction, the perforator, the new safety pressure detonating device for oil and gas well perforating, the screen, the packer, the pressure recorder, the tester and the oil pipe are sequentially lowered into the well, and the oil pipe is transported to the designated layer. After the depth calibration is completed, the wellhead annulus is pressurized. The pressure is in the casing of the oil and gas well and acts on the input end of the upper device body 1. The pressure difference piston 3 moves upward and opens the liquid inlet channel. After the pressure is loaded to the piston assembly to the expected detonation pressure, the pin is sheared and the piston moves downward, and the firing component 11 is detonated, thereby realizing pressure-induced detonation;

[0043] During the process of lowering the tubing string, the upper part of the piston 8 is not affected by the fluctuating pressure, thus avoiding the occurrence of the phenomenon of mis-perforation caused by the pin being cut off by mistake; only when the device body 1 is lowered to the specified layer, after the packer is set and the annulus is pressurized to the pre-designed upward pressure of the differential pressure piston 3, the differential pressure piston 3 moves upward to open the liquid inlet channel, and further pressurizes the piston 8 to the designed detonation pressure, and then the detonation is completed;

[0044] The above is the working principle of the safety pressure transmission device for oil and gas well perforation.

[0045] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A safety pressure transmission device for oil and gas well perforation, comprising a device body, a piston hole and a mounting hole are provided in the device body, and an oil pipe buckle for connecting with an oil pipe is provided at one end of the device body, and the mounting hole is connected to a pressure detonation device, characterized in that: Also includes: A sieve cup, one end of which is threadedly mounted on the outer end of the piston hole, and a through hole is provided in the sieve cup, the through hole is communicated with the piston hole, and the sieve cup is used to limit the movement of the pressure difference piston; A pressure differential piston, one end of which is a stepped cylinder, one end of which is inwardly mounted in the piston hole, and liquid inlet holes are provided on the side walls at both ends of the piston hole, and two groups of liquid inlet holes cooperate with the pressure differential piston, and the pressure differential piston is used to control the communication between the two groups of liquid inlet holes; The two groups of liquid inlet holes are respectively connected to the oil pipe buckle and the mounting hole, and the diameter of the liquid inlet hole connected to the oil pipe buckle is larger than the diameter of the liquid inlet hole connected to the mounting hole; The lower part of the differential pressure piston is a rotating body with a needle-like structure, a countersunk hole is provided on the top of the differential pressure piston, and five groups of sealing grooves are provided in the middle of the differential pressure piston, and sealing rings are installed in the sealing grooves; The diameter of the liquid inlet hole connected to the oil pipe buckle is consistent with the step height of the pressure difference piston step column.

2. The safety pressure transmission device for oil and gas well perforation according to claim 1, characterized in that: A thread groove is arranged on the inner wall of the mounting hole, and the thread groove is matched with the outer wall thread of the pressure detonator.

3. The safety pressure transmission device for oil and gas well perforation according to claim 2, characterized in that: The pressure detonating device includes a pressure detonating body, in which a piston, a striker rod and a firing component are installed, one end of the piston is connected to the striker rod, the other end of the piston is installed with a piston sleeve, a buffer cover is installed on the piston sleeve, one end of the pressure detonating body close to the buffer cover is threadedly installed in the mounting hole, and the striker rod cooperates with the firing component.

4. The safety pressure transmission device for oil and gas well perforation according to claim 1, characterized in that: The device body and the sieve cup are both cylindrical structures.

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