Device and method for testing sealing performance

Abstract

The invention relates to a device for testing sealing performance. The device comprises a shell and a test block arranged in the shell. The test block defines a first loading cavity and a second loading cavity which are separated from each other in the shell, and a test cavity located between the first loading cavity and the second loading cavity. And a sealing convex part is arranged on the test block and is used for being in interference fit with a sealing cylinder in the shell. Wherein the test block is configured to reciprocate relative to the sealing cylinder when pressurized fluid is input into the first loading cavity or the second loading cavity until the pressurized fluid in the second loading cavity can flow into the test cavity through the sealing convex part. Therefore, the sealing life of the sealing convex part can be judged according to the moving times of the sealing convex part on the test block relative to the sealing cylinder, so that effective guidance is provided for the metal sealing design of the underground tool.

Description

Technical Field

[0001] The present invention relates to the technical field of sealing tests, and in particular, to a device and method for testing sealing performance. Background Art

[0002] Currently, elastomers such as O-ring seals are mostly used for sealing on existing downhole tools. However, in the high-temperature, high-pressure, and complex liquid environment downhole, the elastomers have poor tolerance and short sealing life, and are prone to failure and leakage, thus affecting the normal use of the pipe string. Compared with the traditional elastomer sealing technology, the metal sealing technology has better tolerance and reliability, and has good resistance to high-temperature, high-pressure, and strong corrosion environments. Therefore, the metal sealing technology will not have problems such as aging and relaxation like the elastomer sealing technology during long-term use, thereby improving the service life of downhole tools. Metal sliding seals are bound to become the future trend of downhole seal development.

[0003] However, elastomer seals are still mostly used in China. Therefore, developing self-designed metal seals is the future development trend of downhole tools, and material selection, structural design, surface treatment methods, etc. are all key factors affecting the metal sealing performance. To reduce the design cost of metal seals, it is necessary to develop a set of test devices and methods for verifying material selection, structural design, surface treatment methods, etc., in order to assist the development of metal seals for downhole tools. Summary of the Invention

[0004] Based on the above problems existing in the prior art, the present invention provides a device and method for testing sealing performance, which can provide effective guidance for the metal seal design of downhole tools.

[0005] The first aspect of the present invention: provides a device for testing sealing performance, including,

[0006] A housing;

[0007] A test block, which defines a mutually separated first loading chamber, a second loading chamber, and a test chamber located between the first loading chamber and the second loading chamber in the housing. The test block is provided with a sealing convex portion for interference fit with a sealing cylinder in the housing.

[0008] Wherein, the test block is configured to be able to move relative to the sealing cylinder when pressurized fluid is input into the first loading chamber or the second loading chamber, until the pressurized fluid in the second loading chamber can flow into the test chamber through the sealing convex portion.

[0009] Further, a first loading hole and a second loading hole are provided on the housing, which are respectively communicated with the first loading chamber and the second loading chamber, and are used to convey pressurized fluid into the first loading chamber and the second loading chamber respectively.

[0010] Further, a test hole communicating with the test chamber is provided on the housing, and is used for the pressurized fluid flowing into the test chamber from the second loading chamber to flow out.

[0011] Further, the housing includes a first end shell for arranging the first loading hole and the test hole, and a second end shell for arranging the second loading hole, and the first end shell and the second end shell are detachably connected.

[0012] Further, a step surface facing the first end shell is provided on the inner wall of the second end shell, and the step surface is configured to be able to limit the sealing cylinder together with the first end shell.

[0013] Further, a pushing member is provided at one end of the test block located in the first end shell, and a sealing ring is provided between the pushing member and the inner wall of the first end shell, and is used to separate the first loading chamber and the test chamber.

[0014] Further, a first positioning member is provided at the end of the first end shell, and a second positioning member is provided at the end of the second end shell, and the second positioning member is configured to be able to adjust the distance from the first positioning member, so as to adjust the moving distance of the test block relative to the sealing cylinder.

[0015] Further, an adjusting rod extending in the direction facing the first positioning member is provided in the second positioning member, and the adjusting rod is configured to be able to adjust the distance between the first positioning member and the second positioning member.

[0016] In the second aspect of the present invention, a method for testing the sealing performance is provided. Using the device described in any one of the above, the method includes the following steps.

[0017] Step S1: Inject pressurized fluid into the second loading chamber so that the pressure in the second loading chamber reaches a first pressure value.

[0018] Step S2: After the second loading chamber is depressurized, inject pressurized fluid into the first loading chamber so that the test block moves to the rightmost end in the housing.

[0019] Then, after the first loading chamber is depressurized, inject pressurized fluid into the second loading chamber again so that the pressure in the second loading chamber reaches a second pressure value, and then maintain the pressure for a first predetermined time period.

[0020] Step S3: Continuously inject pressurized fluid into the second loading cavity, causing the test block to move to the leftmost end within the housing, and then maintain the pressure for a second predetermined duration.

[0021] Step S4: Repeat Step S2 and Step S3, record the number of movements of the test block until the pressure in the second loading cavity decreases after pressure maintenance and / or pressurized fluid flows out of the test hole in the housing.

[0022] Furthermore, the first pressure value is equal to the second pressure value.

[0023] The beneficial effects of the present invention are as follows: A device for testing sealing performance provided by the present invention includes a housing and a test block disposed within the housing. The test block defines a first loading cavity, a second loading cavity that are separated from each other, and a test cavity located between the first loading cavity and the second loading cavity within the housing. A sealing convex portion is provided on the test block for interference fit with a sealing cylinder within the housing. Among them, the test block is configured to be able to move relative to the sealing cylinder when pressurized fluid is input into the first loading cavity or the second loading cavity until the pressurized fluid in the second loading cavity can flow into the test cavity through the sealing convex portion. In this way, the sealing life of the sealing convex portion can be judged according to the number of movements of the sealing convex portion on the test block relative to the sealing cylinder, so as to provide effective guidance for the metal seal design of downhole tools.

[0024] In addition, since the housing includes a first end housing and a second end housing detachably connected to the first end housing. Therefore, on the basis of not changing the device structure, sealing performance tests can be carried out by designing test blocks with different diameters and sleeve sealing cylinders with different inner diameters. Moreover, by replacing different test blocks and sealing cylinders, the effects of the material of the sealing convex portion and its surface treatment method on the sealing ability and wear resistance can be quickly verified. Furthermore, the moving distance of the test block is adjusted by the first positioning member and the second positioning member provided on the housing, so as to quickly test the effects of the sealing sliding distance on the sealing ability and wear resistance of the sealing convex portion. Description of the Drawings

[0025] The present invention will be further described below with reference to the drawings and embodiments.

[0026] Figure 1 Shown is a schematic structural diagram of a device for testing sealing performance from one perspective.

[0027] Figure 2 Shown as Figure 1 Shown is an exploded view of the structure of the device for testing sealing performance.

[0028] Figure 3 Shown as Figure 1Structural sectional view of the shown device for testing sealing performance from another perspective.

[0029] Figure 4 As shown Figure 1 Schematic structural diagram of the test block of the shown device for testing sealing performance.

[0030] Among them, each reference numeral in the figure: 10, housing; 11, first loading cavity; 111, first loading hole; 12, second loading cavity; 121, second loading hole; 13, test cavity; 131, test hole; 14, first end shell; 15, second end shell; 151, stepped surface; 16, sealing cylinder; 17, sealing ring; 20, first positioning member; 30, second positioning member; 31, limiting portion; 32, adjusting rod; 40, test block; 41, pushing member; 50, sealing convex portion. Detailed implementation manners

[0031] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer, the present invention will be described in detail below with reference to the accompanying drawings. This figure is a simplified schematic diagram, which only illustrates the basic structure of the present invention in a schematic manner, so it only shows the components related to the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0032] Refer to Figures 1-3As shown in the figure, a device for testing sealing performance provided by the present invention includes a housing 10, a first positioning member 20 and a second positioning member 30 disposed at both ends of the housing 10, and a test block 40 disposed inside the housing 10. The test block 40 defines a first loading chamber 11 near the first positioning member 20, a second loading chamber 12 near the second positioning member 30, and a test chamber 13 located between the first loading chamber 11 and the second loading chamber 12 inside the housing 10. A first loading hole 111 communicating with the first loading chamber 11, a second loading hole 121 communicating with the second loading chamber 12, and a test hole 131 communicating with the test chamber 13 are further provided on the housing 10. A sealing protrusion 50 is provided between the test block 40 and the housing 10 so as to form a seal between the test block 40 and the housing 10. Thus, a pressurizing device (not shown in the figure) connected respectively through pipelines by the first loading hole 111 and the second loading hole 121 can continuously inject pressurized fluid into the first loading chamber 11 and / or the second loading chamber 12, enabling the test block 40 to reciprocate or remain stationary between the first positioning member 20 and the second positioning member 30 until the pressurized fluid in the second loading chamber 12 flows into the test chamber 13 through the sealing protrusion 50 and then flows out from the test hole 131, thereby determining the failure of the sealing protrusion 50. Thus, the sealing life of the sealing protrusion 50 can be determined according to the number of movements of the sealing protrusion 50 on the test block 40, so as to provide effective guidance for the metal seal design of downhole tools.

[0033] Combined with Figures 1-3 As shown in the figure, in some embodiments, the housing 10 includes a first end shell 14 connected to the first positioning member 20 and a second end shell 15 connected to the second positioning member 30. The first loading hole 111 and the test hole 131 are both provided on the first end shell 14, while the second loading hole 121 is provided on the second end shell 15. A step surface 151 facing the first end shell 14 is provided on the inner wall of the second end shell 15 for abutting against a sealing cylinder 16 that is in interference fit with the sealing protrusion 50 of the test block 40. When the first end shell 14 and the second end shell 15 are in a connected state, the step surface 151 and the end surface of the first end shell 14 can jointly limit the sealing cylinder 16, thereby preventing the sealing cylinder 16 from moving during the test.

[0034] Since the sealing cylinder 16 can make the diameter of the test block 40 smaller than the inner diameters of the first end housing 14 and the second end housing 15, a test chamber 13 can be formed between the test block 40 and the housing 10. A pushing member 41 is provided on one side of the test block 40 located inside the first end housing 14, and a sealing ring 17 is provided between the pushing member 41 and the inner wall of the first end housing 14 to separate the first loading chamber 11 and the test chamber 13. In this way, the pressurized fluid flowing into the first loading chamber 11 from the first loading hole 111 cannot flow into the test chamber 13, thus ensuring the reliability of the test. By arranging the sealing cylinder 16 in the housing 10 to be in interference fit with the sealing convex portion 50, the sealing performance test can be carried out by designing test blocks 40 and sealing cylinders 16 with different sizes without changing the main structure of the device, thereby improving the applicability of the device.

[0035] In some embodiments, when the pressurizing device injects pressurized fluid into the first loading chamber 11 only through the first loading hole 111, the pressurized fluid can push the test block 40 to move towards the second positioning member 30 through the pushing member 41 until the test block 40 moves to the rightmost end inside the housing 10. When the pressurizing device injects pressurized fluid into the second loading chamber 12 only through the second loading hole 121, the pressurized fluid can push the test block 40 and the pushing member 41 to move towards the first positioning member 20 until the test block 40 moves to the leftmost end inside the housing 10.

[0036] In some of these embodiments, a sealing ring 17 is also provided between the inner wall of the second end housing 15 and the outer wall of the sealing cylinder 16 to increase the sealing performance between the second end housing 15 and the sealing cylinder 16 and prevent the pressurized fluid in the second loading chamber 12 from flowing into the test chamber 13 between the second end housing 15 and the sealing cylinder 16, thereby ensuring the reliability of the test.

[0037] In some of these embodiments, the initial interference amount between the sealing convex portion 50 on the test block 40 and the inner wall of the sealing cylinder 16 is in the range of 0.05 mm to 1.00 mm. During the sliding seal test, as the test block 40 moves relative to the sealing cylinder 16, wear occurs due to friction between the sealing convex portion 50 and the inner wall of the sealing cylinder 16. Therefore, the interference amount between the sealing convex portion 50 and the sealing cylinder 16 changes as the sliding seal test progresses. Therefore, it is necessary to determine an appropriate initial interference amount according to the requirements of the sliding seal test.

[0038] It should be understood that in some other embodiments, the sealing convex portion 50 can also be provided on the inner wall of the sealing cylinder 16.

[0039] In some of the preferred embodiments, the cross-section of the sealing convex portion 50 can be in the shape of a circle, trapezoid, rectangle, or the like. The material of the sealing convex portion 50 can be the same as or different from the materials of the test block 40 and the sealing cylinder 16. It should be understood that the material of the sealing convex portion 50 can be a hard metal material such as aluminum alloy or ferroalloy, or a flexible non-metal material such as rubber or silica gel.

[0040] In some of the preferred embodiments, the surface of the sealing convex portion 50 can also be strengthened to improve the wear resistance of the sealing convex portion 50. This can provide practical reference for the surface treatment required for the sealing structure of downhole tools.

[0041] In some of the embodiments, the first end shell 14 and the second end shell 15 can be connected by means such as screwing, welding, or clamping. Preferably, the first end shell 14 and the second end shell 15 are connected by a detachable means such as screwing or clamping, so as to be able to clean the inside of the device regularly and prevent debris generated by the wear of the sealing convex portion 50 on the test block 40 due to long-term sliding seal testing with the sealing cylinder 16 from affecting the subsequent seal testing.

[0042] Similarly, by the detachable connection between the first end shell 14 and the second end shell 15, it is also possible to facilitate the regular replacement of the sealing rings 17 between the first end shell 14 and the pushing member 41, and between the second end shell 15 and the sealing cylinder 16, so as to effectively prevent the pressurized fluid in the first loading chamber 11 and the second loading chamber 12 from flowing into the test chamber 13, thereby avoiding interference with the results of the seal testing.

[0043] Reference Figure 2 and Figure 3 As shown, in some of the embodiments, the first positioning member 20 is generally a rod-shaped structure penetrating the end of the first end shell 14. The first positioning member 20 can be connected to the first end shell 14 by threads so as to adjust the length of the first positioning member 20 extending into the first end shell 14, thereby adjusting the leftmost position that the test block 40 can reach within the housing 10. And, the first positioning member 20 can also form a seal with the first end shell 14 through the sealing ring 17.

[0044] In some of the embodiments, the second positioning member 30 is also generally a rod-shaped structure penetrating the end of the second end shell 15. A limiting portion 31 extending radially is provided at one end of the second positioning member 30 located inside the second end shell 15 for abutting against the end of the second end shell 15. The limiting portion 31 can cooperate with a nut screwed on the second positioning member 30 to fix the second positioning member 30 at the end of the second end shell 15.

[0045] In some of these embodiments, an adjusting rod 32 extending towards the first positioning member 20 is further provided inside the second positioning member 30. The adjusting rod 32 is configured to be able to adjust the distance between the first positioning member 20 and the second positioning member 30, so as to adjust the moving distance of the test block 40 during the sliding seal test between the first positioning member 20 and the second positioning member 30, so that the sliding seal test can meet the test requirements. Preferably, the adjusting rod 32 is screwed into the threaded hole of the second positioning member 30. By adjusting the screwed length of the adjusting rod 32 inside the second positioning member 30, the effective distance between the first positioning member 20 and the second positioning member 30 can be adjusted.

[0046] Based on the above device, the present invention further provides a method for testing the sealing performance, including the following steps.

[0047] In step S1, a pressurized fluid is injected into the second loading chamber 12 through the second loading hole 121, and the pressure in the second loading chamber 12 reaches a first pressure value.

[0048] After step S1 ends, the static sealing performance of the sealing protrusion 50 between the test block 40 and the sealing cylinder 16 can be initially judged, and it can be verified whether the device is assembled in place to avoid affecting the subsequent test.

[0049] In step S2, after the second loading chamber 12 is depressurized through the second loading hole 121, a pressurized fluid is injected into the first loading chamber 11 through the first loading hole 111, so that the test block 40 moves to the rightmost end inside the housing 10. Then, after the first loading chamber 11 is depressurized through the first loading hole 111, a pressurized fluid is injected into the second loading chamber 12 through the second loading hole 121 again, and the pressure in the second loading chamber 12 reaches a second pressure value, and then pressure is maintained for a first predetermined time period.

[0050] In some of these embodiments, the first pressure value may be equal to the second pressure value.

[0051] After step S2 ends, the sealing performance of the sealing protrusion 50 after moving relative to the sealing cylinder 16 can be judged.

[0052] In step S3, the pressure in the second loading chamber 12 is continuously increased, so that the test block 40 moves to the leftmost end inside the housing 10, and then pressure is maintained for a second predetermined time period.

[0053] In some of these embodiments, the first predetermined time period may be equal to the second predetermined time period.

[0054] In step S4, steps S2 and S3 are repeated, and the number of times the sealing protrusion 50 on the test block 40 moves relative to the sealing cylinder 16 is recorded until the pressure in the second pressure chamber 12 decreases after pressure holding, and / or pressurized fluid flows out of the test hole 131 of the housing 10.

[0055] During the process of performing step S4, once the sealing performance of the sealing protrusion 50 deteriorates, the pressurized fluid in the second pressure chamber 12 can flow into the test chamber 13 through the sealing protrusion 50. If only a small amount of pressurized fluid flows from the second pressure chamber 12 into the test chamber 13, the pressure in the second pressure chamber 12 will decrease after pressure holding. If a large amount of pressurized fluid flows from the second pressure chamber 12 into the test chamber 13, the pressurized fluid will continue to flow out through the test hole 131. At this time, it can be determined that the sealing protrusion 50 no longer has sealing performance. Thus, the sealing life of the sealing protrusion 50 can be judged by the number of times the sealing protrusion 50 moves relative to the sealing cylinder 16.

[0056] In some other preferred embodiments, the device can also be placed in a high-temperature and high-pressure liquid environment for testing, so as to simulate the actual use state of downhole tools, and thus the sealing life of the sealing protrusion 50 can be obtained more accurately.

[0057] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection or an integral connection, a mechanical connection, a direct connection or an indirect connection through an intermediate medium, and can be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0058] It should be understood that the orientation or positional relationship indicated by the terms "length", "width", "upper", "lower", "front and back", "left and right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention.

[0059] Although the present invention has been described with reference to the preferred embodiments, various improvements can be made to it and components therein can be replaced with equivalents without departing from the scope of the present invention. In particular, as long as there is no structural conflict, the technical features mentioned in each embodiment can be combined in any way. The present invention is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims.

Claims

1. A device for testing sealing performance, comprising: Housing (10); A test block (40) is defined in the housing (10) as a first loading chamber (11), a second loading chamber (12) separated from each other, and a test chamber (13) located between the first loading chamber (11) and the second loading chamber (12); the test block (40) is provided with a sealing protrusion (50) for interference fit with a sealing cylinder (16) in the housing (10); in, The test block (40) is configured to be able to move relative to the sealing cylinder (16) when pressurized fluid is input into the first loading chamber (11) or the second loading chamber (12), until the pressurized fluid in the second loading chamber (12) can flow into the test chamber (13) through the sealing protrusion (50).

2. The device for testing sealing performance according to claim 1, characterized in that: The housing (10) is provided with a first loading hole (111) and a second loading hole (121) which are respectively connected to the first loading chamber (11) and the second loading chamber (12), and are used to transport pressurized fluid to the first loading chamber (11) and the second loading chamber (12), respectively.

3. The device for testing sealing performance according to claim 2, characterized in that: The housing (10) is provided with a test hole (131) connected to the test cavity (13) and used for the pressurized fluid flowing from the second loading cavity (12) into the test cavity (13) to flow out.

4. The device for testing sealing performance according to claim 3, characterized in that: The housing (10) comprises a first end shell (14) for arranging the first loading hole (111) and the test hole (131), and a second end shell (15) for arranging the second loading hole (121), and the first end shell (14) and the second end shell (15) are detachably connected.

5. The device for testing sealing performance according to claim 4, characterized in that: A step surface (151) facing the first end shell (14) is provided on the inner wall of the second end shell (15), and the step surface (151) is configured to limit the sealing cylinder (16) together with the first end shell (14).

6. The device for testing sealing performance according to claim 4 or 5, characterized in that: A pushing member (41) is provided at one end of the test block (40) located inside the first end shell (14), and a sealing ring (17) is provided between the pushing member (41) and the inner wall of the first end shell (14) for separating the first loading chamber (11) and the test chamber (13).

7. The device for testing sealing performance according to claim 4 or 5, characterized in that: A first positioning member (20) is provided at the end of the first end shell (14), and a second positioning member (30) is provided at the end of the second end shell (15). The second positioning member (30) is configured to be able to adjust the distance between the second positioning member (30) and the first positioning member (20), thereby adjusting the distance that the test block (40) moves relative to the sealing cylinder (16).

8. The device for testing sealing performance according to claim 7, characterized in that: An adjustment rod (32) extending in the direction of the first positioning member (20) is arranged inside the second positioning member (30), and the adjustment rod (32) is configured to be able to adjust the distance between the first positioning member (20) and the second positioning member (30).

9. A method for testing sealing performance, characterized in that: Using the device as described in any one of claims 1 to 8, comprising the steps of: Step S1: injecting pressurized fluid into the second loading chamber (12) so that the pressure in the second loading chamber (12) reaches a first pressure value; Step S2: After the second loading chamber (12) is depressurized, a pressurized fluid is injected into the first loading chamber (11), so that the test block (40) moves to the rightmost end in the housing (10). Then, after the first loading chamber (11) is depressurized, pressurized fluid is injected into the second loading chamber (12) again, so that the pressure in the second loading chamber (12) reaches a second pressure value, and then the pressure is maintained for a first predetermined time period; Step S3: continue to inject pressurized fluid into the second loading chamber (12), so that the test block (40) moves to the leftmost end in the housing (10), and then maintains pressure for a second predetermined time period; Step S4: repeating steps S2 and S3, and recording the number of movements of the test block (40), until the pressure in the second loading chamber (12) decreases after maintaining the pressure, and / or the pressurized fluid flows out of the test hole (131) of the housing (10).

10. The method for testing sealing performance according to claim 9, characterized in that: The first pressure value is equal to the second pressure value.

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