Performance testing device, testing assembly and testing method for dissolvable temporary plugging balls

Abstract

This invention provides a performance testing device for soluble temporary plugging balls, comprising a test chamber, a fixing sleeve concentrically arranged within the test chamber, and a limiting mechanism. The limiting mechanism includes a ball seat embedded within the fixing sleeve and a pressure ring installed within the ball seat for limiting the soluble temporary plugging ball. The lower end face of the pressure ring contacts and engages with the soluble temporary plugging ball. Furthermore, this invention also provides a test assembly and a testing method.

Description

Technical Field

[0001] This invention relates to the field of well completion technology in petroleum engineering, and specifically to a performance testing device, testing assembly, and testing method for soluble temporary plugging balls. Background Technology

[0002] In the fracturing and stimulation process of unconventional oil and gas wells, temporary plugging balls possess short-term plugging and self-degradation functions. They can temporarily plug fractures when needed and lose their plugging effect when no longer required, allowing the fractures to reopen. This characteristic makes temporary plugging technology an important technical means for the stimulation of unconventional oil and gas reservoirs. The pressure-bearing performance of the soluble material in the temporary plugging ball under high temperature and pressure directly determines the quality of downhole fracturing operations. Currently, temporary plugging ball products undergo pressure-bearing tests simulating high-temperature and high-pressure downhole environments during the research and development stage and before industrial production.

[0003] Currently, existing temporary plugging ball testing devices have many shortcomings. On the one hand, the cavity is relatively large, making the plugging ball prone to floating during pressure testing and water injection, leading to test failure. Furthermore, some devices are equipped with an inner sleeve to hold the plugging ball in place, but because the inner sleeve and the plugging ball have a planar rigid contact, the plugging ball is more likely to be crushed prematurely before the test after mechanical pressure, resulting in test failure. On the other hand, the testing devices are cumbersome to assemble and disassemble, the ball seat takes a long time to remove, and residual stress after the test can easily cause jamming and make disassembly difficult.

[0004] Therefore, it is desirable in the art to provide a performance testing apparatus, testing assembly, and testing method for soluble temporary plugging balls to solve the above-mentioned technical problems. Summary of the Invention

[0005] The purpose of this invention is to provide a performance testing device, testing assembly, and testing method for soluble temporary plugging balls, wherein the ball seat and the temporary plugging ball can be quickly installed and disassembled before and after completing the static high temperature and high pressure strength test, thereby significantly improving the testing efficiency.

[0006] According to a first aspect of the present invention, a performance testing apparatus for soluble temporary plugging balls is provided, comprising a test chamber. The fixing sleeves are concentrically arranged inside the test chamber. A limiting mechanism includes a ball seat embedded in the fixed sleeve and a pressure ring installed in the ball seat for limiting the soluble temporary plugging ball, the lower end face of the pressure ring being in contact with the soluble temporary plugging ball.

[0007] In one embodiment, the lower end face of the pressure ring is configured as a spherical structure adapted to the soluble temporary plugging ball.

[0008] In one embodiment, the pressure ring is provided with a first through hole that allows the liquid phase to pass through, and there is a gap between the pressure ring and the ball seat that allows the liquid phase to pass through.

[0009] In one embodiment, sealing grease is filled at the junction of the ball seat and the soluble temporary plug ball.

[0010] In one embodiment, the lower end of the ball seat is flush with the lower end of the fixing sleeve.

[0011] In one embodiment, the performance testing apparatus further includes a first end cap sleeved outside the test chamber, and a first channel and a second channel that allow liquid phase to pass through are respectively formed in the ball seat and the first end cap.

[0012] In one embodiment, the performance testing apparatus further includes a collection box connected to the outlet end of the second channel for recycling waste liquid.

[0013] In one embodiment, the performance testing apparatus further includes a second end cap embedded in the upper end of the test chamber, a pressure injection pump connected to the second end cap, and a pressure sensor disposed between the pressure injection pump and the first end cap.

[0014] According to a second aspect of the invention, a test assembly is provided, comprising a performance test apparatus as described above, a temperature control chamber enclosed by the performance test apparatus, and a computer data acquisition module connected to the temperature control chamber and a pressure sensor respectively.

[0015] According to a third aspect of the present invention, a test method utilizing the test assembly described above is provided, comprising the following steps: The soluble temporary plugging ball is confined within the ball seat by a pressure ring; Liquid is injected into the test chamber to the test pressure using a pressure injection pump, and then heated to the test temperature using a temperature control box and maintained for a period of time. After the test is completed, remove the limiting mechanism, observe the deformation and surface dissolution of the soluble temporary plugging ball, and record the residual deformation size and compare it with the mass loss before and after the test.

[0016] Compared with the prior art, the advantages of the present invention are as follows: The ball seat and temporary plugging ball in this application can be quickly installed and disassembled before and after completing the static high-temperature and high-pressure strength test, thus significantly improving test efficiency. The pressure ring in this application makes contact with the soluble temporary plugging ball, and after engaging with the ball seat, it effectively limits the position of the soluble temporary plugging ball, thus preventing sealing failure due to floating or eccentricity during water injection and pressurization, thereby increasing the test success rate to over 98%. The pressure ring in this application, through its spherical structure, provides a larger contact area with the soluble temporary plugging ball, allowing the ball to be evenly stressed, thus preventing premature crushing of the ball due to excessive downward pressure. The temperature control chamber in this application can achieve precise temperature control from 20℃ to 200℃, thus achieving coordinated operation of temperature control and pressure bearing, reducing heat loss and test preparation time. Attached Figure Description

[0017] The present invention will now be described in detail with reference to the accompanying drawings.

[0018] Figure 1 The schematic diagram illustrates the structure of a performance testing apparatus for soluble temporary plugging balls according to the present invention.

[0019] Figure 2 The schematic diagram illustrates the structure of the test assembly according to the invention.

[0020] In the accompanying drawings, the same parts use the same reference numerals. The drawings are not drawn to scale. Detailed Implementation

[0021] To make the technical solutions and advantages of the present invention clearer, exemplary embodiments of the present invention will be described in further detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not an exhaustive list of all embodiments. Furthermore, without conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0022] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0023] In this invention, unless otherwise explicitly specified and limited, the terms “installation,” “connection,” “linking,” “fixing,” etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components.

[0024] Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0025] The invention will now be further described with reference to the accompanying drawings.

[0026] According to a first aspect of the present invention, a performance testing apparatus for soluble temporary plugging balls is provided, mainly comprising a test chamber 11, a fixing sleeve 12 concentrically arranged within the test chamber 11, and a limiting mechanism. The limiting mechanism includes a ball seat 21 longitudinally embedded within the fixing sleeve 12, and a pressure ring 22 installed within the ball seat 21. In this invention, the ball seat 21 and the pressure ring 22 define the chamber, and the soluble temporary plugging ball 18 is confined within the chamber, thus effectively preventing test failure due to floating or sliding of the soluble temporary plugging ball 18 during water injection.

[0027] In such Figure 1 In the illustrated embodiment, during testing, the lower end face of the pressure ring 22 can contact and engage with the soluble temporary plugging ball 18 to engage with the ball seat 21. Therefore, after the pressure ring 22 is embedded in the ball seat 21, it can effectively limit the position of the soluble temporary plugging ball 18. Preferably, the lower end face of the pressure ring 22 is constructed as a spherical structure. Therefore, the pressure ring 22 can have a larger contact area with the soluble temporary plugging ball 18 through the spherical structure, thereby avoiding premature crushing of the ball due to excessive downward pressure, and further improving the effectiveness and safety of the performance testing device for soluble temporary plugging balls of this application.

[0028] In such Figure 1 In the illustrated embodiment, the performance testing apparatus for the soluble temporary plugging ball further includes a second end cap 15, a pressure injection pump 16, and a pressure sensor 17. The second end cap 15 is embedded in the upper end of the test chamber 11, and a hollow channel allowing liquid flow is formed within the second end cap 15. The pressure injection pump 16 communicates with the hollow channel, thereby injecting liquid into the test chamber 11 to simulate a real high-pressure environment for the soluble temporary plugging ball 18. The pressure sensor 17 is positioned between the pressure injection pump 16 and the first end cap 13, and is used to observe and record pressure fluctuation data in real time.

[0029] In such Figure 1In the illustrated embodiment, a first through-hole 221 allowing liquid phase to pass through is provided on the pressure ring 22. Simultaneously, a gap allowing liquid phase to pass through exists between the pressure ring 22 and the ball seat 21. Therefore, the liquid phase can flow into the ball seat 21 through the gap to contact the soluble temporary plugging ball 18, thereby dissolving the soluble temporary plugging ball 18. In this way, not only can the ball seat 21 and pressure ring 22 effectively limit the soluble temporary plugging ball 18, preventing it from floating or sliding, but the increased contact area also ensures that the force applied by the pressure ring 22 is fully applied to the surface of the soluble temporary plugging ball 18, ensuring uniform force distribution. Therefore, the soluble temporary plugging ball 18 can stably abut radially against the ball seat 21 throughout the entire test process, further ensuring the stability of the soluble temporary plugging ball 18.

[0030] A limiting arc surface is formed inside the ball seat 21 to abut against the temporary plugging ball 18. The performance testing device for soluble temporary plugging balls in this application also fills the joint between the ball seat 21 and the soluble temporary plugging ball 18 with sealing grease. In this way, it can be ensured that the soluble temporary plugging ball 18 can achieve a sealed fit with the limiting arc surface of the ball seat 21 in the working state, thereby ensuring that the pressure injected into the test chamber 11 can be fully applied to the surface of the soluble temporary plugging ball 18 through the liquid phase, further improving the realism and accuracy of the simulation experiment.

[0031] In such Figure 1 In the illustrated embodiment, after installation, the lower end of the ball seat 21 is flush with the lower end of the fixing sleeve 12 to ensure accurate positioning. The performance testing apparatus for soluble temporary plugging balls also includes a first end cap 13. The first end cap 13 is installed at the bottom of the test chamber 11 until it is tightened, thereby ensuring the sealing performance of the performance testing apparatus for soluble temporary plugging balls.

[0032] The ball seat 21 in this application is a replaceable ball seat. Therefore, after the test is completed, it is not necessary to remove the first end cap 13 located at the top; only the second end cap 15 located at the bottom needs to be removed to take out the temporary plugging ball 18 and the ball seat 21. This allows for the rapid installation and positioning of the temporary plugging ball 18 and the ball seat 21, further improving the efficiency of the test. Preferably, the first channel 211 of the ball seat 21 (see...) Figure 1 It can be designed in different sizes, making it easier to meet the testing needs of temporary blocking balls of different specifications.

[0033] In such Figure 1 In the illustrated embodiment, a first channel 211 and a second channel 131, allowing liquid phase passage, are respectively formed within the ball seat 21 and the first end cap 13. The first channel 211 and the second channel 131 are arranged in series, and the diameter of the second channel 131 is larger than the diameter of the first channel 211. Figure 2In the embodiment shown, the performance testing device for the soluble temporary plugging ball also includes a collection box 14 connected to the outlet end of the second channel 131, and the collection box 14 is located below the second channel 131. Therefore, after the experiment is completed and the pressure ring 22 and the soluble temporary plugging ball 18 are removed, the waste liquid in the test chamber 11 will flow into the collection box 14 through the first channel 211 and the second channel 131 in sequence.

[0034] In this invention, the performance testing device for soluble temporary plugging balls also includes a pressure relief safety valve (not shown). The pressure relief safety valve in this invention can manually release the residual pressure in the test chamber 11 when encountering pressure buildup and jamming, thereby reducing the residual stress after the test and further solving the technical problems of cumbersome disassembly and assembly and jamming caused by residual stress in the performance testing device of this application.

[0035] According to a second aspect of the present invention, a test assembly is provided, which mainly includes a performance test apparatus as described above, a temperature control box 201 covered outside the performance test apparatus, and a computer data acquisition module 202 connected to the temperature control box 201 and the pressure sensor 17 respectively.

[0036] In this invention, the pressure injection pump 16 is connected to the test chamber 11, thereby enabling the injection of liquid into it to provide a high-pressure environment for the soluble temporary plugging ball 18; the temperature control box 201 can be used in the performance test device of the soluble temporary plugging ball to maintain a constant high-temperature environment, and the computer data acquisition module 202 can detect and record the changes in pressure and temperature values ​​in real time through the pressure sensor 17 and the temperature control box 201 respectively.

[0037] This application integrates the performance testing apparatus for soluble temporary plugging balls directly into the temperature control chamber 201 for unified design. The temperature control chamber 201 is constructed as an explosion-proof high-temperature environment chamber, allowing testing to proceed with the door closed without the need for additional external heating devices. The temperature control chamber 201 of this application can achieve linear temperature rise within the range of 20℃ to 200℃, with a temperature control accuracy of ±0.5℃, thereby improving heating efficiency by more than 40%. Simultaneously, the temperature control chamber 201 is equipped with a temperature control system that monitors and adjusts the temperature in real time to avoid deviations in test results caused by temperature variations. Furthermore, the power consumption of this application's testing assembly is 3.8 kWh, compared to 5.5 kWh for traditional split-type heating devices, representing an energy saving of at least 30.9%.

[0038] According to a third aspect of the present invention, a testing method is provided. First, the soluble temporary plugging ball 18 is confined within the ball seat 21 by the pressure ring 22; Secondly, liquid is injected into the test chamber 11 to the test pressure through the pressure injection pump 16, and then heated to the test temperature by the temperature control box 201 and maintained for a period of time. Finally, after the test is completed, the limiting mechanism is removed, the deformation and surface dissolution of the soluble temporary plugging ball 18 are observed, and the residual deformation size is recorded and compared with the mass loss before and after the test.

[0039] During the experiment, the pressure injection pump 16 must first be turned on, and the test pressure must be set according to the pre-set technical requirements. After the pressure reaches the test pressure and stabilizes, the temperature control box 201 is turned on to heat to the test temperature required by the technical requirements. After the temperature rises to the set value and remains constant, the constant temperature and pressure time required by the technical requirements is set in the computer data acquisition module 202. During this period, the pressure fluctuation and temperature change data can also be recorded by the computer data acquisition module 202, and adjustments can be made in real time according to the technical requirements.

[0040] After the experiment, the temperature control box 201 and the pressure injection pump 16 were turned off in sequence. After the performance testing device for the soluble temporary plugging ball of this application cooled naturally to room temperature and the pressure dropped to 0, the first end cap 13 was opened, the ball seat 21 was removed, and the pressure ring 22 and the soluble temporary plugging ball 18 were removed. The waste liquid was discharged into the collection box 14. By observing the deformation and surface dissolution of the soluble temporary plugging ball 18, the residual deformation size and the mass loss before and after the test were recorded and compared. Then, the mechanical stability and dissolution characteristics of the material under high temperature and high pressure environment were analyzed in combination with the pressure-temperature curve. This further verified the reliable sealing performance and controllable dissolution behavior of the soluble temporary plugging ball 18 under complex downhole conditions, so that the temperature and pressure were dynamically controlled throughout the entire test process.

[0041] Compared with existing technologies, the advantages of this invention are: The ball seat and temporary plugging ball in this application can be quickly installed and disassembled before and after completing the static high-temperature and high-pressure strength test, thus significantly improving test efficiency. The pressure ring 22 in this application makes contact with the soluble temporary plugging ball 18, and after engaging with the ball seat 21, it effectively limits the position of the soluble temporary plugging ball 18, thus preventing sealing failure due to floating or eccentricity during water injection and pressurization, thereby increasing the test success rate to over 98%. The pressure ring 22 in this application, through its spherical structure, provides a larger contact area with the soluble temporary plugging ball 18, allowing the ball to be evenly stressed, thus preventing premature crushing due to excessive downward pressure. The temperature control chamber 201 in this application can achieve precise temperature control from 20℃ to 200℃, thus achieving coordinated operation of temperature control and pressure bearing, reducing heat loss and test preparation time.

[0042] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art can easily make changes or modifications within the scope of the present invention, and such changes or modifications should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A performance testing apparatus for soluble temporary plugging balls, comprising: Test chamber (11). Fixing sleeves (12) are concentrically arranged inside the test chamber (11). The limiting mechanism includes a ball seat (21) embedded in the fixed sleeve (12) and a pressure ring (22) installed in the ball seat (21) for limiting the soluble temporary plugging ball (18), the lower end face of the pressure ring (22) being in contact with the soluble temporary plugging ball (18).

2. The performance testing apparatus for soluble temporary plugging balls according to claim 1, characterized in that, The lower end face of the pressure ring (22) is constructed as a spherical structure adapted to the soluble temporary plugging ball (18).

3. The performance testing apparatus for soluble temporary plugging balls according to claim 2, characterized in that, The pressure ring (22) is provided with a first through hole (221) that allows the liquid phase to pass through, and there is a gap between the pressure ring (22) and the ball seat (21) that allows the liquid phase to pass through.

4. The performance testing apparatus for soluble temporary plugging balls according to claim 3, characterized in that, Fill the joint between the ball seat (21) and the soluble temporary plug ball (18) with sealant.

5. The performance testing apparatus for soluble temporary plugging balls according to claim 4, characterized in that, The lower end of the ball seat (21) is flush with the lower end of the fixing sleeve (12).

6. The performance testing apparatus for soluble temporary plugging balls according to claim 5, characterized in that, The performance testing device also includes a first end cap (13) sleeved outside the test chamber (11), and a first channel (211) and a second channel (131) that allow liquid phase to pass through are respectively formed in the ball seat (21) and the first end cap (13).

7. The performance testing apparatus for soluble temporary plugging balls according to claim 6, characterized in that, The performance testing device also includes a collection box (14) connected to the outlet end of the second channel (131) and used for recycling waste liquid.

8. The performance testing apparatus for soluble temporary plugging balls according to claim 7, characterized in that, The performance testing device also includes a second end cap (15) embedded in the upper end of the test chamber (11), a pressure injection pump (16) connected to the second end cap (15), and a pressure sensor (17) disposed between the pressure injection pump (16) and the first end cap (13).

9. A test assembly comprising a performance test apparatus according to any one of claims 1 to 8, a temperature control box (201) enclosed outside the performance test apparatus, and a computer data acquisition module (202) connected to the temperature control box (201) and a pressure sensor (17) respectively.

10. A testing method using the test assembly according to claim 9, comprising the following steps: The soluble temporary plugging ball (18) is confined within the ball seat (21) by the pressure ring (22); Liquid is injected into the test chamber (11) to the test pressure using a pressure injection pump (16), and then heated to the test temperature using a temperature control box (201) and maintained for a period of time. After the test is completed, remove the limiting mechanism, observe the deformation and surface dissolution of the soluble temporary plugging ball (18), and record the residual deformation size and compare the mass loss before and after the test.

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