Squeezing bridge plug indoor experiment device, evaluation system and experiment method

Abstract

The invention discloses a squeeze bridge plug indoor experiment device, evaluation system and experiment method.The squeeze bridge plug indoor experiment device comprises a pressurization assembly, a heating assembly and a sleeve tool, the downhole high-temperature and high-pressure and polluting liquid environment can be simulated, the squeeze bridge plug performance can be accurately evaluated, and a downhole tool experiment evaluation system simulates actual working conditions through a setting tool, an experiment sleeve and the like; the performance of the bridge plug can be comprehensively evaluated, the experimental method comprises a plurality of steps such as a setting hanging checking test and releasing operation, the heating rate and pressure are strictly controlled in the heating process, and experimental safety is ensured; by means of the method, sealing failure parts can be accurately checked, powerful support is provided for bridge plug structure optimization, the reliability and safety of the bridge plug in oil and gas well exploitation are improved, and the method has great significance in promoting oil and gas well exploitation technology development.

Description

Technical Field

[0001] This invention relates to the field of oil production engineering technology, specifically to an indoor experimental device, evaluation system, and experimental method for a squeeze-injection bridge plug. Background Technology

[0002] As the application of layer-by-layer sealing technology continues to expand into deep and ultra-deep wells, traditional layer-by-layer sealing technologies, represented by "cement plug + bridge plug + cement plug," have gradually revealed numerous problems. Their operation cycles are lengthy, involving complex procedures, severely impacting extraction efficiency. The emergence of hydraulically set and injected bridge plug layer-by-layer sealing technology offers a new solution to these problems. It can complete the bridge plug setting and cement injection at both ends of the bridge plug in a single tubing run, significantly improving layer-by-layer sealing efficiency in deep and ultra-deep wells.

[0003] Regarding related technologies, CN107461168A discloses an integrated automatic mixing and pumping system for coiled tubing operations. This system mainly consists of an automatic drag-reducing agent mixing pump truck, a coiled tubing roller truck, a coiled tubing injection head assembly, a wellhead assembly, a downhole production system, and a surface recovery device for the return fluid. The automatic drag-reducing agent mixing pump truck continuously and automatically mixes the agent and working fluid, directly injecting the working fluid downhole to complete the flushing and purging of the coiled tubing inner wall. It is suitable for pumping fracturing fluid and drilling bridge plug processes under various operating conditions. However, its tool string structure is fundamentally different from the process measures involved in this patent and cannot be directly applied to the relevant experiments and evaluations of squeeze-type bridge plugs.

[0004] CN105003220B proposes a coiled tubing horizontal well drilling and pumping composite bridge plug process, which allows for direct drilling and plugging under pressure after fracturing without releasing pressure. This process offers advantages such as short construction time, low labor intensity, and effective prevention of formation energy loss. However, it differs fundamentally from this patent in terms of enabling rapid layer transition and sealing, and cannot meet the experimental requirements for injection-type bridge plugs.

[0005] CN104653136B discloses a method for drilling and grinding composite bridge plugs in conventional tubing downhole power drilling, which enables rapid removal of the bridge plug and can meet the requirements for drilling plugs in special geological environments. It broadens the adaptability of hydraulic bridge plug staged fracturing technology and reduces drilling plug costs compared to coiled tubing operations. However, it also differs fundamentally from this patent in achieving rapid layer transition and sealing functionality.

[0006] Currently, the application of injection-type bridge plugs in deep and ultra-deep wells in China is still in its initial stage, and the laboratory evaluation methods still follow the traditional bridge plug laboratory testing methods. However, hydraulically set injection-type bridge plugs differ significantly from traditional bridge plugs. After setting, injection-type bridge plugs rely on slips, rubber sleeves, and internal sliding sleeve sealing rings for anchoring and sealing. The setting tool insertion tube needs to be lowered and inserted into the internal slide valve of the bridge plug and moved downwards to open the injection channel to inject cement. During the injection process, the slips, rubber sleeves, and setting tool sealing assembly ensure effective anchoring and sealing. Traditional bridge plug laboratory testing methods mainly focus on testing the bridge plug slips and rubber sleeves, which has many limitations. On the one hand, there is a lack of evaluation experiments on the impact of injection pressure on the performance of the setting tool sealing assembly during the injection process; on the other hand, when sealing problems occur during the experiment, it is impossible to accurately locate the failed components inside the bridge plug. Furthermore, traditional laboratory testing environments for bridge plugs typically use a single medium, such as clean water or brine, neglecting the impact of downhole contaminants on the performance of hydraulically set injection bridge plugs and setting tools. These realities highlight the urgent need and necessity to develop a dedicated laboratory testing device and method for injection bridge plugs. Summary of the Invention

[0007] To address the problem that existing indoor testing methods for bridge plugs cannot accurately evaluate the key sealing performance of hydraulically set extrusion bridge plugs, this invention provides an indoor testing device, evaluation system, and testing method for extrusion bridge plugs. This method can simulate the high-temperature, high-pressure, and contaminated fluid environment downhole, accurately evaluate the impact of extrusion pressure on sealing performance, and precisely identify failed components when the seal fails, thus assisting in the optimization of bridge plug structure.

[0008] This invention is achieved through the following technical solution:

[0009] An indoor experimental device for extrusion-type bridge plugs includes a pressurization assembly, a heating assembly, and a sleeve fixture;

[0010] The casing tooling includes a casing short section, a tail plug, and a pressure relief connector. The two ends of the casing short section are respectively connected to the tail plug and the pressure relief connector by threads, so that a closed space is formed inside the casing short section to place the squeeze-type bridge plug body and the contaminating liquid.

[0011] The pressurizing component is connected to the enclosed space. When the internal pressure of the enclosed space is low, the internal pressure of the enclosed space is stabilized to high pressure by pressurizing.

[0012] The heating component is wrapped around the outside of the enclosed space to keep the enclosed space at a high temperature.

[0013] In this scheme, a casing fixture consisting of a casing sub, a tail plug, and a pressure-increasing / reducing connector forms a closed space for placing the bridge plug body and the contaminating liquid, simulating actual downhole working conditions. The pressurizing component is connected to the closed space and can pressurize from low pressure to high pressure to test the bridge plug's performance under different pressures. The heating component is wrapped around the outside of the closed space to maintain a high temperature. Combined with the contaminating liquid, this comprehensively simulates the high-temperature, high-pressure, and complex fluid environment downhole. This provides an effective means to accurately evaluate the sealing performance and pressure resistance of the injection-type bridge plug in actual operation, helps to study the impact of injection pressure on sealing performance, and provides conditions for troubleshooting failed components when the seal fails, thus promoting the optimization of the subsequent bridge plug structure.

[0014] Furthermore, the heating assembly includes a heating strip wound around the outside of the enclosed space, with the spacing between each turn of the heating strip wound around the outside of the enclosed space maintained within the range of 1-2 cm.

[0015] In this design, this winding method ensures uniform and efficient heating of the internal space of the casing fixture, allowing the temperature of the squeeze-type bridge plug and the contaminating liquid inside to rise rapidly and stably to the simulated high-temperature state of the downhole environment, thus guaranteeing the accuracy and stability of the experimental temperature conditions. Furthermore, appropriate spacing helps to distribute heat reasonably across the surface of the enclosed space, avoiding localized overheating or uneven heating, thereby making the experimental environment closer to the temperature field distribution in a real downhole environment.

[0016] Furthermore, a one-way valve is also connected between the pressurizing component and the sleeve tooling.

[0017] In this scheme, during pressurization of the casing fixture, the one-way valve ensures that pressure can only be transmitted from the pressurization assembly to the inside of the casing fixture, effectively preventing liquid or gas inside the casing fixture from flowing back to the pressurization assembly. This ensures the smooth progress of the pressurization process and allows the pressure to act stably on the test objects such as the injection bridge plug and the internal contaminating liquid, thereby accurately simulating the impact of the downhole high-pressure environment on the bridge plug. At the same time, when the temperature inside the casing fixture changes due to the experimental process, causing pressure changes due to thermal expansion and contraction of the liquid, the one-way valve can prevent the high-pressure liquid generated by thermal expansion from flowing back to the pressurization assembly, avoiding damage to the pressurization assembly. It also prevents the interference of the experiment due to pressure instability or negative pressure caused by contraction, ensuring the relative stability of the pressure environment inside the casing fixture during the experiment.

[0018] Furthermore, the experimental apparatus also includes a detection component, which includes a pressure sensor and a pneumatic control valve, wherein the pressure sensor is connected to the pneumatic control valve via a pipe section.

[0019] The pressure sensor monitors the internal pressure of the enclosed space in real time.

[0020] When the pressure sensor detects that the pressure inside the enclosed space is greater than the safety value, the pressure is remotely released through the pneumatic control valve, and the overflowing contaminated liquid during the pressure release is diverted into the pressure relief tank.

[0021] In this scheme, the pressure sensor monitors the internal pressure of the enclosed space in real time. Once the pressure exceeds the safe value, the pneumatic control valve responds immediately and remotely performs a pressure relief operation. This effectively prevents damage to the bushing fixture, bridge plug failure, or even safety accidents caused by excessive pressure, ensuring that the entire experimental process is carried out within a safe and controllable pressure range. At the same time, the overflowing contaminated liquid during pressure relief is diverted to the pressure relief tank, avoiding pollution of the experimental environment caused by contaminated liquid leakage, which meets environmental protection requirements.

[0022] A downhole tool testing and evaluation system includes a setting tool and a test casing;

[0023] The experimental sleeve has a central cavity in the middle. The setting tool and the extrusion bridge plug body of the experimental device described in any of the above technical solutions are placed in the central cavity in sequence. The setting tool is sealed to the opening of the central cavity, and the extrusion bridge plug body abuts against the inner wall of the central cavity.

[0024] The outer wall of the experimental sleeve is provided with an upper pressure chamber pressure port and a lower pressure chamber pressure port that are connected to the central cavity. The heat-conducting oil passing through the upper pressure chamber pressure port and the lower pressure chamber pressure port raises the temperature in the central cavity to the experimental temperature.

[0025] In this design, the central cavity in the middle of the experimental casing provides a stable installation and working space for the setting tool and the injection-type bridge plug, simulating actual downhole conditions. This allows both to be tested in a near-realistic environment. The sealed connection between the setting tool and the opening of the central cavity, as well as the contact between the injection-type bridge plug and the inner wall of the cavity, ensures the effective action and transmission of pressure and fluid during the experiment, facilitating accurate simulation of the bridge plug's working state downhole. Furthermore, the upper and lower pressure ports on the outer wall of the experimental casing, through the circulation of heat transfer oil, precisely control the temperature of the central cavity, raising it to the experimental temperature. This not only simulates the high-temperature environment downhole but also provides a basis for studying the performance changes of the injection-type bridge plug under different temperature conditions. Simultaneously, this system organically combines the experimental device with the setting tool and the experimental casing, enabling a comprehensive and systematic evaluation of the injection-type bridge plug's performance in complex downhole environments, including setting performance, sealing performance, and temperature and pressure resistance. This provides a crucial experimental platform and data support for optimizing bridge plug design and improving its reliability and safety.

[0026] Furthermore, the evaluation system also includes a loader and a central tube. The central tube is connected to the setting tool string in the setting tool. The loader clamps the central tube, so that the setting tool and the extrusion bridge plug body are slowly lowered to the corresponding setting position.

[0027] Specifically, the setting tool string is gradually pressurized to the rated setting pressure through the central cavity pressure port at the upper part of the central tube, thereby completing the setting of the setting tool and the extrusion bridge plug body.

[0028] In this scheme, the loader clamps the central tube, enabling precise control of the lowering process of the setting tool and the injection-type bridge plug, allowing them to slowly reach the corresponding setting position. This ensures the accuracy and stability of the experimental operation and avoids affecting the experimental results due to excessively fast lowering speed or inaccurate positioning. Simultaneously, the pressure is gradually increased to the rated setting pressure through the central cavity pressure port at the top of the central tube. This process simulates the setting operation of the bridge plug by the setting tool in actual downhole operations, accurately controlling the setting pressure and ensuring that the injection-type bridge plug can complete the setting according to design requirements in the experimental environment. This provides a foundation for subsequent performance tests of the bridge plug. This scheme enables the evaluation system to comprehensively and realistically simulate the setting process of the injection-type bridge plug downhole, providing a powerful means to accurately evaluate the setting performance, reliability, and collaborative working ability of the bridge plug with the setting tool.

[0029] Furthermore, the setting tool also includes a setting tool cannula. When an injection operation is required, the setting tool cannula is lowered and inserted into the body of the injection-type bridge plug. The pressure applied to the setting tool cannula through the central cavity pressure port pushes the slide valve inside the bridge plug to move down, thereby opening the injection channel of the injection-type bridge plug.

[0030] In this design, when extrusion is required, the setting tool cannula is lowered and inserted into the body of the extrusion bridge plug, providing a direct way to open the extrusion channel. Applying pressure to the setting tool cannula through the central cavity pressure port allows for precise control of the movement of the internal slide valve of the bridge plug, pushing the valve downwards to open the extrusion channel of the extrusion bridge plug. This design ensures that the key steps of actual extrusion operations can be simulated during experiments, enabling accurate evaluation of the performance of the extrusion bridge plug during the extrusion process.

[0031] A method for laboratory testing of injection-type bridge plugs includes an injection-type bridge plug laboratory testing device and a downhole tool testing and evaluation system. The experimental steps are as follows:

[0032] Step 1: Connect the squeezing bridge plug body and the setting tool and place them into the casing tooling. Then inject kill fluid into the casing tooling until the kill fluid can submerge the squeezing bridge plug body and the setting tooling. Let it stand at room temperature.

[0033] Step 2: Gradually heat the sleeve fixture to the test temperature using the heating components, then maintain the temperature for the rated time. After the heat maintenance is completed, allow the sleeve fixture to stand in a natural environment until it reaches the artificial operating temperature.

[0034] Step 3: Take out the injection bridge plug body and matching setting tool, clamp the center tube with the loader, connect the center tube to the injection bridge plug body and setting tool string, and put the setting ball into the setting tool in advance;

[0035] Step 4: By circulating heat transfer oil in the upper and lower pressure chambers, the temperature in the evaluation system is raised to the test temperature. Once the system temperature stabilizes at the rated temperature, the setting and sealing operation begins.

[0036] Step 5: After the setting is completed, use a loader to lift and lower the setting tool string, observe whether there is any displacement of the setting tool string, and complete the setting test.

[0037] Step 6: After the bridge plug passes the inspection, use the loader to keep the setting tool string in the raised state, and then pressurize through the central cavity pressure port to gradually increase the pressure until the setting tool and the extrusion bridge plug body are separated, thus completing the release operation.

[0038] Step 7: After successfully releasing the tool, lift the setting tool string to the designated position using the loader to completely separate the setting tool from the extrusion bridge plug body. Then, continue pressurizing through the central cavity pressurization port until the central cavity pressure suddenly drops to 0, completing the shear ball seat operation.

[0039] Step 8: After the shear ball seat is successfully cut, the setting tool string is lowered by the loader, so that the setting tool insert is pressed down into the body of the extrusion bridge plug. A certain overpressure is maintained, the pressure port of the lower pressure chamber is opened, and pressure is applied step by step through the pressure port of the central chamber until the central chamber and the lower pressure chamber are connected. The purpose of this test extrusion is to simulate whether the setting tool insert can successfully open the extrusion channel of the extrusion bridge plug during the on-site construction process.

[0040] Step 9: After the trial extrusion test is completed, close the upper pressure chamber pressure port and the lower pressure chamber pressure port, and slowly pressurize to the rated pressure value through the central chamber pressure port until the central chamber pressure value stabilizes. This completes the sealing performance test, which aims to determine the sealing performance of the bridge plug rubber sleeve and the setting tool sealing assembly.

[0041] Step 10: After completing the sealing performance test, remove the setting tool from the injection bridge plug body, heat the central cavity to the rated temperature, pressurize the upper and lower pressure chambers at the rated temperature, close the central cavity, and stabilize the pressure for the rated time to complete the high temperature pressure test. The purpose is to determine the sealing performance of the rubber barrel and slide valve sealing assembly.

[0042] Furthermore, in step two, during the heating process, the heating rate is controlled at 5-10℃ / min until the experimental temperature is 105℃. If the pressure rises above the safe pressure value during the heating process, the pneumatic control valve is opened to release the pressure until the tooling pressure stabilizes within the safe pressure value. If the pressure is low, the pressurization component is activated to pressurize the sleeve tooling and stabilize the pressure at the safe pressure value.

[0043] Furthermore, in step five, when the setting tool string is lifted, the tension is slowly increased to check if there is any displacement of the setting tool string; when the setting tool string is lowered, the pressure is slowly increased to check the displacement of the setting tool string again. If there is no displacement of the setting tool string during the lifting and lowering process, the bridge plug is qualified.

[0044] Furthermore, in step six, if the setting tool and the injection bridge plug body fail to separate successfully, the pressure is released through the central cavity, the lifting tonnage is readjusted, and the pressure is restored to the specified pressure. The separation of the setting tool and the injection bridge plug body is then observed until the tool is successfully released.

[0045] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0046] 1. This invention can effectively simulate the effect of the internal pressure generated during the on-site cement injection process on the sealing performance of the sealing section formed between the inside of the injection-type bridge plug and the setting tool tube. This makes the evaluation of the bridge plug sealing performance more comprehensive and accurate, and provides a stronger basis for ensuring the reliability of the bridge plug in practical applications.

[0047] 2. This invention can more accurately determine which component inside the bridge plug is malfunctioning through a systematic experimental method, based on experimental steps and phenomenon analysis. This provides a clear direction for subsequent bridge plug structure optimization, reduces the time and cost of troubleshooting, and improves the efficiency of oil and gas well production operations. Attached Figure Description

[0048] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0049] Figure 1 A simplified diagram of the connection structure of a high-temperature contamination device for an injection-type bridge plug and setting tool;

[0050] Figure 2 This is a schematic diagram of the anchoring and sealing of an injection-type bridge plug;

[0051] Figure 3 For high-temperature and high-pressure downhole tool testing and evaluation system;

[0052] Figure 4This is a flowchart illustrating the evaluation method.

[0053] The attached diagram shows the markings and corresponding component names:

[0054] 1-High-pressure water pump; 2-One-way valve; 3-Pipe section; 4-Tee; 5-Heating belt; 6-Casing tool; 7-Power supply; 8-Pressure sensor; 9-Pneumatic control valve; 10-Pressure relief tank; 11-Setting tool insert; 12-Extrusion type bridge plug body; 13-Setting tool sealing assembly; 14-Bridge plug slide valve seal; 15-Slipper; 16-Rubber sleeve; 17-Pressure cap; 18-Central cavity pressure port; 19-Loader; 20-Central tube; 21-Upper pressure chamber pressure port; 22-Lower pressure chamber pressure port; 23-Setting tool; 24-Experimental casing. Detailed Implementation

[0055] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0056] Example 1

[0057] This embodiment 1 provides an indoor experimental device for injecting bridge plugs, such as... Figure 1 As shown, it includes a pressurization assembly, a heating assembly, and a sleeve tooling 6;

[0058] Among them, such as Figure 1 As shown, the casing fixture 6 includes a casing short section, a tail plug, and a pressure relief connector. The two ends of the casing short section are connected to the tail plug and the pressure relief connector respectively by threads, so that the inside of the casing short section forms a closed space for placing the injection bridge plug body 12 and the contaminating liquid. The heating assembly includes a heating band 5 wrapped around the outside of the closed space. The heating band 5 is made of long strip glass fiber material and is wrapped around the outside of the closed space. At the same time, the spacing between each turn of the heating band 5 is maintained within 1-2 cm. The heating band 5 is connected to the indoor 220V power supply 7 to ensure that the experimental temperature is kept at a high temperature, thereby simulating the on-site downhole temperature.

[0059] In this embodiment, the internal space length of the casing fixture 6 is greater than the connection length between the injection-type bridge plug body 12 and the matching setting tool 23. During use, the tail end of the casing short section needs to be sealed with the tail plug first, and then the injection-type bridge plug body 12 and the matching setting tool 23 are inserted. Then, while keeping the casing fixture 6 vertical, the contaminating liquids such as kill fluid and mud are poured in. Finally, the pressure increase / depression connector is connected to the casing fixture. The pressure increase / depression connector is then connected to the pressure increase assembly through the pipe short section 3. The pressure increase assembly includes a high-pressure water pump 1 and a one-way valve 2. The high-pressure water pump 1, the one-way valve 2, and the pressure increase / depression connector are connected in sequence. When the internal pressure of the closed space is low, the internal pressure of the closed space is stabilized to high pressure by pressurization.

[0060] Please also refer to Figure 1 As shown, this embodiment also includes a detection component, which includes a pressure sensor 8 and a pneumatic control valve 9. One end of the pressure sensor 8 is connected to the pneumatic control valve 9 through a pipe section 3, and the other end of the pressure sensor 8 is connected to the high-pressure water pump 1 through a tee 4. The pressure sensor 8 monitors the internal pressure of the enclosed space in real time. When the pressure sensor 8 detects that the internal pressure of the enclosed space is greater than the safe value, it remotely releases the pressure through the pneumatic control valve 9 and diverts the overflowing polluting liquid during the pressure release into the pressure relief tank 10 to prevent environmental pollution.

[0061] Example 2

[0062] This embodiment 2 provides a downhole tool testing and evaluation system, such as Figure 3 As shown, the apparatus includes a setting tool 23 and an experimental sleeve 24. The experimental sleeve 24 has a central cavity in the middle. The setting tool 23 and the extrusion bridge plug body 12, which completes the experiment using the experimental device in Example 1, are placed in the central cavity in sequence. The setting tool 23 is sealed to the opening of the central cavity, and the extrusion bridge plug body abuts against the inner wall of the central cavity.

[0063] Please refer to the following: Figure 3 As shown, the outer wall of the experimental sleeve 24 is respectively provided with an upper pressure chamber pressure port 21 and a lower pressure chamber pressure port 22 that connect to the central cavity. The heat transfer oil passing through the upper pressure chamber pressure port 21 and the lower pressure chamber pressure port 22 raises the temperature in the central cavity to the experimental temperature. Specifically, the external heating system injects heated heat transfer oil through the lower pressure chamber pressure port 22. The heat transfer oil that has released its heat returns to the heater of the heating system through the upper pressure chamber pressure port 21. At the same time, the external pressure test system uses compressed air as a power source to output high-pressure heat transfer oil through a pneumatic-hydraulic pump. The pressure of the experiment is controlled by controlling the central cavity pressure port 18, the upper pressure chamber pressure port 21, and the lower pressure chamber pressure port 22.

[0064] Please refer to the following: Figure 3As shown, the evaluation system also includes a loader 19 and a central tube 20. The central tube 20 is connected to the setting tool string in the setting tool 23. The loader 19 clamps the central tube 20, causing the setting tool 23 and the extrusion-type bridge plug body 12 to be slowly lowered to the corresponding setting position. During the setting process, the setting tool string plays the role of transmitting the setting force. The loader 19 applies an axial force to the setting tool string, which is transmitted along the string to the setting mechanism of the bridge plug, causing the bridge plug's slips 15 to expand outward and bite the inner wall of the test sleeve 24. At the same time, the compression of the rubber sleeve 16 achieves a seal. Specifically, before the setting test begins, the extrusion-type bridge plug body 12 and the setting tool string 23 are connected to the central tube 20. The tube 20 is placed in the setting tool 23 beforehand, and then the loading machine 19 clamps the central tube 20. The upper part of the central tube 20 is connected to the pressure cap 17, which is connected to the central cavity pressure port 18 on the upper part of the central tube 20. The tube 20 is slowly lowered to the setting position of the experimental sleeve 24, and heat transfer oil is injected through the lower pressure port 22. The upper pressure port 21 is opened, and the temperature in the central cavity is raised to the experimental temperature by heating the heat transfer oil. Then, the pressure is gradually increased to the rated setting pressure through the central cavity pressure port 18 inside the central tube 20. After setting is completed, the pressure is released, and then the setting tube column is lifted and pressed down by the loading machine 19. The displacement of the tube column can be observed.

[0065] Meanwhile, the aforementioned setting tool 23 also includes a setting tool insert, which is an extension of the setting tool string. It is a slender rod-shaped structure with a relatively small diameter, capable of being inserted into a specific channel or cavity inside the extrusion bridge plug. When extrusion operation is required, the setting tool insert is lowered and inserted into the body 12 of the extrusion bridge plug. The pressure applied to the setting tool insert through the central cavity pressure port 18 pushes the slide valve inside the bridge plug to move down, thereby opening the extrusion channel of the extrusion bridge plug and providing a direct operating method for opening the extrusion channel.

[0066] Example 3

[0067] This embodiment 3 provides a method for indoor testing of injection-type bridge plugs, including the indoor testing device for injection-type bridge plugs provided in embodiment 1 and the downhole tool testing and evaluation system provided in embodiment 2, such as... Figures 1-4 As shown, the experimental steps are as follows:

[0068] Step 1: Connect the squeezing bridge plug body 12 and the setting tool 23 and place them into the casing tool 6. Then inject kill fluid into the casing tool 6 until the kill fluid can submerge the squeezing bridge plug body 12 and the setting tool 23. Let it stand at room temperature for 18 hours.

[0069] Step 2: Gradually heat the sleeve fixture 6 to the test temperature using heating belt 5, and then maintain the temperature for 6 hours. After the heat maintenance is completed, allow the sleeve fixture 6 to stand in the natural environment until the manual operation temperature reaches 60℃. During the heating process, the heating rate is controlled at 5-10℃ / min until the test temperature reaches 105℃. If the pressure rises above the safe pressure value during the heating process, open the pneumatic control valve 9 to release the pressure until the fixture pressure stabilizes within the safe pressure value. If the pressure is low, start the high-pressure water pump 1 to pressurize the sleeve fixture 6 and stabilize the pressure at the safe pressure value.

[0070] Step 3: Take out the injection-type bridge plug body 12 and the matching setting tool 23. Use the loader 19 to clamp the center tube 20. The center tube 20 is connected to the injection-type bridge plug body 12 and the setting tool string. The setting ball is put into the setting tool 23 in advance. Specifically, the loader 19 clamps the center tube 20 smoothly and connects the top of the center tube 20 tightly to the pressure cap 17 so that the pressure cap 17 is connected to the pressure port 18 of the center cavity. Then, lower the center tube 20 at a slow and stable speed (generally controlled at 0.1-0.2m / s) until the bridge plug reaches the predetermined setting position in the sleeve. During this process, pay attention to the depth and position of the center tube at all times to avoid deviation.

[0071] Step 4: By circulating heat transfer oil in the upper pressure chamber pressure port 21 and the lower pressure chamber pressure port 22, the temperature in the evaluation system is raised to the experimental temperature. After the system temperature stabilizes at 105℃, the setting operation begins. Specifically, heat transfer oil is injected through the lower pressure chamber pressure port 22, the upper pressure chamber pressure port 21 is opened, and the temperature in the central cavity is raised to the experimental temperature by heating the heat transfer oil. Then, the pressure is gradually increased to 5 MPa through the central cavity pressure port 18 inside the central tube 20, and stabilized for 1 minute; then increased to 10 MPa, and stabilized for 5 minutes; then increased to 10 MPa, and stabilized for 5 minutes; then increased to 19 MPa, and stabilized for 15 minutes. After the setting is completed, the pressure relief valve is slowly opened to release the pressure in the central cavity to zero at a rate of 0.05-0.1 MPa / s.

[0072] Step 5: After setting is completed, the setting tool string is lifted and lowered using the loader 19. The loader is then used to observe whether there is any displacement of the setting tool string, thus completing the setting verification test. Specifically, the loader 19 performs lifting and pressing operations on the setting tool string. During lifting, the tension is increased by 0.5-1T each time, gradually increasing to 5.4T, while carefully observing whether there is any displacement of the setting tool string. During pressing, the pressure is increased by 0.5-1MPa each time, until reaching 5.5T, while carefully observing whether there is any displacement of the setting tool string. Throughout the lifting and pressing process, the real-time display data of the loader is accurately recorded, including tension, pressure, and the corresponding displacement of the setting tool string. If the displacement of the setting tool string is extremely small (e.g., less than 0.5mm) when lifted and pressed to the predetermined tonnage, the setting verification test can be considered successful, indicating that the slip 15 of the extrusion bridge plug is reliably anchored and the overall structure is stable under setting and under certain tension and pressure. Conversely, if abnormal pressure fluctuations occur, the rated setting pressure cannot be reached, or the displacement of the tubing is too large, the cause needs to be analyzed in depth. This may involve factors such as damage to the bridge plug components, failure of the slip 15 anchoring, or incomplete setting, which will provide a basis for subsequent improvements or further testing.

[0073] Step Six: After the bridge plug passes the test, the setting tool string is kept in an elevated state by the loader 19, and then pressure is applied through the central cavity pressure port 18 to gradually increase the pressure until the setting tool 23 separates from the extrusion bridge plug body 12, thus completing the release operation. Specifically, the loader 19 keeps the setting tool string in an over-lifted state. The over-lifting tonnage is generally set to be slightly higher than the lifting tonnage in the setting test (e.g., 1-2T higher) to ensure that there is sufficient separation tendency between the setting tool 23 and the bridge plug.

[0074] Step 7: After successful release, lift the setting tool string to the designated position using the loader 19, so that the setting tool 23 is completely separated from the extrusion bridge plug body 12. Then, continue pressurizing through the central cavity pressurization port until the central cavity pressure suddenly drops to 0, completing the shearing of the ball seat. Specifically, pressurize slowly and gradually through the central cavity pressurization port 18, increasing the pressure by 2-3 MPa each time. Pause for 5-10 seconds after each pressure increase to observe whether the setting tool 23 and the bridge plug begin to separate. When they begin to separate, continue to pressurize slowly until the ball seat shearing pressure value is reached. At the moment the pressure value is reached, closely monitor the change in central cavity pressure. If the pressure suddenly drops to 0, it indicates that the ball seat has been sheared. Record the pressure value at this time and the phenomenon at the moment of shearing.

[0075] Step 8: After the shear ball seat is successfully installed, the setting tool string is lowered using the loader 19, causing the setting tool tube to be inserted into the extrusion bridge plug body 12. A certain overpressure is maintained, and the pressure port 22 of the lower pressure chamber is opened. Pressure is applied step by step through the pressure port 18 of the central cavity until the central cavity and the lower pressure chamber are connected, completing the trial extrusion test. Specifically, the setting tool string is lowered, causing its tube to be inserted into the extrusion bridge plug. During the insertion process, a certain overpressure is maintained. The overpressure tonnage is generally set to 3-5T. To ensure that the cannula can effectively push the internal slide valve of the bridge plug downward, after the cannula is inserted into place, open the pressure port 22 of the lower pressure chamber and slowly pressurize through the pressure port of the central chamber, increasing the pressure by 3-5 MPa each time, pausing for 8-12 seconds after each pressure increase, and observing the pressure change in the central chamber at the same time; when the pressure in the central chamber drops to 0, it indicates that the internal squeezing channel of the squeezing bridge plug has been opened, realizing the connection between the central chamber and the lower pressure chamber. At this time, stop pressurizing, and record the pressure value when this state is reached and the phenomena during the pressurization process;

[0076] Step Nine: After the trial extrusion test is completed, close the upper pressure chamber pressure port 21 and the lower pressure chamber pressure port 22, and slowly pressurize to the rated pressure value through the central pressure port until the central pressure value stabilizes. This completes the sealing performance test, which aims to determine the sealing performance of the bridge plug sleeve 16 and the setting tool sealing assembly 13. Specifically, close the upper pressure chamber pressure port 21 and the lower pressure chamber pressure port 22, and slowly pressurize to the rated pressure value (e.g., 20) through the central pressure port 18. -30MPa), because the pressure port 22 of the lower pressure chamber is closed, a closed space is formed below the bridge plug. During the pressure test, an upward force will be generated on the squeezing bridge plug sleeve 16 and the setting tool tube, affecting its sealing performance. The purpose is to simulate the situation during the field squeezing process. If the formation absorption is poor, it is necessary to determine whether the bridge plug can prevent the squeezing liquid below from returning to the upper annulus. During the pressure test, the pressure is increased by 2-4MPa each time, and the pressure is paused for 10-15 seconds after each increase. After reaching the rated pressure, the pressure is stabilized for the rated time (e.g., 30-60 minutes). During the pressure stabilization period, the pressure value of the pressure port 18 of the central cavity is continuously observed and the pressure value change curve over time is recorded. At the same time, attention should be paid to whether there are any signs of liquid leakage around the bridge plug and the setting tool 23. If the pressure value of the pressure port 18 of the central cavity remains basically stable during the pressure stabilization period (the pressure drop is within the allowable range, such as less than 0.5MPa), and there is no liquid leakage around the bridge plug and the setting tool 23, then the sealing performance test is considered successful.

[0077] Step 10: After completing the sealing performance test, remove the setting tool 23 from the extrusion bridge plug body 12, heat the central cavity to 90℃, pressurize the upper pressure chamber 21 to 70MPa at 90℃, stabilize the pressure for 30 minutes and the test is qualified. Pressurize the lower pressure chamber 22 to 70MPa at 90℃, stabilize the pressure for 30 minutes and the test is qualified. The high temperature pressure test is completed. If the pressure in both the upper and lower pressure chambers can remain stable during the pressure stabilization period (the pressure drop is within the allowable range, such as less than 0.5MPa), the high temperature pressure test is considered successful, indicating that the sealing performance of the rubber sleeve 16 and the bridge plug slide valve seal 14 is reliable under high temperature and high pressure environment and can withstand the corresponding pressure.

[0078] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A chamber experimental apparatus for injection-type bridge plugs, characterized in that, Includes pressurization components, heating components and sleeve tooling (6); The casing tool (6) includes a casing short section, a tail plug and a pressure relief connector. The two ends of the casing short section are respectively connected to the tail plug and the pressure relief connector by threads, so that a closed space is formed inside the casing short section to place the squeeze-type bridge plug body (12) and the contaminating liquid. The pressurizing component is connected to the enclosed space. When the internal pressure of the enclosed space is low, the internal pressure of the enclosed space is stabilized to high pressure by pressurizing. The heating component is wrapped around the outside of the enclosed space to keep the enclosed space at a high temperature.

2. The chamber experimental apparatus for injection-type bridge plugs according to claim 1, characterized in that, The heating assembly includes a heating band (5) wrapped around the outside of the enclosed space, with the spacing between each turn of the heating band (5) wrapped around the outside of the enclosed space maintained within the range of 1-2 cm.

3. The chamber experimental apparatus for injection-type bridge plugs according to claim 2, characterized in that, The heating belt (5) is made of long strip glass fiber material.

4. The chamber experimental apparatus for injection-type bridge plugs according to claim 1, characterized in that, The internal space length of the sleeve tool (6) is greater than the connection length between the extrusion bridge plug body (12) and the matching setting tool (23).

5. The chamber experimental apparatus for injection-type bridge plugs according to claim 1, characterized in that, A one-way valve (2) is also connected between the pressurizing component and the sleeve tooling (6).

6. The chamber experimental apparatus for extrusion-type bridge plugs according to claim 1, characterized in that, The experimental apparatus also includes a detection component, which includes a pressure sensor (8) and a pneumatic control valve (9). The pressure sensor (8) is connected to the pneumatic control valve (9) through a pipe section (3). The pressure sensor (8) monitors the internal pressure of the enclosed space in real time; When the pressure sensor (8) detects that the pressure inside the enclosed space is greater than the safety value, it remotely releases the pressure through the pneumatic control valve (9) and diverts the overflowing contaminated liquid during the pressure release into the pressure relief tank (10).

7. A downhole tool testing and evaluation system, characterized in that, Includes setting tool (23) and experimental sleeve (24); The experimental sleeve (24) has a central cavity in the middle. The setting tool (23) and the extrusion bridge plug body (12) of the experimental device according to any one of claims 1-6 are placed in the central cavity in sequence. The setting tool (23) is sealed to the opening of the central cavity, and the extrusion bridge plug body (12) abuts against the inner wall of the central cavity. The outer wall of the experimental sleeve (24) is provided with an upper pressure chamber pressure port (21) and a lower pressure chamber pressure port (22) that connect to the central cavity. The heat-conducting oil passing through the upper pressure chamber pressure port (21) and the lower pressure chamber pressure port (22) raises the temperature in the central cavity to the experimental temperature.

8. The downhole tool testing and evaluation system according to claim 7, characterized in that, The evaluation system also includes a loader (19) and a central tube (20). The central tube (20) is connected to the setting tool string in the setting tool (23). The loader (19) clamps the central tube (20) so that the setting tool (23) and the extrusion bridge plug body (12) are slowly lowered to the corresponding setting position. The setting tool string is gradually pressurized to the rated setting pressure through the central cavity pressure port (18) at the top of the central tube (20), thereby completing the setting of the setting tool (23) and the injection-type bridge plug body (12).

9. The downhole tool testing and evaluation system according to claim 8, characterized in that, The setting tool (23) also includes a setting tool tube (11). When an injection operation is required, the setting tool tube (11) is lowered and inserted into the body (12) of the injection bridge plug. The pressure applied to the setting tool tube (11) through the central cavity pressure port (18) pushes the slide valve inside the bridge plug to move down, thereby opening the injection channel of the injection bridge plug.

10. A laboratory experimental method for injection-type bridge plugs, characterized in that, The experimental steps of the following are as follows: A squeeze-type bridge plug chamber test apparatus as described in any one of claims 1-6 and a downhole tool test evaluation system as described in claim 8: Step 1: Connect the squeezing bridge plug body (12) and the setting tool (23) and place them into the casing tool (6). Then inject kill fluid into the casing tool (6) until the kill fluid can submerge the squeezing bridge plug body (12) and the setting tool (23). Let it stand at room temperature. Step 2: Gradually heat the sleeve fixture (6) to the test temperature using the heating components, then keep it warm for the rated time. After the warming is completed, let the sleeve fixture (6) stand in the natural environment until it reaches the artificial operating temperature. Step 3: Take out the injection bridge plug body (12) and the matching setting tool (23), use the loader (19) to clamp the center tube (20), the center tube (20) is connected to the injection bridge plug body (12) and the setting tool string, and the setting ball is put into the setting tool (23) in advance; Step 4: By circulating heat transfer oil in the upper pressure chamber pressure port (21) and the lower pressure chamber pressure port (22), the temperature in the evaluation system is raised to the experimental temperature. After the system temperature stabilizes at the rated temperature, the setting and sealing operation is started. Step 5: After the setting is completed, the setting tool string is lifted and lowered by the loader (19) to observe whether the setting tool string has displacement, and the setting test is completed. Step 6: After the bridge plug passes the inspection, use the loader (19) to keep the setting tool string in the upward state, and then pressurize through the central cavity pressure port (18) to gradually increase the pressure until the setting tool (23) and the squeezing bridge plug body (12) are separated, and the release operation is completed. Step 7: After the release is successful, the setting tool string is lifted to the designated position by the loader (19) so that the setting tool (23) is completely separated from the squeezing bridge plug body (12). Then, pressure is continued through the central cavity pressure port (18) until the pressure in the central cavity suddenly drops to 0, and the shear ball seat operation is completed. Step 8: After the shear ball seat is successfully cut, the setting tool tube is lowered by the loader (19) so that the setting tool tube (11) is pressed down and inserted into the body (12) of the extrusion bridge plug. A certain overpressure state is maintained, the pressure port (22) of the lower pressure chamber is opened, and the pressure is applied step by step through the pressure port (18) of the central chamber until the central chamber and the lower pressure chamber are connected, thus completing the trial extrusion test. Step 9: After the trial extrusion test is completed, close the upper pressure chamber pressure port (21) and the lower pressure chamber pressure port (22), and slowly pressurize to the rated pressure value through the central chamber pressure port (18) until the central chamber pressure value stabilizes, thus completing the sealing performance test operation. Step 10: After completing the sealing performance test, remove the setting tool (23) from the injection bridge plug body (12), heat the central cavity to the rated temperature, pressurize the upper and lower pressure chambers respectively under the rated temperature, close the central cavity, stabilize the pressure for the rated time respectively, and complete the high temperature pressure test.

11. The method for indoor testing of a squeeze-type bridge plug according to claim 10, characterized in that, In step two, during the heating process, the heating rate is controlled at 5-10℃ / min until the experimental temperature is 105℃. If the pressure rises above the safe pressure value during the heating process, the pneumatic control valve (9) is opened to release the pressure until the tooling pressure stabilizes within the safe pressure value. If the pressure is low, the pressurization component is started to pressurize the sleeve tooling (6) so that the pressure stabilizes within the safe pressure value.

12. The method for indoor testing of a squeeze-type bridge plug according to claim 10, characterized in that, In step five, when lifting the setting tool string, slowly increase the tension and check if the setting tool string has any displacement; when lowering the setting tool string, slowly increase the pressure and check the displacement of the setting tool string again. If the setting tool string has no displacement during the lifting and lowering process, the bridge plug is qualified.

13. The method for indoor testing of a squeeze-type bridge plug according to claim 10, characterized in that, In step six, if the setting tool (23) and the injection bridge plug body (12) fail to separate successfully, the pressure is released through the central cavity, the lifting tonnage is readjusted, and the pressure is increased again to the specified pressure. The separation of the setting tool (23) and the injection bridge plug body (12) is observed until the separation is successfully completed.

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