Gas-phase carrier pressure difference plugging agent evaluation system based on ultrasonic atomization and application method of gas-phase carrier pressure difference plugging agent evaluation system

Abstract

The invention discloses a gas-phase carrier pressure difference plugging agent evaluation system based on ultrasonic atomization and an application method thereof, and belongs to plugging material performance testing technologies in the fields of oil and gas development technologies, underground energy storage technologies and the like. According to the technical scheme, the device comprises an ultrasonic atomization system and a leaking stoppage system, the ultrasonic atomization system comprises a precise injection pump, a high-frequency intelligent atomizer, an atomization cavity, a visual cavity, a nitrogen cylinder and a pressure reducing valve, and the leaking stoppage system comprises a pressurizing pump, a clamping device, an annular pressure pump, a back pressure pump, a screw thread model, a post-processing device and a valve structure. The evaluation system has the beneficial effects that aiming at the problems of cracks of an underground shaft and leakage of a screw thread device, the evaluation system evaluates the effect and the performance of the differential pressure plugging agent by constructing a simulation experiment. According to the method, the safety and convenience can be improved, the success rate of plugging is increased, and a scientific basis is provided for performance evaluation of the plugging agent.

Description

Technical Field

[0001] The present invention belongs to the fields of oil and gas exploitation and energy storage, and relates to a dynamic evaluation method for the atomization and plugging efficiency of leak stoppage agents for annulus pressure control in oil and gas production wells, injection and production wells of underground gas storage, etc.; in the field of industrial seal safety engineering, it relates to an on-line leak stoppage technology for pressure-bearing equipment such as oil and gas pipelines and chemical containers, and specifically relates to a gas-phase carrier differential pressure leak stoppage agent evaluation system based on ultrasonic atomization and its application method. Background Art

[0002] During the development of a large number of oil and gas wells, continuous annulus pressure phenomena have successively occurred, and injection and production wells for gas geological storage also face serious annulus pressure problems.

[0003] The annulus of the injection and production well is composed of multiple layers of casing and cement for well cementing, forming a safety barrier, and its sealing performance directly affects the injection and production efficiency and environmental safety. However, due to factors such as geological stress changes, cement aging, chemical corrosion, construction defects, and high-intensity alternating injection and production, microcracks or interface peeling are likely to form in the annulus, resulting in the failure of the safety barrier, the escape of gas along the leakage channel, causing annulus pressure, and even leading to ground leakage, seriously affecting production safety and environmental safety.

[0004] Traditional physical leak stoppage technologies include cement well cementing repair and mechanical plugging tools. Cement well cementing repair has problems such as uncontrollable setting time and weak bonding force with the crack interface, and is prone to shrinkage and cracking in low-temperature or high-pressure environments, resulting in secondary leakage. Mechanical plugging tools usually use devices such as clamps and glue injection guns, which require manual operation, are difficult to adapt to the narrow space of the annulus, and have high safety risks for personnel in high-temperature and toxic environments. Summary of the Invention

[0005] In order to solve the problems existing in the above-mentioned prior art, the purpose of the present invention is to disperse the differential pressure leak stoppage agent in the gas-phase carrier through ultrasonic atomization, simulate the leakage of underground cracks and threaded devices through an experimental device, and when the gas-phase carrier is transported to the leakage point, activate the leak stoppage agent by using the differential pressure at the leakage point, so as to achieve the purpose of leak stoppage without the need for tools and manual entry into the well, and then evaluate the performance of the differential pressure leak stoppage agent through this experimental device after the leak stoppage is completed.

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

[0007] A gas-phase carrier differential pressure plugging agent evaluation system based on ultrasonic atomization. This system is targeted at differential pressure plugging agents and uses ultrasonic atomization to disperse them in the gas-phase carrier. It is transported to the leakage point through the airflow, and the differential pressure plugging agent is activated by the differential pressure to solidify at the leakage point to achieve the purpose of plugging, and its plugging effect is tested and evaluated. This system includes: a precision injection pump, a high-frequency intelligent atomizer, an atomization chamber, a visual chamber, a nitrogen cylinder, a pressure reducing valve, a pressure pump inlet valve, a pressure pump, a pressure pump outlet valve, a gripper inlet valve, a gripper, a ring pressure pump valve, a ring pressure pump, a back pressure pump valve, a back pressure pump, a threaded model inlet valve, a threaded model, and a post-treatment device;

[0008] In the plugging agent evaluation system, the precision injection pump is connected to the atomization chamber through an infusion pipeline for transporting the differential pressure plugging agent solution; the high-frequency intelligent atomizer is connected to the atomization chamber through a wire for ultrasonic electrical signal transmission; the nitrogen cylinder is connected to the atomization chamber through a pipeline, and a pressure reducing valve is set on its pipeline to control the inlet pressure; the atomization chamber is connected to the visual chamber through an atomization nozzle; the visual chamber is connected to the pressure pump through a pipeline, and a pressure pump inlet valve is set on the pipeline; the pressure pump is connected to the gripper and the threaded model through pipelines, and a pressure pump outlet valve, a gripper inlet valve, a threaded model inlet valve or a similar tee structure is set on the pipelines; the ring pressure pump is connected to the gripper through a pipeline, and a ring pressure pump valve is set on the pipeline; the gripper is connected to the back pressure pump and the post-treatment device through pipelines and a back pressure pump valve or a similar tee structure; the threaded model outlet is connected to the post-treatment device through a pipeline.

[0009] Further, the atomization chamber includes an ultrasonic electrical signal receiver, a plugging agent inlet, a vibration element, a plug, an adjusting nut, an atomization nozzle, and a nitrogen inlet. The atomization chamber is connected to the visual chamber through the atomization nozzle, and the connection method uses threaded sealing connection; the high-frequency intelligent atomizer transmits the ultrasonic electrical signal into the atomization chamber through the ultrasonic signal receiver, drives the vibration element to vibrate, atomizes the differential pressure plugging agent injected through the precision injection pump, and the nitrogen input from the nitrogen cylinder is atomized through the atomization nozzle and enters the visual chamber. The visual chamber is made of quartz material to facilitate observing the atomization quality.

[0010] Further, the threaded model includes a pressure sensor, a housing inlet, a thread inlet, a pressure sensor, a fixing bolt, a thread, a housing, a thread outlet, a housing outlet, a bracket, and a fixing bolt. Among them, the pressure sensor is arranged on the inner wall of the housing to detect the internal pressure change of the housing; the pressure sensor is connected to the thread inlet to detect the internal pressure of the thread; the thread inlet is connected to the thread through a pipeline for inputting the gas-phase carrier differential pressure plugging agent; the thread is divided into two upper and lower kettle bodies, and the two kettle bodies are connected by threads, and the tightness of the connection is controlled by the threads to simulate the leakage of the thread; the thread is fixed in the housing; there are a thread outlet and a housing outlet at the lower part of the housing; the housing is supported by a bracket, and the two are fixed by a fixing bolt.

[0011] Further, the connection lines and pipelines of each device are subjected to sealing and waterproof treatment.

[0012] An application method of an evaluation system for a differential pressure plugging agent with a gas-phase carrier based on ultrasonic atomization includes the following steps:

[0013] 1). Leak plugging experiment on the crack model:

[0014] a). Ensure that all valves in the device are closed, install the crack model in the clamp, and check the airtightness of the device;

[0015] b). Open the precision injection pump, pump the configured differential pressure plugging agent into the atomization chamber. At the same time, open the pressure reducing valve, introduce nitrogen into the atomization chamber, control the pressure of the injected nitrogen through the pressure reducing valve. At the same time, open the high-frequency intelligent atomizer to generate an ultrasonic signal to vibrate the vibration element, and spray the gas into the visible chamber through the atomization nozzle to achieve the atomization process. The visible chamber can evaluate the atomization effect;

[0016] c). Open the intake valve of the pressure pump, pressurize the atomized gas through the pressure pump, raise the pressure to the specified pressure, open the outlet valve of the pressure pump, and introduce the pressurized gas-phase carrier into the clamp;

[0017] d). Leak plugging:

[0018] Open the ring pressure pump valve and the back pressure pump valve, set the ring pressure and the back pressure, keep the intake valve of the threaded model closed, open the intake valve of the clamp, introduce the pressurized gas-phase carrier into the clamp. The ring pressure should be higher than the intake pressure, and its function is to prevent the gas from flowing through the gap between the crack model and the clamp. When the pressure of the introduced gas is higher than the back pressure, the gas will pass through the crack model in the clamp and enter the post-treatment device. At the same time, the differential pressure plugging agent is activated and solidified at the crack under the action of the differential pressure to achieve the purpose of leak plugging. Observe in the post-treatment device. When no gas appears in the post-treatment device, it is regarded as the completion of leak plugging. Then close all instruments and valves.

[0019] e). Evaluate the leak plugging effect. Keep the precision injection pump and the high-frequency intelligent atomizer closed, open the pressure reducing valve, introduce nitrogen into the pipeline, open the intake valve and the outlet valve of the pressure pump, gradually increase the pressure of the gas through the pressure pump, open the ring pressure pump valve and the back pressure pump valve, set the ring pressure and the back pressure, keep the intake valve of the threaded model closed, open the intake valve of the clamp, introduce the pressurized nitrogen into the clamp. The ring pressure should be higher than the intake pressure, and its function is to prevent the gas from flowing through the gap between the crack model and the clamp. Make the pressure of the introduced gas higher than the back pressure, observe the post-treatment device. If gas appears in the post-treatment device, it is regarded as the crack plugging being washed open. At this time, the intake pressure is regarded as the maximum pressure that the differential pressure plugging agent can withstand under this condition, and the leak plugging effect is evaluated accordingly.

[0020] 2). Thread model plugging experiment:

[0021] a). Ensure that all valves in the device are closed, place the crack model in the clamp, and check the airtightness of the device;

[0022] b). Keep the precision injection pump and the high-frequency intelligent atomizer closed, open the pressure reducing valve, introduce nitrogen into the system, open the intake valve and the outlet valve of the pressure pump, increase the gas pressure to the specified value through the pressure pump, close the intake valve of the clamp, adjust the tightness of the upper and lower thread bodies to simulate thread leakage, open the intake valve of the thread model, record the data of the pressure sensors in the thread device at this time, and then close the intake valve of the thread model;

[0023] c). Open the precision injection pump, pump the prepared differential pressure plugging agent into the atomization cavity. At the same time, open the pressure reducing valve, introduce nitrogen into the atomization cavity, control the pressure of the injected nitrogen through the pressure reducing valve, open the high-frequency intelligent atomizer at the same time, generate ultrasonic signals to make the vibration element vibrate, and spray the gas into the visible cavity through the atomization nozzle to achieve the atomization process. The visible cavity can evaluate the atomization effect;

[0024] d). Open the intake valve of the pressure pump, pressurize the atomized gas through the pressure pump, raise the pressure to the specified pressure, open the outlet valve of the pressure pump, and introduce the pressurized gas carrier into the thread model;

[0025] e). Plugging:

[0026] Keep the thread tightness unchanged, close the intake valve of the clamp, open the intake valve of the thread model, block the intake port of the outer shell and the outlet of the thread, introduce the pressurized gas carrier into the thread model. The gas will enter the outer shell through the leakage point and enter the post-treatment device through the outlet of the outer shell. The differential pressure plugging agent is activated and solidified at the leakage point under the action of the differential pressure to achieve the purpose of plugging. Observe in the post-treatment device 18 and record the data of the pressure sensors. When the data of the pressure sensors hardly change anymore, it is regarded as the completion of plugging. Close all instruments and valves.

[0027] f). Evaluate the plugging effect. According to the measured pressure results, plot the pressure-time change curve. At the same time, turn off the precision injection pump and the high-frequency intelligent atomizer, open the pressure reducing valve, open the intake valve and the outlet valve of the pressure pump. Gradually increase the gas pressure through the pressure pump, open the screw thread intake port and the housing outlet port, close the screw thread outlet port and the housing intake port, and introduce pressurized nitrogen into the screw thread model. Observe the pressure sensor and the post-treatment device. When there is an obvious change in the pressure of the pressure sensor or gas appears in the post-treatment device, it is regarded that the plugging point of the screw thread is washed open. The intake pressure at this time is regarded as the maximum pressure that the differential pressure plugging agent can withstand under this condition, so as to evaluate the plugging effect. It is also possible to close the screw thread intake port and the housing outlet port, open the screw thread outlet port and the housing intake port, and use the same test method to test the negative pressure to evaluate the plugging effect.

[0028] Advantages of the present invention:

[0029] Compared with the prior art, the differential pressure plugging agent evaluation system based on ultrasonic atomization and its application method of the present invention have the following technical characteristics and advantages:

[0030] (1) Traditional mechanical plugging tools require manual operation, and in high-temperature and toxic environments, the safety risk of personnel is extremely high. However, this solution uses ultrasonic atomization to disperse the differential pressure plugging agent in the gas-phase carrier, and transports it to the leakage point with the help of air flow, without the need for tools and manual entry into the well, avoiding personnel working in dangerous environments and greatly improving the safety and convenience of operation;

[0031] (2) Traditional cementing repair has problems such as uncontrollable setting time and weak bonding force with the crack interface. It is prone to shrinkage and cracking in low-temperature or high-pressure environments, which may lead to secondary leakage. This solution makes the plugging agent evenly dispersed through ultrasonic atomization, activates it using the differential pressure at the leakage point and makes it solidify at the leakage point, which can effectively avoid secondary leakage and significantly improve the success rate and stability of plugging;

[0032] (3) This solution can not only achieve plugging, but also evaluate the performance of the differential pressure plugging agent using the same experimental device after plugging. By testing the maximum pressure that can be withstood after plugging and plotting the pressure-time change curve and other methods, it provides a scientific and quantitative basis for evaluating the performance of the plugging agent;

[0033] (4) The annulus structure of injection-production wells is complex, and traditional plugging technologies are difficult to adapt to the narrow annulus space. This solution transports the plugging agent through the gas-phase carrier, which is not restricted by space. At the same time, based on the stronger penetration ability of the gas phase compared to the liquid phase, it can better cope with complex downhole environments and micro-leakage situations, showing stronger applicability in the annulus leakage problems of injection-production wells. Description of the Drawings

[0034] To more clearly illustrate the technical solutions of the embodiments of the present invention, the present invention will be described in detail below in conjunction with the accompanying drawings and detailed embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings. Among them:

[0035] Figure 1 is the content flowchart of the evaluation system for the gas-phase carrier differential pressure plugging agent based on ultrasonic atomization of the present invention;

[0036] Figure 2 is the process flowchart of the experimental device in the present invention;

[0037] Figure 3 is the structural schematic diagram of the atomization cavity and the visual cavity in the present invention;

[0038] Figure 4 is the structural schematic diagram of the thread model in the present invention;

[0039] Reference numerals in the drawings: 1 - precision syringe pump, 2 - high-frequency intelligent atomizer, 3 - atomization cavity, 4 - visual cavity, 5 - nitrogen cylinder, 6 - pressure reducing valve, 7 - inlet valve of the pressure pump, 8 - pressure pump, 9 - outlet valve of the pressure pump, 10 - inlet valve of the gripper, 11 - gripper, 12 - ring pressure pump valve, 13 - ring pressure pump, 14 - back pressure pump valve, 15 - back pressure pump, 16 - inlet valve of the thread model, 17 - thread model, 18 - post-treatment device, 19 - ultrasonic electrical signal receiver, 20 - inlet of the plugging agent, 21 - vibration element, 22 - plug, 23 - adjusting nut, 24 - atomizing nozzle, 25 - nitrogen inlet, 26 - pressure sensor, 27 - inlet of the housing, 28 - thread inlet, 29 - pressure sensor, 30 - fixing bolt, 31 - thread, 32 - housing, 33 - thread outlet, 34 - housing outlet, 35 - bracket, 36 - fixing bolt. Detailed Embodiments

[0040] In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. The following combines the attached Figures 1-4 to further illustrate the evaluation system for the gas-phase carrier differential pressure plugging agent based on ultrasonic atomization and its application method.

[0041] Example 1

[0042] This embodiment discloses a gas-phase carrier differential pressure plugging agent evaluation system based on ultrasonic atomization. Through ultrasonic atomization, the differential pressure plugging agent is dispersed in the gas-phase carrier. The experimental device is used to simulate the leakage of downhole fractures and threaded devices. When the gas-phase carrier is transported to the leakage point, the differential pressure at the leakage point is utilized to activate the plugging agent, thereby achieving the purpose of plugging without the need for tools and manual entry into the well. After the plugging is completed, the performance of the differential pressure plugging agent is evaluated through this experimental device.

[0043] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0044] A gas-phase carrier differential pressure plugging agent evaluation system based on ultrasonic atomization is proposed. For the differential pressure plugging agent, this system uses ultrasonic atomization to disperse it in the gas-phase carrier, transports it to the leakage point through the airflow, activates the differential pressure plugging agent using the differential pressure, makes it solidify at the leakage point to achieve the purpose of plugging, and tests and evaluates its plugging effect. This system includes: a precision injection pump 1, a high-frequency intelligent atomizer 2, an atomization chamber 3, a visible chamber 4, a nitrogen cylinder 5, a pressure reducing valve 6, a pressurized pump intake valve 7, a pressurized pump 8, a pressurized pump outlet valve 9, a gripper intake valve 10, a gripper 11, an annular pressure pump valve 12, an annular pressure pump 13, a back pressure pump valve 14, a back pressure pump 15, a threaded model intake valve 16, a threaded model 17, and a post-treatment device 18;

[0045] The precision injection pump 1 of the plugging agent evaluation system is connected to the atomization chamber 3 through an infusion pipeline for transporting the differential pressure plugging agent solution; the high-frequency intelligent atomizer 2 is connected to the atomization chamber 3 through a wire for ultrasonic electrical signal transmission; the nitrogen cylinder 5 is connected to the atomization chamber 3 through a pipeline, and a pressure reducing valve 6 is provided on its pipeline for controlling the intake pressure; the atomization chamber 3 is connected to the visible chamber 4 through an atomization nozzle 24; the visible chamber 4 is connected to the pressurized pump 8 through a pipeline, and a pressurized pump intake valve 7 is provided on the pipeline; the pressurized pump 8 is connected to the gripper 11 and the threaded model 17 through pipelines, and a pressurized pump outlet valve 9, a gripper intake valve 10, a threaded model intake valve 16 or a similar tee structure is provided on the pipelines; the annular pressure pump 13 is connected to the gripper 11 through a pipeline, and an annular pressure pump valve 13 is provided on the pipeline; the gripper 11 is connected to the back pressure pump 15 and the post-treatment device 18 through pipelines and a back pressure pump valve 14 or a similar tee structure; the outlet of the threaded model is connected to the post-treatment device through a pipeline.

[0046] Further, the atomization cavity 3 includes an ultrasonic electrical signal receiver 19, a plugging agent inlet 20, a vibration element 21, a plug 22, an adjusting nut 23, an atomizing nozzle 24, and a nitrogen inlet 25. The atomization cavity 3 is connected to the visual cavity 4 through the atomizing nozzle 24, and the connection method is threaded seal connection; the high-frequency intelligent atomizer 2 transmits the ultrasonic electrical signal into the atomization cavity 3 through the ultrasonic signal receiver 19, drives the vibration element 21 to vibrate, atomizes the differential pressure plugging agent injected through the precision injection pump 1, and the nitrogen gas input from the nitrogen cylinder 5 is atomized through the atomizing nozzle 24 and enters the visual cavity 4. The visual cavity 4 is made of quartz material for easy observation of the atomization quality.

[0047] Further, the thread model 17 includes a pressure sensor 26, a housing air inlet 27, a thread air inlet 28, a pressure sensor 29, a fixing bolt 30, a thread 31, a housing 32, a thread air outlet 33, a housing air outlet 34, a bracket 35, and a fixing bolt 36. Among them, the pressure sensor 26 is arranged on the inner wall of the housing 32 to detect the pressure change inside the housing; the pressure sensor 29 is connected to the thread air inlet 28 to detect the pressure inside the thread; the thread air inlet 28 is connected to the thread 31 through a pipeline to input the gas-phase carrier differential pressure plugging agent; the thread 31 is divided into upper and lower kettles, and the two kettles are connected by threads, and the tightness of the connection is controlled by the threads to simulate the leakage of the thread; the thread 31 is fixed in the housing 32; the housing 32 is provided with a thread air outlet 33 and a housing air outlet 34 at the lower part; the housing 32 is supported by the bracket 35, and the two are fixed by the fixing bolt 36.

[0048] Further, the connection lines and pipelines of each device are subjected to sealing and waterproof treatment.

[0049] Embodiment 2

[0050] This embodiment provides an application method of a gas-phase carrier differential pressure plugging agent evaluation system based on ultrasonic atomization, including the following steps:

[0051] 1). Leakage plugging experiment on the crack model:

[0052] a). Ensure that all valves in the device are closed, install the crack model in the gripper, and check the airtightness of the device;

[0053] b). Open the precision injection pump 1, pump the configured differential pressure plugging agent into the atomization cavity 3. At the same time, open the pressure reducing valve 6, introduce nitrogen gas into the atomization cavity 3, control the pressure of the injected nitrogen gas through the pressure reducing valve 6, and at the same time open the high-frequency intelligent atomizer 2 to generate ultrasonic signals to make the vibration element 21 vibrate, and spray the gas into the visual cavity 4 through the atomizing nozzle 24 to realize the atomization process. The visual cavity 4 can evaluate the atomization effect;

[0054] c). Open the intake valve 7 of the pressure pump, introduce the atomized gas into the pressure pump 8 for pressurization, raise the pressure to the specified value, open the outlet valve 9 of the pressure pump, and introduce the pressurized gas carrier into the holder 11;

[0055] d). Leak plugging: Open the ring pressure pump valve 12 and the back pressure pump valve 14, set the ring pressure and back pressure, keep the thread model intake valve 16 closed, open the holder intake valve 10, introduce the pressurized gas carrier into the holder 11. The ring pressure should be higher than the intake pressure, which is used to prevent the gas from flowing through the gap between the crack model and the holder. When the introduced gas pressure is higher than the back pressure, the gas will pass through the crack model in the holder 11 and enter the post-treatment device 18. At the same time, the differential pressure plugging agent is activated and solidified at the crack under the action of the differential pressure to achieve the purpose of leak plugging. Observe in the post-treatment device 18. When there is no gas in the post-treatment device, it is regarded as the completion of leak plugging. Then close all instruments and valves.

[0056] e). Evaluate the leak plugging effect. Keep the precision syringe pump 1 and the high-frequency intelligent atomizer 2 closed, open the pressure reducing valve 6, introduce nitrogen into the pipeline, open the intake valve 7 and the outlet valve 9 of the pressure pump, gradually increase the gas pressure through the pressure pump 8, open the ring pressure pump valve 12 and the back pressure pump valve 14, set the ring pressure and back pressure, keep the thread model intake valve 16 closed, open the holder intake valve 10, introduce the pressurized nitrogen into the holder 11. The ring pressure should be higher than the intake pressure, which is used to prevent the gas from flowing through the gap between the crack model and the holder. Make the introduced gas pressure higher than the back pressure, observe the post-treatment device 18. If gas appears in the post-treatment device 18, it is regarded as the crack plugging being washed out. At this time, the intake pressure is regarded as the maximum pressure that the differential pressure plugging agent can withstand under this condition, and thus evaluate the leak plugging effect.

[0057] 2). Thread model leak plugging experiment:

[0058] a). Ensure that all valves in the device are closed, install the crack model in the holder, and check the airtightness of the device;

[0059] b). Keep the precision syringe pump 1 and the high-frequency intelligent atomizer 2 closed, open the pressure reducing valve 6, introduce nitrogen into the system, open the intake valve 7 and the outlet valve 9 of the pressure pump, increase the gas pressure to the specified value through the pressure pump 8, close the holder intake valve 10, adjust the tightness of the upper and lower bodies of the thread 31 to simulate thread leakage, open the thread model intake valve 16, record the data of the pressure sensor 26 and the pressure sensor 29 in the thread device at this time, and then close the thread model intake valve 16;

[0060] c). Turn on the precision injection pump 1, pump the configured differential pressure plugging agent into the atomization cavity 3. At the same time, turn on the pressure reducing valve 6, introduce nitrogen into the atomization cavity 3, control the pressure of the injected nitrogen through the pressure reducing valve 6. At the same time, turn on the high-frequency intelligent atomizer 2 to generate ultrasonic signals to vibrate the vibration element 21, and spray the gas into the visual cavity 4 through the atomization nozzle 24 to achieve the atomization process. The visual cavity 4 can evaluate the atomization effect;

[0061] d). Open the intake valve 7 of the pressure pump, introduce the atomized gas into the pressure pump 8 for pressurization, raise the pressure to the specified pressure, open the outlet valve 9 of the pressure pump, and introduce the pressurized gas carrier into the thread model 17;

[0062] e). Plugging: Keep the tightness of the thread 31 unchanged, close the intake valve 10 of the gripper, open the intake valve 16 of the thread model, block the housing intake port 27 and the thread outlet port 33, introduce the pressurized gas carrier into the thread model 17. The gas will enter the housing 32 through the leakage point and enter the post-treatment device 18 through the housing outlet port 34. The differential pressure plugging agent is activated and solidified at the leakage point under the action of the differential pressure to achieve the purpose of plugging. Observe and record the data of the pressure sensor 26 and the pressure sensor 29 in the post-treatment device 18. When the data of the pressure sensor 26 hardly changes anymore, it is regarded as the completion of plugging. Then turn off all instruments and valves.

[0063] f). Evaluate the plugging effect. According to the measured pressure results, draw the pressure-time change curve. At the same time, turn off the precision injection pump 1 and the high-frequency intelligent atomizer 2, open the pressure reducing valve 6, open the intake valve 7 of the pressure pump and the outlet valve 9 of the pressure pump, gradually increase the gas pressure through the pressure pump 8, open the thread intake port 28 and the housing outlet port 34, close the thread outlet port 33 and the housing intake port 27, introduce the pressurized nitrogen into the thread model 17, observe the pressure sensor 26 and the post-treatment device 18. When the pressure of the pressure sensor 26 changes significantly or gas appears in the post-treatment device 18, it is regarded as the plugging at the thread being washed out. The intake pressure at this time is regarded as the maximum pressure that the differential pressure plugging agent can withstand under this condition.

[0064] As mentioned above, it is only the preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered within the protection scope of the present invention.

Claims

1. An evaluation system for a gas-phase carrier differential pressure plugging agent based on ultrasonic atomization, characterized in that Including: Precision injection pump (1), high-frequency intelligent atomizer (2), atomization cavity (3), visible cavity (4), nitrogen cylinder (5), pressure reducing valve (6), pressure pump inlet valve (7), pressure pump (8), pressure pump outlet valve (9), gripper inlet valve (10), gripper (11), ring pressure pump valve (12), ring pressure pump (13), back pressure pump valve (14), back pressure pump (15), screw thread model inlet valve (16), screw thread model (17), post-treatment device (18); The precision injection pump (1) of the leak plugging agent evaluation system is connected to the atomization cavity (3) through an infusion pipeline for transmitting differential pressure leak plugging agent solution; the high-frequency intelligent atomizer (2) is connected to the atomization cavity (3) through a wire for ultrasonic electrical signal transmission; the nitrogen cylinder (5) is connected to the atomization cavity (3) through a pipeline, and a pressure reducing valve (6) is provided on its pipeline for controlling the inlet pressure; the atomization cavity (3) is connected to the visible cavity (4) through an atomization nozzle (24); the visible cavity (4) is connected to the pressure pump (8) through a pipeline, and a pressure pump inlet valve (7) is provided on the pipeline; the pressure pump (8) is connected to the gripper (11) and the screw thread model (17) through a pipeline, and a pressure pump outlet valve (9), a gripper inlet valve (10), a screw thread model inlet valve (16) or a similar tee structure are provided on the pipeline; the ring pressure pump (13) is connected to the gripper (11) through a pipeline, and a ring pressure pump valve (12) is provided on the pipeline; the gripper (11) is connected to the back pressure pump (15) and the post-treatment device (18) through a pipeline and a back pressure pump valve (14) or a similar tee structure; the outlet of the screw thread model is connected to the post-treatment device through a pipeline.

2. The evaluation system for the differential pressure plugging agent of the gas phase carrier based on ultrasonic atomization according to claim 1, wherein, The atomization cavity (3) includes an ultrasonic electrical signal receiver (19), a leak plugging agent inlet (20), a vibration element (21), a plug (22), an adjusting nut (23), an atomization nozzle (24), a nitrogen inlet (25). The atomization cavity (3) is connected to the visible cavity (4) through the atomization nozzle (24), and the connection method is a threaded seal connection; the visible cavity (4) is made of quartz material; the ultrasonic electrical signal receiver (19) and the leak plugging agent inlet (20) are arranged above the vibration element (21), the plug (22) and the nitrogen inlet (25) are arranged on the side of the vibration element (21), and the adjusting nut (23) is arranged below the vibration element (21).

3. The evaluation system for the gas-phase carrier differential pressure plugging agent based on ultrasonic atomization according to claim 1, wherein The screw thread model (17) includes a pressure sensor A (26), a housing air inlet (27), a screw thread air inlet (28), a pressure sensor B (29), a fixing bolt (30), a screw thread (31), a housing (32), a screw thread air outlet (33), a housing air outlet (34), a bracket (35), and a fixing bolt (36). Among them, the pressure sensor A (26) is arranged on the inner wall of the housing (32) to detect the pressure change inside the housing; the pressure sensor B (29) is connected to the screw thread air inlet (28) to detect the pressure inside the screw thread; the screw thread air inlet (28) is connected to the screw thread (31) through a pipeline; the screw thread (31) is divided into upper and lower kettle bodies, and the two kettle bodies are connected by threads; the screw thread (31) is fixed in the housing (32); the housing (32) is provided with a screw thread air outlet (33) and a housing air outlet (34) at the lower part; the housing (32) is supported by the bracket (35), and the two are fixed by the fixing bolt (36); the housing air inlet (27) and the fixing bolt (30) are arranged above the screw thread model (17).

4. The evaluation system for the gas-phase carrier differential pressure plugging agent based on ultrasonic atomization according to claim 1, wherein Seal and waterproof the connection lines and pipelines of each device.

5. An application method of an evaluation system for a gas-phase carrier differential pressure plugging agent based on ultrasonic atomization, characterized in that, Use any of the systems in claims 1-4 to conduct a crack plugging experiment and a screw thread model plugging experiment to simulate the plugging effect of the differential pressure plugging agent in the underground wellbore and screw thread, and evaluate its effect.

6. The application method of the gas-phase carrier differential pressure plugging agent evaluation system based on ultrasonic atomization according to claim 5, characterized in that, Atomize the differential pressure plugging agent into tiny particles by ultrasonic atomization, transport it to the leakage point with the gas-phase carrier, activate the plugging agent by the pressure difference at the leakage point, and solidify it at the leakage point to achieve plugging, and evaluate the performance of the differential pressure plugging agent through this system.

7. The application method of the gas-phase carrier differential pressure plugging agent evaluation system based on ultrasonic atomization according to claim 5, characterized in that, When conducting the crack model plugging experiment, the following steps are executed: S1. Ensure that all valves in the device are closed, install the crack model in the clamp, and check the airtightness of the device. S2. Open the precision injection pump (1), pump the configured differential pressure plugging agent into the atomization cavity (3). At the same time, open the pressure reducing valve (6), introduce nitrogen into the atomization cavity (3), control the pressure of the injected nitrogen through the pressure reducing valve (6), and at the same time open the high-frequency intelligent atomizer (2) to generate ultrasonic signals to vibrate the vibration element (21), and spray the gas into the visible cavity (4) through the atomization nozzle (24) to achieve the atomization process, and the visible cavity (4) evaluates the atomization effect. S3. Open the intake valve (7) of the pressure pump, introduce the atomized gas into the pressure pump (8) for pressurization, raise the pressure to the specified pressure, open the outlet valve (9) of the pressure pump, and introduce the pressurized gas-phase carrier into the clamp (11). S4. Leak plugging: Open the annular pressure pump valve (12) and the back pressure pump valve (14), set the magnitudes of the annular pressure and the back pressure, keep the thread model intake valve (16) closed, open the gripper intake valve (10), introduce the pressurized gas carrier into the gripper (11). The annular pressure should be higher than the intake pressure, which is to prevent the gas from flowing through the gap between the fracture model and the gripper. When the introduced gas pressure is higher than the back pressure, the gas will pass through the fracture model in the gripper (11) and enter the post-treatment device (18). Meanwhile, under the action of the pressure difference, the pressure difference plugging agent is activated and solidified at the fracture to achieve the purpose of leak plugging. Observe in the post-treatment device (18). When no gas appears in the post-treatment device anymore, it is regarded that the leak plugging is completed. Then close all instruments and valves; S5. Evaluate the leak plugging effect. Keep the precision injection pump (1) and the high-frequency intelligent atomizer (2) closed. Open the pressure reducing valve (6) and introduce nitrogen into the pipeline. Open the pressurizing pump intake valve (7) and the pressurizing pump outlet valve (9). Gradually increase the gas pressure through the pressurizing pump (8). Open the annular pressure pump valve (12) and the back pressure pump valve (14), set the magnitudes of the annular pressure and the back pressure, keep the thread model intake valve (16) closed, open the gripper intake valve (10), introduce the pressurized nitrogen into the gripper (11). The annular pressure should be higher than the intake pressure, which is to prevent the gas from flowing through the gap between the fracture model and the gripper. Make the introduced gas pressure higher than the back pressure. Observe the post-treatment device (18). If gas appears in the post-treatment device (18), it is regarded that the fracture plugging is washed out. At this time, the intake pressure is regarded as the maximum pressure that the pressure difference plugging agent can withstand under this condition, and the leak plugging effect is evaluated accordingly.

8. The application method of the gas-phase carrier differential pressure plugging agent evaluation system based on ultrasonic atomization according to claim 5, characterized in that When conducting the thread model leak plugging experiment, the following steps are carried out: T1. Ensure that all valves in the device are closed, install the fracture model in the gripper, and check the airtightness of the device; T2. Keep the precision injection pump (1) and the high-frequency intelligent atomizer (2) closed. Open the pressure reducing valve (6) and introduce nitrogen into the system. Open the pressurizing pump intake valve (7) and the pressurizing pump outlet valve (9). Increase the gas pressure to the specified value through the pressurizing pump (8). Close the gripper intake valve (10), adjust the tightness of the upper and lower bodies of the thread (31) to simulate thread leakage, open the thread model intake valve (16), record the data of the pressure sensor (26) and the pressure sensor (29) in the thread device at this time, and then close the thread model intake valve (16); T3. Open the precision injection pump (1) and pump the configured pressure difference plugging agent into the atomization cavity (3). Meanwhile, open the pressure reducing valve (6) and introduce nitrogen into the atomization cavity (3). Control the pressure of the injected nitrogen through the pressure reducing valve (6). At the same time, open the high-frequency intelligent atomizer (2) to generate ultrasonic signals to vibrate the vibration element (21), and spray the gas into the visual cavity (4) through the atomization nozzle (24) to achieve the atomization process. The visual cavity (04) can evaluate the atomization effect; T4. Open the intake valve (7) of the pressure pump, introduce the atomized gas into the pressure pump (8) for pressurization, raise the pressure to the specified pressure, open the outlet valve (9) of the pressure pump, and introduce the pressurized gas carrier into the threaded model (17). T5. Leak plugging: Keep the tightness of the thread (31) unchanged, close the intake valve (10) of the gripper, open the intake valve (16) of the threaded model, block the housing intake port (27) and the thread outlet (33), introduce the pressurized gas carrier into the threaded model (17). The gas will enter the housing (32) through the leakage point and enter the post-treatment device (18) through the housing outlet (34). The differential pressure plugging agent is activated and solidified at the leakage point under the action of the differential pressure to achieve the purpose of leak plugging. Observe in the post-treatment device (18) and record the data of the pressure sensor (26) and the pressure sensor (29). When the data of the pressure sensor (26) no longer changes, it is regarded as the completion of leak plugging. Then close all instruments and valves. T6. Conduct an evaluation of the leak plugging effect. According to the measured pressure results, plot the pressure-time change curve. At the same time, close the precision injection pump (1) and the high-frequency intelligent atomizer (2), open the pressure reducing valve (6), open the intake valve (7) and the outlet valve (9) of the pressure pump. Gradually increase the gas pressure through the pressure pump (8), open the thread intake port (28) and the housing outlet (34), close the thread outlet (33) and the housing intake port (27), introduce the pressurized nitrogen into the threaded model (17), and observe the pressure sensor (26) and the post-treatment device (18). When the pressure of the pressure sensor (26) changes significantly or gas appears in the post-treatment device (18), it is regarded as the threaded plugging point being washed open. The intake pressure at this time is regarded as the maximum pressure that the differential pressure plugging agent can withstand under this condition, so as to evaluate the leak plugging effect; or close the thread intake port (28) and the housing outlet (34), open the thread outlet (33) and the housing intake port (27), and use the same test method to test the negative pressure to evaluate the leak plugging effect.

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