Annular protection liquid displacement ground simulation device for high-pressure oil-water environment in shaft

Abstract

The invention relates to the technical field of oil-gas field development, in particular to an annulus protection fluid displacement ground simulation device for a high-pressure oil-water environment in a shaft, which comprises a high-pressure container system for simulating a high-pressure sealing environment of an underground annulus and providing pressure for a displacement process; the fluid control system is used for injecting annulus protection fluid into the high-pressure container system, controlling the flow and the pressure of the high-pressure container system and receiving displaced fluid at the same time; the visual system is used for observing and recording the displacement process in the high-pressure container system in real time; the fixing system is used for supporting and fixing the high-pressure container system, the fluid control system and the visual system; the underground complex working condition can be accurately reproduced in a ground laboratory environment, technicians are helped to quantitatively evaluate the actual effect of the annulus protection fluid in a real shaft environment, and real-time visual monitoring of behaviors such as fluid interface change, the flowing state and sediment migration in the displacement process can be achieved.

Description

Technical Field

[0001] This invention relates to the field of oil and gas field development technology, and in particular to a device for simulating the displacement of the surface by annular protective fluid in a high-pressure oil-water environment inside a wellbore. Background Technology

[0002] In oil and gas field development, annular protective fluids are widely used to isolate different fluid systems within the annulus, prevent corrosion of tubing and casing, suppress annular cross-flow, and maintain the integrity of the wellbore structure. This is crucial for ensuring the long-term safe and stable operation of oil and gas wells. Under high downhole pressure conditions, the annular protective fluid displaces and replaces existing fluids such as oil and water. Its displacement efficiency, flow stability, rheological properties, and compatibility with downhole fluids directly affect the annular sealing effect and the service life of the oil and gas well.

[0003] Due to the elongated and confined internal structure of the wellbore annulus, and its typically complex operating conditions involving high pressure and multiphase flow, the displacement behavior of annulus protective fluid in actual downhole environments exhibits significant dynamic and nonlinear characteristics. Therefore, constructing an experimental setup on the surface capable of simulating the high-pressure oil-water environment of the wellbore annulus is of significant engineering and application value for systematically studying the displacement process, performance evaluation, and formulation optimization of annulus protective fluid.

[0004] Currently, some experimental devices for simulating downhole conditions have been developed both domestically and internationally, such as high-pressure reaction vessels and fluid displacement experimental systems. However, existing devices mostly focus on single fluid property testing or core displacement experiments, making it difficult to realistically reflect the dynamic displacement process between the annular protective fluid and multiphase fluids such as oil and water within the wellbore annulus. In particular, there are still significant shortcomings in simulating flow behavior under high-pressure conditions, mainly in the following aspects:

[0005] The ability to stably construct high-pressure displacement conditions is insufficient. Existing experimental devices mainly rely on static pressure resistance or simple loading under high-pressure conditions, making it difficult to achieve stable pressure maintenance and precise control during displacement. This results in significant pressure fluctuations during experiments, making it impossible to realistically simulate the pressure change characteristics generated in the wellbore annulus as displacement progresses. Consequently, it affects the accurate assessment of the annulus protection fluid displacement efficiency and interface propagation law.

[0006] Simulation capabilities for multiphase flow displacement processes are limited. The wellbore annulus typically contains multiple fluids simultaneously, including oil, water, and annular protective fluid, with complex interfacial evolution and interactions among these fluids. However, existing devices are mostly designed for single-phase or simple two-phase fluids, lacking the ability to coordinate the control of fluid proportions, flow sequence, and interfacial morphology in multiphase flow systems, making it difficult to reproduce the actual dynamic displacement conditions of multiphase fluids within a real wellbore annulus.

[0007] The displacement process lacks intuitive and effective visualization and monitoring methods. Most existing devices adopt a closed structure, and the analysis during the experiment mainly relies on indirect parameters such as pressure and flow rate. It is difficult to directly observe the distribution of different fluids in the annulus, the interfacial propagation process, and unstable flow phenomena, thus limiting in-depth research on the displacement mechanism of the annulus protective fluid and key influencing factors.

[0008] Insufficient precision in flow and pressure regulation leads to poor repeatability of experimental conditions. In annular displacement experiments, precise control of fluid flow and pressure is a key factor in ensuring the reliability of experimental results. However, existing devices have limited precision in fluid delivery and regulation, making it difficult to accurately simulate annular flow states under different well conditions, thus affecting the comparability and repeatability of experimental data.

[0009] The sealing reliability and operational safety under high pressure conditions need to be improved. During high-pressure displacement experiments, the reliability of the device's sealing structure directly affects experimental safety and data validity. Some existing devices exhibit sealing failure, leakage, or overpressure risks during high-pressure operation and lack robust fixing and protection structures, hindering the development of long-term, stable displacement experiments.

[0010] Therefore, there is an urgent need to develop an annular fluid displacement experimental device that can accurately simulate the high-pressure oil and water environment inside the wellbore under ground conditions, in order to fill the research gap in this field and provide reliable technical support for the performance evaluation, formulation optimization and field application of annular fluids. Summary of the Invention

[0011] This invention aims to address the problems existing in the prior art by providing a surface simulation device for annular protective fluid displacement in high-pressure oil-water environments within wellbores. This device can accurately reproduce complex downhole conditions in a surface laboratory environment. By preparing standardized experimental samples and environments, and combining real-time monitoring of multiple parameters such as pressure and flow rate, it can systematically acquire key performance data such as displacement efficiency, rheology, and compatibility of the annular protective fluid. This helps technicians quantitatively evaluate the actual effect of the annular protective fluid in real wellbore environments. Furthermore, it integrates advanced observation equipment such as downhole television, pipeline endoscopes, and supplemental lighting systems, enabling real-time visual monitoring of fluid interface changes, flow states, and sediment migration during the displacement process. This provides an effective research platform for further revealing the multiphase flow mechanism and annular protective fluid behavior under high-pressure oil-water environments, contributing to the optimization and development of wellbore integrity management and annular protective fluid technology in oil and gas fields.

[0012] The present invention adopts the following technical solution:

[0013] A surface simulation device for annular protective fluid displacement in a high-pressure oil-water environment inside a wellbore includes a high-pressure container system for simulating the high-pressure sealed environment of the downhole annulus and providing pressure for the displacement process; a fluid control system for injecting annular protective fluid into the high-pressure container system and controlling its flow rate and pressure, while simultaneously receiving the displaced fluid; a vision system for real-time observation and recording of the displacement process inside the high-pressure container system; and a fixing system for supporting and fixing the high-pressure container system, the fluid control system, and the vision system.

[0014] Preferably, the high-pressure vessel system includes a high-pressure vessel body that is vertically arranged and has flanges at both the top and bottom. An upper end cover and a lower end cover are respectively installed and fixed at the top and bottom of the high-pressure vessel body through the flanges. An upper pressure sensor is provided on the upper part of the side of the high-pressure vessel body, and a lower pressure sensor is provided on the lower part of the side of the high-pressure vessel body. Both the upper pressure sensor and the lower pressure sensor are used to read the pressure inside the high-pressure vessel body in real time during the displacement process. A drain is provided at the lower end of the high-pressure vessel body for draining the waste liquid generated by the displacement.

[0015] Preferably, the high-pressure vessel body has a front viewing window on its side for observing the displacement process.

[0016] Preferably, a plurality of anchor bolts are fixed on the flange at the lower end of the high-pressure vessel body for fixing the high-pressure vessel body to the fixing system and for leveling.

[0017] Preferably, the fluid control system includes a high-pressure tank and a waste liquid tank. The high-pressure tank is connected to the main body of the high-pressure container through a high-pressure pipeline to provide annular fluid for the displacement process. The waste liquid tank is connected to a drainer through a high-pressure pipeline. A needle valve is provided between the waste liquid tank and the drainer for fine-tuning the annular fluid flow rate.

[0018] Preferably, the high-pressure pipeline between the waste liquid tank and the diverter is also equipped with a lower outlet flow meter and a lower electrically controlled shut-off valve.

[0019] Preferably, the waste liquid tank is also connected to the upper outlet located in the middle of the side of the high-pressure container body via a high-pressure pipeline. The high-pressure pipeline is equipped with an upper outlet flow meter, an upper electrically controlled shut-off valve, and an upper needle valve.

[0020] Preferably, the high-pressure vessel body is provided with an inlet check valve, which is connected to the high-pressure tank through a high-pressure pipeline, and the high-pressure pipeline is provided with an inlet flow meter.

[0021] Preferably, the vision system includes a pipe endoscope camera and a downhole television camera. The pipe endoscope camera is positioned above and observes the displacement process through an upper viewing window on the upper end cover. The downhole television camera is installed inside the high-pressure vessel body for real-time imaging of the displacement process.

[0022] Preferably, the vision system further includes a supplementary flashlight for supplemental lighting and a supplementary lighting enhancement device for enhancing supplemental lighting, both of which are mounted on the upper end cover.

[0023] Compared with the prior art, the present invention has at least the following beneficial effects:

[0024] 1. This invention integrates a multi-dimensional monitoring system consisting of a downhole television, a pipeline endoscope, a supplementary lighting device, and a pressure / flow sensor. It enables real-time, multi-angle imaging of the displacement process inside a high-pressure vessel, and simultaneously records key parameters such as pressure and flow rate. This overcomes the limitations of existing technologies that rely on single observation methods and cannot directly capture dynamic changes in the fluid interface, providing comprehensive and reliable data support for in-depth analysis of the displacement mechanism and efficiency of annular protective fluids.

[0025] 2. By employing a fluid control system comprised of upper and lower electrically controlled shut-off valves, needle valves, check valves, and multiple high-precision flow meters, this invention can precisely regulate the injection and discharge flow rate and pressure of annular fluid, flexibly simulating various high-pressure displacement conditions at different depths and under different production conditions within the wellbore. This refined control capability effectively solves the problems of existing devices having limited simulation capabilities and insufficient control precision, making experimental data closer to actual field conditions and providing more instructive evaluation results. Attached Figure Description

[0026] Figure 1 Isometric side view of a surface simulation device for annular protective fluid displacement in a high-pressure oil-water environment within a wellbore. Figure 1 ;

[0027] Figure 2 A front view of a simulation device for annular protective fluid displacement of the surface in a high-pressure oil-water environment inside a wellbore;

[0028] Figure 3 A top view of a surface simulation device for annular protective fluid displacement in a high-pressure oil-water environment inside a wellbore;

[0029] Figure 4 This is an exploded view of a high-pressure vessel system.

[0030] Figure 5 This is a schematic diagram illustrating the fluid control system.

[0031] Figure 6 This is a schematic diagram of the structure of a vision system;

[0032] Figure 7 This is a schematic diagram of the supplementary lighting device;

[0033] Figure 8 Isometric view of a surface simulation device for annular protective fluid displacement in a high-pressure oil-water environment within a wellbore. Figure 2 .

[0034] In the picture:

[0035] High-pressure vessel system 1; Upper end cover 1.1; Upper viewing window gasket 1.2; Upper viewing window 1.3; Upper viewing window sealing ring 1.4; Viewing window seat 1.5; Upper sealing ring 1.6; Upper pressure sensor 1.7; High-pressure vessel body 1.8; Lower pressure sensor 1.9; Front viewing window end cover 1.10; Front viewing window silicone gasket 1.11; Front viewing window 1.12; Front viewing window end cover sealing ring 1.13; Drainage device 1.14; Lower end cover sealing ring 1.15; Lower end cover 1.16; Anchor bolts 1.17;

[0036] 2. Fluid control system; 2.1. High pressure tank; 2.2. Inlet flow meter; 2.3. Inlet check valve; 2.4. Upper outlet flow meter; 2.5. Lower outlet flow meter; 2.6. Upper solenoid shut-off valve; 2.7. Lower solenoid shut-off valve; 2.8. Lower needle valve; 2.9. Upper needle valve; 2.10. Waste liquid tank;

[0037] 3. Vision system; 3.1 Supplemental lighting flashlight; 3.2 Supplemental lighting enhancement device; 3.2.1 Fresnel lens; 3.2.2 Upper bracket; 3.2.3 Lower bracket; 3.2.4 Middle bracket; 3.3 Pipe endoscope; 3.4 Downhole television alignment device; 3.5 Downhole television; 3.6 Downhole television bracket; 3.7 Computer;

[0038] Fixed system 4; High pressure vessel system bracket 4.1; Flow meter bracket 4.2; Electrically controlled shut-off valve bracket 4.3; Integrated bracket 4.4; Detailed Implementation

[0039] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0040] Participate in the attached Figure 1-3 The present invention provides a simulation device for annular protective fluid displacement of the surface in a high-pressure oil-water environment inside a wellbore, comprising a high-pressure container system 1, a fluid control system 2, a vision system 3, and a fixing system 4.

[0041] The high-pressure vessel system 1 is shown in the appendix. Figure 4 It includes an upper end cap 1.1, an upper viewing window gasket 1.2, an upper viewing window 1.3, an upper viewing window sealing ring 1.4, a viewing window seat 1.5, an upper end cap sealing ring 1.6, an upper pressure sensor 1.7, a high-pressure vessel body 1.8, a lower pressure sensor 1.9, a front viewing window end cap 1.10, a front viewing window silicone gasket 1.11, a front viewing window 1.12, a front viewing window end cap sealing ring 1.13, a drain 1.14, a lower end cap sealing ring 1.15, a lower end cap 1.16, and an anchor bolt 1.17.

[0042] The upper end cover 1.1 is connected to the high-pressure container body 1.8 by bolts and is used to fix the lower support of the supplementary lighting device.

[0043] The upper viewing window gasket 1.2 is installed between the upper viewing window 1.3 and the upper cover 1.1 to protect the upper viewing window 1.3.

[0044] The upper window sealing ring 1.4 is installed in the sealing groove of the window seat 1.5 for sealing the high-pressure vessel system.

[0045] The viewing window seat 1.5 is installed in the groove of the upper end cover 1.1 to fix the upper viewing window 1.3.

[0046] The upper end cover sealing ring 1.6 is located between the upper end cover 1.1 and the high pressure vessel body 1.8, and is installed in the groove of the upper flange face of the high pressure vessel body 1.8 for sealing the high pressure vessel system.

[0047] The upper pressure sensor 1.7 is threadedly connected to the high-pressure vessel body 1.8 and is used to read the pressure inside the high-pressure vessel body in real time during the displacement process.

[0048] The high-pressure vessel body 1.8 is welded from upper and lower flanges and a middle body. The upper flange is bolted to the upper cover 1.1, and a sealing groove is provided on the upper flange surface for installing the upper cover sealing ring. The lower flange is bolted to the lower cover 1.16, and a sealing groove is provided on the flange surface for installing the lower cover sealing ring 1.15. It is connected to the anchor bolt 1.17 by threads. The outer wall of the middle body is provided with multiple threaded connection ports for installing functional components.

[0049] The pressure sensor 1.9 is threadedly connected to the high-pressure vessel body 4.8 and is used to read the pressure inside the high-pressure vessel body in real time during the displacement process.

[0050] The front end cap 1.10 is bolted to the front end of the high-pressure vessel body 1.8 to fix the front end cap 1.12. The front end cap 1.12 is installed between the front end cap 1.10 and the high-pressure vessel body 1.8 for observing the displacement process. The front end cap silicone gasket 1.11 is installed between the front end cap 1.10 and the front end cap 1.12 for sealing and protecting the front end cap 1.12. The front end cap sealing ring 1.13 is installed in the sealing groove of the front end cap 1.10 for sealing the high-pressure vessel body 1.8.

[0051] The drainer 1.14 is connected to the lower end of the high-pressure vessel body 1.8 via a thread and is used to drain and displace the generated waste liquid.

[0052] The lower end cover sealing ring 1.15 is installed in the sealing groove of the lower end cover 1.16 for sealing; the lower end cover 1.16 is connected to the lower end of the high pressure vessel body 1.8 by bolts.

[0053] The anchor bolt 1.17 is connected to the lower flange of the high-pressure vessel body 1.8 by bolts, fixing the high-pressure vessel body 1.8 to the high-pressure vessel system support 4.1, and has the function of leveling and fixing the high-pressure vessel body.

[0054] The fluid control system 2 includes a high-pressure tank 2.1, an inlet flow meter 2.2, an inlet check valve 2.3, an upper outlet flow meter 2.4, a lower outlet flow meter 2.5, an upper electrically controlled shut-off valve 2.6, a lower electrically controlled shut-off valve 2.7, a lower needle valve 2.8, an upper needle valve 2.9, and a waste liquid tank 2.10.

[0055] The high-pressure tank 2.1 is connected to the high-pressure container body 1.8 via a high-pressure pipeline, providing annular fluid for the displacement process.

[0056] The inlet flow meter 2.2 is mounted on the flow meter bracket 4.2 and connected to the high-pressure pipe, high-pressure tank 2.1, and inlet check valve 2.3 for real-time monitoring of the flow rate of the annular fluid.

[0057] The inlet check valve 2.3 is connected to the high-pressure vessel body 1.8 via a thread to prevent the backflow of the annular fluid inside the high-pressure vessel body.

[0058] The upper outlet flow meter 2.4 is installed on the flow meter bracket 4.2 and connected to the upper outlet of the high-pressure vessel body 1.8 through a high-pressure pipeline, and is used to monitor the flow rate at the upper outlet in real time.

[0059] The upper electrically controlled shut-off valve 2.6 is mounted on the electrically controlled shut-off valve bracket 4.3 and connected to the upper outlet flow meter 2.4 via a high-pressure pipeline to prevent the waste liquid from flowing back from the upper outlet.

[0060] The lower needle valve 2.8 is connected to the upper electrically controlled shut-off valve 2.6 and the waste liquid tank 2.10 via a high-pressure pipeline and is used to fine-tune the flow rate of the annular fluid.

[0061] The lower outlet flow meter 2.5 is mounted on the flow meter bracket 4.2 and connected to the flow meter 1.14 via a high-pressure pipe, and is used to monitor the flow rate at the lower outlet in real time.

[0062] The lower electrically controlled shut-off valve 2.7 is mounted on the electrically controlled shut-off valve bracket 4.3 and is connected to the lower outlet flow meter 2.5 via a high-pressure pipeline to prevent the waste liquid from flowing back from the lower outlet.

[0063] The lower needle valve 2.8 is connected to the lower electrically controlled shut-off valve 2.7 and the waste liquid tank 2.10 via a high-pressure pipeline and is used to fine-tune the flow rate of the annular fluid.

[0064] The waste liquid tank 2.10 is installed on the integrated bracket 4.5 and is used to recover the waste liquid generated during the displacement process.

[0065] The vision system 3 is shown in the appendix. Figure 6 and attached Figure 7 It includes a supplementary flashlight 3.1, a supplementary light enhancement device 3.2, a pipeline endoscope camera 3.3, a downhole television alignment device 3.4, a downhole television 3.5, a downhole television bracket 3.6, and a computer 3.7. Among them, the supplementary light enhancement device 3.2 includes a Fresnel lens 3.2.1, an upper bracket 3.2.2, a lower bracket 3.2.3, and a middle bracket 3.2.4.

[0066] The supplementary flashlight 3.1 is mounted on the upper bracket 3.2.2 and is used for supplementary lighting of the vision system 3.

[0067] The supplementary lighting enhancement device 3.2 is installed in the groove of the upper end cover 1.1 to enhance supplementary lighting. The Fresnel lens 3.2.1 is installed on the middle bracket to focus light and enhance supplementary lighting; the lower bracket 3.2.3 is installed in the groove of the upper end cover 1.1 to fix the supplementary lighting enhancement device 3.2.

[0068] The endoscopic camera 3.3 is installed inside the supplementary lighting enhancement device and is used to observe the displacement process.

[0069] The downhole television device 3.5 is installed inside the high-pressure vessel body 1.8 and is used for real-time imaging of the displacement process.

[0070] The downhole television straightener 3.4 is used to fix the downhole television 3.5; the downhole television bracket 3.6 is installed at the bottom of the high-pressure vessel body 1.8 and is used to fix the downhole television 3.5.

[0071] The computer 3.7 is used to store and display the pressure read in real time by the pressure sensor, the flow rate of the flow meter, the electronically controlled shut-off valve, and the video from the downhole television and pipeline endoscope camera.

[0072] The fixed system 4 is shown in the appendix. Figure 8 This includes high-pressure vessel system bracket 4.1, flow meter bracket 4.2, electrically controlled shut-off valve bracket 4.3, computer bracket 4.4, and integrated bracket 4.5.

[0073] The high-pressure system bracket 4.1 is used to fix the high-pressure vessel system 1.

[0074] The flow meter bracket 4.2 is used to fix the flow meter.

[0075] The electrically controlled shut-off valve bracket 4.3 is used to fix the electrically controlled shut-off valve.

[0076] The computer stand 4.4 is used to place the computer 3.5.

[0077] The integrated bracket 4.5 is used to fix the high-pressure vessel system bracket 4.1, the flow meter bracket 4.2, and the electrically controlled shut-off valve bracket 4.3.

[0078] The steps for using this invention are as follows:

[0079] I. Equipment Assembly Stage

[0080] Secure the high-pressure vessel system bracket 4.1, flow meter bracket 4.2, and electrically controlled shut-off valve bracket 4.3 together via the integrated bracket 4.5. Install the high-pressure vessel body 1.8 onto the high-pressure vessel system bracket 4.1 using anchor bolts 1.17 and level it. Install the upper end cover 1.1 and lower end cover 1.16, ensuring the upper end cover sealing ring 1.6 and lower end cover sealing ring 1.15 are located within the sealing groove; install the upper pressure sensor 1.7 and lower pressure sensor 1.9, and install the flow guide 1.14; connect the fluid control system piping, and sequentially install the inlet flow meter 2.2, inlet check valve 2.3, upper outlet flow meter 2.4, and lower outlet flow meter 2.5. Install the upper electrically controlled shut-off valve 2.6 and lower electrically controlled shut-off valve 2.7 onto the electrically controlled shut-off valve bracket 4.3. Place the computer 3.7 on the computer bracket 4.4 and connect all sensors, valves, and vision equipment.

[0081] II. Experimental Preparation Stage

[0082] Determine the required environmental parameters for simulation based on actual working conditions, such as pressure and flow rate; check whether the fluid storage in the high-pressure tank 2.1 has been reorganized, and ensure that the high-pressure tank is tightly connected to the high-pressure pipeline; ensure that all valves are closed and check the sealing performance of the sealing parts; turn on the computer 3.7 and data acquisition system, and check whether the pressure sensors (upper pressure sensor 1.7, lower pressure sensor 1.9), flow meters (inlet flow meter 2.2, upper outlet flow meter 2.4, lower outlet flow meter 2.5), downhole television 3.5 and pipeline endoscope 3.3 are working properly.

[0083] III. Displacement Simulation Process

[0084] Slowly open the outlet valve of the high-pressure tank 2.1 to allow fluid to enter the system; monitor the inlet flow rate using the inlet flow meter 2.2 and adjust the high-pressure tank pressure to the set value; observe the values ​​of the upper pressure sensor 1.7 and the lower pressure sensor 1.9 to ensure the container pressure meets the experimental requirements; observe the displacement process in real time using the downhole television 3.5 and the pipeline endoscope 3.3, recording the fluid flow state and interface changes; monitor the data from the upper outlet flow meter 2.4 and the lower outlet flow meter 2.5, and use the upper solenoid shut-off valve 2.6 and the lower solenoid shut-off valve 2.7 to prevent fluid backflow. Continuously collect and save pressure, flow rate, and video data until the displacement process is complete.

[0085] IV. Post-processing

[0086] Close the outlet valve of high-pressure tank 2.1 to stop fluid injection; perform a pressure relief operation on high-pressure vessel system 1 to ensure that the internal pressure of the high-pressure vessel body is zero. Analyze the experimental data and video materials stored on the computer.

[0087] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A device for simulating surface displacement of annular protective fluid in a high-pressure oil-water environment within a wellbore, characterized in that: It includes a high-pressure vessel system (1) for simulating the high-pressure sealing environment of the downhole annulus and providing pressure for the displacement process; a fluid control system (2) for injecting annulus protection fluid into the high-pressure vessel system and controlling its flow and pressure, while receiving the displaced fluid; a vision system (3) for real-time observation and recording of the displacement process inside the high-pressure vessel system; and a fixing system (4) for supporting and fixing the high-pressure vessel system (1), the fluid control system (2) and the vision system (3).

2. The annular protective fluid displacement ground simulation device according to claim 1, characterized in that: The high-pressure vessel system (1) includes a high-pressure vessel body (1.8) that is vertically arranged and has flanges at both the top and bottom. The upper end cover (1.1) and the lower end cover (1.16) of the high-pressure vessel body (1.8) are respectively fixed by flanges at the top and bottom. An upper pressure sensor (1.7) is provided on the upper side of the high-pressure vessel body (1.8), and a lower pressure sensor (1.9) is provided on the lower side of the high-pressure vessel body (1.8). Both the upper pressure sensor (1.7) and the lower pressure sensor (1.9) are used to read the pressure inside the high-pressure vessel body (1.8) in real time during the displacement process. A drainer (1.14) is provided at the lower end of the high-pressure vessel body (1.8) for draining the waste liquid generated by the displacement.

3. The annular protective fluid displacement ground simulation device according to claim 2, characterized in that: The high-pressure vessel body (1.8) has a front viewing window (1.12) on its side for observing the displacement process.

4. The annular protective fluid displacement ground simulation device according to claim 2, characterized in that: Multiple anchor bolts (1.17) are fixed on the flange at the lower end of the high-pressure vessel body (1.8) to fix the high-pressure vessel body (1.8) to the fixing system (4) and level it.

5. The annular protective fluid displacement ground simulation device according to claim 1, characterized in that: The fluid control system (2) includes a high-pressure tank (2.1) and a waste liquid tank (2.10). The high-pressure tank (2.1) is connected to the high-pressure vessel body (1.8) through a high-pressure pipeline to provide annular fluid for the displacement process. The waste liquid tank (2.10) is connected to a flow guide (1.14) through a high-pressure pipeline. A needle valve (2.8) is provided between the waste liquid tank (2.10) and the flow guide (1.14) for fine-tuning the annular fluid flow rate.

6. The annular protective fluid displacement ground simulation device according to claim 1, characterized in that: The high-pressure pipeline between the waste liquid tank (2.10) and the diverter (1.14) is also equipped with a lower outlet flow meter (2.5) and a lower electrically controlled shut-off valve (2.7).

7. The annular protective fluid displacement ground simulation device according to claim 5, characterized in that: The waste liquid tank (2.10) is also connected to the upper outlet located in the middle of the side of the high pressure vessel body (1.8) via a high pressure pipeline. The high pressure pipeline is equipped with an upper outlet flow meter (2.4), an upper electrically controlled shut-off valve (2.6), and an upper needle valve (2.9).

8. The annular protective fluid displacement ground simulation device according to claim 5, characterized in that: The high-pressure vessel body (1.8) is provided with an inlet check valve (2.3), which is connected to the high-pressure tank (2.1) through a high-pressure pipeline, and the high-pressure pipeline is provided with an inlet flow meter (2.2).

9. The annular protective fluid displacement ground simulation device according to claim 1, characterized in that: The vision system (3) includes a pipe endoscope (3.3) and a downhole television (3.5). The pipe endoscope (3.3) is located on top and observes the displacement process through the upper viewing window (1.3) on the upper end cover (1.1). The downhole television (3.5) is installed inside the high-pressure vessel body (1.8) for real-time imaging of the displacement process.

10. The annular protective fluid displacement ground simulation device according to claim 9, characterized in that: The vision system (3) also includes a supplementary light flashlight (3.1) for supplementary lighting and a supplementary light enhancement device (3.2) for enhancing supplementary lighting. Both the supplementary light flashlight (3.1) and the supplementary light enhancement device (3.2) are mounted on the upper end cover (1.1).

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