Multi-phase state co2 jet simulation experiment device and experiment method thereof
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA UNIV OF PETROLEUM (BEIJING)
- Filing Date
- 2026-05-29
- Publication Date
- 2026-07-24
AI Technical Summary
Existing experimental techniques are insufficient to realistically simulate the physical process of multiphase CO2 leakage within the casing-tubing annulus of a wellbore, cannot accurately simulate actual field conditions, and lack sufficient safety and parameter adjustment flexibility, thus limiting the safe and stable operation of the CCUS project.
A multiphase CO2 jet simulation experimental device was designed. Dry ice is stored in a pressure-bearing unit and a high-pressure CO2 source is generated by heating. The leakage process is simulated by a pressure relief structure and a wellbore simulation unit. Temperature and pressure measurements and a high-speed camera are used to record the jet situation, so as to realize multi-parameter adjustment and safety monitoring.
It achieves high-fidelity experimental simulation, can flexibly adjust leakage conditions, improves experimental safety and operability, and provides key means for research on leakage mechanisms and verification of monitoring technologies.
Smart Images
Figure CN122447073A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the fields of oil and gas field development and carbon dioxide geological sequestration (CCUS), and particularly to a multiphase CO2 jet simulation experimental device and its experimental method. Background Technology
[0002] The continued advancement of global industrialization has led to excessive carbon dioxide (CO2) emissions, exacerbating the global warming problem. The Paris Agreement explicitly sets global temperature control targets. Against this backdrop, Carbon Capture, Utilization and Storage (CCUS) technology has emerged as a key means to achieve large-scale carbon emission reduction, becoming a crucial support for global energy transition and low-carbon development. It is currently the only low-carbon technology capable of achieving large-scale carbon emission reduction while continuing to use fossil fuels. In the underground storage phase of CCUS projects, the CO2 injected into the formation is typically in a supercritical or liquid state to achieve efficient storage and stability. However, the wellbore, as the core channel for CO2 injection and storage, directly determines the storage effectiveness and environmental safety of CCUS projects. During long-term operation, the wellbore cement sheath is prone to deterioration and casing corrosion due to multiple factors such as formation temperature and pressure changes, formation fluid corrosion, and mechanical wear. Simultaneously, the sealing structure may fail. All of these issues can lead to leakage of supercritical or liquid CO2 injected into the formation, becoming a key hidden danger restricting the safe and stable operation of the CCUS project. This type of CO2 leakage typically occurs within the confined space of the casing-tubing annulus. During leakage, CO2 rapidly enters the relatively low-pressure environment of the annulus from the high-pressure environment of the formation, undergoing complex depressurization, expansion, and phase transition processes, ultimately forming a multiphase jet. In-depth research into the flow field structure characteristics, CO2 phase evolution laws, and associated temperature, pressure, and concentration signals during this leakage process is crucial for quantitatively assessing leakage risks in CCUS projects, optimizing leakage monitoring technology, and developing effective leakage prevention and control measures. This has significant engineering implications and practical value for ensuring the long-term safe operation of CCUS projects and reducing environmental risks.
[0003] Currently, research on multiphase CO2 leakage jets within the annulus of the casing-tubing system in CCUS projects mainly relies on laboratory simulation experiments. However, existing experimental techniques have significant shortcomings and cannot meet the needs of actual research, specifically in the following aspects: First, the simulation mechanism of CO2 leakage sources does not match the actual field situation. In existing experiments, CO2 sources are mostly simulated by directly supplying gas from high-pressure cylinders. This method cannot simulate CO2 leakage caused by factors such as solid phase blockage and pressure accumulation in confined spaces in actual field situations. It is fundamentally different from the real physical mechanism of leakage in the field, making it difficult for the leakage patterns revealed by the experiments to reflect the actual field situation.
[0004] Second, the geometric and environmental simulation of the experimental setup is not realistic enough. Existing experimental setups cannot realistically reproduce the actual geometric structure of the well casing-tubing annulus on a laboratory scale, and cannot accurately simulate the formation temperature field distribution when a leak occurs on site. This results in a large deviation between the experimental simulation scenario and the actual on-site working conditions, greatly reducing the engineering applicability of the experimental results.
[0005] Third, the experimental operating conditions are not flexible enough and the parameters are not controllable enough. Key leakage parameters, such as the size of the leakage orifice and the leakage initiation pressure, are difficult to adjust in the existing experimental setup. It is impossible to achieve flexible adjustment of multiple parameters over a wide range, resulting in relatively simple experimental operating conditions and making it difficult to comprehensively explore the evolution of multiphase CO2 jets under different leakage conditions.
[0006] Fourth, the experimental safety assurance capabilities are insufficient. The rapid release process of high-pressure CO2 carries high safety risks, and the existing experimental equipment lacks effective remote active safety control measures. It is impossible to monitor and precisely control the release process in real time, making it difficult to fully avoid safety hazards during the experiment and limiting the conduct of experiments under high pressure and extreme conditions.
[0007] In summary, with the large-scale application of CCUS technology, the requirements for leakage risk assessment and monitoring technologies are constantly increasing. The shortcomings of existing experimental techniques have become bottlenecks restricting in-depth research. Therefore, there is an urgent need for a safe, realistic, flexible, and parameter-adjustable multiphase CO2 jet simulation experimental device to address the deficiencies of existing technologies, provide reliable experimental support for leakage-related research in CCUS projects, and promote the safe and efficient development of CCUS technology. Summary of the Invention
[0008] In order to overcome the above-mentioned defects of the prior art, the technical problem to be solved by the embodiments of the present invention is to provide a multiphase CO2 jet simulation experimental device and experimental method, which can solve the problem that the existing experiments cannot simulate the CO2 leakage caused by solid phase blockage, pressure accumulation in closed space and other factors in the actual field due to the direct gas supply of CO2 source by high-pressure gas cylinder.
[0009] The specific technical solution of this invention is as follows: A multiphase CO2 jet simulation experimental device, the multiphase CO2 jet simulation experimental device comprising: A pressure-bearing unit that can be opened, the pressure-bearing unit being used to store dry ice, and the pressure-bearing unit being in a closed state when closed; A pressure relief structure is installed on the pressure-bearing unit, the pressure relief structure is connected to the inside of the pressure-bearing unit, and when the pressure inside the pressure-bearing unit reaches a preset value, the pressure relief structure allows the inside of the pressure-bearing unit to communicate with the outside. A wellbore simulation unit includes a casing, which is transparent, and the pressure-bearing unit and the pressure relief structure are disposed in the casing. A heating assembly for heating the sleeve; A temperature measuring unit, wherein the temperature measuring unit is used to measure the temperature inside the pressure-bearing unit; A pressure measuring unit, wherein the pressure measuring unit is used to measure the pressure inside the pressure-bearing unit; A high-speed camera device is used to record, through the transparent sleeve, the jet of high-pressure carbon dioxide ejected from the pressure relief structure when the pressure inside the pressure-bearing unit reaches a preset value and the pressure relief structure connects the inside of the pressure-bearing unit to the outside.
[0010] Preferably, the pressure-bearing unit includes a pipe body, an upper sealing head, and a lower sealing head, wherein the upper sealing head is threadedly connected to the upper end of the pipe body, and the lower sealing head is threadedly connected to the lower end of the pipe body. The upper sealing head is connected to a safety relief valve for overpressure protection, the temperature measuring unit, and the pressure measuring unit.
[0011] Preferably, the pipe body includes an upper pipe body and a lower pipe body, and the pressure relief structure is connected between the upper pipe body and the lower pipe body. The pressure relief structure includes: an intermediate pipe body, a first nozzle and a bursting bolt. An outlet is provided on the side wall of the intermediate pipe body. The first nozzle is fastened to the outlet of the intermediate pipe body by the bursting bolt. A bursting disc is pressed inside the bursting bolt. The first nozzle is removable and replaceable to simulate leakage holes of different sizes through the first nozzle with different center orifice diameters; The rupture bolt can be disassembled and replaced to set different leakage initiation pressures by using the rupture disc with different rated rupture pressures.
[0012] Preferably, the wellbore simulation unit further includes: An end cap for sealing the upper end of the sleeve is detachably connected to the sleeve. The pulleys mounted on the end cap; A rope passes through the end cap and can be wound around the pulley. One end of the rope is connected to the pressure-bearing unit, and the other end is used to connect to an external lifting device. The rope allows the height of the pressure-bearing unit in the sleeve to be adjusted.
[0013] Preferably, the multiphase CO2 jet simulation experimental device further includes: A remote venting unit includes: a protective housing, the upper end of which is sealed to the pressure-bearing unit, and the lower end of which is sealed by a bottom cover; an electric valve and a three-way connector disposed within the protective housing, one end of which is connected to the interior of the pressure-bearing unit, the first end of which is connected to the other end of the electric valve, and the second end of which is connected to a second nozzle mounted on the protective housing.
[0014] Preferably, the bottom cover is equipped with a breathable and waterproof valve and a high-pressure sealing connector for balancing the air pressure inside and outside the protective housing, and the control line of the electric valve is led out through the high-pressure sealing connector.
[0015] Preferably, the heating assembly includes a heating strip tightly wrapped around the outside of the sleeve; The multiphase CO2 jet simulation experimental device also includes: An acoustic emission sensor array is used to collect acoustic emission signal characteristics when high-pressure carbon dioxide is ejected from the pressure relief structure when the pressure inside the pressure-bearing unit reaches a preset value and the pressure relief structure connects the inside of the pressure-bearing unit with the outside.
[0016] An experimental method using a multiphase CO2 jet simulation experimental apparatus as described above, the experimental method comprising: Calculate and weigh the required dry ice based on the volume of the pressure unit, the target experimental pressure and temperature, and then install and seal the dry ice into the pressure unit. The pressure-bearing unit containing the dry ice is installed into the casing of the wellbore simulation unit and the casing is sealed. The heating assembly is turned on to heat the sleeve. During this process, the temperature and pressure changes inside the pressure-bearing unit are monitored in real time by the temperature measurement unit and the pressure measurement unit. When the pressure inside the pressure-bearing unit reaches a preset value, the pressure relief structure connects the inside of the pressure-bearing unit with the outside world. The high-pressure, multiphase CO2 inside the pressure-bearing unit is injected into the casing through the pressure relief structure to form a transient jet.
[0017] Preferably, the pressure relief structure includes: an intermediate pipe body, a first nozzle, and a bursting bolt. An outlet is provided on the side wall of the intermediate pipe body. The first nozzle is fastened to the outlet of the intermediate pipe body by the bursting bolt. The first nozzle is removable and replaceable. A bursting disc is pressed inside the bursting bolt to simulate leakage holes of different sizes through the first nozzles with different center diameters. The bursting bolt is removable and replaceable to set different leakage initiation pressures through the bursting discs with different rated burst pressures. The experimental method also includes: Based on the required leakage orifice diameter and initiation pressure for the experiment, select a first nozzle and a bursting bolt with appropriate parameters and install them onto the outlet of the intermediate pipe.
[0018] Preferably, the multiphase CO2 jet simulation experimental device further includes: A remote venting unit, comprising: a protective housing, the upper end of which is sealed to the pressure-bearing unit, and the lower end of which is sealed by a bottom cover; an electric valve and a three-way connector disposed within the protective housing, one end of which is connected to the interior of the pressure-bearing unit, the first end of which is connected to the other end of which is connected to the electric valve, and the second end of which is connected to a second nozzle mounted on the protective housing; The experimental method also includes: After the transient jet is completed, the electric valve is remotely controlled to open and discharge the residual CO2 in the pressure unit.
[0019] The technical solution of the present invention has the following significant beneficial effects: The multiphase CO2 jet simulation experimental device in this application realizes the geometric and temperature simulation of the wellbore environment by using a wellbore simulation unit and heating components. It utilizes the natural generation of high-pressure CO2 source by the sublimation phase change of dry ice in the pressure-bearing unit and, together with the pressure relief structure, can safely and conveniently simulate CO2 leakage under different working conditions. The temperature and pressure changes inside the pressure-bearing unit and the jet situation of high-pressure carbon dioxide ejected from the pressure relief structure are recorded by a temperature measurement unit, a pressure measurement unit and a high-speed camera device during the experiment. This provides a key experimental means for the study of leakage mechanism and the verification of monitoring technology.
[0020] This application has high-fidelity simulation capabilities. The experimental setup uses a casing to accurately simulate wellbore dimensions, and by placing the pressure-bearing unit inside, it can realistically reproduce the physical process of CO2 leakage within the confined space of the casing and annulus. The high-pressure CO2 generated naturally by the sublimation of dry ice has a phase change and pressure accumulation mechanism that is closer to actual working conditions, resulting in high simulation fidelity.
[0021] Specific embodiments of the invention are disclosed in detail below with reference to the description and accompanying drawings, indicating how the principles of the invention can be employed. It should be understood that the embodiments of the invention are not therefore limited in scope. Features described and / or shown for one embodiment may be used in the same or similar manner in one or more other embodiments, combined with features in other embodiments, or substituted for features in other embodiments. Attached Figure Description
[0022] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of the invention in any way. Furthermore, the shapes and proportions of the components in the drawings are merely illustrative to aid in understanding the invention and do not specifically limit the shapes and proportions of the components. Those skilled in the art, guided by the teachings of this invention, can select various possible shapes and proportions to implement the invention according to specific circumstances.
[0023] Figure 1 This is a schematic diagram of the multiphase CO2 jet simulation experimental device in an embodiment of the present invention; Figure 2 This is a schematic diagram of the pressure-bearing unit, pressure-relief structure, and remote release unit in an embodiment of the present invention; Figure 3 This is a top view of the pressure-bearing unit, pressure-relief structure, and remote release unit in an embodiment of the present invention; Figure 4 This is a schematic diagram of the pressure relief structure in an embodiment of the present invention; Figure 5 This is a schematic diagram of the structure of the remote discharge unit in an embodiment of the present invention.
[0024] The reference numerals in the above figures are as follows: 1. Pressure relief structure; 11. Intermediate pipe body; 12. First nozzle; 13. Bursting bolt; 2. Pressure bearing unit; 21. Pipe body; 211. Upper pipe body; 212. Lower pipe body; 22. Upper sealing head; 23. Lower sealing head; 24. Safety pressure relief valve; 25. Needle valve; 3. Wellbore simulation unit; 31. Casing; 32. End cap; 33. Pulley; 34. Rope; 35. Bolt; 36. Base; 5. Pressure measurement unit; 6. Remote release unit; 61. Protective housing; 62. Bottom cover; 63. Electric valve; 64. T-connector; 65. Second nozzle; 66. Adapter; 67. Breathable and waterproof valve; 68. High-pressure sealing connector. Detailed Implementation
[0025] The details of the present invention can be more clearly understood by referring to the accompanying drawings and the description of specific embodiments. However, the specific embodiments of the present invention described herein are for illustrative purposes only and should not be construed as limiting the invention in any way. Under the teachings of this invention, those skilled in the art can conceive of any possible modifications based on the invention, all of which should be considered within the scope of the invention. It should be noted that when an element is referred to as being "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or there may be an intervening element. The terms "mounted," "connected," and "connected" should be interpreted broadly, for example, they can refer to mechanical or electrical connections, or internal communication between two elements, and can be direct or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only embodiments.
[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.
[0027] To address the limitations of existing experiments that use high-pressure gas cylinders to directly supply CO2, which fail to simulate real-world CO2 leaks caused by solid blockages and pressure buildup in confined spaces, this application proposes a multiphase CO2 jet simulation experimental device. Figure 1 This is a schematic diagram of the multiphase CO2 jet simulation experimental device in an embodiment of the present invention. Figure 2 This is a schematic diagram of the pressure-bearing unit, pressure-relief structure, and remote release unit in an embodiment of the present invention. Figure 3 This is a top view of the pressure-bearing unit, pressure-relief structure, and remote venting unit in an embodiment of the present invention. Figure 4 This is a schematic diagram of the pressure relief structure in an embodiment of the present invention, as shown below. Figure 1 and Figure 2As shown, the multiphase CO2 jet simulation experimental device may include: an openable pressure-bearing unit 2, which stores dry ice and is closed when shut down; a pressure relief structure 1 installed on the pressure-bearing unit 2, which communicates with the interior of the pressure-bearing unit 2 and allows communication between the interior of the pressure-bearing unit 2 and the outside when the pressure inside the pressure-bearing unit 2 reaches a preset value; and a wellbore simulation unit 3, including a casing 31, which is transparent, connecting the pressure-bearing unit 2 and the pressure relief structure 1. The following components are installed in the sleeve 31: a heating assembly for heating the sleeve 31; a temperature measuring unit for measuring the temperature inside the pressure-bearing unit 2; a pressure measuring unit 5 for measuring the pressure inside the pressure-bearing unit 2; and a high-speed camera for recording, through the transparent sleeve 31, the jet of high-pressure carbon dioxide ejected from the pressure relief structure 1 when the pressure inside the pressure-bearing unit 2 reaches a preset value, allowing the inside of the pressure-bearing unit 2 to communicate with the outside.
[0028] The multiphase CO2 jet simulation experimental device in this application realizes the geometric and temperature simulation of the well environment using the well simulation unit 3 and heating components. It utilizes the dry ice sublimation phase change in the pressure-bearing unit 2 to naturally generate a high-pressure CO2 source, and with the help of the pressure relief structure 1, it can safely and conveniently simulate CO2 leakage under different working conditions. The temperature and pressure changes inside the pressure-bearing unit 2 and the jet situation of high-pressure carbon dioxide ejected from the pressure relief structure 1 are recorded by the temperature measurement unit, pressure measurement unit 5 and high-speed camera device during the experiment. Thus, it can provide key experimental means for leakage mechanism research and monitoring technology verification.
[0029] like Figure 2 As shown, the pressure-bearing unit 2 can be opened, allowing an appropriate amount of dry ice to be installed into it according to specific experimental needs. After the dry ice is installed, the pressure-bearing unit 2 can be closed, thus achieving a sealed state. The pressure-bearing unit 2 may include a tube body 21, an upper sealing head 22, and a lower sealing head 23. The upper sealing head 22 is threadedly connected to the upper end of the tube body 21 to achieve a sealed state when openable and closed. The lower sealing head 23 is threadedly connected to the lower end of the tube body 21 to achieve a seal.
[0030] As a feasible option, such as Figure 2 and Figure 3As shown, the upper sealing head 22 is connected to a safety relief valve 24 for overpressure protection, the temperature measuring unit, and the pressure measuring unit 5. The safety relief valve 24 protects the pressure-bearing unit 2 during the experiment, preventing excessive internal pressure that could exceed the unit's tolerance and cause a safety accident. The temperature measuring unit measures the temperature change inside the pressure-bearing unit 2 throughout the experiment, and the pressure measuring unit 5 measures the pressure change inside the pressure-bearing unit 2 during the experiment.
[0031] As a feasible option, such as Figure 2 and Figure 3 As shown, a needle valve 25 can also be connected to the upper sealing head 22. The needle valve 25 can be used to evacuate or slightly depressurize the tube body 21, thereby eliminating interference from other gases and regulating the pressure inside the tube body 21.
[0032] In one alternative implementation, such as Figure 2 As shown, the pipe body 21 may include an upper pipe body 211 and a lower pipe body 212. The pressure relief structure 1 can be connected between the upper pipe body 211 and the lower pipe body 212. The pressure relief structure 1 can be connected to the upper pipe body 211 and the lower pipe body 212 respectively by threaded connection. The above method facilitates the assembly and modular processing of the entire device.
[0033] The heating assembly is used to heat the casing 31 to provide a controllable temperature field for the entire wellbore simulation unit 3, simulating the formation temperature environment. Additionally, it can provide a stable heat source for the dry ice in the pressure-bearing unit 2, accelerating its sublimation and pressurization process. In an optional embodiment, the heating assembly includes a heating belt tightly wrapped around the casing 31, thereby enabling uniform heating of the casing 31.
[0034] like Figure 2 As shown, the pressure relief structure 1 is installed on the pressure-bearing unit 2. The pressure relief structure 1 is connected to the interior of the pressure-bearing unit 2, and when the pressure inside the pressure-bearing unit 2 reaches a preset value, the pressure relief structure 1 connects the interior of the pressure-bearing unit 2 with the outside. That is, when dry ice absorbs heat and sublimates inside the pressure-bearing unit 2, the CO2 pressure and temperature inside the pressure-bearing unit 2 continuously rise to form multiphase CO2. When the pressure inside the pressure-bearing unit 2 reaches the preset value, the pressure relief structure 1 connects the interior of the pressure-bearing unit 2 with the outside, and the multiphase CO2 is ejected through the pressure relief structure 1 into the wellbore simulation unit 3, forming a transient jet.
[0035] In one alternative implementation, such as Figure 2 and Figure 4As shown, the pressure relief structure 1 may include: an intermediate tube 11, a first nozzle 12, and a bursting bolt 13. An outlet is provided on the side wall of the intermediate tube 11. The first nozzle 12 is fastened to the outlet of the intermediate tube 11 by the bursting bolt 13, and a rupture disc is pressed inside the bursting bolt 13. The first nozzle 12 is removable and replaceable to simulate leak holes of different sizes using nozzles with different central orifice diameters. The bursting bolt 13 is removable and replaceable to set different leakage initiation pressures using rupture discs with different rated burst pressures. By replacing the first nozzle 12 with different central orifice diameters, leak holes of different sizes can be simulated. By replacing the rupture discs installed inside the bursting bolt 13 with different rated burst pressures, different leakage initiation pressures can be set. The above structural design enables modular and quantitative adjustment of leakage conditions, thereby meeting the needs of different experimental parameters. Furthermore, at least two pressure relief structures 1 can be fabricated during the entire experiment. In this way, when one of them is being tested, the first nozzle 12 and burst bolt 13 of the other can be replaced, so that the pressure relief structure 1 with the first nozzle 12 and burst bolt 13 already replaced can be used directly in the next experiment.
[0036] like Figure 1As shown, the wellbore simulation unit 3 is used to simulate the actual wellbore casing 31. The wellbore simulation unit 3 includes the casing 31, which is transparent to provide a full-view observation window. There can be one or more casings 31, which can be connected in a sealed manner to form a whole. The pressure-bearing unit 2 and the pressure relief structure 1 are disposed in the casing 31. When the pressure-bearing unit 2 and the pressure relief structure 1 are disposed in the casing 31 for multiphase CO2 jet simulation experiments, the casing 31 needs to be in a largely closed state, that is, the upper and lower ends of the casing 31 need to be sealed. Therefore, the wellbore simulation unit 3 may include an end cap 32 for sealing the upper end of the casing 31, which is detachably connected to the casing 31, thereby facilitating the installation of the pressure-bearing unit 2 and the pressure relief structure 1 into the casing 31. For example, the end cap 32 can be a flange that is sealed to the casing 31 by bolts 35. The wellbore simulation unit 3 may include: a pulley 33 mounted on the end cover 32; a rope 34 passing through the end cover 32 and wound around the pulley 33. One end of the rope 34 is connected to the pressure-bearing unit 2, and the other end is used to connect to an external lifting device. The rope 34 allows the height of the pressure-bearing unit 2 in the casing 31 to be adjusted, thereby achieving precise positioning and safe hoisting of the pressure-bearing unit 2, the pressure relief structure 1, etc., within the casing 31. When the end cap 32 needs to be lifted together, the rope 34 can be wound around the pulley 33. When both the pressure-bearing unit 2 and the pressure-relief structure 1 are suspended inside the sleeve 31, the rope 34 can be wound around the pulley. The operator pulls the rope 34 down from the ground on the side of the rope 34 away from the pressure-bearing unit 2. Since the rope 34 passes around the pulley 33, the downward pull of the rope 34 can be converted into an upward pull on the pressure-bearing unit 2 under the action of the pulley 33. In this way, the height of the pressure-bearing unit 2 inside the sleeve 31 can be manually adjusted. The lower end of the sleeve 31 can also be sealed in a similar way. Furthermore, the lower end of the sleeve 31 may include a base 36, which includes a base plate and a support frame. The base plate is sealed to the sleeve 31, for example, by bolts. The support frame has a larger footprint in the horizontal direction to make the base 36 more stable, thereby supporting the sleeve 31.
[0037] The high-speed camera device is used to record, through the transparent sleeve 31, the jet of high-pressure carbon dioxide ejected from the pressure relief structure 1 when the pressure inside the pressure-bearing unit 2 reaches a preset value and the pressure relief structure 1 connects the inside of the pressure-bearing unit 2 with the outside world. This allows for the acquisition of a visual image of the jet development for later analysis.
[0038] In an optional embodiment, the multiphase CO2 jet simulation experimental device may further include: an acoustic emission sensor array, which is used to collect the acoustic emission signal characteristics of high-pressure carbon dioxide ejected from the pressure relief structure 1 when the pressure inside the pressure-bearing unit 2 reaches a preset value and the pressure relief structure 1 connects the inside of the pressure-bearing unit 2 with the outside.
[0039] In one alternative implementation, such as Figure 2 As shown, the multiphase CO2 jet simulation experimental device may include a remote venting unit 6. Through the remote venting unit 6, experimental personnel can remotely control the spatial communication between the pressure-bearing unit 2 and the space outside the pressure-bearing unit 2 and inside the sleeve 31, thereby achieving pressure relief and discharge of residual CO2 in the pressure-bearing unit 2 after the transient jet is completed, thus ensuring the safety of the experimental personnel.
[0040] In one alternative implementation, Figure 5 This is a schematic diagram of the structure of the remote discharge unit 6 in an embodiment of the present invention, as shown below. Figure 5 As shown, the remote venting unit 6 includes: a protective housing 61, the upper end of which is sealed to the pressure-bearing unit 2, and the lower end of which is sealed by a bottom cover 62; an electric valve 63 and a three-way connector 64 disposed within the protective housing 61. One end of the electric valve 63 communicates with the interior of the pressure-bearing unit 2, the first end of the three-way connector 64 is connected to the other end of the electric valve 63, and the second end of the three-way connector 64 is connected to a second nozzle 65 mounted on the protective housing 61. The third end of the three-way connector 64 communicates with the space inside the protective housing 61.
[0041] The electric valve 63 can be connected to the inside of the pressure unit 2 through an adapter 66. One end of the adapter 66 is connected to the lower sealing head 23 of the pressure unit 2 and communicates with the inside of the pipe body 21 above the lower sealing head 23. One end of the electric valve 63 is connected to the other end of the adapter 66.
[0042] Furthermore, such as Figure 5 As shown, the bottom cover 62 is equipped with a breathable and waterproof valve 67 and a high-pressure sealing connector 68 for balancing the air pressure inside and outside the protective housing 61. The control circuit of the electric valve 63 is led out through the high-pressure sealing connector 68 to connect with an external control system, thereby enabling remote control of the opening and closing of the electric valve 63 to achieve active and rapid pressure relief in emergencies or after experiments. The breathable and waterproof valve 67 can prevent condensation or liquid from entering the interior of the protective housing 61.
[0043] This application also proposes an experimental method for a multiphase CO2 jet simulation experimental device, the experimental method comprising: The required dry ice is calculated and weighed based on the volume of the pressure unit 2, the target experimental pressure, and the temperature, and then the dry ice is installed into the pressure unit 2 and sealed.
[0044] In this step, the upper sealing head 22 of the pressure unit 2 can be disassembled by threaded connection. The required dry ice is calculated and weighed according to the volume of the pressure unit 2, the experimental target pressure and temperature, and the dry ice is installed into the pressure unit 2. After that, the upper sealing head 22 is fastened to the tube body 21.
[0045] The pressure-bearing unit 2 containing the dry ice is installed into the casing 31 of the wellbore simulation unit 3 and the casing 31 is sealed.
[0046] In this step, the end cap 32, which seals the upper end of the casing 31, can be removed. The pressure-bearing unit 2 and the end cap 32 are then slowly lifted using a lifting device and rope 34 and lowered vertically to a predetermined depth inside the casing 31. Subsequently, the top end cap 32 is sealed and installed to ensure that the entire wellbore simulation unit 3 is airtight.
[0047] The heating assembly is turned on to heat the sleeve 31. During this process, the temperature and pressure changes inside the pressure-bearing unit 2 are monitored in real time by the temperature measurement unit and the pressure measurement unit 5.
[0048] In this step, the heating belt wrapped around the sleeve 31 is turned on to heat the sleeve 31, and the target heating temperature is set. The dry ice in the pressure-bearing unit 2 begins to absorb heat and sublimate, causing the CO2 pressure and temperature inside the tank to rise continuously. This process is monitored and recorded in real time by the temperature measurement unit and the pressure measurement unit 5.
[0049] When the pressure inside the pressure-bearing unit 2 reaches a preset value, the pressure relief structure 1 connects the inside of the pressure-bearing unit 2 with the outside world. The high-pressure, multiphase CO2 inside the pressure-bearing unit 2 is injected into the sleeve 31 through the pressure relief structure 1 to form a transient jet.
[0050] In this step, when the pressure inside the pressure-bearing unit 2 reaches a preset value, the pressure relief structure 1 connects the inside of the pressure-bearing unit 2 with the outside. The high-pressure, multiphase CO2 inside the pressure-bearing unit 2 is injected into the annular simulation region outside the pipe body 21 and inside the sleeve 31 through the pressure relief structure 1 to form a transient jet. During this process, a high-speed camera device records the morphology and development process of the jet. Furthermore, an acoustic emission sensor array collects the acoustic emission signal characteristics generated by the leak and combines them with the pressure and temperature data inside the tank to form a complete multiphysics experimental dataset.
[0051] Furthermore, the experimental method also includes: Before the dry ice is installed into the pressure unit 2 for sealing, the first nozzle 12 and the bursting bolt 13 with appropriate parameters can be selected and installed on the outlet of the intermediate tube 11 according to the leakage orifice diameter and bursting pressure required for the experiment.
[0052] Furthermore, the experimental method also includes: after the transient jet is completed, remotely controlling the electric valve 63 to open so as to discharge the residual CO2 in the pressure unit 2.
[0053] In this step, after the transient jet is completed and the experimental data is collected, the operator can remotely send a command from the control room to open the electric valve 63, safely and completely releasing the residual CO2 in the pressure-bearing unit 2 and pipeline into the sleeve 31, and then diffusing it outdoors or to the recovery device. After the system confirms that the pressure has dropped to atmospheric pressure, the end cap 32 at the upper end of the sleeve 31 is opened, and the pressure-bearing unit 2, pressure relief structure 1, remote release unit 6, etc., are lifted out using external lifting equipment for cleaning and component replacement, in preparation for the next experiment.
[0054] The multiphase CO2 jet simulation experimental apparatus and experimental method described in this application can achieve the following beneficial effects: First, it has high-fidelity simulation capabilities. The experimental device uses casing 31 to accurately simulate the wellbore size. By placing the pressure-bearing unit 2 inside, it can realistically reproduce the physical process of CO2 leakage in the confined space of "casing 31-annulus". High-pressure CO2 is naturally generated by the sublimation of dry ice, and its phase change and pressure accumulation mechanism are closer to the actual working conditions, resulting in high simulation fidelity.
[0055] Secondly, the parameters are flexible and adjustable, and the operating conditions are widely covered. By replacing the rupture disc in the first nozzle 12 and the rupture bolt 13, the size of the simulated leak hole and the pressure threshold for the leak can be controlled independently and precisely. One set of equipment can simulate various operating conditions, from micron-level pinhole leaks to millimeter-level hole leaks, and from low pressure to high pressure, making the experiment extremely flexible.
[0056] Third, a multi-faceted safety design was implemented. The device integrates multiple safety safeguards for venting: first, a main venting channel composed of rupture discs; second, a safety relief valve 24 connected to the upper sealing head 22; and third, an active venting channel controlled by a remotely controllable electric valve 63. The design of the remote venting unit 6 enables "human-machine separation" operation, greatly improving safety when handling high-pressure risks. Moreover, the high-pressure sealing connector 68 and the ventilated and waterproof valve 67 ensure the safety and sealing of the electrical components in high-pressure and humid environments.
[0057] Fourth, it is easy to operate and highly modular. The end caps 32 of the pressure-bearing unit 2 and the well shaft simulation unit 3 can be hoisted, and can be quickly installed and disassembled using ropes 34 and fixed pulleys 33. The pressure relief structure 1 is designed as a modular structure, which is easy to replace, effectively shortening the experimental preparation time and improving the experimental efficiency.
[0058] This application, through ingenious structural and system design, successfully solves the problem of balancing realism, safety, flexibility, and operability in CCUS wellbore CO2 leakage simulation. It provides an indispensable basic experimental means and theoretical support for a deeper understanding of leakage mechanisms, assessment of leakage risks, and development of reliable monitoring and early warning technologies.
[0059] All articles and references disclosed herein, including patent applications and publications, are incorporated herein by reference for various purposes. The term “substantially constitutes…” used to describe a combination should include the identified element, component, part, or step, as well as other elements, components, parts, or steps that do not substantially affect the essential novelty of the combination. The use of the terms “comprising” or “including” to describe combinations of elements, components, parts, or steps herein also contemplates embodiments substantially constituted by such elements, components, parts, or steps. The use of the term “may” herein is intended to indicate that any described attribute “may” include is optional. Multiple elements, components, parts, or steps can be provided by a single integrated element, component, part, or step. Alternatively, a single integrated element, component, part, or step can be divided into multiple separate elements, components, parts, or steps. The disclosure of “a” or “an” used to describe an element, component, part, or step does not imply exclusion of other elements, components, parts, or steps.
[0060] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made according to the spirit and essence of the present invention should be covered within the scope of protection of the present invention.
Claims
1. A multiphase CO2 jet simulation experimental device, characterized in that, The multiphase CO2 jet simulation experimental device includes: A pressure-bearing unit that can be opened, the pressure-bearing unit being used to store dry ice, and the pressure-bearing unit being in a closed state when closed; A pressure relief structure is installed on the pressure-bearing unit, the pressure relief structure is connected to the inside of the pressure-bearing unit, and when the pressure inside the pressure-bearing unit reaches a preset value, the pressure relief structure allows the inside of the pressure-bearing unit to communicate with the outside. A wellbore simulation unit includes a casing, which is transparent, and the pressure-bearing unit and the pressure relief structure are disposed in the casing. A heating assembly for heating the sleeve; A temperature measuring unit, wherein the temperature measuring unit is used to measure the temperature inside the pressure-bearing unit; A pressure measuring unit, wherein the pressure measuring unit is used to measure the pressure inside the pressure-bearing unit; A high-speed camera device is used to record, through the transparent sleeve, the jet of high-pressure carbon dioxide ejected from the pressure relief structure when the pressure inside the pressure-bearing unit reaches a preset value and the pressure relief structure connects the inside of the pressure-bearing unit to the outside.
2. The multiphase CO2 jet simulation experimental apparatus according to claim 1, characterized in that, The pressure-bearing unit includes a pipe body, an upper sealing head, and a lower sealing head. The upper sealing head is threadedly connected to the upper end of the pipe body, and the lower sealing head is threadedly connected to the lower end of the pipe body. The upper sealing head is connected to a safety relief valve for overpressure protection, the temperature measuring unit, and the pressure measuring unit.
3. The multiphase CO2 jet simulation experimental apparatus according to claim 2, characterized in that, The pipe body includes an upper pipe body and a lower pipe body. The pressure relief structure is connected between the upper pipe body and the lower pipe body. The pressure relief structure includes: an intermediate pipe body, a first nozzle and a bursting bolt. An outlet is provided on the side wall of the intermediate pipe body. The first nozzle is fastened to the outlet of the intermediate pipe body by the bursting bolt. A bursting disc is pressed inside the bursting bolt. The first nozzle is removable and replaceable to simulate leakage holes of different sizes through the first nozzle with different center orifice diameters; The rupture bolt can be disassembled and replaced to set different leakage initiation pressures by using the rupture disc with different rated rupture pressures.
4. The multiphase CO2 jet simulation experimental apparatus according to claim 1, characterized in that, The wellbore simulation unit also includes: An end cap for sealing the upper end of the sleeve is detachably connected to the sleeve. The pulleys mounted on the end cap; A rope passes through the end cap and can be wound around the pulley. One end of the rope is connected to the pressure-bearing unit, and the other end is used to connect to an external lifting device. The rope allows the height of the pressure-bearing unit in the sleeve to be adjusted.
5. The multiphase CO2 jet simulation experimental apparatus according to claim 1, characterized in that, The multiphase CO2 jet simulation experimental device also includes: A remote venting unit includes: a protective housing, the upper end of which is sealed to the pressure-bearing unit, and the lower end of which is sealed by a bottom cover; an electric valve and a three-way connector disposed within the protective housing, one end of which is connected to the interior of the pressure-bearing unit, the first end of which is connected to the other end of the electric valve, and the second end of which is connected to a second nozzle mounted on the protective housing.
6. The multiphase CO2 jet simulation experimental apparatus according to claim 5, characterized in that, The bottom cover is equipped with a breathable and waterproof valve and a high-pressure sealing connector for balancing the air pressure inside and outside the protective housing. The control line of the electric valve is led out through the high-pressure sealing connector.
7. The multiphase CO2 jet simulation experimental apparatus according to claim 1, characterized in that, The heating assembly includes a heating strip, which is tightly wrapped around the outside of the sleeve; The multiphase CO2 jet simulation experimental device also includes: An acoustic emission sensor array is used to collect acoustic emission signal characteristics when high-pressure carbon dioxide is ejected from the pressure relief structure when the pressure inside the pressure-bearing unit reaches a preset value and the pressure relief structure connects the inside of the pressure-bearing unit with the outside.
8. An experimental method using the multiphase CO2 jet simulation experimental apparatus as described in claim 1, characterized in that, The experimental methods include: Calculate and weigh the required dry ice based on the volume of the pressure unit, the target experimental pressure and temperature, and then install and seal the dry ice into the pressure unit. The pressure-bearing unit containing the dry ice is installed into the casing of the wellbore simulation unit and the casing is sealed. The heating assembly is turned on to heat the sleeve. During this process, the temperature and pressure changes inside the pressure-bearing unit are monitored in real time by the temperature measurement unit and the pressure measurement unit. When the pressure inside the pressure-bearing unit reaches a preset value, the pressure relief structure connects the inside of the pressure-bearing unit with the outside world. The high-pressure, multiphase CO2 inside the pressure-bearing unit is injected into the casing through the pressure relief structure to form a transient jet.
9. The experimental method according to claim 8, characterized in that, The pressure relief structure includes: an intermediate pipe body, a first nozzle, and a bursting bolt. An outlet is provided on the side wall of the intermediate pipe body. The first nozzle is fastened to the outlet of the intermediate pipe body by the bursting bolt. The first nozzle is removable and replaceable. A bursting disc is pressed inside the bursting bolt to simulate leakage holes of different sizes through the first nozzles with different center orifice diameters. The bursting bolt is removable and replaceable to set different leakage initiation pressures through the bursting discs with different rated burst pressures. The experimental method also includes: Based on the required leakage orifice diameter and initiation pressure for the experiment, select a first nozzle and a bursting bolt with appropriate parameters and install them onto the outlet of the intermediate pipe.
10. The experimental method according to claim 8, characterized in that, The multiphase CO2 jet simulation experimental device also includes: A remote venting unit, comprising: a protective housing, the upper end of which is sealed to the pressure-bearing unit, and the lower end of which is sealed by a bottom cover; an electric valve and a three-way connector disposed within the protective housing, one end of which is connected to the interior of the pressure-bearing unit, the first end of which is connected to the other end of which is connected to the electric valve, and the second end of which is connected to a second nozzle mounted on the protective housing; The experimental method also includes: After the transient jet is completed, the electric valve is remotely controlled to open and discharge the residual CO2 in the pressure unit.