Experimental device and simulation experiment method for natural gas hydrate eruption

Abstract

The embodiment of the invention discloses an experiment device and a simulation experiment method for natural gas hydrate eruption. The experiment device comprises an eruption simulation box; a sample preparation system; an eruption medium simulation system; a monitoring system and a data collecting and processing system; the eruption medium simulation system comprises an eruption medium storage mechanism and an eruption medium providing mechanism which are sequentially communicated with the eruption simulation box, and a parameter adjusting mechanism used for controlling preset parameter values of eruption media in the eruption medium storage mechanism. The preset parameter value of the eruption medium at least comprises a pressure value and eruption duration of the eruption medium. According to the invention, the environmental parameters can be adjusted, on the premise that variable environmental parameters are simulated to the maximum extent, the pressure, duration and other parameters of the eruption medium are further accurately controlled according to the preset parameter values, the actual eruption condition can be restored to the maximum extent in the eruption simulation process, and the simulation accuracy is improved.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of natural gas hydrate exploitation, and in particular to an experimental device and a simulation experimental method for natural gas hydrate eruption. Background Art

[0002] As a strategic resource with great potential, natural gas hydrate is internationally recognized as a successor energy source to oil and other energy sources because it causes far less pollution than coal, oil, etc. and has huge reserves.

[0003] During the extraction process, natural gas hydrates, under temperature or pressure fluctuations, decompose from a solid phase into water and methane gas. The previously continuous hydrate-containing formation becomes divided into decomposed and undecomposed zones. During this decomposition process, the soil gradually softens, and under conditions of slow fluid pressure dissipation, pore gas pressure accumulates. Consequently, hydrate decomposition can cause deformation and damage to local soil layers and wellbore structures, and even lead to widespread submarine landslides and methane leaks. Methane gas decomposes and accumulates from the hydrate reservoir, causing uplift of the overlying layer and ultimately erupting with gas-carrying sediments, forming deep pits.

[0004] Currently, research on natural gas hydrate decomposition and eruption suffers from numerous shortcomings, including difficulty capturing solid behaviors such as the geometric characteristics of soil failure and critical conditions, and an inability to describe the novel mechanical behaviors of multi-interface formation and the development of gas-liquid-solid three-phase flow during gas eruption. Furthermore, existing experimental devices and methods struggle to comprehensively and accurately simulate and study the critical conditions and multiphase flow processes of hydrate eruptions, failing to meet the demands for the development of efficient hydrate extraction technologies. Summary of the Invention

[0005] To this end, an embodiment of the present invention provides an experimental device and a simulation experimental method for natural gas hydrate eruption. On the premise of being able to adjust environmental parameters to maximize the simulation of variable environmental parameters, parameters such as the pressure, temperature, and duration of the eruption medium are further precisely controlled according to preset parameter values, so that the eruption process can restore the actual eruption situation to the greatest extent, thereby improving the accuracy of the simulation.

[0006] In order to achieve the above objectives, the embodiments of the present invention provide the following technical solutions:

[0007] In one aspect of an embodiment of the present invention, an experimental device for natural gas hydrate eruption is provided, comprising:

[0008] An eruption simulation box is formed with a receiving cavity for placing a sample simulating an eruption environment;

[0009] a sample preparation system, at least partially located in the receiving chamber, for adjusting the sample in the receiving chamber to a preset simulation value;

[0010] an eruption medium simulation system, connected to the eruption simulation box, for providing an eruption medium with preset parameter values ​​into the eruption simulation box;

[0011] A monitoring system for dynamically monitoring the eruption process in the eruption simulation box;

[0012] The data collection and processing system is used to collect and process the data monitored by the monitoring system; wherein,

[0013] The spray medium simulation system comprises at least a spray medium storage mechanism and a spray medium supply mechanism sequentially connected to the spray simulation box, and a parameter adjustment mechanism for controlling a preset parameter value of the spray medium in the spray medium storage mechanism; and

[0014] The preset parameter values ​​of the ejection medium at least include a pressure value and an ejection duration of the ejection medium.

[0015] As a preferred embodiment of the present invention, the sample preparation system comprises at least a vibration table in contact with the eruption simulation box and capable of oscillating the eruption simulation box, and a leveling structure movably disposed in the accommodating cavity along an extension direction of the accommodating cavity;

[0016] The flattening structure is used to flatten the surface of the sample in the containing cavity.

[0017] As a preferred solution of the present invention, the monitoring system at least includes a high-speed camera for photographing the eruption process in the eruption simulation box, and a pressure sensor arranged on the inner wall of the eruption simulation box.

[0018] As a preferred solution of the present invention, the monitoring system further includes a light source, which is used to provide observation light to the eruption simulation box.

[0019] As a preferred embodiment of the present invention, a gas valve is provided between the ejection medium storage mechanism and the ejection medium supply mechanism, and a control device is provided for controlling the gas valve to control the output parameters of the ejection medium in the ejection medium storage mechanism;

[0020] The parameter adjustment mechanism includes at least an eruption duration control unit arranged between the eruption simulation box and the eruption medium storage mechanism, and the eruption duration control unit is used to control the eruption duration of the eruption medium introduced into the eruption simulation box by the eruption medium storage mechanism.

[0021] As a preferred solution of the present invention, the eruption duration control unit includes a solenoid valve connected between the eruption medium storage mechanism and the eruption simulation box, a time relay electrically connected to the solenoid valve, and a signal triggering device electrically connected to the time relay, and the time relay triggers the opening and closing of the solenoid valve according to the signal triggering device.

[0022] As a preferred solution of the present invention, the parameter adjustment mechanism further includes a temperature control unit for adjusting the temperature of the ejection medium in the ejection medium storage mechanism, and the temperature control unit is electrically connected to the signal triggering device.

[0023] As a preferred solution of the present invention, the temperature control unit includes a multi-stage temperature control structure arranged sequentially from the spraying medium providing mechanism to the spraying medium storage mechanism, and the temperature control of the multi-stage temperature control structure increases or decreases step by step.

[0024] As a preferred solution of the present invention, a pressure detection feedback unit is further provided in the spray medium storage mechanism, and the pressure detection feedback unit is used to monitor the gas pressure in the spray medium storage mechanism and feed back the pressure to the signal triggering device.

[0025] In another aspect of the present invention, a natural gas hydrate eruption simulation experimental method is provided, using the above-mentioned experimental device for natural gas hydrate eruption, the natural gas hydrate eruption simulation experimental method is as follows: Figure 5 Shown, including:

[0026] S100, constructing a simulated eruption environment with preset simulation values ​​in an eruption simulation box;

[0027] S200, adjusting the pressure value and the duration of the eruption medium until they reach the preset parameter values;

[0028] S300, opening the eruption medium supply mechanism until the eruption medium reaches at least some of the preset parameter values, triggering the eruption medium to simulate eruption in the eruption simulation box, and monitoring the eruption process through the monitoring system;

[0029] S400: Collect monitoring data of the monitoring system.

[0030] As a preferred embodiment of the present invention, the construction method in step S100 specifically includes:

[0031] S101, mixing silty clay with water until the moisture content is 15%-20% to obtain a soil sample;

[0032] S102, placing the obtained soil sample in an eruption simulation box and vibrating and compacting it until the porosity ratio of the soil sample is no more than 0.6, and then leveling the soil sample to obtain a soil sample layer;

[0033] S103, pouring simulated seawater into the eruption simulation box until the liquid level is 3 / 5-4 / 5 of the eruption simulation box, thereby constructing a simulated eruption environment.

[0034] As a preferred embodiment of the present invention, in step S300, the simulated eruption process includes multiple intermittent eruptions performed at intervals, and the preset parameter values ​​of each intermittent eruption are not completely the same; and,

[0035] The preset parameter values ​​in step S200 include multiple sets of pressure values ​​and eruption durations of the eruption medium, and each set of pressure values ​​and eruption durations of the eruption medium corresponds to one intermittent eruption.

[0036] As a preferred embodiment of the present invention, the preset pressure values ​​of adjacent intermittent eruptions increase or decrease in a gradient manner.

[0037] As a preferred solution of the present invention, the preset parameter value in step S200 also includes the temperature of the spraying medium.

[0038] As a preferred solution of the present invention, in step S300, when the pressure value and the eruption temperature of the eruption medium both reach a preset parameter range, the eruption medium is triggered to erupt.

[0039] The embodiments of the present invention have the following advantages:

[0040] The present invention further incorporates a sample preparation system within the eruption simulation chamber that dynamically adjusts internal samples, enabling simulation of natural gas hydrate and eruption environment samples closer to reality. Gas eruptions are conducted within a specialized eruption simulation chamber, where soil density, pressure, and eruption duration are precisely controlled to ensure the quality and stability of the experimental samples, laying the foundation for the accuracy of subsequent experiments. Simultaneously, a monitoring system is implemented to dynamically capture the entire eruption process. Furthermore, based on the separate configuration of the eruption medium storage mechanism and the eruption medium supply mechanism, combined with the linkage of the parameter adjustment mechanism, precise regulation of key parameters such as the pressure loading rate and eruption duration is achieved.

[0041] Based on the above settings, the effects of different pressure gradients on the eruption flow pattern, soil failure mode, and particle migration law of natural gas hydrates can be verified, providing an experimental basis for the design of a safe pressure window for deep-sea drilling, and a theoretical basis for the stability analysis of submarine hydrate mining wellbores and the design of blowout preventers. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are merely exemplary, and those skilled in the art can derive other implementation drawings based on the provided drawings without inventive effort.

[0043] The structures, proportions, sizes, etc. illustrated in this specification are intended only to complement the contents disclosed herein and to facilitate understanding and reading by persons familiar with the art. They are not intended to limit the conditions under which the present invention may be implemented and therefore have no substantive technical significance. Any structural modifications, changes in proportions, or adjustments in sizes, without affecting the efficacy and objectives of the present invention, shall still fall within the scope of the technical contents disclosed herein.

[0044] Figure 1 A schematic structural diagram of an experimental device for natural gas hydrate eruption provided in an embodiment of the present invention;

[0045] Figure 2 A schematic diagram of the structure of an eruption simulation box and a sample preparation system provided in an embodiment of the present invention;

[0046] Figure 3 A side view of an eruption simulation chamber and a sample preparation system provided by an embodiment of the present invention;

[0047] Figure 4 A schematic diagram of the partial structure of another ejection medium simulation system provided by an embodiment of the present invention;

[0048] Figure 5 This is a flowchart of a simulation method provided by an embodiment of the present invention.

[0049] In the picture:

[0050] 1- Eruption simulation chamber; 2- Sample preparation system; 3- Eruption medium simulation system; 4- Monitoring system; 5- Data collection and processing system; 6- Soil sample;

[0051] 11-accommodation cavity;

[0052] 21-vibrating table; 22-scraper; 23-guide rail;

[0053] 31- Eruption medium storage mechanism; 32- Eruption medium supply mechanism; 33- Gas valve; 34- Eruption duration control unit; 35- Multi-stage temperature control structure;

[0054] 41-pressure sensor; 42-high-speed camera; 43-light source. DETAILED DESCRIPTION

[0055] The following describes the implementation of the present invention using specific embodiments. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. Obviously, the embodiments described are only a portion of the present invention, not all of it. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are intended to fall within the scope of protection of the present invention.

[0056] like Figure 1 As shown, an experimental device for natural gas hydrate eruption provided by the present invention specifically comprises:

[0057] Eruption simulation box 1: This is the reaction site for the entire experiment. It has a chamber 11 for placing soil samples 6, which simulate the eruption environment, and constructing the overall eruption environment. Specifically, it can be a transparent box structure. For example, to facilitate observation, the main body of the box can be made of transparent high-strength plexiglass (thickness ≥ 20 mm) to ensure experimental safety and facilitate observation of the gas-liquid-solid three-phase flow phenomena within. The dimensions (length × width × height) can be specifically selected to be 1.0 m × 0.5 m × 1.0 m. It should be noted that the dimensions here are not limited to this, and those skilled in the art will be able to design the dimensions based on experimental requirements. The side walls of the box are reserved for multiple sensor interfaces for installing pressure sensors 41 to measure the pressure inside the box throughout the eruption process. In a more specific embodiment, the sensor interfaces can be arranged every 20 cm along the height of the box, for installing pressure sensors 41. (Similarly, the specific arrangement and number of pressure sensors 41 can be selected based on actual conditions and are not limited to this in actual operation.) The gas input port is located at the center of the bottom of the box and is connected to the pressure box (i.e., the eruption medium storage mechanism 31) through a flange, so that the gaseous eruption medium in the pressure box can enter the eruption simulation box 1 to complete the eruption.

[0058] Sample preparation system 2: Figure 2 and Figure 3 As shown, a sample for simulating the decomposition eruption of natural gas hydrates (i.e., simulating an underwater solid-liquid environment) is prepared. Specifically, a pre-prepared overburden soil sample 6 is placed on a vibrating table 21 (driven by a variable frequency motor with a vibration frequency range of 0-50 Hz) for compaction. The surface of the soil sample 6 is then evenly leveled using a leveling mechanism (e.g., an adjustable scraper 22 driven horizontally along the eruption simulation chamber 1 by a guide rail 23) to ensure a surface flatness error of ≤1 mm.

[0059] The spraying medium simulation system 3 has a spraying medium storage mechanism 31 (i.e., a pressure box) and a spraying medium supply mechanism 32 (specifically, a high-pressure gas tank) connected in sequence, and is also provided with a parameter adjustment mechanism for adjusting the parameters of the spraying medium in the pressure box.

[0060] In the first case, parameter adjustment includes the pressure value of the eruption medium and the duration of the eruption. In this case, the pressure value of the eruption medium can be directly achieved through the combination of a pressure box and a high-pressure gas tank. In a specific embodiment, the high-pressure gas tank stores high-pressure nitrogen (pressure range 0-10 MPa) and is connected to a gas valve 33 (specifically, a pressure regulating valve) via a stainless steel pipeline. The pressure regulating valve receives control signals from a function generator and precisely adjusts the output pressure (accuracy ±0.01 MPa). The pressure box has a volume of 5 L and a built-in porous buffer layer (made of sintered metal) to stabilize the gas flow and reduce pressure fluctuations. The function generator is a multi-channel waveform generator with a preset pressure loading curve, which is used to output a control signal to the pressure regulating valve to adjust the gas input pressure. (It should be noted that the present invention is not limited to the use of a function generator as a specific control device; any suitable control device that can control the pressure regulating valve and adjust the output pressure can be used.) Furthermore, a pressure gauge and pressure reducing valve can be installed at the outlet of the high-pressure gas tank. Combined with the pressure cell, this allows for more controllable parameters of the eruption medium provided by the entire eruption medium simulation system 3 to the eruption simulation box 1, improving the accuracy of the eruption simulation process. Eruption duration can be controlled by a solenoid valve and a time relay connected to the eruption simulation box 1. For example, in one specific embodiment, the solenoid valve can be a high-pressure direct-acting solenoid valve (with a pressure resistance of ≥15 MPa and a response time of ≤10 ms). It is installed in the pipeline between the pressure cell and the eruption simulation box 1 and rapidly opens and closes upon receiving a trigger signal, controlling the injection and shutoff of high-pressure gas into the eruption simulation box 1, thereby regulating the eruption duration. The time relay can be a digital programmable time relay (with a time resolution of 0.01 s and an error of ±0.1%), which is linked to the solenoid valve and function generator via a signal line. Its function is to set the solenoid valve's opening duration (adjustable from 0.1 to 5.0 s) and to trigger the eruption upon receiving a threshold signal from the pressure sensor 41. That is, the pressure sensor 41 here transmits the pressure signal to the signal triggering device. When the pressure signal sensed by the signal triggering device reaches a threshold value, the signal triggering device controls the time relay to complete the eruption according to the preset eruption duration.

[0061] In the second scenario, parameter adjustment includes not only the pressure and duration of the eruption medium but also the temperature of the eruption medium. In this case, in addition to the structure of the first scenario, a temperature control unit capable of regulating the temperature of the eruption medium is further required, located within the gas passages of the pressure box and the high-pressure gas cylinder, and / or within the pressure box. In this case, the temperature signal from the temperature control unit is also transmitted to the signal triggering device. Specifically, the pressure and temperature of the gas in the pressure box (which is fed back to the signal triggering device via the pressure detection feedback unit) are both fed back to the signal triggering device. The signal triggering device (for example, in the present invention, a computer may be used) adjusts the pressure and temperature values ​​based on the difference between them and preset parameter values, thereby activating the eruption signal when both pressure and temperature values ​​fall within the preset parameter range. It should be noted that when the pressure and temperature values ​​differ from the preset parameter values, these adjustments can be made in a manner understood by those skilled in the art. For example, if the temperature value is not within the preset parameter range, temperature adjustment can be achieved by controlling the temperature control unit. At the same time, the gas valve 33 here can also be a two-way valve, so that during the temperature change process, if the gas pressure is above the preset parameter range, a part of the ejected gas in the pressure box can be passed into the high-pressure gas tank through the two-way valve to ensure the dynamic regulation of the pressure value and the temperature value, and finally make the two be within the preset parameter range. At the same time, the preset parameter ranges of the pressure value and the temperature value here can be selected accordingly according to the actual situation, and will not be elaborated here. Furthermore, in order to reduce the problem of sudden large changes in temperature during temperature regulation and reduce the reverse passage of the two-way valve as much as possible, the temperature control unit here can adopt a multi-stage temperature control structure 35, and the temperature is gradually increased or decreased until the temperature of the temperature control structure closest to or located on the pressure box is within the preset parameter range. As Figure 4 As shown, the multi-stage temperature control structure 35 is three-stage. Of course, this is only a specific embodiment, and the present invention is not limited to the specific three-stage temperature control structure. Moreover, the temperature control structure can also be at least partially arranged in the pressure box. At the same time, adjacent temperature control structures can be arranged at intervals or continuously, which will not be elaborated here.

[0062] It should be explained that in the first case, because the introduction of gas is preset, the pressure of the gas in the pressure box is relatively controllable after the gas is introduced, and a pressure detection feedback unit does not need to be installed in the pressure box. In the second case, due to the introduction of temperature, the pressure has a certain variable effect. Therefore, in the second case, an additional pressure detection feedback unit needs to be set up to monitor and feedback the pressure of the gas in the pressure box.

[0063] Monitoring system 4 includes a high-speed camera 42 and a pressure sensor 41 (located within the eruption simulation chamber 1, as mentioned above). Multiple high-speed cameras 42 can be installed, for example, at the front and side of the natural gas hydrate decomposition pipeline (more high-speed cameras 42 can also be installed at other angles). These cameras can capture the particle decomposition process, flow pattern changes, and bed expansion in all directions. With a frame rate of at least 5000 frames per second, they clearly capture the flow and reaction details within the natural gas hydrate decomposition pipeline, providing intuitive image data for subsequent analysis. Simultaneously, a light source 43 provides observation light to the eruption simulation chamber 1. Specifically, a ring-shaped LED cold light source 43 can be used to prevent heat generation and flow field interference during the experiment. Pressure sensors 41 (range 0-5 MPa, accuracy ±0.1%) can be arranged every 20 cm along the height of the chamber to monitor pressure and pressure gradient changes within the natural gas hydrate eruption.

[0064] Data collection and processing system 5: Connected to the eruption medium simulation system 3, high-speed camera 42, and pressure sensor 41, it utilizes a high-speed data acquisition card and specialized data processing software to collect, store, and process experimental data in real time, enabling visualization and analysis of the data, facilitating rapid acquisition and analysis of experimental results. Data collection and recording can also be accomplished using a computer 5 capable of data analysis and processing.

[0065] The following is a further explanation in conjunction with a specific simulation method.

[0066] Step 1, sample preparation: silty clay (particle size ≤ 0.075 mm) from the seabed hydrate distribution area is selected as the sediment skeleton for natural gas hydrate synthesis, and the silty clay is mixed with distilled water to a certain moisture content of soil sample 6, which is placed in the eruption simulation box 1, and the moisture content of the soil sample 6 is controlled at 15%-25%; the soil sample 6 is vibrated and compacted uniformly using the vibration table 21 in the sample preparation system 2, and the vibration compaction time is ≥ 30 minutes, and the porosity ratio after compaction is ≤ 0.6 (for example, in a specific operation, the vibration frequency is 35 Hz, the amplitude is 4 mm, the time is 40 minutes, and the porosity ratio after compaction is 0.53); then, the surface of the soil sample 6 is leveled using a leveling structure to a surface flatness error of ≤ 1 mm;

[0067] Step 2, eruption simulation experiment: After the sample prepared in advance in the eruption simulation box 1 is leveled, a certain height of salt water is added (the salt water should simulate the water parameters in the actual environment as much as possible, and the liquid level is preferably about 2 / 3 of the box height. For example, in a specific embodiment, the salt water concentration is 3.5% NaCl solution, and the liquid level is 1.5m); the eruption duration control unit 34 sets the time through a custom Matlab program through a function generator, and sets it to 0.01-5s adjustable. The pressure control is to adjust the preset parameter value of the pressure by the pressure regulating valve, and the gas is After the gas is input into the pressure box, the high-pressure gas tank is closed; the monitoring system 4 is used to measure and record data information; after the solenoid valve connected to the pressure box is opened, the high-pressure gas is input into the eruption simulation box 1 by the pressure box, and the high-speed camera 42 of the monitoring system 4 is used to record the flow process of the gas, liquid and solid three-phases and the soil layer damage characteristics in the eruption simulation box 1 during the gas eruption, and the flow pattern changes of the gas, liquid and solid three-phases are recorded; the pressure sensor 41 is used to collect the change information of the gas pressure during the eruption process; the data collection and processing system 5 (for example, it can be a computer) analyzes the impact of the eruption process on the soil layer damage and the height expansion of the particles.

[0068] In step 2, the eruption process is a multiple gradient eruption. For example, three eruptions can be performed according to the low pressure group, medium pressure group and high pressure group. In a specific embodiment, the eruption control parameter pressure gradient is set as follows: 1.5MPa (low pressure group), 2.5MPa (medium pressure group), 3.5MPa (high pressure group); solenoid valve opening time: 1.0s; trigger threshold: 1.5MPa (low pressure group), 2.0MPa (medium pressure group), 2.5MPa (high pressure group). The measurement system is configured with a high-speed camera 42 with a frame rate of 2000fps (local flow field capture); and a pressure sensor 41 with a sampling rate of 2kHz. In specific operations, the pressure loading and eruption triggering are set by a function generator to form a stepped pressure loading curve: low pressure group: 0.15MPa per level, 15s interval; high pressure group: 0.3MPa per level, 5s interval; when the pressure reaches the preset threshold, the time relay triggers the solenoid valve to open for 1.0s. The data is collected synchronously by a high-speed camera 42 to record the evolution of the eruption flow pattern; the pressure sensor 41 monitors the dynamic changes of the pressure in the box.

[0069] The sample preparation system 2 of the present invention uses silty clay from a submarine hydrate distribution area as the raw material for soil sample 6. This sample is prepared using a specific method in the sample preparation system 2, resulting in a simulation that more closely resembles an actual hydrate sample. The gas eruption is conducted in a specialized eruption simulation chamber 1, precisely controlling the density, pressure, and duration of the soil sample 6. This ensures the quality and stability of the experimental sample, laying the foundation for the accuracy of subsequent experiments.

[0070] The effective placement of 42 high-speed cameras allows for comprehensive and clear capture of instantaneous details such as the particle eruption process, flow pattern changes, and bed expansion. Through pressure gradient control and a visualization chamber design, the coupled gas-liquid-solid flow following hydrate decomposition eruption is accurately reproduced, particularly the dynamic process of gas breakthrough through the overlying soil layer. Furthermore, the high-temporal and spatial resolution measurement system enables quantification of flow pattern changes, particle migration, and energy dissipation mechanisms during the eruption process.

[0071] The eruption medium simulation system 3 of the present invention is further linked with a function generator through a time relay to achieve precise control of key parameters such as pressure loading rate and eruption duration.

[0072] At the same time, based on the separate design of the eruption medium storage mechanism 31 and the eruption medium supply mechanism 32 in the eruption medium simulation system 3, gradient experiments with adjustment of parameters such as pressure can be carried out, so that the experimental data can verify the influence of different pressure gradients on the hydrate eruption flow pattern, soil failure mode and particle migration law, providing an experimental basis for the design of the safe pressure window for deep-sea drilling, and providing a theoretical basis for the stability analysis of submarine hydrate mining wells and the design of blowout preventers.

[0073] Based on this, the present invention focuses on indoor gas-liquid-solid three-phase flow experiments simulating natural gas hydrate extraction. This approach addresses the shortcomings of existing technologies in studying multiphase flows involved in hydrate decomposition. Compared to traditional experimental setups, this invention can more accurately and comprehensively simulate and study these processes, providing strong support for the development of efficient natural gas hydrate extraction technologies.

[0074] Although the present invention has been described in detail above using general descriptions and specific embodiments, it will be apparent to those skilled in the art that modifications and improvements may be made thereto. Therefore, such modifications and improvements, without departing from the spirit of the present invention, are intended to be within the scope of protection claimed herein.

Claims

1. An experimental device for natural gas hydrate eruption, characterized in that: include: An eruption simulation box (1) is formed with a receiving cavity (11) for placing a sample simulating an eruption environment; a sample preparation system (2), at least partially located in the receiving chamber (11), for adjusting the sample in the receiving chamber (11) to a preset simulation value; An eruption medium simulation system (3), which is in communication with the eruption simulation box (1) and is used to provide an eruption medium with preset parameter values ​​into the eruption simulation box (1); A monitoring system (4) for dynamically monitoring the eruption process in the eruption simulation box (1); The data collection and processing system (5) is used to collect and process the data monitored by the monitoring system (4); wherein, The spray medium simulation system (3) comprises at least a spray medium storage mechanism (31) and a spray medium supply mechanism (32) which are sequentially connected to the spray simulation box (1), and a parameter adjustment mechanism for controlling a preset parameter value of the spray medium in the spray medium storage mechanism (31); and The preset parameter values ​​of the ejection medium at least include a pressure value and an ejection duration of the ejection medium.

2. The experimental device for natural gas hydrate eruption according to claim 1, characterized in that: The sample preparation system (2) at least comprises a vibration table (21) in contact with the eruption simulation box (1) and capable of oscillating the eruption simulation box (1), and a leveling structure movably arranged in the accommodating chamber (11) along the extension direction of the accommodating chamber (11); The flattening structure is used to flatten the surface of the sample in the containing cavity (11).

3. An experimental device for natural gas hydrate eruption according to claim 1 or 2, characterized in that: The monitoring system (4) comprises at least a high-speed camera (42) for photographing the eruption process in the eruption simulation box (1), and a pressure sensor (41) arranged on the inner wall of the eruption simulation box (1); Preferably, the monitoring system (4) further comprises a light source (43), and the light source (43) is used to provide observation light to the eruption simulation box (1).

4. An experimental device for natural gas hydrate eruption according to claim 1 or 2, characterized in that: A gas valve (33) is provided between the ejection medium storage mechanism (31) and the ejection medium supply mechanism (32), and a control device for controlling the output parameters of the ejection medium in the ejection medium storage mechanism (31) by controlling the gas valve (33); The parameter adjustment mechanism comprises at least an eruption duration control unit (34) arranged between the eruption simulation box (1) and the eruption medium storage mechanism (31), wherein the eruption duration control unit (34) is used to control the eruption duration of the eruption medium introduced into the eruption simulation box (1) by the eruption medium storage mechanism (31).

5. The experimental device for natural gas hydrate eruption according to claim 4, characterized in that: The eruption duration control unit (34) includes a solenoid valve connected between the eruption medium storage mechanism (31) and the eruption simulation box (1), a time relay electrically connected to the solenoid valve, and a signal triggering device electrically connected to the time relay, wherein the time relay triggers the opening and closing of the solenoid valve according to the signal triggering device.

6. The experimental device for natural gas hydrate eruption according to claim 5, characterized in that: The parameter adjustment mechanism further includes a temperature control unit for adjusting the temperature of the ejection medium in the ejection medium storage mechanism (31), and the temperature control unit is electrically connected to the signal triggering device; Preferably, the temperature control unit comprises a multi-stage temperature control structure (35) sequentially arranged from the spraying medium providing mechanism (32) to the spraying medium storage mechanism (31), and the control temperature of the multi-stage temperature control structure (35) increases or decreases step by step; More preferably, a pressure detection feedback unit is further provided in the spraying medium storage mechanism (31), and the pressure detection feedback unit is used to monitor the gas pressure in the spraying medium storage mechanism (31) and feed back the pressure to the signal triggering device.

7. A natural gas hydrate eruption simulation experimental method, characterized in that: Using the experimental device for natural gas hydrate eruption according to any one of claims 1 to 6, the natural gas hydrate eruption simulation experimental method comprises: S100, constructing a simulated eruption environment with preset simulation values ​​in an eruption simulation box; S200, adjusting the pressure value and the duration of the eruption medium until they reach the preset parameter values; S300, opening the eruption medium supply mechanism until the eruption medium reaches at least some of the preset parameter values, triggering the eruption medium to simulate eruption in the eruption simulation box, and monitoring the eruption process through the monitoring system; S400: Collect monitoring data of the monitoring system.

8. A natural gas hydrate eruption simulation experimental method according to claim 7, characterized in that: The construction method in step S100 specifically includes: S101, mixing silty clay with water until the moisture content is 15%-20% to obtain a soil sample; S102, placing the obtained soil sample in an eruption simulation box and vibrating and compacting it until the porosity ratio of the soil sample is no more than 0.6, and then leveling the soil sample to obtain a soil sample layer; S103, pouring simulated seawater into the eruption simulation box until the liquid level is 3 / 5-4 / 5 of the eruption simulation box, thereby constructing a simulated eruption environment.

9. A natural gas hydrate eruption simulation experimental method according to claim 7, characterized in that: In step S300, the simulated eruption process includes multiple intermittent eruptions performed at intervals, and the preset parameter values ​​of each intermittent eruption are not exactly the same; and, The preset parameter values ​​in step S200 include multiple sets of pressure values ​​and eruption durations of the eruption medium, each set of pressure values ​​and eruption durations corresponding to one intermittent eruption; Preferably, the preset pressure values ​​of adjacent intermittent eruptions increase or decrease in a gradient manner.

10. A natural gas hydrate eruption simulation experimental method according to claim 9, characterized in that: The preset parameter values ​​in step S200 also include the temperature of the spraying medium; Preferably, in step S300, when the pressure value and the eruption temperature of the eruption medium both reach a preset parameter range, the eruption medium is triggered to erupt.

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