CN114624419B - Visual development simulation device and experimental method for hydrate - Google Patents

Abstract

The invention discloses a hydrate visual development simulation device and an experimental method, which belong to the technical field of petroleum and natural gas exploitation simulation, and comprise the following steps: the visual development simulation device host is provided with a closed space and a plurality of visual windows; the pressure control unit is communicated with the closed space; the liquid supply unit is communicated with the closed space; the sensor unit comprises a plurality of temperature and pressure sensors pre-buried at the bottom of the rock core; a temperature control unit; the vacuum unit is communicated with the closed space; the gas-liquid separation and collection unit is communicated with the closed space; the data and image acquisition, storage and processing unit comprises a plurality of high-speed cameras and computers, wherein the high-speed cameras and the computers are arranged corresponding to the visual window. The invention solves the problems that the existing natural gas hydrate development simulation device cannot realize visualization and indirect visualization, and the working pressure of the visualization device is low, and realizes the real-time observation, image and data acquisition and the associated processing of data and images by a computer of an experimenter in the natural gas hydrate development process.

Description

A hydrate visual development simulation device and experimental method

Technical field

The invention belongs to the technical field of oil and natural gas exploitation simulation, and specifically relates to a hydrate visual development simulation device and an experimental method.

Background technique

As a potential new energy source, natural gas hydrate has extremely broad development prospects and huge application space. In order to effectively reduce the technical cost of commercial extraction of natural gas hydrate and reduce its actual development technical risk, it is necessary to carry out natural gas hydrate development simulation. Experimental Study. In order to develop a more suitable mining method, evaluate the mechanism and mining effect of the mining method, and understand the characteristics of hydrate more truly and effectively, it is necessary to conduct a large number of simulation experiments in indoor experiments to simulate hydrate storage conditions and optimize the project. Parameters, in which the natural gas development simulation device is the necessary basic equipment.

The principle of natural gas hydrate development simulation experiment is to simulate the synthesis and decomposition process of hydrate in the core under different conditions such as natural and mining temperature and pressure. Most of the existing development simulation devices cannot observe the actual conditions that occur when simulating formations in experiments; or they can achieve indirect visualization through CT scanning and other methods; or the development simulation devices with visible surfaces can simulate low working pressure and cannot be visualized. The area is small and the application is limited.

Contents of the invention

In order to solve the above technical problems, the present invention adopts the following technical solutions:

A hydrate visualization development simulation device, including:

Visual development simulation device host, the visual development simulation device host has a closed space, the closed space is used to simulate the hydrate synthesis and decomposition process in the core under different conditions; the visual development simulation device host is provided with multiple viewing windows ;

A pressure control unit, the pressure control unit is connected to the sealed space and is used to provide methane gas into the sealed space and provide the pressure environment required for hydrate generation in the sealed space;

A liquid supply unit, the liquid supply unit is connected with the sealed space and is used to input pure water into the sealed space;

A sensor unit, which includes a plurality of temperature and pressure sensors embedded at the bottom of the rock core to achieve data collection of temperature and pressure fields during natural gas hydrate development simulation;

A temperature control unit, used to provide the temperature conditions required for hydrate generation to the host computer of the visualization development simulation device;

A vacuum unit, which is connected to the sealed space and is used to maintain a certain degree of vacuum in the sealed space;

A gas-liquid separation and collection unit, which is connected to the enclosed space and is used to separate and collect the water and gas of the generated natural gas during the development and simulation of natural gas hydrate, and can monitor water and methane gas in real time. quality changes;

A data and image acquisition, storage and processing unit. The data and image acquisition, storage and processing unit includes a computer and a plurality of high-speed cameras arranged corresponding to the viewing window. The high-speed cameras are used to record every step of the core decomposition. A state with the function of adjusting the frequency of recorded images as needed; the computer is connected to the sensor unit, the liquid supply unit, the pressure control unit, the gas-liquid separation and collection unit, and the high-speed camera signal , to achieve real-time collection and recording of the temperature, pressure, and water consumption, gas volume, water production, and gas volume in the closed space during the natural gas hydrate development simulation, and to perform correlation processing on the collected and recorded data and images.

Further, the top of the host computer of the visual development simulation device is provided with a top plate and a visual layer that are nested up and down; the top plate has multiple viewing holes, the visual layer is made of transparent material, and the visual layer is provided with There are a plurality of raised portions corresponding to the view holes of the top plate; the raised portions cooperate with the view holes to achieve the sealing of the host of the visual development simulation device and serve as the visual development simulation device The host's viewport.

Further, the pressure control unit includes a methane cylinder connected to the enclosed space and a first balance for measuring the mass change of the methane cylinder, and a connecting air pipe is provided between the methane cylinder and the enclosed space, A first one-way valve, a booster pump and a first pressure gauge are arranged in sequence on the connecting air pipe, and the first one-way valve is located on the side away from the methane cylinder.

Further, the liquid supply unit includes a pure water supplier connected to the sealed space and a second balance for measuring the quality change of the pure water supplier, with a A connecting water pipe is provided with a second one-way valve and a first constant flow pump in sequence, and the second one-way valve is located on a side away from the pure water supplier.

Further, the temperature control unit further includes a temperature control water tank, which is connected to the enclosed space through a temperature control water pipe, and a third one-way valve and a second constant flow pump are sequentially provided on the temperature control water pipe. , the third one-way valve is located on the side away from the temperature-controlled water tank.

Further, it also includes an input pipe, the connecting air pipe, the connecting water pipe and the temperature control water pipe are all connected to one end of the input pipe; the other end of the input pipe is connected to the enclosed space; A seventh pressure gauge and a second flow meter are provided.

Further, the gas-liquid separation and collection unit includes a gas-liquid separation component, a gas collection component and a water storage component. The gas-liquid separation component is connected to the enclosed space through a separation pipeline; a fourth gas-liquid separation component is provided on the separation pipeline. One-way valve and second pressure gauge; the fourth one-way valve is located on the side close to the gas collection component, and the gas-liquid separation component is used to separate water and gas from the natural gas produced during the development simulation of natural gas hydrates. ;

The gas collection assembly includes a gas collection bottle and a third balance for measuring the mass change of the gas collection bottle; the gas collection bottle and the gas-liquid separation assembly are connected by a gas collection pipeline, and the gas collection pipeline A first flow meter is provided;

The water storage assembly includes a water storage container and a fourth electronic balance for measuring mass changes of the water storage container; the water storage container and the gas-liquid separation assembly are connected through a liquid collection pipeline.

Further, the host computer of the visual development simulation device is provided with a plurality of external pipes connected to the enclosed space and provided independently, and the plurality of external pipes are respectively connected to the separation pipes; each external pipe is provided with There are one-way valves and pressure gauges.

Further, the vacuum unit includes a vacuum pump, the vacuum pump is connected to the separation pipeline through a vacuum pipeline, and the connection end of the vacuum pipeline and the separation pipeline is located between the fourth one-way valve and the second Between the pressure gauges; a fifth one-way valve is provided on the vacuum pipeline.

An experimental method for a hydrate visualization development simulation device, using the hydrate visualization development simulation device described in any one of the above, and the experimental method includes the following steps:

S10. Turn on the data and image acquisition, storage and processing unit. The preset high-speed camera image recording interval is 1s. The subsequent recording interval can be increased or reduced by the experimenter according to the real-time situation reflected in the device. Prepare to develop the simulation device from visualization. Materials are injected into the central wellhead of the host machine. The materials are methane gas, pure and gas-insoluble pure water, and the thermal fluid NaCl solution used in the development simulation. After confirming that all devices are assembled and connected, close all valves and start the temperature control unit. , set the working temperature to 2±0.5℃, and pre-cool the core environment in the host computer of the visual development simulation device;

S20. When the temperature sensor data arranged in the core stabilizes at the predetermined temperature, sequentially open the one-way valve and pressure gauge respectively provided on the external pipeline, as well as the fifth one-way valve and the second pressure gauge, and start the vacuum pump at the same time. The environment in the closed space of the host computer of the visual development simulation device is vacuumed, and the pre-vacuum degree is -0.1MPa. When the values of the above pressure gauges stably display the predetermined pressure value, the vacuum pump and the fifth one-way valve are closed. The vacuum stage has been reached in the confined space;

S30. Start the second electronic balance, the fourth electronic balance, the second one-way valve, the fourth one-way valve, and the first constant flow pump, and input pure water into the closed space of the host computer of the visual development simulation device. When the quality is equal to the value of pure water recovered in the water recovery container, close the first constant flow pump and the second one-way valve;

S40. Open the first one-way valve, the methane cylinder, the first electronic balance, the third electronic balance, the first flow meter, the second flow meter, the third electronic balance, and the booster pump. During the working process, the booster pump will The gas is pumped into the closed space. When the second flow meter is equal to the first flow meter and the value decreased by the first electronic balance is the same as the value increased by the third electronic balance, the fourth one-way valve and the one-way check valve installed on the external pipe line are closed. directional valve;

S50. The air inlet pipeline continues to work. When the value of the pressure sensor in the core reaches 5MPa, it stops working and closes the first one-way valve, booster pump and methane cylinder;

S60. Close all equipment except the data and image acquisition, storage and processing unit, and temperature control unit. Wait for the methane and water in the reaction chamber to continue to react. Observe the data and images displayed by the data and image processing computer. According to the characteristics of natural gas hydrate The phase diagram is synthesized and developed to determine the normal progress of the reaction. When the pressure and temperature data no longer change, each pressure gauge, temperature sensor and pressure sensor in the core collect real-time data to ensure that multiple high-definition cameras capture images of the entire reaction process. At the same time, the experimenter can observe the situation inside the device through the visual window in real time, increase or decrease the frequency of camera shooting according to the real-time reaction in the device, and save and analyze the data and image processing computer; when all the data no longer changes , proceed to the next step;

S70. After the natural gas hydrate generation stage is completed, conduct a mining simulation experiment. All the above devices remain unchanged. Open the temperature-controlled water tank. The temperature-controlled water tank storing the saturated NaCl solution is heated to 60 degrees Celsius. After the temperature-controlled water tank is heated up, open the third One-way valve, second constant flow pump, one-way valve installed on the external pipeline, gas-liquid separation component, third electronic balance, gas storage bottle, water storage container, fourth electronic balance, inject 60 degrees Celsius into the closed space Saturate the NaCl solution and wait for the natural gas hydrate to decompose. When the third electronic balance reading no longer changes, it proves that the natural gas hydrate decomposition stage is completed. At this time, all pipelines and devices except the data and image processing computers are closed in sequence. , after the data and image records are saved, all valves will be restored to the initial mode for data processing and image comparison.

Beneficial effects:

The invention provides a hydrate visual development simulation device and an experimental method. It adopts a nested combination of organic glass and stainless steel to manufacture the host in the development simulation device, and provides camera image recording and recording for the process of natural gas hydrate synthesis and decomposition. The method of real-time human eye observation solves the problems of low visualization and low simulation working pressure of existing natural gas hydrate development simulation devices, and realizes real-time observation, data collection and computerization by experimenters during the synthesis and decomposition of natural gas hydrates. Correlation processing of data and images.

Description of the drawings

Figure 1 is a schematic connection diagram of the overall structure of the visualization development simulation device of the present invention;

Figure 2 is a schematic structural diagram of the host computer of the visualization development simulation device of the present invention;

Figure 3 is a schematic structural diagram of the visual layer of the host computer of the visual development simulation device of the present invention;

Figure 4 is a schematic structural diagram of the stainless steel top plate of the host computer of the visualization development simulation device of the present invention;

Among them, 1. Data and image acquisition, storage and processing unit; 2. Visual development simulation device host; 3. Temperature control frame; 4. Third pressure gauge; 5. Fourth pressure gauge; 6. Fifth pressure gauge; 7 , the sixth pressure gauge; 8. the sixth one-way valve; 9. the seventh one-way valve; 10. the eighth one-way valve; 11. the ninth one-way valve; 12. the second pressure gauge; 13. the fifth one-way valve Directional valve; 14. Vacuum pump; 15. Fourth one-way valve; 16. Gas-liquid separation device; 17. First flow meter; 18. Gas storage bottle; 19. Third electronic balance; 20. Water storage container; 21. The fourth electronic balance; 22. The second flow meter; 23. The seventh pressure gauge; 24. The first one-way valve; 25. Booster pump; 26. The first pressure gauge; 27. Methane cylinder; 28. The first Electronic balance; 29. The third one-way valve; 30. The second constant flow pump; 31. Temperature control water tank; 32. The second one-way valve; 33. The first constant flow pump; 34. Pure water supplier; 35. Second electronic balance.

Detailed ways

This embodiment provides a hydrate visual development simulation device. The setting and connection process of the device are as follows:

The host computer 2 of the visual development simulation device has a closed space, and the closed space is used to simulate the hydrate synthesis and decomposition process in the core under different conditions; the host computer 2 of the visual development simulation device is provided with multiple viewing windows;

A pressure control unit, which is connected to the confined space and is used to provide methane gas into the confined space and provide the confined space with the pressure environment required for hydrate generation;

A liquid supply unit, which is connected to the confined space and is used to input pure water into the confined space;

Sensor unit, the sensor unit includes multiple temperature and pressure sensors embedded at the bottom of the core to achieve data collection of temperature and pressure during natural gas hydrate development simulation;

A temperature control unit, used to provide the temperature conditions required for hydrate generation to the visualization development simulation device host 2;

Vacuum unit, the vacuum unit is connected with the enclosed space and is used to maintain a certain degree of vacuum in the enclosed space;

Gas-liquid separation and collection unit, the gas-liquid separation and collection unit is connected to the closed space, used to separate and collect the water and gas of the generated natural gas during the development and simulation of natural gas hydrate, and can monitor the quality changes of water and methane gas in real time;

Data and image acquisition, storage and processing unit 1. The data and image acquisition, storage and processing unit 1 includes a computer and a plurality of high-speed cameras set corresponding to the viewing windows. The high-speed cameras are used to record every state of core decomposition and have the ability to It is necessary to adjust the frequency of recording images; the computer is connected to the sensor unit, liquid supply unit, pressure control unit, gas-liquid separation and collection unit, and high-speed camera signal to realize the temperature, pressure and natural gas hydrate development simulation in the closed space. The water consumption, gas volume, water production, and gas volume are collected and recorded in real time, and the collected and recorded data and images are correlated and processed.

In this embodiment, the top of the host computer 2 of the visualization development simulation device is provided with a top plate and a visual layer that are nested up and down; the top plate has multiple viewing holes, the visual layer is transparent, and the visual layer is provided with multiple and The viewing holes of the top plate correspond to the raised portions one by one; the raised portions cooperate with the viewing holes to achieve the sealing of the visual development simulation device host 2 and serve as the viewing window of the visual development simulation device host 2 .

Among them, the host computer 2 of the visual development simulation device has a maximum working pressure of 10MPa and an operating temperature of -10~85°C. It is composed of a self-made new visual high-pressure reaction device.

The host computer 2 of the visual development simulation device is mainly composed of cores, plates and other accessories. Specifically, they include: cuboid artificial core, rubber sleeve, high-strength stainless steel top plate with eight viewing hole openings, and polymethyl methacrylate (PMMA) plate. Visual layer, stainless steel side plates with no openings on all sides, bottom plate with injection and extraction interfaces, bolts, bolt holes, fluororubber seals, rubber gaskets, etc.

Among them, the main body of the visualization development simulation device host 2 adopts a rectangular parallelepiped structure composed of six panels, and each panel is a stainless steel plate with a thickness of 20 mm.

In this embodiment, the specifications of the artificial rock core are 300mm×300mm×45mm inside; four temperature and pressure sensors are pre-embedded at the bottom of the core, and the distance between each two is more than 90mm in the front, back, left, and right.

The specifications of the stainless steel top plate are 300mm × 300mm × 40mm. In order to facilitate real-time observation and recording of the process of hydrate generation and decomposition, eight viewing holes with a diameter of 26mm are provided on the top plate as viewing windows.

Among them, there are 8 circular visual windows on the top plate, evenly distributed at the midpoint of the diagonal line connecting the collection point of the upper square wall to the position of the lower wall and the midpoint of the line.

Considering the strength of the visual window of the developed simulation device, as an optimization solution of the embodiment of the present invention, the visible layer in the present invention is made of high-strength polymethacrylate (PMMA) sheet plexiglass, with a specification of 300mm×300mm×20mm The rectangular parallelepiped has a cylindrical protrusion with a diameter of 26mm and a height of 20mm at the position where the window is opened. The specific shape is shown in Figure 3.

The roof is made of stainless steel walls with dimensions of 300mm × 300mm × 20mm. During the development simulation, 8 windows with a diameter of 26mm are evenly distributed on the connection line corresponding to the injection and production wellheads. The specific distribution positions are shown in Figure 4.

The visible organic glass layer and the high-strength stainless steel layer are assembled in a nested form and fixed with polyurethane glue. The thickness after mating is 300mm×300mm×40mm.

The left and right side plates of the host computer of the visual development simulation device are 360×340×20mm stainless steel plates, the front and rear side plates are 360×300×20mm stainless steel plates, and the bottom plate is 300×300×20mm stainless steel, as shown in Figure 2.

The host computer of the visual development simulation device has a total of 24 bolts and corresponding bolt ports. The bolt specifications are M6×30. The bolt installation positions are shown in Figure 2.

Among them, four 10mm openings are evenly distributed on the four connections between the four corners of the bottom plate and the center, and are provided with wellheads for collection during simulation. A 10mm opening is designed in the center of the bottom plate, and a wellhead for injection during simulation is provided.

The circuit connects the pressure and temperature sensors and the computer through the acquisition wellhead in the bottom plate. Through the processing of the data acquisition system, the real-time pressure and temperature conditions of the model in the experiment can be obtained.

In this embodiment, rubber sleeves are tightly fitted on the four sides of the artificial rock core, and six splints are clamped on the six sides of the artificial rock core. The joints of the six plates are sealed with rubber gaskets and tightened with bolt structures. , a fluororubber sealing ring is installed at the joint between the bottom plate and the simulated wellhead.

In this embodiment, the pressure control unit includes a methane cylinder 27 connected to the closed space and a first balance for measuring the mass change of the methane cylinder 27. A connecting gas pipe is provided between the methane gas cylinder 27 and the closed space. The connecting gas pipe is connected in sequence. A first one-way valve 24 , a booster pump 25 and a first pressure gauge 26 are provided. The first one-way valve 24 is located on the side away from the methane cylinder 27 .

In this embodiment, the liquid supply unit includes a pure water supplier 34 connected to the sealed space and a second balance for measuring the quality change of the pure water supplier 34. A connecting water pipe is provided between the pure water supplier 34 and the sealed space. A second one-way valve 32 and a first constant flow pump 33 are arranged on the water pipe in sequence. The second one-way valve 32 is located on the side away from the pure water supplier 34 .

In this embodiment, the temperature control unit also includes a temperature control water tank 31. The temperature control water tank 31 is connected to the enclosed space through a temperature control water pipe. The temperature control water pipe is sequentially provided with a third one-way valve 29 and a second constant flow pump 30. The third one-way valve 29 is located on the side away from the temperature control water tank 31 .

In this embodiment, an input pipe is also included. The connecting air pipe, connecting water pipe and temperature control water pipe are all connected to one end of the input pipe; the other end of the input pipe is connected to the enclosed space; a seventh pressure gauge and a second pressure gauge are provided on the input pipe. Flowmeter22.

In this embodiment, the gas-liquid separation and collection unit includes a gas-liquid separation component, a gas collection component and a water storage component. The gas-liquid separation component is connected to the closed space through a separation pipeline; a fourth one-way valve 15 and a fourth check valve 15 are provided on the separation pipeline. The second pressure gauge 12 and the fourth one-way valve 15 are located on the side close to the gas collection assembly. The gas-liquid separation assembly is used to separate water and gas from the natural gas produced during the development simulation of natural gas hydrate.

In this embodiment, the gas-liquid separation component is the gas-liquid separation device 16, which belongs to the existing technology and will not be described again here.

The gas collection assembly includes a gas collection bottle and a third balance for measuring the mass change of the gas collection bottle; the gas collection bottle and the gas-liquid separation assembly are connected through a gas collection pipeline, and the gas collection pipeline is provided with a first flow meter 17 .

The water storage assembly includes a water storage container 20 and a fourth electronic balance 21 for measuring the mass change of the water storage container 20; the water storage container 20 and the gas-liquid separation assembly are connected through a liquid collection pipeline.

In this embodiment, the host computer of the visual development simulation device is provided with a plurality of external pipes connected to the enclosed space and set independently. The plurality of external pipes are respectively connected to the separation pipes; each external pipe is provided with a one-way pipe. Valves and pressure gauges.

In this embodiment, four external pipes are included, which are respectively set as the first external pipe, the second external pipe, the third external pipe and the fourth external pipe; wherein, the first external pipe is provided with The third pressure gauge 4 and the sixth one-way valve 8; the second external pipe is provided with the fourth pressure gauge 5 and the seventh one-way valve 9; the third external pipe is provided with the fifth pressure gauge 6 and the eighth one-way valve Valve 10; the fourth external pipe is provided with a sixth pressure gauge 7 and a ninth one-way valve 11.

In this embodiment, the vacuum unit includes a vacuum pump 14. The vacuum pump 14 is connected to the separation pipeline through a vacuum pipeline. The connection end of the vacuum pipeline and the separation pipeline is located between the fourth one-way valve 15 and the second pressure gauge 12; on the vacuum pipeline A fifth one-way valve 13 is provided.

In this embodiment, the temperature control unit is a temperature control frame 3, in which eight high-speed cameras are fixedly installed on the temperature control frame 3.

An experimental method for a hydrate visual development simulation device, using the hydrate visual development simulation device provided above, the experimental method includes the following steps:

S10. Turn on the data and image acquisition, storage and processing unit. The preset high-speed camera image recording interval is 1s. The subsequent recording interval can be increased or reduced by the experimenter according to the real-time situation reflected in the device. Prepare to develop the simulation device from visualization. Inject materials into the central wellhead of host 2. The materials are methane gas, pure and gas-insoluble pure water, and the hot fluid NaCl solution used in the development simulation. After confirming that all devices are assembled and connected, close all valves and start temperature control. unit, set the working temperature to 2±0.5°C, and pre-cool the core environment in the host computer 2 of the visual development simulation device.

S20. When the temperature sensor data arranged in the core stabilizes at the predetermined temperature, open the third pressure gauge 4, the sixth one-way valve 8, the fourth pressure gauge 5, the seventh one-way valve 9, and the fifth pressure gauge in sequence. 6. The eighth one-way valve 10, the sixth pressure gauge 7 and the ninth one-way valve 11, as well as the fifth one-way valve 13 and the second pressure gauge 12, start the vacuum pump 14 at the same time to seal the visualization development simulation device host 2 The environment in the space is vacuumed, and the pre-vacuum degree is -0.1MPa. When the values of the above-mentioned pressure gauges stably display the predetermined pressure value, close the vacuum pump 14 and the fifth one-way valve 13. At this time, the enclosed space has reached vacuum stage.

S30. Start the second electronic balance 35, the fourth electronic balance 21, the second one-way valve 32, the fourth one-way valve 15, and the first constant flow pump 33, and input pure water into the closed space of the visualization development simulation device host 2 , when the quality of the input pure water is equal to the value of the recovered pure water in the water recovery container, it is proved that the pores of the core in the closed space have been filled with pure water, and the first constant flow pump 33 and the second one-way valve 32 are closed. At this time, the water in the core voids in the closed space has reached the saturation stage, and the next step is carried out.

S40. Open the first one-way valve 24, the methane cylinder 27, the first electronic balance 28, the third electronic balance 19, the first flow meter 17, the second flow meter 22, the third electronic balance 19, and the booster pump 25. During operation, the booster pump 25 pumps methane gas into the closed space. When the second flow meter 22 is equal to the first flow meter 17 and the value decreased by the first electronic balance 28 is the same as the value increased by the third electronic balance 19, It is proved that the reaction chamber has been filled with methane gas. At this time, the fourth one-way valve 15 as well as the sixth one-way valve 8, the seventh one-way valve 9, the eighth one-way valve 10 and the ninth one-way valve 11 are closed.

S50. The air inlet pipeline continues to work. When the value of the pressure sensor in the core reaches 5MPa, it stops working. Close the first one-way valve 24, the booster pump 25 and the methane cylinder 27. At this time, the reaction chamber has reached the saturation of gas drive water. stage, proceed to the next step.

S60. Close all equipment except the data and image acquisition, storage and processing unit, and temperature control unit. Wait for the methane and water in the reaction chamber to continue to react. Observe the data and images displayed by the data and image processing computer. According to the characteristics of natural gas hydrate The phase diagram is synthesized and developed to determine the normal progress of the reaction. When the pressure and temperature data no longer change, each pressure gauge, temperature sensor and pressure sensor in the core collect real-time data to ensure that multiple high-definition cameras capture images of the entire reaction process. At the same time, the experimenter can observe the situation inside the device through the visual window in real time, increase or decrease the frequency of camera shooting according to the real-time reaction in the device, and save and analyze the data and image processing computer; when all the data no longer changes , proceed to the next step.

S70. After the natural gas hydrate generation stage is completed, conduct a mining simulation experiment. All the above devices remain unchanged. The temperature-controlled water tank 31 is opened, and the temperature-controlled water tank 31 storing the saturated NaCl solution is heated to 60 degrees Celsius. After the temperature control water tank 31 is heated up, open the third one-way valve 29, the second constant flow pump 30, the one-way valve set on the external pipe line, the gas-liquid separation component, the third electronic balance 19, the gas storage bottle 18, and the water collection tank. The container 20 and the fourth electronic balance 21 inject a saturated NaCl solution of 60 degrees Celsius into the closed space and wait for the natural gas hydrate to decompose. When the reading of the third electronic balance 19 no longer changes, it proves that the natural gas hydrate decomposition stage has progressed. After completion, all pipelines and devices except the data and image processing computers will be closed in sequence. After the data and image records are saved, all valves will be restored to their initial mode for data processing, image comparison, and data and image correlation processing.

The above are only preferred embodiments of the present invention and do not limit the technical scope of the present invention. Therefore, any minor modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention still belong to the scope of the present invention. the scope of the technical solution of the present invention.

Claims (9)

1. A hydrate visual development simulation device, characterized by including: Visual development simulation device host, the visual development simulation device host has a closed space, the closed space is used to simulate the hydrate synthesis and decomposition process in the core under different conditions; the visual development simulation device host is provided with multiple viewing windows ; A pressure control unit, the pressure control unit is connected to the sealed space and is used to provide methane gas into the sealed space and provide the pressure environment required for hydrate generation in the sealed space; A liquid supply unit, the liquid supply unit is connected with the sealed space and is used to input pure water into the sealed space; A sensor unit, which includes a plurality of temperature and pressure sensors embedded at the bottom of the rock core to achieve data collection of temperature and pressure fields during natural gas hydrate development simulation; A temperature control unit, used to provide the temperature conditions required for hydrate generation to the host computer of the visualization development simulation device; A vacuum unit, which is connected to the sealed space and is used to maintain a certain degree of vacuum in the sealed space; A gas-liquid separation and collection unit, which is connected to the enclosed space and is used to separate and collect the water and gas of the generated natural gas during the development and simulation of natural gas hydrate, and can monitor water and methane gas in real time. quality changes; A data and image acquisition, storage and processing unit. The data and image acquisition, storage and processing unit includes a computer and a plurality of high-speed cameras arranged corresponding to the viewing window. The high-speed cameras are used to record every step of the core decomposition. A state with the function of adjusting the frequency of recorded images as needed; the computer is connected to the sensor unit, the liquid supply unit, the pressure control unit, the gas-liquid separation and collection unit, and the high-speed camera signal , to achieve real-time collection and recording of the temperature, pressure, water consumption, gas volume, water production, and gas volume in the closed space during the natural gas hydrate development simulation, and to perform correlation processing on the collected and recorded data and images; The top of the host computer of the visual development simulation device is provided with a top plate and a visible layer that are nested up and down; the top plate has multiple viewing holes, the visible layer is made of transparent material, and the visible layer is provided with multiple A raised portion that corresponds one-to-one with the view hole of the top plate; the raised portion cooperates with the view hole to achieve the sealing of the host of the visual development simulation device and serves as a removable seal of the host of the visual development simulation device. Windows; The top plate is made of stainless steel, the visible layer is polymethylmethacrylate (PMMA) plate, and the side plates are made of stainless steel. 2. The hydrate visualization development simulation device according to claim 1, characterized in that the pressure control unit includes a methane cylinder connected to the closed space and a first electronic balance for measuring mass changes of the methane cylinder. , a connecting air pipe is provided between the methane cylinder and the enclosed space, a first one-way valve, a booster pump and a first pressure gauge are arranged in sequence on the connecting air pipe, and the first one-way valve is located away from One side of the methane cylinder. 3. The hydrate visual development simulation device according to claim 2, characterized in that the liquid supply unit includes a pure water supplier connected to the closed space and a second measuring device for measuring quality changes of the pure water supplier. Electronic balance, a connecting water pipe is provided between the pure water supplier and the enclosed space, a second one-way valve and a first constant flow pump are arranged in sequence on the connecting water pipe, the second one-way valve is located far away One side of the pure water supplier. 4. The hydrate visual development simulation device according to claim 3, characterized in that the temperature control unit further includes a temperature control water tank, the temperature control water tank is connected to the enclosed space through a temperature control water pipe, and the temperature control unit A third one-way valve and a second constant-flow pump are arranged on the warm water pipe in sequence, and the third one-way valve is located on a side away from the temperature-controlled water tank. 5. The hydrate visual development simulation device according to claim 4, further comprising an input pipe, the connecting air pipe, the connecting water pipe and the temperature control water pipe are all connected to one end of the input pipe; The other end of the input pipe is connected to the enclosed space; a seventh pressure gauge and a second flow meter are provided on the input pipe. 6. The hydrate visual development simulation device according to claim 5, characterized in that the gas-liquid separation and collection unit includes a gas-liquid separation component, a gas collection component and a water storage component, and the gas-liquid separation component and the The sealed spaces are connected through a separation pipeline; a fourth one-way valve and a second pressure gauge are provided on the separation pipeline; the fourth one-way valve is located on the side close to the gas collection component, and the gas-liquid separation component Used for water and gas separation of natural gas produced during natural gas hydrate development simulation; The gas collection assembly includes a gas storage bottle and a third electronic balance for measuring the mass change of the gas storage bottle; the gas storage bottle and the gas-liquid separation assembly are connected by a gas collection pipeline, and the gas collection pipe The road is equipped with a first flow meter; The water storage assembly includes a water storage container and a fourth electronic balance for measuring mass changes of the water storage container; the water storage container and the gas-liquid separation assembly are connected through a liquid collection pipeline. 7. The hydrate visualization development simulation device according to claim 6, characterized in that the host computer of the visualization development simulation device is provided with a plurality of external pipes connected to the enclosed space and independently arranged, and the plurality of external pipes are connected to the enclosed space. The pipelines are respectively connected with the separation pipelines; each external pipeline is equipped with a one-way valve and a pressure gauge. 8. The hydrate visualization development simulation device according to claim 7, characterized in that the vacuum unit includes a vacuum pump, the vacuum pump is connected to the separation pipeline through a vacuum pipeline, and the vacuum pipeline is connected to the separation tube. The connection end of the pipeline is located between the fourth one-way valve and the second pressure gauge; a fifth one-way valve is provided on the vacuum pipeline. 9. An experimental method for a hydrate visual development simulation device, characterized in that the hydrate visual development simulation device according to any one of claims 1 to 8 is used, and the experimental method includes the following steps: S10. Turn on the data and image acquisition, storage and processing unit. The preset high-speed camera image recording interval is 1s. The subsequent recording interval can be increased or reduced by the experimenter according to the real-time situation reflected in the device. Prepare to develop the simulation device from visualization. Materials are injected into the central wellhead of the host machine. The materials are methane gas, pure and gas-insoluble pure water, and the thermal fluid NaCl solution used in the development simulation. After confirming that all devices are assembled and connected, close all valves and start the temperature control unit. , set the working temperature to 2±0.5℃, and pre-cool the core environment in the host computer of the visual development simulation device; S20. When the temperature sensor data arranged in the core stabilizes at the predetermined temperature, sequentially open the one-way valve and pressure gauge respectively provided on the external pipeline, as well as the fifth one-way valve and the second pressure gauge, and start the vacuum pump at the same time. The environment in the closed space of the host computer of the visual development simulation device is vacuumed, and the pre-vacuum degree is -0.1MPa. When the values of the above pressure gauges stably display the predetermined pressure value, the vacuum pump and the fifth one-way valve are closed. The vacuum stage has been reached in the confined space; S30. Start the second electronic balance, the fourth electronic balance, the second one-way valve, the fourth one-way valve, and the first constant flow pump, and input pure water into the closed space of the host computer of the visual development simulation device. When the quality is equal to the value of pure water recovered in the water storage container, close the first constant flow pump and the second one-way valve; S40. Open the first one-way valve, the methane cylinder, the first electronic balance, the third electronic balance, the first flow meter, the second flow meter, and the booster pump. During the working process, the booster pump pumps the methane gas into the closed space. Within, when the second flow meter is equal to the first flow meter and the value decreased by the first electronic balance is the same as the value increased by the third electronic balance, close the fourth one-way valve and the one-way valve provided on the external pipeline; S50. The air inlet pipeline continues to work. When the value of the pressure sensor in the core reaches 5MPa, it stops working and closes the first one-way valve, booster pump and methane cylinder; S60. Close all equipment except the data and image acquisition, storage and processing unit, and temperature control unit. Wait for the methane and water in the reaction chamber to continue to react. Observe the data and images displayed by the data and image processing computer. According to the characteristics of natural gas hydrate The phase diagram is synthesized and developed to determine the normal progress of the reaction. When the pressure and temperature data no longer change, each pressure gauge, temperature sensor and pressure sensor in the core collect real-time data to ensure that multiple high-definition cameras capture images of the entire reaction process. At the same time, the experimenter can observe the situation inside the device through the visual window in real time, increase or decrease the frequency of camera shooting according to the real-time reaction in the device, and save and analyze the data and image processing computer; when all the data no longer changes , proceed to the next step; S70. After the natural gas hydrate generation stage is completed, conduct a mining simulation experiment. All the above devices remain unchanged. Open the temperature-controlled water tank and heat the temperature-controlled water tank storing the saturated NaCl solution to 60 degrees Celsius; After the temperature control water tank is heated up, open the third one-way valve, the second constant flow pump, the one-way valve set on the external pipe line, the gas-liquid separation component, the third electronic balance, the gas storage bottle, the water storage container, and the fourth electronic balance. Balance, inject a saturated NaCl solution of 60 degrees Celsius into the closed space, and wait for the natural gas hydrate to decompose. When the reading of the third electronic balance no longer changes, it proves that the natural gas hydrate decomposition stage is completed. At this time, turn off the data in turn. And all pipelines and devices outside the image processing computer. After the data and image records are saved, all valves will be restored to the initial mode to perform data processing, image comparison, and data and image correlation processing.