Submicron micro-fluidic experimental device under high-temperature and high-pressure conditions and use method of submicron micro-fluidic experimental device

Abstract

The invention relates to the technical field of microscopic observation, and discloses a submicron micro-fluidic experimental device under high-temperature and high-pressure conditions and a use method of the submicron micro-fluidic experimental device. The heating insulation sleeve wraps the observation device chamber main body; the chamber main body upper gland is arranged above the observation device chamber main body; the water circulation cavity is arranged above the upper gland of the cavity main body in a sealing manner; the microscopic observation opening is formed above the water circulation cavity; the rotary bearing is arranged on the outer wall surface of the microscopic observation opening and is positioned in the water circulation cavity; the microcosmic chip is arranged in the microcosmic chip holder; the microscopic chip holder is arranged on the side surface of the observation device chamber main body; the water circulation temperature detection and flow velocity controller is connected with a water cooling circulation outlet of the water circulation cavity and the rotating bearing through a pipeline and an electric wire. And the water cooling device is respectively connected with the water circulation temperature detection and flow velocity controller and the water cooling circulation inlet through pipelines. According to the invention, high-precision microfluidic visualization experiments can be carried out under high-temperature and high-pressure conditions.

Description

Technical Field

[0001] The present application relates to the field of microscopic observation technology, and in particular to a submicron microfluidic experimental device and a method of using the device under high temperature and high pressure conditions. Background Art

[0002] Studying the flow laws of fluids in microscopic porous media is an important research method in many basic fields, and its application range covers fluid mechanics, energy development, environmental governance, materials science, biomedicine, etc. Taking the field of oil and gas as an example, understanding the flow laws of oil, gas and water in porous media is crucial to improving oil and gas recovery, optimizing mining plans and predicting production capacity. The combination of microfluidic chip technology and optical microscope creates conditions for intuitively studying the state of fluid occurrence and migration mechanism at the pore scale. For deep high-temperature and high-pressure oil and gas reservoirs, microfluidic chip holders are usually used to load microchips to simulate multiphase seepage experiments under high temperature and high pressure conditions. Under existing technical conditions, the channel size of microfluidic chips etched by conventional wet etching is usually between a few microns and hundreds of microns. High-end manufacturing processes (such as photolithography) can achieve 1 micron or even submicron level channel production. This level of channel can reflect the pores of low permeability oil and gas reservoirs. As the channel size of channel microfluidic chips continues to decrease, if microfluidic experiments are to be carried out under high temperature and high pressure conditions to accurately observe fluid migration, higher requirements are placed on microscopes and microfluidic model holders.

[0003] Prior art CN 118130756 A discloses a composite device and experimental method for dense sandstone rock electricity experiment and teaching. The experimental device uses a microscope combined with image processing technology to observe the seepage process and distribution state of multiphase fluid in a microscopic model chip, but it cannot simulate the real formation environment of high temperature and high pressure. Prior art CN118010587 A discloses a high temperature and high pressure microscopic visualization microscopic displacement model clamping device and use method. The experimental device uses a vacuum layer to ensure stable formation temperature conditions during the microscopic visualization displacement experiment, and can realize continuous observation of the microscopic model in different directions, but the clamping device is large in size and is only suitable for stereo microscopes.

[0004] The necessary experimental condition for conducting high-temperature and high-pressure microfluidics is a microfluidic chip holder that is resistant to high-temperature and high-pressure conditions. The current means of observation for conducting microfluidic experiments under high-temperature and high-pressure conditions is a stereo microscope. The advantages of stereo microscopes are long focal lengths and large observation fields, but the magnification is limited, and the effective observation size is usually tens of microns or more. The corresponding optical microscope or metallographic microscope can clearly observe the channel fluid conditions within a range of 10 microns, but the problem is that the focal length is too short. Taking a 100x objective lens as an example, the focal length is about 4mm. The thickness of the observation window of the high-temperature and high-pressure microfluidic holder involved in the currently disclosed technology is generally more than 2cm, which far exceeds the focal length range of the high-power objective lens, and cannot effectively support the study of the flow laws of high-temperature and high-pressure fluids in 10-micron channels. Summary of the invention

[0005] The purpose of the present application is to provide a submicron microfluidic experimental device under high temperature and high pressure conditions, so as to fully consider the problem that the conventional optical microscope high-power objective lens has a small focal length and is not resistant to high temperatures when observing high-precision microscopic models under different pressure conditions, and to realize high-precision microfluidic visualization experiments under high temperature and high pressure conditions.

[0006] In order to achieve the above purpose, the technical solutions adopted are as follows:

[0007] In the first aspect, the present application provides a submicron microfluidic experimental device under high temperature and high pressure conditions, including a heating and insulation sleeve, an observation device chamber body, a pressure cover on the chamber body, a water circulation cavity, a microscopic observation port, a rotating bearing, a microscopic chip, a microscopic chip holder, a water circulation temperature detection and flow rate controller, a water cooling device, a heating controller and a microscope;

[0008] The heating and insulation sleeve wraps the observation device chamber body; the upper pressure cover of the chamber body is arranged above the observation device chamber body; the water circulation cavity is sealingly arranged above the upper pressure cover of the chamber body; the microscope observation port is arranged above the water circulation cavity; the rotating bearing is arranged on the outer wall surface of the microscope observation port and is located inside the water circulation cavity; the micro chip is arranged inside the micro chip holder; the micro chip holder is sealingly arranged on the side of the observation device chamber body; the water circulation temperature detection and flow rate controller are respectively connected to the water cooling circulation outlet and the rotating bearing of the water circulation cavity through pipelines and wires; the water cooling device is respectively connected to the water circulation temperature detection and flow rate controller and the water cooling circulation inlet of the water circulation cavity through pipelines; the microscope is arranged above the microscope observation port.

[0009] Furthermore, it also includes a glass observation window and a glass observation window fixing plate, and the glass observation window is sealingly arranged at the bottom of the water circulation cavity through the glass observation window fixing plate.

[0010] Furthermore, the distance between the glass observation window and the micro chip does not exceed 0.1 mm.

[0011] Furthermore, a water circulation rotating blade is provided on the outer wall surface of the rotating bearing. When the rotating bearing is in operation, the water circulation rotating blade rotates around the central axis of the microscope observation port to accelerate the water circulation flow rate.

[0012] Furthermore, the microchip holder includes a microchip fixing plate, a microchip clamping plate and a connecting component, the microchip is placed on the microchip fixing plate, the microchip fixing plate is fixedly connected to the microchip clamping plate, the connecting component is fixedly connected to the microchip clamping plate, the connecting component is used to seal the microchip holder on the side of the observation device chamber body, a displacement inlet and a displacement outlet are provided on the connecting component, and the displacement inlet and the displacement outlet are connected to the microchip arranged on the microchip clamping plate through pipelines.

[0013] Furthermore, it also includes a first intermediate container, a second intermediate container, a double-cylinder displacement pump and a fluid metering container, the double-cylinder displacement pump is respectively equipped with the first intermediate container and the second intermediate container, the first intermediate container and the second intermediate container are respectively connected to the displacement inlet through pipelines, and the fluid metering container is connected to the displacement outlet through a pipeline.

[0014] Furthermore, a hydraulic oil through hole is arranged on the micro chip clamping plate, a confining pressure inlet and a confining pressure outlet are arranged on the upper pressure cover of the chamber body, and a confining pressure pump is also included, and the confining pressure pump is connected to the confining pressure inlet through a pipeline.

[0015] In a second aspect, the present application provides a method for using the submicron microfluidic experimental device under high temperature and high pressure conditions as described above, the method comprising:

[0016] Assemble submicron-scale microfluidic experimental devices under high temperature and high pressure conditions;

[0017] The objective lens waterproof sheet is embedded on the internal lens of the objective lens of the microscope; the objective lens is placed in the microscope observation port, the heating controller is turned on, and it is set to the constant temperature mode, and the main body of the observation device chamber is heated to the target temperature T; after reaching the target temperature T, the water circulation temperature detection and flow rate controller and the water cooling device are turned on, the rotation speed of the water circulation rotating blades is controlled, and the water temperature of the water cooling circulation outlet is monitored in real time to ensure that the water temperature is maintained at the temperature that the objective lens of the microscope can withstand;

[0018] Turn on the confining pressure pump and slowly inject hydraulic oil into the main body of the observation device chamber until no bubbles appear at the confining pressure outlet. Then plug the confining pressure outlet and turn on the constant pressure mode of the confining pressure pump to allow the hydraulic oil to fill the space between the microchip and the glass observation window through the hydraulic oil port, so that the upper and lower sides of the microchip maintain a constant confining pressure of the first pressure P1;

[0019] Focus by adjusting the height of the objective lens until the microscopic structure inside the microscopic chip is clearly observed;

[0020] Open the switch of the first intermediate container filled with water, start the double-cylinder displacement pump, saturate the microchip with water, observe the migration of the water phase in the microchip, maintain the internal pressure of the micromodel at the second pressure P2, and close the displacement inlet after the saturation is completed;

[0021] Turn on the switch of the second intermediate container filled with gas, start the double-cylinder displacement pump, and pressurize the gas to the third pressure P3, P3>P2; open the displacement inlet, inject gas into the microchip, and open the displacement outlet at the same time, and observe and record the seepage process of gas and water in the microchip through a microscope.

[0022] Furthermore, a submicron microfluidic experimental device under high temperature and high pressure conditions was assembled in the following manner:

[0023] Placing the microchip on the microchip fixing plate and fixing it on the microchip clamping plate by fixing bolts to obtain a microchip fixture; sealingly assembling the microchip fixture in the inlet of the side wall of the main body of the observation device chamber;

[0024] The upper gland of the chamber body is fixed to the chamber body of the observation device by bolts; the glass observation window is placed on the sapphire glass observation window fixing plate and fixed to the bottom of the water circulation chamber by bolts; the water circulation chamber is screwed into the hole in the middle of the upper gland of the chamber body through threads and rubber sealing rings; the microscopic observation port is screwed into the inside of the water circulation chamber through threads;

[0025] After wrapping the heating insulation sleeve around the main body of the observation device chamber, connect it to the heating controller through electric wires; connect the confining pressure pump to the confining pressure inlet on the pressure cover on the chamber body through pipelines; connect the water circulation temperature detection and flow rate controller to the water cooling circulation outlet and the water cooling device on the water circulation cavity through pipelines; connect the water cooling device to the water cooling circulation inlet on the water circulation cavity through pipelines; connect the double-cylinder displacement pump to the first intermediate container filled with water and the second intermediate container filled with gas through pipelines; connect the first intermediate container and the second intermediate container to the displacement inlet 16 on the micro chip fixture.

[0026] Use a vacuum pump to connect the displacement outlet on the microchip fixture, turn on the vacuum pump, extract the air in the microchip, close the outlet switch, and connect the fluid metering container.

[0027] Furthermore, after observing and recording the seepage process of air and water in the microscopic chip through a microscope, the method of use further includes a step of ending the experiment, and the step of ending the experiment includes:

[0028] Turn off the dual-cylinder displacement pump and stop heating. After the temperature reaches room temperature, turn off the confining pressure pump. After unloading the confining pressure, turn off the water circulation temperature detection, flow rate controller and water cooling device, and clean them.

[0029] The beneficial effects of this application are:

[0030] The focal length of a conventional optical microscope high-power objective lens is usually less than 1 cm and cannot withstand high temperatures. However, the device proposed in this application can use a high-power optical microscope objective lens to closely observe high-precision microscopic chips under high temperature and high pressure conditions to conduct microfluidic visualization experiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A schematic structural cross-sectional diagram of a submicron microfluidic experimental device under high temperature and high pressure conditions according to an embodiment of the present application is shown.

[0032] Figure 2 A three-dimensional schematic diagram of a microscopic chip holder of a submicron microfluidic experimental device under high temperature and high pressure conditions according to an embodiment of the present application is shown.

[0033] Figure 3 A schematic diagram of the overall layout of a submicron microfluidic experimental device under high temperature and high pressure conditions according to an embodiment of the present application is shown.

[0034] Figure 4 A real-object observation picture of a microscopic chip under a 100x metallographic microscope objective lens according to an embodiment of the present application is shown.

[0035] Reference numerals:

[0036] 1-heating and heat preservation sleeve; 2-observation device chamber body; 3-chamber body upper cover; 4-fixing bolt; 5-confining pressure inlet; 6-water cooling circulation inlet; 7-microscope observation port; 8-water cooling circulation outlet; 9-rotating bearing; 10-rubber sealing ring I; 11-confining pressure outlet; 12-water circulation chamber; 13-water circulation rotating blade; 14-objective lens waterproof sheet; 15-glass observation window; 16-displacement inlet; 17-displacement outlet; 18-rubber sealing ring Ⅱ; 19-micro chip; 20-glass observation window fixing plate; 21-micro chip fixing plate; 22-micro chip clamping plate; 23-confining pressure pump; 24-microscope; 25-water circulation temperature detection and flow rate controller; 26-water cooling device; 27-microscopic observation device; 28-first intermediate container; 29-second intermediate container; 30-dual-cylinder displacement pump; 31-heating controller; 32-fluid metering container; 33-hydraulic oil port; 34-connecting assembly. DETAILED DESCRIPTION

[0037] The following describes the embodiments of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. The present application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0038] The specific implementation of the present application is further described in detail below in conjunction with the drawings and examples.

[0039] Embodiment 1:

[0040] The present application embodiment provides a submicron microfluidic experimental device under high temperature and high pressure conditions, such as Figures 1 to 3As shown, the submicron microfluidic experimental device under high temperature and high pressure conditions includes a heating and insulation sleeve 1, an observation device chamber body 2, a chamber body upper pressure cover 3, a water circulation cavity 12, a microscopic observation port 7, a rotating bearing 9, a microscopic chip 19, a microscopic chip holder, a water circulation temperature detection and flow rate controller 25, a water cooling device 26, a heating controller 31 and a microscope 24; the heating and insulation sleeve 1 wraps the observation device chamber body 2; the chamber body upper pressure cover 3 is arranged above the observation device chamber body 2 by fixing bolts 4; the water circulation cavity 12 is sealed above the chamber body upper pressure cover 3; the microscopic observation port 7 It is arranged above the water circulation cavity 12; the rotating bearing 9 is arranged on the outer wall surface of the microscopic observation port 7 and is located inside the water circulation cavity 12; the microscopic chip 19 is arranged inside the microscopic chip holder; the microscopic chip holder is sealedly arranged on the side of the observation device chamber body 2; the water circulation temperature detection and flow rate controller is connected to the water cooling circulation outlet 8 and the rotating bearing 9 of the water circulation cavity 12 through pipelines and wires respectively; the water cooling device 26 is connected to the water circulation temperature detection and flow rate controller and the water cooling circulation inlet 6 of the water circulation cavity 12 through pipelines respectively; the microscope 24 is arranged above the microscopic observation port 7.

[0041] The heating and heat preservation sleeve 1 is a structure with a constant temperature heating and heat preservation function. For example, the heating and heat preservation sleeve 1 can be composed of a heating component, a temperature sensing component and a heat preservation layer, wherein the heating component is attached to the observation device chamber body 2, and the temperature sensing component can be arranged in the heat preservation layer. The heating component and the temperature sensing component are both connected to the heating controller 31. The heating controller 31 controls the heating component to work, and according to the set target temperature, combined with the temperature signal collected by the temperature sensing component, after the temperature signal reaches the target temperature, controls the heating component to stop working. Of course, the temperature sensing component can also be arranged on the outside of the heating component, which is in contact with the outside of the observation device chamber body 2, so that the collected temperature signal can better reflect the temperature of the observation device chamber body 2.

[0042] The observation device chamber body 2 is used to assemble a microscopic chip holder fixed with a microscopic chip 19, and the chamber body upper pressure cover 3 fixed at the upper end of the observation device chamber body 2 can facilitate the installation of the water circulation chamber 12. For example, the water circulation chamber 12 can be screwed into the hole set in the middle of the chamber body upper pressure cover 3 through the thread and the rubber sealing ring Ⅰ10; at the same time, the microscopic observation port 7 can be screwed into the water circulation chamber 12 through the thread, so as to facilitate the installation of the microscope 24. The microscope 24 can be selected as a metallographic microscope.

[0043] The water circulation cavity 12 is internally flowed with cooling water or heat transfer oil, and the temperature is adjusted by the water cooling device 26 and the water circulation temperature detection and flow rate controller 25 to prevent local overheating and ensure the cooling effect of the objective lens of the microscope 24. The function of the water circulation temperature detection and flow rate controller 25 is to detect the circulating water temperature and flow rate of the water circulation cavity 12 and to adjust the rotation speed of the rotating bearing 9 according to the detected circulating water temperature. The specific structure of the water circulation temperature detection and flow rate controller 25 can be, for example, a structure composed of a temperature sensor and a control chip, wherein the temperature sensor can be assembled on a pipeline corresponding to the required detection temperature, the control chip can be integrated with the temperature sensor, and the control chip is electrically connected to the temperature sensor to obtain the circulating water temperature collected by the temperature sensor. The rotating bearing 9 is an electric rotating shaft, specifically a structure that realizes rotation by driving the shaft with a motor, wherein a water circulation rotating blade 13 is provided on the outer wall surface of the rotating bearing 9, and when the rotating bearing 9 is running, the water circulation rotating blade 13 rotates around the central axis of the microscope observation port to accelerate the water circulation flow rate. The control chip can adjust the flow rate by controlling the rotation speed of the rotating bearing 9. For example, when the circulating water temperature is too high, the rotation speed can be appropriately increased to generate centrifugal force to accelerate the water circulation flow rate. The water cooling device 26 is a device that can achieve temperature reduction. For example, the water cooling device 26 can be a refrigerator, and the circulating water is cooled by the refrigerator and then circulated.

[0044] In some embodiments, Figure 1 As shown, the submicron microfluidic experimental device under high temperature and high pressure conditions also includes a glass observation window 15 and a glass observation window fixing plate 20 , and the glass observation window 15 is sealedly arranged at the bottom of the water circulation cavity 12 through the glass observation window fixing plate 20 .

[0045] Exemplarily, the glass observation window 15 can be placed on the glass observation window fixing plate 20 and fixed to the bottom of the water circulation chamber 12 by bolts, wherein the glass observation window 15 can be made of sapphire glass.

[0046] In some embodiments, Figure 1 As shown, the distance between the glass observation window 15 and the micro chip 19 does not exceed 0.1 mm, and the thickness of the glass observation window 15 can be set to 3.9 mm. During observation, the objective lens of the microscope 24 can be close to the glass observation window 15, and the minimum distance from the micro chip 19 can be controlled at 4 mm.

[0047] In some embodiments, Figure 2As shown, the microchip holder includes a microchip fixing plate 21, a microchip clamping plate 22 and a connecting component 34, the microchip 19 is placed on the microchip fixing plate 21, the microchip fixing plate 21 is fixedly connected to the microchip clamping plate 22, the connecting component 34 is fixedly connected to the microchip clamping plate 22, the connecting component 34 is used to seal the microchip holder on the side of the observation device chamber body 2, the connecting component 34 is provided with a displacement inlet 16, a displacement outlet 17 and a rubber sealing ring II, the displacement inlet 16 and the displacement outlet 17 are connected to the microchip 19 arranged on the microchip clamping plate 21 through a pipeline. The connecting assembly 34 can be assembled on the micro chip clamping plate 22 by bolts cooperating with the screw holes provided on the micro chip clamping plate 22, and the pipelines connected to the displacement inlet 16 and the displacement outlet 17 can be connected to the space where the micro chip 19 is located through the pipe holes provided on the micro chip clamping plate 22.

[0048] In some embodiments, Figure 2 and Figure 3 As shown, the submicron microfluidic experimental device under high temperature and high pressure conditions also includes a first intermediate container 28, a second intermediate container 29, a double-cylinder displacement pump 30 and a fluid metering container 32. The double-cylinder displacement pump 30 is respectively equipped with the first intermediate container 28 and the second intermediate container 29, the first intermediate container 28 and the second intermediate container 29 are respectively connected to the displacement inlet 16 through pipelines, and the fluid metering container 32 is connected to the displacement outlet 17 through a pipeline.

[0049] The first intermediate container 28 and the second intermediate container 29 are used to load different displacement media. For example, the first intermediate container 28 can be loaded with liquid medium, and the second intermediate container 29 can be loaded with gas medium. Control valves are respectively arranged on the pipelines connecting the first intermediate container 28 and the second intermediate container 29 with the displacement inlet 16. The two corresponding control valves serve as switches of the first intermediate container 28 and the second intermediate container 29 respectively. The double-cylinder displacement pump 30 is used to provide displacement power for the first intermediate container 28 or the second intermediate container 29. After the displacement is completed, the displacement media loaded in the first intermediate container 28 and the second intermediate container 29 will enter the fluid metering container 32 through the displacement outlet 17. The fluid metering container 32 can be configured with metering components, such as mass sensors, flow sensors, etc., which are used to measure data such as the mass and flow rate of the displacement media according to experimental needs.

[0050] In some embodiments, Figures 1 to 3 As shown, a hydraulic oil port 33 is provided on the micro chip clamping plate 22, a confining pressure inlet 5 and a confining pressure outlet 11 are provided on the upper pressure cover 3 of the chamber body, and a confining pressure pump 23 is also included, and the confining pressure pump 23 is connected to the confining pressure inlet 5 through a pipeline.

[0051] The function of the confining pressure pump 23 is to pressurize the micro chip 19 through the confining pressure inlet 5 and the hydraulic oil through hole 33 to achieve a constant confining pressure when the confining pressure outlet 11 is blocked. When the pressure is released, the confining pressure pump 23 is closed and the confining pressure outlet 11 is opened.

[0052] In some embodiments, Figure 1 As shown, an objective lens waterproof sheet 14 is embedded on the internal lens of the objective lens of the microscope 24 to play a waterproof role.

[0053] Embodiment 2:

[0054] The present application embodiment provides a method for using the submicron microfluidic experimental device under high temperature and high pressure conditions as described in Example 1, and the method comprises the following steps:

[0055] Step 1, prepare experimental equipment and tools, place the microchip 19 on the microchip fixing plate 21, and fix it on the microchip clamping plate 22 by fixing bolts; then put the entire microchip fixture into the entrance of the side wall of the observation device chamber body 2, and fix and seal it by fixing bolts and sealing rubber ring Ⅱ18.

[0056] Step 2, fix the upper pressure cover 3 of the chamber body to the chamber body 2 of the observation device by bolts; place the glass observation window 15 on the sapphire glass observation window fixing plate 20, and fix it to the bottom of the water circulation cavity 12 by bolts; screw the water circulation cavity 12 into the middle hole of the upper pressure cover of the chamber body through threads and rubber sealing ring Ⅰ10; screw the microscope observation port 7 into the inside of the water circulation cavity 12 through threads.

[0057] Step 3, after wrapping the entire microscopic observation device 27 with the heating insulation sleeve 1, connect it to the heating controller 31 through electric wires; connect the confining pressure pump 23 to the confining pressure inlet 5 on the pressure cover 3 on the chamber body through a pipeline; connect the water circulation temperature detection and flow rate controller 25 to the water cooling circulation outlet 6 and the water cooling device 26 on the water circulation cavity 12 through pipelines; connect the water cooling device 26 to the water cooling circulation inlet 8 on the water circulation cavity 12 through pipelines; connect the double-cylinder displacement pump 30 to the first intermediate container 28 filled with water and the second intermediate container 29 filled with gas through pipelines; then connect the first intermediate container 28 and the second intermediate container 29 to the displacement inlet 16 on the micro chip fixture.

[0058] Step 4, use a vacuum pump to connect to the displacement outlet 17 on the micro chip fixture, then turn on the vacuum pump, extract the air in the micro chip, close the outlet switch, and connect the fluid metering container 32.

[0059] Step 5, embed the objective lens waterproof sheet 14 on the internal lens of the metallographic microscope objective lens to play a waterproof role; then put the objective lens into the microscope observation port 7, turn on the heating controller 31, and set it to the constant temperature mode to heat the microscopic device to the target temperature T; at the same time, when it rises to a certain temperature, turn on the water circulation temperature detection and flow rate controller 25 and the water cooling device 26, control the rotation speed of the water circulation rotating blade 13 and monitor the water temperature of the water cooling circulation outlet 8 in real time to ensure that the water temperature is maintained within the temperature that the objective lens of the metallographic microscope can withstand.

[0060] Step 6, start the confining pressure pump 23, slowly inject hydraulic oil into the observation device chamber body 2, until no bubbles appear at the confining pressure outlet 11, plug the confining pressure outlet 11 with a dead plug, and start the confining pressure pump constant pressure mode. The hydraulic oil will fill the space between the micro chip and the sapphire observation window through the hydraulic oil port 33, so that the upper and lower sides of the micro chip maintain a constant confining pressure of the first pressure P1.

[0061] Step 7, focusing is then performed by adjusting the height of the objective lens until the microscopic structure inside the microscopic chip 19 can be clearly observed.

[0062] Step 8, open the switch of the first intermediate container 28 filled with water, start the double-cylinder displacement pump 30, saturate the micro chip 19 with water, observe the migration of the water phase in the micro chip, and then maintain the internal pressure of the micro model at the second pressure P2. After the saturation of water is completed, close the inlet switch.

[0063] Step 9, open the switch of the second intermediate container 29 filled with gas, start the dual-cylinder displacement pump 30, first pressurize the gas to the third pressure P3 (P3>P2), then open the inlet switch, inject gas into the microscopic model, and open the outlet switch at the same time, observe and record the seepage process of gas and water in the microscopic chip through a metallographic microscope.

[0064] Step 10, after the experiment is over, turn off the dual-cylinder displacement pump 30 and stop heating. After the temperature reaches room temperature, turn off the confining pressure pump 23, unload the confining pressure, then turn off the water circulation temperature detection and flow rate controller 25 and the water cooling device 26, and clean the device.

[0065] Finally, after the above steps, the microscopic chip observation image under the 100x metallographic microscope objective is as follows: Figure 4 As shown by Figure 4 It can be seen that the device proposed in this application can use a high-power optical microscope objective to closely observe high-precision microscopic chips under high temperature and high pressure conditions and conduct microfluidic visualization experiments.

[0066] The above implementation modes are only used to illustrate the present application, and are not intended to limit the present application. Ordinary technicians in the relevant technical field may make various changes and modifications without departing from the spirit and scope of the present application. Therefore, all equivalent technical solutions also belong to the scope of the present application, and the scope of patent protection of the present application shall be limited by the claims.

Claims

1. A submicron microfluidic experimental device under high temperature and high pressure conditions, characterized in that: It includes a heating and heat preservation sleeve, an observation device chamber body, a pressure cover on the chamber body, a water circulation cavity, a microscopic observation port, a rotating bearing, a microscopic chip, a microscopic chip holder, a water circulation temperature detection and flow rate controller, a water cooling device, a heating controller and a microscope; The heating and insulation sleeve wraps the observation device chamber body; the upper pressure cover of the chamber body is arranged above the observation device chamber body; the water circulation cavity is sealingly arranged above the upper pressure cover of the chamber body; the microscope observation port is arranged above the water circulation cavity; the rotating bearing is arranged on the outer wall surface of the microscope observation port and is located inside the water circulation cavity; the micro chip is arranged inside the micro chip holder; the micro chip holder is sealingly arranged on the side of the observation device chamber body; the water circulation temperature detection and flow rate controller are respectively connected to the water cooling circulation outlet and the rotating bearing of the water circulation cavity through pipelines and wires; the water cooling device is respectively connected to the water circulation temperature detection and flow rate controller and the water cooling circulation inlet of the water circulation cavity through pipelines; the microscope is arranged above the microscope observation port.

2. The submicron microfluidic experimental device under high temperature and high pressure conditions as claimed in claim 1, characterized in that: It also includes a glass observation window and a glass observation window fixing plate, and the glass observation window is sealingly arranged at the bottom of the water circulation cavity through the glass observation window fixing plate.

3. The submicron microfluidic experimental device under high temperature and high pressure conditions as claimed in claim 2, characterized in that: The distance between the glass observation window and the micro chip does not exceed 0.1 mm.

4. The submicron microfluidic experimental device under high temperature and high pressure conditions as claimed in claim 1, characterized in that: The outer wall surface of the rotary bearing is provided with water circulation rotating blades. When the rotary bearing is in operation, the water circulation rotating blades rotate around the central axis of the microscope observation port to accelerate the water circulation flow rate.

5. The submicron microfluidic experimental device under high temperature and high pressure conditions as claimed in claim 1, characterized in that: The microchip holder includes a microchip fixing plate, a microchip clamping plate and a connecting component, the microchip is placed on the microchip fixing plate, the microchip fixing plate is fixedly connected to the microchip clamping plate, the connecting component is fixedly connected to the microchip clamping plate, the connecting component is used to seal the microchip holder on the side of the observation device chamber body, a displacement inlet and a displacement outlet are provided on the connecting component, and the displacement inlet and the displacement outlet are connected to the microchip arranged on the microchip clamping plate through pipelines.

6. The submicron microfluidic experimental device under high temperature and high pressure conditions as claimed in claim 5, characterized in that: It also includes a first intermediate container, a second intermediate container, a double-cylinder displacement pump and a fluid metering container. The double-cylinder displacement pump is respectively equipped with the first intermediate container and the second intermediate container. The first intermediate container and the second intermediate container are respectively connected to the displacement inlet through pipelines, and the fluid metering container is connected to the displacement outlet through a pipeline.

7. The submicron microfluidic experimental device under high temperature and high pressure conditions as claimed in claim 5, characterized in that: The micro chip clamping plate is provided with a hydraulic oil through hole, the upper pressure cover of the chamber body is provided with a confining pressure inlet and a confining pressure outlet, and also includes a confining pressure pump, and the confining pressure pump is connected to the confining pressure inlet through a pipeline.

8. A method for using a submicron microfluidic experimental device under high temperature and high pressure conditions as claimed in any one of claims 1 to 7, characterized in that: The method of use includes: Assemble submicron-scale microfluidic experimental devices under high temperature and high pressure conditions; The objective lens waterproof sheet is embedded on the internal lens of the objective lens of the microscope; the objective lens is placed in the microscope observation port, the heating controller is turned on, and it is set to the constant temperature mode, and the main body of the observation device chamber is heated to the target temperature T; after reaching the target temperature T, the water circulation temperature detection and flow rate controller and the water cooling device are turned on, the rotation speed of the water circulation rotating blades is controlled, and the water temperature of the water cooling circulation outlet is monitored in real time to ensure that the water temperature is maintained at the temperature that the objective lens of the microscope can withstand; Turn on the confining pressure pump and slowly inject hydraulic oil into the main body of the observation device chamber until no bubbles appear at the confining pressure outlet. Then plug the confining pressure outlet and turn on the constant pressure mode of the confining pressure pump to allow the hydraulic oil to fill the space between the microchip and the glass observation window through the hydraulic oil port, so that the upper and lower sides of the microchip maintain a constant confining pressure of the first pressure P1; Focus by adjusting the height of the objective lens until the microscopic structure inside the microscopic chip is clearly observed; Open the switch of the first intermediate container filled with water, start the double-cylinder displacement pump, saturate the microchip with water, observe the migration of the water phase in the microchip, maintain the internal pressure of the micromodel at the second pressure P2, and close the displacement inlet after the saturation is completed; Turn on the switch of the second intermediate container filled with gas, start the double-cylinder displacement pump, and pressurize the gas to the third pressure P3, P3>P2; open the displacement inlet, inject gas into the microchip, and open the displacement outlet at the same time, and observe and record the seepage process of gas and water in the microchip through a microscope.

9. The method of use according to claim 8, characterized in that: Assemble the submicron microfluidic experimental device under high temperature and high pressure conditions as follows: Placing the microchip on the microchip fixing plate and fixing it on the microchip clamping plate by fixing bolts to obtain a microchip fixture; sealingly assembling the microchip fixture in the inlet of the side wall of the main body of the observation device chamber; The upper gland of the chamber body is fixed to the chamber body of the observation device by bolts; the glass observation window is placed on the sapphire glass observation window fixing plate and fixed to the bottom of the water circulation chamber by bolts; the water circulation chamber is screwed into the hole in the middle of the upper gland of the chamber body through threads and rubber sealing rings; the microscopic observation port is screwed into the inside of the water circulation chamber through threads; After wrapping the chamber body of the observation device with the heating insulation sleeve, connect it to the heating controller through electric wires; connect the confining pressure pump to the confining pressure inlet on the pressure cover on the chamber body through pipelines; connect the water circulation temperature detection and flow rate controller to the water cooling circulation outlet and the water cooling device on the water circulation cavity through pipelines; connect the water cooling device to the water cooling circulation inlet on the water circulation cavity through pipelines; connect the double-cylinder displacement pump to the first intermediate container filled with water and the second intermediate container filled with gas through pipelines; connect the first intermediate container and the second intermediate container to the displacement inlet on the micro chip fixture; Use a vacuum pump to connect the displacement outlet on the microchip fixture, turn on the vacuum pump, extract the air in the microchip, close the outlet switch, and connect the fluid metering container.

10. The method of use according to claim 8, characterized in that: After observing and recording the seepage process of air and water in the microscopic chip through a microscope, the method of use further includes a step of ending the experiment, and the step of ending the experiment includes: Turn off the dual-cylinder displacement pump and stop heating. After the temperature reaches room temperature, turn off the confining pressure pump. After unloading the confining pressure, turn off the water circulation temperature detection, flow rate controller and water cooling device, and clean them.

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