Emulsion droplet preparation apparatus and method, contact angle measurement apparatus and method

Abstract

An emulsion droplet preparation device and method, a contact angle measuring device and method. The emulsion droplet preparation device comprises: a stirring tank; a gas charging device connected to the stirring tank through a first pipeline and configured to charge gas into the closed stirring cavity to form a pressurized gas-dissolved crude oil emulsion in the closed stirring cavity; a piston storage device connected to the stirring tank through a second pipeline and configured to extract the pressurized gas-dissolved crude oil emulsion in the closed stirring cavity; a closed operation table connected to the closed stirring cavity through a third pipeline and connected to the piston storage device through a fourth pipeline, the end of the fourth pipeline is provided with a sample injection needle, and the sample injection needle is located in the closed operation table; and a vacuum pumping device configured to pump vacuum in the internal space of the closed stirring cavity and the closed operation table. The scheme can prepare pressurized gas-dissolved crude oil emulsion droplets and measure the contact angle, and can more truly measure the contact angle of the gas-dissolved crude oil emulsion.

Description

Technical Field

[0001] This article relates to, but is not limited to, oilfield oil and gas gathering and transportation technology, and in particular to an emulsion droplet preparation device, an emulsion droplet preparation method, an emulsion droplet contact angle measuring device, and an emulsion droplet contact angle measuring method. Background Technology

[0002] Currently, the methods for testing the contact angle of crude oil or oil-water emulsions are only measured under normal pressure, without considering the changes in the properties of crude oil or oil-water emulsions after gas dissolution. Consequently, when characterizing the adhesion work of dissolved gas crude oil, only microscopic observation can be used, which will affect the accuracy of the crude oil adhesion characteristics test results in actual gas-containing crude oil gathering and transportation pipelines.

[0003] One of the challenges in the test is that it is difficult to prepare pressurized dissolved crude oil emulsion droplets during the contact angle measurement process. Summary of the Invention

[0004] This application provides an emulsion droplet preparation device and method, a contact angle measurement device and method, which can prepare pressurized dissolved gas crude oil emulsion droplets and measure their contact angles. The contact angle of the dissolved gas crude oil emulsion is measured more realistically, which can effectively support subsequent research on the microscopic mechanism of unheated gathering and transportation of dissolved gas crude oil.

[0005] This application provides an apparatus for preparing emulsion droplets, comprising: a stirring tank including a sealed stirring chamber; an aeration device connected to the stirring tank via a selectively on / off first pipeline, configured to aeration the sealed stirring chamber to form a pressurized dissolved gas crude oil emulsion from the oil-water mixture within the sealed stirring chamber; a piston-type storage device connected to the stirring tank via a second pipeline, configured to extract the pressurized dissolved gas crude oil emulsion from the sealed stirring chamber; a sealed operating platform connected to the sealed stirring chamber via a selectively on / off third pipeline and connected to the piston-type storage device via a selectively on / off fourth pipeline, the end of the fourth pipeline being provided with an injection needle located within the sealed operating platform; and a vacuum device configured to evacuate the internal space of the sealed stirring chamber and the sealed operating platform.

[0006] In one exemplary embodiment, the inflation device includes: a standard gas cylinder connected to the first pipeline via a selectively on / off fifth pipeline, configured to inflate the first pipeline; the vacuuming device is further configured to evacuate the standard gas cylinder; and a gas storage cylinder connected to the standard gas cylinder via a selectively on / off sixth pipeline, configured to inflate the standard gas cylinder.

[0007] In one exemplary embodiment, the emulsion droplet preparation device further includes a pressure control and monitoring system connected to the stirring tank and the sealed operating table, configured to detect and control the air pressure in the sealed stirring chamber, the sealed operating table, and the air filling device.

[0008] This application also provides a device for measuring the contact angle of emulsion droplets, comprising: an emulsion droplet preparation device as described in any of the above embodiments, wherein the sealed operating table includes a worktable, the worktable being configured to carry a medium for contacting pressurized dissolved gas crude oil emulsion droplets; and an information acquisition and data analysis system configured to acquire images within the sealed operating table and analyze and determine the contact angle between the pressurized dissolved gas crude oil emulsion droplets and the medium.

[0009] In one exemplary embodiment, the worktable is a height-adjustable worktable.

[0010] This application also provides a method for preparing emulsion droplets, using the emulsion droplet preparation apparatus as described in any of the above embodiments. The method includes: preparing an oil-water mixture and placing it into the sealed stirring chamber of a stirring tank; pushing the piston of a piston-type storage device to the bottom to close the sealed working chamber of the piston-type storage device; connecting the first and third pipelines, and turning on the vacuum device to evacuate the sealed stirring chamber and the sealed operating table; turning on the gas filling device to fill the sealed stirring chamber and the sealed operating table with gas; starting the stirring tank to stir the oil-water mixture in the sealed stirring chamber to prepare a pressurized dissolved gas crude oil emulsion; turning on the piston-type storage device, connecting the fourth pipeline, so that the piston-type storage device draws the pressurized dissolved gas crude oil emulsion from the sealed stirring chamber and outputs pressurized dissolved gas crude oil emulsion droplets into the sealed operating table through a injection needle.

[0011] In one exemplary embodiment, before the step of opening the gas filling device and filling the sealed stirring chamber and the sealed operating table with gas, the emulsion droplet preparation method further includes: evacuating a standard gas cylinder; opening the gas filling device and filling the sealed stirring chamber and the sealed operating table with gas includes: closing the first pipeline and the third pipeline, and opening the fifth pipeline and the sixth pipeline to allow the gas storage cylinder to fill the standard gas cylinder; closing the sixth pipeline, and opening the first pipeline and the third pipeline to allow the standard gas cylinder to fill the sealed stirring chamber and the sealed operating table with gas until the gas pressure in the sealed stirring chamber, the sealed operating table, and the standard gas cylinder is balanced.

[0012] In one exemplary embodiment, the emulsion droplet preparation method further includes: monitoring and controlling the pressure in the sealed stirring chamber and the sealed operating table through a pressure control and monitoring system; and calculating the amount of dissolved gas in the pressurized dissolved gas crude oil emulsion in the sealed stirring chamber.

[0013] This application also provides a method for measuring the contact angle of emulsion droplets, using an emulsion droplet contact angle measuring device as described in any of the above embodiments. The method includes: placing the medium to be measured on the worktable of a sealed operating table; preparing a pressurized dissolved gas crude oil emulsion using the emulsion droplet preparation method as described in any of the above embodiments and outputting droplets into the sealed operating table; allowing the pressurized dissolved gas crude oil emulsion droplets to contact the medium and drip onto the medium; acquiring images of the pressurized dissolved gas crude oil emulsion droplets and the medium, and analyzing and determining the contact angle between the pressurized dissolved gas crude oil emulsion droplets and the medium.

[0014] In one exemplary embodiment, the step of bringing the pressurized dissolved gas crude oil emulsion droplets into contact with the medium and dripping onto the medium includes: controlling the worktable to rise, bringing the pressurized dissolved gas crude oil emulsion droplets into contact with the medium and dripping onto the medium, and then controlling the worktable to descend to a set position.

[0015] Compared with the prior art, the embodiments of this application have the following effects:

[0016] (1) The preparation and acquisition of dissolved gas crude oil emulsion droplets were realized. By controlling the pressure environment inside the stirred tank and operating table, the dissolved gas crude oil emulsion prepared in the stirred tank was drawn into the tank using a piston-type storage device and droplets were generated through the injection needle.

[0017] (2) The contact angle test between pressurized dissolved gas crude oil emulsion droplets and the pipe surface is considered. The traditional method for testing the contact angle of non-gas-containing crude oil emulsion under normal pressure fails to fully consider the effect of pressurized dissolved gas on the reduction of interfacial energy between the dissolved crude oil emulsion droplets and the pipe surface, resulting in a large deviation between the measurement results and the actual dissolved gas working conditions. The test method proposed in this invention overcomes the shortcomings of the traditional test method in failing to fully consider dissolved gas and is closer to the actual dissolved gas working conditions.

[0018] Other features and advantages of this application will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the application. Other advantages of this application can be realized and obtained by means of the solutions described in the description and the accompanying drawings. Attached Figure Description

[0019] The accompanying drawings are used to provide an understanding of the technical solutions of this application and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of this application and do not constitute a limitation on the technical solutions of this application.

[0020] Figure 1 This is a schematic diagram of the structure of a milky droplet contact angle measuring device provided in one embodiment of this application.

[0021] The reference numerals in the attached figures are as follows:

[0022] 1. Inflation device; 11. Gas storage cylinder; 12. Standard gas cylinder;

[0023] 2. Vacuum pumping device;

[0024] 3. Mixing tank; 31. Mixing device;

[0025] 4. Piston-type storage device, 41. Piston, 42. Piston rod, 43. Storage chamber;

[0026] 5. Sealed operating table; 51. Workbench; 52. Light source; 53. Injection needle;

[0027] 61 First pipeline, 62 Second pipeline, 63 Third pipeline, 64 Fourth pipeline, 65 Fifth pipeline, 66 Sixth pipeline, 67 Seventh pipeline;

[0028] 71 First valve, 73 Third valve, 74 Fourth valve, 75 Fifth valve, 76 Sixth valve, 77 Seventh valve;

[0029] 81 First pressure gauge, 82 Second pressure gauge, 83 Third pressure gauge, 84 Pressure sensor;

[0030] 9. Information collection and data analysis system; 91. High-definition lenses. Detailed Implementation

[0031] As most of China National Petroleum Corporation's (CNPC) main oilfields have entered the high water-cut stage, with an average comprehensive water cut exceeding 90%, the flow characteristics of the produced fluids have changed significantly, creating favorable conditions for unheated gathering and transportation. For many years, CNPC and numerous research institutions have continuously conducted research and application studies on unheated oil gathering of high water-cut, waxy crude oil under different development stages and production conditions with varying water cuts. Extensive indoor research and field tests have yielded numerous research and application results, and targeted boundary conditions have been established. This has led to a gradual expansion of the application scope of unheated oil gathering, resulting in significant improvements in quality and efficiency.

[0032] Currently, in studying the microscopic mechanisms of crude oil adhesion, scholars both domestically and internationally generally employ the surface wetting theory to characterize oil droplet adhesion properties. This theory is a thermodynamic-based adhesion mechanism that posits that the adhering material and the adherend must first come into close contact and form an adhesive system. In this adhesive system, the two substances constitute an interfacial phase, and the formation of the interface primarily relies on intermolecular forces between the two phases, i.e., van der Waals forces. The surface wetting theory not only quantifies the quantitative relationship between the contact angle and interfacial tension but also proposes a method for calculating the adhesion work / force. Furthermore, by establishing a mathematical model based on the balance between fluid shear and adhesion within the pipeline, it provides the boundary conditions for unheated gathering and transportation pipelines.

[0033] To describe the effect of pipe wall surface wettability on droplet adhesion, it is essential to quantitatively characterize the adhesion strength between the droplet and the solid surface. Wettability depends on the equilibrium state between the attractive force of solid molecules on liquid molecules (related to solid surface energy) and the cohesive force of the liquid (related to liquid surface tension). At this point, the strength of wettability can be measured by the contact angle θ.

[0034] Contact angle is typically measured using an optical contact angle meter, and analytical methods include the tangent method, circle fitting method, ellipse fitting method, Young-Laplace method, and the Wenzel-Cassie model-corrected thermal equilibrium method. However, current testing methods only measure under normal pressure and do not consider the changes in the properties of dissolved crude oil or oil-water emulsions. Consequently, the adhesion work of dissolved crude oil can only be characterized by microscopic observation, which affects the accuracy of the results for testing the adhesion characteristics of actual gas-bearing crude oil in gathering and transportation pipelines, making the proposed adhesion work calculation formula somewhat inapplicable.

[0035] Therefore, this application presents an embodiment of a method for measuring the contact angle between dissolved crude oil emulsion and the pipe wall surface under pressure, which is particularly suitable for experimental research on the adhesion law of gas-containing crude oil gathering and transportation pipelines. It can measure the contact angle of dissolved crude oil emulsion more realistically and can effectively support subsequent research on the micro-mechanism of unheated gathering and transportation of dissolved crude oil.

[0036] To make the purpose, technical solution, and advantages of this valve clearer, embodiments of the valve will be described in detail below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

[0037] This application provides an apparatus for preparing emulsion droplets, including: a stirring tank 3, an aeration device 1, a piston-type storage device 4, a sealed operating table 5, and a vacuum device 2.

[0038] Among them, such as Figure 1As shown, the mixing tank 3 includes a sealed mixing chamber. An aeration device 1 is connected to the mixing tank 3 via a selectively on / off first pipe 61, used to aeration the sealed mixing chamber to form a pressurized dissolved gas crude oil emulsion from the oil-water mixture within. A piston-type storage device 4 is connected to the mixing tank 3 via a second pipe 62, used to extract the pressurized dissolved gas crude oil emulsion from the sealed mixing chamber. A sealed operating platform 5 is connected to the sealed mixing chamber via a selectively on / off third pipe 63, and to the piston-type storage device 4 via a selectively on / off fourth pipe 64. A sampling needle 53 is located at the end of the fourth pipe 64, inside the sealed operating platform 5. A vacuum device 2 is configured to evacuate the internal space of the sealed mixing chamber and the sealed operating platform 5.

[0039] In this embodiment, the mixing tank 3 is a high-pressure mixing tank 3, including a sealed mixing chamber, a mixing device 31 (such as a propeller), and a mixing control device. The sealed mixing chamber can contain crude oil, oil-water mixtures, dissolved gas crude oil emulsions, etc. The mixing control device can control the start and stop of the mixing device 31, the mixing speed, the mixing time, etc. The mixing tank 3 provides a place for the preparation of pressurized dissolved gas crude oil emulsions.

[0040] The gas filling device 1 stores gas, and the type of gas, such as natural gas or carbon dioxide, can be selected as needed. The gas filling device 1 is connected to the mixing tank 3 via a first pipeline 61. A first valve 71 is installed on the first pipeline 61, which controls the opening and closing of the pipeline. When the first valve 71 is open, the first pipeline 61 is open, connecting the gas filling device 1 to the sealed mixing chamber, allowing gas to be injected into the chamber and come into contact with the oil-water mixture. The oil-water mixture in the sealed mixing chamber is then thoroughly stirred, ensuring the gas is uniformly dissolved in the liquid, thus producing a pressurized dissolved gas crude oil emulsion. When the first valve 71 is closed, the first pipeline 61 is disconnected, and the gas filling device 1 is no longer connected to the sealed mixing chamber.

[0041] The piston-type storage device 4 includes a storage chamber 43, a piston 41, and a piston rod 42. The piston 41 is located inside the storage chamber 43 and is slidably connected to it. The piston rod 42 is connected to the piston 41 and is used to drive the piston 41 to move relative to the storage chamber 43. The first end of the storage chamber 43 is connected to the stirring tank 3 through a second pipe 62, with one end of the second pipe 62 inserted below the liquid surface in the sealed stirring chamber. The second end of the storage chamber 43 is open, and the piston rod 42 is located on the side of the piston 41 near the second end of the storage chamber 43. The space between the piston 41 and the first end of the storage chamber 43 is the sealed working chamber of the piston-type storage device 4. When the piston rod 42 pushes the piston 41 to the bottom, the volume of the sealed working chamber is 0, equivalent to being closed; when the piston rod 42 is pulled in the opposite direction, the volume of the sealed working chamber gradually increases, and the pressurized dissolved gas crude oil emulsion in the sealed stirring chamber will be drawn into the sealed working chamber of the piston-type storage device 4 under pressure.

[0042] The sealed operating platform 5 is connected to the sealed mixing chamber via a third pipe 63. A third valve 73 is installed on the third pipe 63, which controls the opening and closing of the third pipe 63. When the third valve 73 is open, the third pipe 63 is open, thus connecting the internal space of the sealed operating platform 5 with the sealed mixing chamber, ensuring that the air pressure inside the sealed operating platform 5 is equal to the air pressure inside the sealed mixing chamber.

[0043] Furthermore, the sealed operating platform 5 is connected to the piston-type storage device 4 via a fourth pipeline 64. A fourth valve 74 is installed on the fourth pipeline 64, which controls the opening and closing of the pipeline. When the fourth valve 74 is open, the fourth pipeline 64 is open, allowing communication between the internal space of the sealed operating platform 5 and the sealed working chamber of the piston-type storage device 4. Therefore, by pushing the piston 41, the pressurized dissolved gas crude oil emulsion in the sealed working chamber can reach the injection needle 53 through the fourth pipeline 64, and droplets are output from the injection needle 53. Since the injection head is located inside the sealed operating platform 5, and the air pressure of the sealed operating platform 5 and the sealed stirring chamber is consistent, it can be assumed that the amount of dissolved gas in the pressurized dissolved gas crude oil emulsion droplets extruded by the injection needle 53 remains unchanged before and after being drawn into the piston-type storage device 4. Therefore, pressurized dissolved gas crude oil emulsion droplets can be prepared in the closed operating table 5, and the pressurized dissolved gas crude oil emulsion droplets can remain stably in the closed operating table 5 under pressure, making it possible to measure the contact angle of the pressurized dissolved gas crude oil emulsion.

[0044] The contact angle measured by pressurized dissolved gas crude oil emulsion droplets can more accurately reflect the contact angle between crude oil emulsion and pipeline wall under actual gas-containing conditions. The measurement results are closer to the actual dissolved gas conditions, thus improving the accuracy of the contact angle measurement of pressurized dissolved gas crude oil emulsion.

[0045] The vacuum pumping device 2 is connected to the sealed stirring chamber and the sealed operating table 5. It can evacuate the internal space of the sealed stirring chamber and the sealed operating table 5 before gas filling, so that only the gas filled by the gas filling device 1 exists in the sealed stirring chamber and the sealed operating table 5 during subsequent preparation and measurement, and no other gas is present. This avoids the large amount of other gas mixed into the system, which would affect the measurement accuracy.

[0046] Conventional testing methods typically involve directly drawing liquid with a syringe, yielding only droplets under normal pressure. This solution cleverly utilizes a high-pressure stirring tank 3 and a piston-type storage device 4 as a link, and designs the sealed operating platform 5 to be pressurized in a sealed state. This allows for the preparation of stable pressurized dissolved gas crude oil emulsion droplets, preparing for subsequent contact angle measurements of the pressurized dissolved gas crude oil emulsion.

[0047] In one exemplary embodiment, the inflation device 1 includes a standard gas cylinder 12 and a gas storage cylinder 11, such as... Figure 1 As shown.

[0048] The standard gas cylinder 12 is connected to the first gas cylinder 61 via a selectively on / off fifth pipeline 65, and is configured to fill the first gas cylinder 61 with gas. The vacuum pumping device 2 is also configured to evacuate the standard gas cylinder 12. The gas storage cylinder 11 is connected to the standard gas cylinder 12 via a selectively on / off sixth pipeline 66, and is configured to fill the standard gas cylinder 12 with gas.

[0049] In this design, the filling device 1 includes a standard gas cylinder 12 and a storage cylinder. The storage cylinder 11 can be selected from suitable types as needed, such as CNG cylinders (compressed natural gas cylinders), carbon dioxide cylinders, etc. The pressure gauge of a conventional storage cylinder 11 has low accuracy. To improve the accuracy of subsequent contact angle measurements, this design introduces a standard gas cylinder 12 capable of high-precision pressure measurement, thereby enhancing the accuracy of subsequent contact angle measurements. Furthermore, the standard gas cylinder 12 is universal, while the storage cylinder 11 can be replaced as needed. This means that when measuring the contact angle of crude oil emulsions with different dissolved gas types, only the storage cylinder 11 needs to be replaced, without needing to replace the standard gas cylinder 12. Moreover, when replacing the storage cylinder 11, a vacuum device 2 is used to evacuate the standard gas cylinder 12, thus preventing the standard gas cylinder 12 from being contaminated with other gases.

[0050] The standard gas cylinder is connected to the first pipeline 61 via a fifth pipeline 65. A fifth valve 75 is installed on the fifth pipeline 65, which controls the opening and closing of the fifth pipeline 65. When the fifth valve 75 is open, the fifth pipeline 65 is connected to the first pipeline 61, allowing the standard gas cylinder 12 to fill the first pipeline 61, which in turn fills the sealed mixing chamber. Since the sealed mixing chamber can be connected to the sealed operating platform 5 via a third pipeline 63, the standard gas cylinder 12 can also simultaneously fill the sealed operating platform 5.

[0051] Gas cylinder 11 is connected to standard gas cylinder 12 via a sixth pipeline 66. A sixth valve 76 is installed on the sixth pipeline 66, which controls the opening and closing of the pipeline. When the sixth valve 76 is open, the sixth pipeline 66 is open, connecting the standard gas cylinder 12 to the gas cylinder 11, allowing the gas cylinder 11 to fill the standard gas cylinder 12. When the sixth valve 76 is closed, the sixth pipeline 66 is closed, disconnecting the standard gas cylinder 12 from the gas cylinder 11.

[0052] The vacuum pumping device 2 can be connected to the first pipeline 61 via a selectively on / off seventh pipeline 67, which is equipped with a seventh valve 77. When the first valve 71, the third valve 73, the fifth valve 75, and the seventh valve 77 are open, the vacuum pumping device 2 can simultaneously evacuate the standard gas cylinder 12, the sealed stirring chamber, and the sealed operating table 5. The vacuum pumping device 2 can be a vacuum pump.

[0053] Before filling the standard gas cylinder 12 with gas from the storage cylinder 11, the sealed stirring chamber, the sealed operating table 5, and the standard gas cylinder 12 can be evacuated using the vacuum pump 2. Then, the first valve 71, the third valve 73, and the seventh valve 77 are closed, and the sixth valve 76 is opened, so that the storage cylinder 11 fills only the standard gas cylinder 12. Since the pressure and capacity of the standard gas cylinder 12 are accurate, the total amount of gas in the standard gas cylinder 12 (denoted as n0) can be calculated using the pressure value of the standard gas cylinder 12 after filling (denoted as P0) and the ideal gas law.

[0054] Then, close the sixth valve 76 and open the first valve 71 and the third valve 73 to fill the sealed stirring chamber and sealed operating table 5 with gas from the standard gas cylinder 12. After the gas pressure in the standard gas cylinder 12, the sealed stirring chamber, and the sealed operating table 51 is balanced (denoted as P1), turn on the stirring device 31 to stir thoroughly, so that the gas is fully dissolved into the oil-water mixture in the sealed stirring chamber. After stirring is completed, the system gas pressure (i.e., the equilibrium gas pressure of the standard gas cylinder 12, the sealed stirring chamber, and the sealed operating table 51, denoted as P2) will decrease. From the pressure difference of the system before and after stirring, according to Boyle's law, the amount of gas dissolved in the oil-water mixture (denoted as nx) can be calculated. The volume of the oil-water mixture added to the sealed stirring chamber is controllable and is a known quantity (denoted as V). Thus, the amount of dissolved gas in the pressurized dissolved crude oil emulsion in the sealed stirring chamber (nx / V) can be obtained.

[0055] Therefore, the contact angle measured by the pressurized dissolved gas crude oil emulsion droplets output by the injection needle 53 inside the sealed operating table 5 is the contact angle of the pressurized dissolved gas crude oil emulsion with operating pressure P2 and dissolved gas volume nx / V.

[0056] In one exemplary embodiment, the emulsion droplet preparation device further includes a pressure control and monitoring system connected to the stirring tank 3 and the sealed operating table 5, configured to detect and control the air pressure in the sealed stirring chamber, the sealed operating table 5 and the air filling device 1.

[0057] The pressure control and monitoring system allows for the monitoring and control of air pressure within the sealed stirring chamber, the sealed operating platform 5, and the aeration device 1. This enables adjustments to the system pressure as needed, thereby adjusting the amount of dissolved gas in the crude oil and preparing pressurized dissolved gas crude oil emulsions under different pressure conditions. Through various experiments, the amount of dissolved gas in the crude oil emulsion under different pressure conditions can be obtained. Analyzing this allows for the establishment of a relationship between the amount of dissolved gas in the crude oil emulsion and the contact angle of the crude oil emulsion under different pressure conditions, effectively supporting subsequent research on the microscopic mechanism of unheated gathering and transportation of dissolved gas crude oil.

[0058] In one example, such as Figure 1 As shown, the pressure control and monitoring system may include: a first pressure gauge 81 for detecting the pressure of the gas storage cylinder 11, a second pressure gauge 82 for detecting the pressure of the sealed stirring chamber, a third pressure gauge 83 for detecting the pressure inside the sealed operating platform 5, a pressure sensor 84 for detecting the pressure inside the first pipeline 61, and a pressure control device electrically connected to the pressure sensor 84. The pressure control device receives the detection results from the pressure sensor 84 and can control the initial pressure P0 of the standard gas cylinder 12 as needed to adjust the pressure conditions. The first pressure gauge 81, the second pressure gauge 82, and the third pressure gauge 83 are all high-precision pressure gauges. When the values ​​of the second pressure gauge 82, the third pressure gauge 83, and the pressure sensor 84 are the same, it indicates that the pressure of the sealed stirring chamber, the sealed operating platform 5, and the standard gas cylinder 12 has reached equilibrium.

[0059] like Figure 1 As shown in the embodiments of this application, a device for measuring the contact angle of an emulsion droplet is also provided, including: an emulsion droplet preparation device as described in any of the above embodiments and an information acquisition and data analysis system 9.

[0060] The enclosed operating table 5 includes a workbench 51, which is configured to carry a medium for contacting pressurized dissolved crude oil emulsion droplets.

[0061] The information acquisition and data analysis system 9 is configured to acquire images within the sealed operating table 5 and analyze and determine the contact angle between pressurized dissolved gas crude oil emulsion droplets and the medium.

[0062] The emulsion droplet contact angle measuring device provided in this application includes the emulsion droplet preparation device of any of the above embodiments, and therefore has all the above-mentioned beneficial effects, which will not be repeated here.

[0063] Furthermore, the emulsion droplet contact angle measuring device provided in this application embodiment simulates the contact angle measurement between crude oil emulsion and pipeline wall under gas-containing conditions. It can also be combined with a pressure control and monitoring system to calculate the dissolved gas content of crude oil emulsion under different pressure conditions, analyze and establish the relationship between the dissolved gas content of crude oil emulsion and the contact angle of crude oil emulsion under different pressure conditions, and effectively support subsequent research on the microscopic mechanism of unheated gathering and transportation of dissolved gas crude oil.

[0064] The sealed operating table 5 is equipped with a workbench 51, which is used to hold the pipe and other media. When the pressurized dissolved gas crude oil emulsion droplets come into contact with the pipe and other media and remain stably on the pipe and other media, the information acquisition and data analysis system 9 can acquire the above images, and then analyze the images to determine the contact angle between the pressurized dissolved gas crude oil emulsion droplets and the media.

[0065] In one example, such as Figure 1 As shown, the information acquisition and data analysis system 9 includes a high-definition lens 91 and a data analysis device. The high-definition lens 91 is connected to the sealed operating table 5 and can acquire images within the sealed operating table 5. The data analysis device is electrically connected to the high-definition lens 91, can receive the images acquired by the high-definition lens 91, and perform data analysis to determine the contact angle between the pressurized dissolved gas crude oil emulsion droplets and the medium. Specific analysis methods can be used, such as the tangent method, circle fitting method, ellipse fitting method, Young-Laplace method, and the Wenzel-Cassie model-corrected heat balance method, which will not be elaborated upon here.

[0066] A light source 52 can also be installed on the side of the sealed operating table 5 opposite to the high-definition lens 91. When the high-definition lens 91 captures an image, the light source 52 can be turned on to ensure the high-definition effect of the image.

[0067] The data analysis device and the pressure control device of the aforementioned pressure control and monitoring system can be integrated into a host (such as a computer).

[0068] In one exemplary embodiment, the worktable 51 is a height-adjustable worktable 51.

[0069] The worktable 51 is a height-adjustable worktable 51, which makes it easy to adjust the position of the worktable 51 as needed to adapt to media of different sizes and shapes, and ensure that when the high-definition lens 91 acquires images of media of different sizes and shapes, the droplets can be at a height comparable to the high-definition lens 91.

[0070] The workbench 51 can be an additional component located inside the enclosed operating table 5. The device for driving the workbench 51 to rise and fall can be located inside the enclosed operating table 5 or partially outside the enclosed operating table 5.

[0071] The workbench 51 may not be an additional component located inside the enclosed operating table 5, but rather the inner bottom surface of the enclosed operating table 5 or a table surface that is fixedly connected to or integrally formed with the inner bottom surface of the enclosed operating table 5. In this case, the lifting device can be located outside the enclosed operating table 5 and directly drive the entire enclosed operating table 5 to lift and lower, thereby realizing the lifting and lowering of the workbench 51.

[0072] This application also provides a method for preparing emulsion droplets, using the emulsion droplet preparation apparatus as described in any of the above embodiments. The emulsion droplet preparation method includes:

[0073] Step S202: Prepare an oil-water mixture and place it into the sealed stirring chamber of the mixing tank 3;

[0074] Step S204: Push the piston 41 of the piston-type storage device 4 to the bottom to close the sealed working chamber of the piston-type storage device 4.

[0075] Step S206: Connect the first pipeline 61 and the third pipeline 63, turn on the vacuum device 2, and evacuate the sealed stirring chamber and the sealed operating table 5.

[0076] Step S208: Open the gas filling device 1 and fill the sealed mixing chamber and sealed operating table 5 with gas;

[0077] Step S210: Start the mixing tank 3 to stir the oil-water mixture in the sealed mixing chamber to prepare pressurized dissolved gas crude oil emulsion;

[0078] Step S212: Turn on the piston-type storage device 4 and connect the fourth pipeline 64 so that the piston-type storage device 4 can draw pressurized dissolved crude oil emulsion from the sealed stirring chamber and output pressurized dissolved crude oil emulsion droplets into the sealed operating table 5 through the injection needle 53.

[0079] The emulsion droplet preparation method provided in this application embodiment can prepare pressurized dissolved gas crude oil emulsion droplets in a closed operating table 5, and the pressurized dissolved gas crude oil emulsion droplets can remain stably in a pressurized state in the closed operating table 5, making it possible to measure the contact angle of the pressurized dissolved gas crude oil emulsion.

[0080] The contact angle measured by pressurized dissolved gas crude oil emulsion droplets can more accurately reflect the contact angle between crude oil emulsion and pipeline wall under actual gas-containing conditions. The measurement results are closer to the actual dissolved gas conditions, thus improving the accuracy of the contact angle measurement of pressurized dissolved gas crude oil emulsion.

[0081] In step S10, crude oil and produced water are first selected, and their physical properties are tested and measured, including the pour point and viscosity of the crude oil and the salinity, pH value, and polymer content of the produced water, and the results are recorded. Then, the oil-water mixture with a certain water content to be measured is prepared according to the specified ratio and placed in the high-pressure mixing tank 3 for later use, and the water content data is recorded.

[0082] In step S206, the first valve 71 and the third valve 73 are opened to connect the first pipeline 61 and the third pipeline 63.

[0083] In step S208, the seventh valve 77 is closed and the seventh pipeline 67 is disconnected.

[0084] In step S212, the fourth valve 74 is opened to connect the fourth pipeline 64.

[0085] In one exemplary embodiment, between step S204 and step S208, the emulsion droplet preparation method further includes: evacuating the standard gas cylinder 12.

[0086] Step S208 includes:

[0087] Step S2082: Close the first pipeline 61 and the third pipeline 63, and open the fifth pipeline 65 and the sixth pipeline 66 to allow the gas storage cylinder 11 to fill the standard gas cylinder 12 with gas;

[0088] Step S2084: Close the sixth pipeline 66, connect the first pipeline 61 and the third pipeline 63, so that the standard gas cylinder 12 fills the sealed mixing chamber and the sealed operating table 5 with gas until the gas pressure in the sealed mixing chamber, the sealed operating table 5 and the standard gas cylinder 12 is balanced.

[0089] In this embodiment, since the standard gas cylinder 12, the sealed stirring chamber, and the sealed operating table 5 can be connected, a vacuum is drawn using the same vacuuming device 2. Therefore, the step of evacuating the standard gas cylinder 12 can be performed simultaneously with the step of evacuating the sealed stirring chamber and the sealed operating table 5 (i.e., step S206).

[0090] In step S2082, the first valve 71 and the third valve 73 are closed to shut off the first pipeline 61 and the third pipeline 63. The fifth valve 75 and the sixth valve 76 are opened to connect the fifth pipeline 65 and the sixth pipeline 66. After the gas pressure is balanced, the initial gas pressure of the standard gas cylinder 12 is recorded as P0.

[0091] In step S2084, open the first valve 71 and the third valve 73 to connect the first pipeline 61 and the third pipeline 63. Close the sixth valve 76 to shut off the sixth pipeline 66. After the gas pressure is balanced, record the pressure of the system before stirring, i.e.: the gas pressure of the standard gas cylinder 12 = the gas pressure of the sealed stirring chamber before stirring = the gas pressure of the sealed operating table 5 = P1.

[0092] In step S210, after stirring is completed and the gas pressure is balanced, the pressure of the system after stirring is recorded, that is: the gas pressure of the standard gas cylinder 12 = the gas pressure of the sealed stirring chamber after stirring = the gas pressure of the sealed operating table 5 = P2, and the amount of gas dissolved in the oil-water mixture during stirring is recorded as nx.

[0093] In step S212, the piston-type storage device 4 can be opened first. By pulling the piston 41, a small amount of pressurized dissolved gas crude oil emulsion is drawn into the sealed working chamber, and the piston 41 is kept stable. Then, the fourth valve 74 is opened, the fourth pipeline 64 is connected, and the piston 41 is slowly pushed so that dissolved gas crude oil emulsion droplets appear on the injection needle 53. At this time, the gas pressure in the sealed stirring chamber is consistent with the gas pressure in the sealed operating table 5, and it can be considered that the amount of dissolved gas in the dissolved gas crude oil emulsion droplets entering the sealed operating table 5 through the piston-type storage device 4 remains unchanged.

[0094] In one exemplary embodiment, the emulsion droplet preparation apparatus further includes a pressure control and monitoring system, and the emulsion droplet preparation method further includes:

[0095] The pressure is monitored and controlled within the sealed mixing chamber and the sealed operating table 5 through a pressure control and monitoring system.

[0096] Calculate the amount of dissolved gas in the pressurized dissolved gas crude oil emulsion within a closed stirring chamber.

[0097] This scheme allows for the monitoring and control of the air pressure within the sealed stirring chamber, the sealed operating platform 5, and the aeration device 1. This enables adjustments to the system pressure as needed, thereby adjusting the amount of dissolved gas in the crude oil and preparing pressurized dissolved gas crude oil emulsions under different pressure conditions. Through various experiments, the amount of dissolved gas in the crude oil emulsion under different pressure conditions can be obtained. This allows for the analysis and establishment of the relationship between the amount of dissolved gas in the crude oil emulsion and the contact angle of the crude oil emulsion under different pressure conditions, effectively supporting subsequent research on the microscopic mechanism of unheated gathering and transportation of dissolved gas crude oil.

[0098] The amount of dissolved gas can be calculated using Boyle's Law / ideal gas law:

[0099] The volume of standard gas cylinder 12 is denoted as V0, the entire process is a constant temperature process, the temperature is denoted as T, and the total volume of standard gas cylinder 12, the sealed stirring chamber, the sealed operating table 5, and the pipelines connected to the three (denoted as system volume) is denoted as V1.

[0100] From step S2082, we can obtain: P0×V0=n0×R×T, where R is the molar gas constant;

[0101] From step S2084, we can obtain: P1×V1=n0×R×T, where R is the molar gas constant;

[0102] From steps S2084 and S210, we can obtain: P2×V1=(n0-nx)×R×T, where R is the molar gas constant.

[0103] The amount of gas dissolved in the mixture can be calculated from the above three equations as nx = (P1-P2)×P0×V0 / (R×T×P1). Let V be the volume of the oil-water mixture added to the sealed stirring chamber. Then, the amount of dissolved gas in the dissolved crude oil emulsion at pressure P2 is nx / V.

[0104] This application also provides a method for measuring the contact angle of an emulsion droplet, using the emulsion droplet contact angle measuring device as described in any of the above embodiments. The method for measuring the contact angle of an emulsion droplet includes:

[0105] Step S302: Place the medium to be tested onto the workbench 51 of the sealed operating table 5;

[0106] Step S304: Using any of the emulsion droplet preparation methods described in the above embodiments, a pressurized dissolved gas crude oil emulsion is prepared and the droplets are output into the sealed operating table 5;

[0107] Step S306: Make pressurized dissolved gas crude oil emulsion droplets contact the medium and drip onto the medium;

[0108] Step S308: Acquire images of pressurized dissolved gas crude oil emulsion droplets and the medium, and analyze and determine the contact angle between the pressurized dissolved gas crude oil emulsion droplets and the medium.

[0109] The emulsion droplet contact angle measurement method provided in this application simulates the contact angle measurement between crude oil emulsion and pipeline wall under gas-containing conditions. It can also be combined with a pressure control and monitoring system to calculate the dissolved gas content of crude oil emulsion under different pressure conditions, analyze and establish the relationship between the dissolved gas content of crude oil emulsion and the contact angle of crude oil emulsion under different pressure conditions, and effectively support subsequent research on the microscopic mechanism of unheated gathering and transportation of dissolved gas crude oil.

[0110] In step S302, the medium can be a pipe (steel pipe or non-metallic pipe). The wall surface of the medium to be tested can be ground and polished to facilitate full contact between the droplets and the medium. Then, the treated medium is placed on the worktable 51 for later use. The worktable 51 should be kept horizontal to facilitate the stable residence of the emulsion droplets on the medium surface.

[0111] In an exemplary embodiment, for a worktable 51 that is a height-adjustable worktable 51, step S306 includes:

[0112] The worktable 51 is raised so that the pressurized dissolved crude oil emulsion droplets come into contact with the medium and drip onto the medium. Then the worktable 51 is lowered to the set position.

[0113] When adjusting the height of the worktable 51, slowly bring it close to the dissolved crude oil emulsion droplet on the injection needle 53, and then pull the worktable 51 down to the appropriate position.

[0114] The position is set to facilitate the acquisition of images of the droplet and the medium by the high-definition lens 91, such as the position where the droplet is directly opposite the high-definition connector. Subsequently, the contact angle value is calculated and generated by software based on the captured image.

[0115] In actual measurement, different crude oil, water, and gas samples can be selected and the above steps can be repeated to measure the contact angle of dissolved gas crude oil emulsion droplets under different conditions. At the same time, the amount of dissolved gas in crude oil emulsion under different pressure conditions can be calculated by combining the pressure control and monitoring system. Then, the relationship between the amount of dissolved gas in crude oil emulsion and the contact angle of crude oil emulsion under different pressure conditions can be analyzed and established, which can effectively support the subsequent research on the micro-mechanism of unheated gathering and transportation of dissolved gas crude oil.

[0116] The following is a specific embodiment that provides a method for measuring the contact angle of pressurized dissolved gas crude oil emulsion, including the following steps:

[0117] Step S402: Select crude oil and produced water, test and measure the physical properties of crude oil and produced water samples, including crude oil pour point, viscosity and produced water salinity, pH value, and polymer content, and record them;

[0118] Step S404: Select the pipe to be tested (steel pipe or non-metallic pipe), grind and polish the wall surface to be tested, and place the treated pipe on the workbench 51 inside the sealed operating table 5 for later use. The sealed operating table 5 should be kept horizontal.

[0119] Step S406: Prepare the oil-water mixture with the required water content according to the specified ratio, place it in the high-pressure mixing tank 3 for later use, and record the water content data;

[0120] Step S408: Push the piston 41 in the piston-type storage device 4 to the bottom to seal its sealed working chamber. Then turn on the vacuum pump to evacuate the standard gas cylinder 12, the high-pressure stirring tank 3, and the sealed operating platform 5. After the pressure is balanced, open the valve of the gas storage cylinder 11 (specifically the CNG cylinder) (i.e., the sixth valve 76) and close the valves of the high-pressure stirring tank 3 and the sealed operating platform 5 (i.e., the first valve 71 and the third valve 73). Only fill the standard gas cylinder 12 with gas. After the gas pressure is balanced, close the valve of the standard gas cylinder 12 (i.e., the fifth valve 75) and record its initial pressure P0. Then close the valve of the gas storage cylinder 11 (i.e., the sixth valve 76).

[0121] Step S410: Open the pressure control and monitoring system, open the information acquisition and data analysis system 9, open the valve of the standard gas cylinder 12 (i.e., the fifth valve 75), and simultaneously open the air inlet valves of the high-pressure mixing tank 3 and the sealed operating platform 5 (i.e., the first valve 71 and the third valve 73). After the gas pressure is balanced, record the system pressure P1. Turn on the propeller of the high-pressure mixing tank 3 to fully stir the oil-water mixture in the dissolved gas environment in the tank, prepare and obtain a dissolved gas crude oil emulsion, and record the system pressure P2 after the stirring is completed. Calculate the amount of natural gas nx absorbed by the crude oil emulsion according to Boyle's law by calculating the system pressure difference before and after stirring, and record it.

[0122] Step S412: Turn on the light source 52 inside the sealed operating table 5, and adjust the angle and position of the high-definition lens 91 so that the computer screen of the information acquisition and data analysis system 9 can display a clear and stable image.

[0123] Step S414: Slowly open the piston 41 of the piston-type storage device 4 upwards to draw in a small amount of dissolved gas crude oil emulsion from the high-pressure stirring tank 3, and keep the piston 41 stable.

[0124] Step S416: Open the liquid inlet valve (i.e., the fourth valve 74) of the sealed operating table 5, and slowly push the piston 41 of the piston storage device 4 so that dissolved gas crude oil emulsion droplets appear on the injection needle 53. At this time, the pressure in the high pressure stirring tank 3 is consistent with the pressure of the sealed operating table 5. It is assumed that the amount of dissolved gas in the dissolved gas crude oil emulsion droplets remains unchanged before and after being sucked in by the piston storage device 4.

[0125] Step S418: Adjust the height of the worktable 51 so that it slowly approaches the dissolved crude oil emulsion droplet on the injection needle 53, then pull the worktable 51 down to a suitable position, select the photograph taken, and use the software to calculate and generate the contact angle value.

[0126] By selecting different crude oil, water, and gas samples and repeating the above steps, the contact angle of dissolved gas crude oil emulsion droplets under different conditions can be measured.

[0127] Compared with the prior art, the embodiments of this application have the following effects:

[0128] (1) The preparation and acquisition of dissolved gas crude oil emulsion droplets were realized. By controlling the pressure environment inside the stirred tank and operating table, the dissolved gas crude oil emulsion prepared in the stirred tank was drawn into the tank using a piston-type storage device and droplets were generated through the injection needle.

[0129] (2) The contact angle test between pressurized dissolved gas crude oil emulsion droplets and the pipe surface is considered. The traditional method for testing the contact angle of non-gas-containing crude oil emulsion under normal pressure fails to fully consider the effect of pressurized dissolved gas on the reduction of interfacial energy between the dissolved crude oil emulsion droplets and the pipe surface, resulting in a large deviation between the measurement results and the actual dissolved gas working conditions. The test method proposed in this invention overcomes the shortcomings of the traditional test method in failing to fully consider dissolved gas and is closer to the actual dissolved gas working conditions.

[0130] In summary, the embodiments of this application, by developing and designing a device and method for measuring the contact angle of pressurized dissolved gas crude oil emulsion, can more closely measure the contact angle between the dissolved gas crude oil emulsion and the pipe wall, overcoming the shortcomings of traditional testing methods that fail to fully consider dissolved gas. This can effectively support subsequent research on the microscopic mechanism of unheated gathering and transportation of dissolved gas crude oil, further optimize the gathering and transportation temperature in high water-cut oilfields in China, and create favorable conditions for the wider and deeper promotion of unheated gathering and transportation technology in various oilfields, achieving cost reduction and efficiency improvement, and building low-carbon and green oilfields.

[0131] In the description of this valve, it should be noted that the terms "upper", "lower", "one side", "the other side", "one end", "the other end", "side", "opposite", "four corners", "periphery", ""U-shaped structure", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the attached drawings. They are only for the convenience of describing this valve and simplifying the description, and do not indicate or imply that the structure referred to has a specific orientation, or is constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this valve.

[0132] In the description of this valve embodiment, unless otherwise expressly specified and limited, the terms "connection," "direct connection," "indirect connection," "fixed connection," "installation," and "assembly" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. The terms "installation," "connection," and "fixed connection" can refer to a direct connection or an indirect connection through an intermediate medium, or a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this valve according to the specific circumstances.

[0133] Although the embodiments disclosed in this valve are as described above, the content is merely for the purpose of understanding this valve and is not intended to limit this valve. Any person skilled in the art may make any modifications and changes to the form and details of the implementation without departing from the spirit and scope disclosed in this valve, but the scope of patent protection for this valve shall still be defined by the appended claims.

[0134] This application describes several embodiments, but these descriptions are exemplary and not restrictive, and it will be apparent to those skilled in the art that many more embodiments and implementations are possible within the scope of the embodiments described herein. Although many possible combinations of features are shown in the drawings and discussed in the detailed description, many other combinations of the disclosed features are also possible. Unless specifically limited, any feature or element of any embodiment may be used in combination with, or may replace, any feature or element of any other embodiment.

[0135] This application includes and contemplates combinations of features and elements known to those skilled in the art. The embodiments, features, and elements disclosed in this application may also be combined with any conventional features or elements to form a unique inventive scheme as defined by the claims. Any feature or element of any embodiment may also be combined with features or elements from other inventive schemes to form another unique inventive scheme as defined by the claims. Therefore, it should be understood that any feature shown and / or discussed in this application may be implemented individually or in any suitable combination. Therefore, the embodiments are not limited except by the limitations imposed by the appended claims and their equivalents. Furthermore, various modifications and changes may be made within the scope of the appended claims.

[0136] Furthermore, in describing representative embodiments, the specification may have presented methods and / or processes as a specific sequence of steps. However, the method or process should not be limited to the specific order of steps described herein, to the extent that it does not depend on such a specific order. As will be understood by those skilled in the art, other sequences of steps are also possible. Therefore, the specific order of steps set forth in the specification should not be construed as a limitation of the claims. Moreover, the claims concerning the method and / or process should not be limited to the steps performed in the written order, and those skilled in the art will readily understand that these orders can be varied and still remain within the spirit and scope of the embodiments of this application.

Claims

1. An apparatus for preparing emulsion droplets, characterized in that, include: A mixing tank, including a sealed mixing chamber; An aeration device is connected to the mixing tank via a selectively on / off first pipeline and is configured to aerate the sealed mixing chamber to form a pressurized dissolved gas crude oil emulsion in the oil-water mixture within the sealed mixing chamber. A piston-type storage device is connected to the stirring tank via a second pipeline and is configured to extract pressurized dissolved gas crude oil emulsion from the sealed stirring chamber. A sealed operating table is connected to the sealed stirring chamber via a selectively on / off third pipeline and to the piston-type storage device via a selectively on / off fourth pipeline. The fourth pipeline ends in a sample injection needle located within the sealed operating table. A vacuum device is configured to evacuate the internal space of the sealed stirring chamber and the sealed operating table. A pressure control and monitoring system is connected to the mixing tank and the sealed operating platform, and is configured to detect and control the air pressure in the sealed mixing chamber, the sealed operating platform and the air filling device.

2. The emulsion droplet preparation apparatus according to claim 1, characterized in that, The inflation device includes: A standard gas cylinder is connected to the first pipeline via a selectively on / off fifth pipeline, configured to fill the first pipeline with gas; the vacuuming device is also configured to evacuate the standard gas cylinder; and The gas storage cylinder is connected to the standard gas cylinder via a selectively on / off sixth pipeline, and is configured to fill the standard gas cylinder with gas.

3. A device for measuring the contact angle of emulsion droplets, characterized in that, include: The emulsion droplet preparation apparatus as described in claim 1 or 2, wherein the sealed operating table includes a worktable, the worktable being configured to carry a medium for contacting pressurized dissolved gas crude oil emulsion droplets; and The information acquisition and data analysis system is configured to acquire images inside the sealed operating table and analyze and determine the contact angle between the pressurized dissolved crude oil emulsion droplets and the medium.

4. The emulsion droplet contact angle measuring device according to claim 3, characterized in that, The worktable is a height-adjustable worktable.

5. A method for preparing emulsion droplets, characterized in that, The emulsion droplet is prepared using the apparatus described in claim 1 or 2, and the method for preparing the emulsion droplet includes: Prepare an oil-water mixture and place it into the sealed stirring chamber of a mixing tank; Push the piston of the piston-type storage device to the bottom to close the sealed working chamber of the piston-type storage device; Connect the first and third pipelines, turn on the vacuum pumping device, and evacuate the sealed stirring chamber and the sealed operating table. Open the inflation device and fill the sealed stirring chamber and the sealed operating table with gas. Start the mixing tank to stir the oil-water mixture in the sealed mixing chamber in order to prepare pressurized dissolved gas crude oil emulsion; Turn on the piston-type storage device and connect the fourth pipeline so that the piston-type storage device can draw the pressurized dissolved gas crude oil emulsion from the sealed stirring chamber and output pressurized dissolved gas crude oil emulsion droplets into the sealed operating table through the injection needle.

6. The method for preparing emulsion droplets according to claim 5, characterized in that, The emulsion droplet preparation device is the emulsion droplet preparation device according to claim 2; Before the step of opening the gas filling device and filling the sealed stirring chamber and the sealed operating table with gas, the method for preparing emulsion droplets further includes: evacuating a standard gas cylinder; The step of opening the inflation device and filling the sealed stirring chamber and the sealed operating table with gas includes: Close the first pipeline and the third pipeline, and open the fifth pipeline and the sixth pipeline to allow the gas storage cylinder to fill the standard gas cylinder; Close the sixth pipeline and connect the first and third pipelines to allow the standard gas cylinder to fill the sealed stirring chamber and the sealed operating table with gas until the gas pressure in the sealed stirring chamber, the sealed operating table and the standard gas cylinder are balanced.

7. The method for preparing emulsion droplets according to claim 5 or 6, characterized in that, The emulsion droplet preparation apparatus is the emulsion droplet preparation apparatus according to claim 1; the emulsion droplet preparation method further includes: The pressure in the sealed stirring chamber and the sealed operating table is monitored and controlled by the pressure control and monitoring system. Calculate the amount of dissolved gas in the pressurized dissolved gas crude oil emulsion within the sealed stirring chamber.

8. A method for measuring the contact angle of an emulsion droplet, characterized in that, The contact angle of the emulsion droplet is measured using the emulsion droplet contact angle measuring device as described in claim 3 or 4, wherein the emulsion droplet contact angle measurement method includes: Place the medium to be tested onto the worktable of the sealed operating table; Using the emulsion droplet preparation method as described in any one of claims 5 to 7, a pressurized dissolved gas crude oil emulsion is prepared and the droplets are output into the sealed operating table; The pressurized dissolved gas crude oil emulsion droplets are brought into contact with the medium and dripped onto the medium; Images of the pressurized dissolved gas crude oil emulsion droplets and the medium were acquired and analyzed to determine the contact angle between the pressurized dissolved gas crude oil emulsion droplets and the medium.

9. The method for measuring the contact angle of emulsion droplets according to claim 8, characterized in that, The emulsion droplet contact angle measuring device is the emulsion droplet contact angle measuring device according to claim 4; The step of bringing the pressurized dissolved gas crude oil emulsion droplets into contact with the medium and dripping onto the medium includes: controlling the worktable to rise, bringing the pressurized dissolved gas crude oil emulsion droplets into contact with the medium and dripping onto the medium, and then controlling the worktable to descend to a set position.

Images