Multiphase flow fluid saturation real-time calculation method based on microfluidic technology

Abstract

The invention is applicable to the technical field of hydrogeology, and provides a multi-phase flow fluid saturation real-time calculation method based on a microfluidic technology, which comprises the following steps: firstly, establishing a multi-phase flow image data set, then cutting original images in the multi-phase flow image data set at different moments into target sizes and rotating to target positions, according to a preset RGB range, target fluid in the cut and rotated original image is identified, the preset RGB range is adjusted until an identification result is accurate and the identification result is a target fluid area, then target fluid saturation data in a real-time state is generated based on the target fluid area, and finally, target fluid saturation data in the real-time state is obtained based on the target fluid saturation data in the real-time state. And drawing a saturation evolution curve of the target fluid in the multiphase flow process. Therefore, the accuracy of real-time calculation of the fluid saturation in the multiphase flow displacement and mass transfer process is improved.

Description

Technical Field

[0001] The present application belongs to the field of hydrogeological technology, and in particular relates to a real-time calculation method for multiphase flow fluid saturation based on microfluidics technology. Background Art

[0002] Multiphase flow problems in porous and fractured media are common in natural processes such as carbonate dissolution-precipitation processes, reservoir anti-seepage and safety control, carbon dioxide geological storage, groundwater pollution and remediation, and microbial mineralization technology, as well as in energy, environment, and water conservancy projects. In the study of multiphase flow in oil and gas production, the efficiency of oil and gas production can be clarified by quantifying the changes in oil or gas saturation; in the field of carbon dioxide geological storage, the microscopic storage mechanism can be analyzed by quantifying the changes in the saturation of gaseous and supercritical carbon dioxide; in the remediation of soil and groundwater pollution caused by non-aqueous liquids, quantifying the changes in the saturation of non-aqueous liquids can reveal the remediation mechanism and thus improve the remediation efficiency. Therefore, the real-time calculation of fluid saturation in multiphase flow processes is of great significance for studying the microscopic mechanism of multiphase flow and improving the engineering efficiency of multiphase flow-related systems.

[0003] In order to calculate the fluid saturation in multiphase flow, many scholars have used computed tomography (CT technology), low-field nuclear magnetic resonance testing (NMR technology) and sand box light transmission experiments to intuitively measure or invert the saturation. However, the CT scanning imaging time is relatively long, and some displacement or repair reactions occur in an instant, making it difficult to capture the changes in saturation in real time; although the NMR technology has a faster imaging time, when the multiphase fluid contains protons, there is a certain degree of difficulty in accurately distinguishing different fluids; and the cost of CT and NMR instruments is relatively high. Although the sand box light transmission experiment is low-cost and has fast imaging, its internal structure cannot be directly observed, and there is still a certain error in inverting the fluid saturation through light intensity. Therefore, the current calculation of fluid saturation in multiphase flow processes has the problem of low accuracy. Summary of the invention

[0004] The embodiment of the present application provides a real-time calculation method for multiphase flow fluid saturation based on microfluidics technology, which can solve the problem of low accuracy in the calculation of fluid saturation in the current multiphase flow process.

[0005] In the first aspect, an embodiment of the present application provides a real-time calculation method for multiphase flow fluid saturation based on microfluidics technology, including: S1 establishing a multiphase flow image data set; conducting a porous medium or fracture medium multiphase flow microfluidics experiment according to actual needs, and acquiring preset resolution images of the multiphase flow process in real time through an image acquisition device to establish the multiphase flow image data set; S2 cropping the original images at different times in the multiphase flow image data set to a target size and rotating them to a target position, identifying the target fluid in the cropped and rotated original images according to a preset RGB range, and adjusting the preset RGB range until the identification result is accurate, and the identification result is the target fluid area; S3 generating target fluid saturation data in real time based on the target fluid area of ​​S2; S4 drawing a saturation evolution curve of the target fluid in the multiphase flow process based on the real-time target fluid saturation data obtained by S3.

[0006] In a possible implementation manner of the first aspect, step S1 specifically includes the following steps:

[0007] S101 Conduct microfluidic visualization experiments of multiphase flow in porous media or fractured media: Prepare microfluidic transparent media with porous structures or fractured structures according to the research objectives, and dye different fluids and inject them into the microfluidic transparent media in sequence;

[0008] S102 Acquiring a multiphase flow image data set: using an image acquisition device to acquire images of a preset resolution in real time during the multiphase flow microfluidic visualization experiment at a preset acquisition frame rate to establish a multiphase flow image data set.

[0009] Optionally, in another possible implementation of the first aspect, step S2 specifically includes the following steps:

[0010] S201 used the imrotate function in MATLAB to rotate the original images at different times in the multiphase flow image dataset to the normalized position, and used the imcrop function to crop the rotated images to the normalized size;

[0011] S202 identifies the target fluid in the cropped and rotated original image according to a preset RGB range;

[0012] S203 determines whether the preset RGB range is accurate according to the recognition result, and if it is inaccurate, adjusts the preset RGB range until the recognition result is correct.

[0013] Optionally, in another possible implementation of the first aspect, step S3 specifically includes the following steps:

[0014] S301 marks the pixel points occupied by the target fluid in the target fluid area as white;

[0015] S302 counts the number of pixels N occupied by the target fluid;

[0016] S303 calculates the target fluid saturation S in the normalized image under the instantaneous state; for porous media, the target fluid saturation S is calculated as follows:

[0017]

[0018] Where N is the number of pixels occupied by the target fluid; δ is the image resolution; h is the channel depth of the microfluidic chip; s is the channel area of ​​the microfluidic chip, is the medium porosity;

[0019] For fractured media, the target fluid saturation S is calculated as:

[0020] S=Nδa / L f W f a=Nδ / L f W f (2)

[0021] Where a is the average opening of the crack; L f is the crack length; W f is the crack width;

[0022] Image resolution δ represents the area occupied by each pixel in the normalized image, and its calculation formula is:

[0023] δ=LW / mn (3)

[0024] Where, L is the real length of the multiphase flow experiment image; W is the real width of the multiphase flow experiment image; m is the lateral resolution of the camera in the multiphase flow experiment, that is, the number of pixels in the horizontal direction of the screen; n is the longitudinal resolution of the camera in the multiphase flow experiment, that is, the number of pixels in the vertical direction of the screen;

[0025] S304 generates target fluid saturation data in real time according to the target fluid saturation S in the normalized image in the instantaneous state.

[0026] Optionally, in another possible implementation of the first aspect, step S4 specifically includes the following steps:

[0027] S401 counts the shooting time t and the target fluid saturation S of each image in the multiphase flow image data set;

[0028] S402 uses time t as the horizontal coordinate and the target fluid saturation S as the vertical coordinate to draw a multiphase flow experiment saturation evolution curve St.

[0029] Optionally, in another possible implementation of the first aspect, after the above step S4, the method further includes:

[0030] Based on the saturation evolution curve St diagram, the saturation change rate is calculated to quantify the multiphase flow process. The saturation change rate includes the instantaneous change rate of the target fluid saturation and the overall change rate of the target fluid saturation:

[0031] The instantaneous change rate k of the target fluid saturation is used to quantify the instantaneous displacement efficiency of two-phase flow or multiphase flow. The calculation formula is:

[0032]

[0033] Where, S1 is the saturation of the target fluid at time t1; S2 is the saturation of the target fluid at time t2;

[0034] The overall change rate K of the target fluid saturation is used to quantify the overall displacement efficiency of two-phase flow or multiphase flow. The calculation formula is:

[0035]

[0036] In the formula, S end is the saturation of the target fluid at the end of the multiphase flow experiment; S init is the saturation of the target fluid at the beginning of the multiphase flow experiment; T is the duration of the multiphase flow experiment.

[0037] Optionally, in another possible implementation of the first aspect, after calculating the saturation change rate to quantify the multiphase flow process based on the saturation evolution curve St diagram, the method further includes:

[0038] When the target fluid is in a residual state and is no longer displaced by the invading phase fluid during the two-phase flow process, the saturation change is caused by mass transfer. The two-phase mass transfer rate coefficient K is calculated based on the saturation change. mf , the calculation formula is:

[0039]

[0040] In the formula, S l is the saturation of the residual fluid in the experiment; t is the time (T); ρ is the density of the residual fluid; is the porosity of the medium; c e is the equilibrium solubility of the residual fluid in the invading phase fluid; c is the concentration of the residual fluid in the invading phase fluid, where c is expressed as:

[0041]

[0042] Where s is the channel area of ​​the microfluidic chip; h is the channel depth of the microfluidic chip; v is the injection flow rate of the invading phase fluid.

[0043] In the technical solution of the present application, a multiphase flow image data set is first established, and then the original images at different times in the multiphase flow image data set are cropped to the target size and rotated to the target position. The target fluid in the cropped and rotated original image is identified according to the preset RGB range, and the preset RGB range is adjusted until the identification result is accurate. The identification result is the target fluid area, and then the target fluid saturation data in the real-time state is generated based on the target fluid area. Finally, based on the target fluid saturation data in the real-time state, the saturation evolution curve of the target fluid in the multiphase flow process is drawn. As a result, the accuracy of real-time calculation of fluid saturation in the multiphase flow displacement and mass transfer process is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0045] Figure 1 It is a flow chart of a method for real-time calculation of multiphase flow fluid saturation based on microfluidics technology provided in one embodiment of the present application;

[0046] Figure 2 This is a schematic diagram of the structure of a microfluidic chip with a pore structure provided in one embodiment of the present application;

[0047] Figure 3 This is a schematic diagram of target fluid identification results in an instantaneous state provided by an embodiment of the present application;

[0048] Figure 4 It is a saturation evolution curve of the target fluid provided in one embodiment of the present application. DETAILED DESCRIPTION

[0049] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0050] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof.

[0051] It should also be understood that the term “and / or” used in the specification and appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0052] As used in the specification and appended claims of this application, the term "if" can be interpreted as "when" or "uponce" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrase "if it is determined" or "if [described condition or event] is detected" can be interpreted as meaning "uponce it is determined" or "in response to determining" or "uponce [described condition or event] is detected" or "in response to detecting [described condition or event]", depending on the context.

[0053] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0054] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0055] The following is a detailed description of a real-time calculation method for multiphase flow fluid saturation based on microfluidics provided in the present application with reference to the accompanying drawings.

[0056] Figure 1 A schematic flow chart of a method for real-time calculation of multiphase flow fluid saturation based on microfluidics provided in an embodiment of the present application is shown.

[0057] like Figure 1 As shown, the real-time calculation method of multiphase flow fluid saturation based on microfluidics technology includes the following steps:

[0058] S1 Establish a multiphase flow image data set; carry out a porous medium or fracture medium multiphase flow microfluidic experiment according to actual needs, and use an image acquisition device to acquire preset resolution images of the multiphase flow process in real time to establish a multiphase flow image data set;

[0059] S2 crops the original images at different times in the multiphase flow image data set into a target size and rotates them to a target position, identifies the target fluid in the cropped and rotated original images according to a preset RGB range, and adjusts the preset RGB range until the identification result is accurate, and the identification result is the target fluid area;

[0060] S3 generates target fluid saturation data in real time based on the target fluid region of S2;

[0061] S4 draws a saturation evolution curve of the target fluid in the multiphase flow process based on the target fluid saturation data in the real-time state obtained by S3.

[0062] Furthermore, in an embodiment of the present application, the above step S1 specifically includes the following steps:

[0063] S101 Conduct microfluidic visualization experiments of multiphase flow in porous media or fractured media: Prepare microfluidic transparent media with porous structures or fractured structures according to the research objectives, and dye different fluids and inject them into the microfluidic transparent media in sequence;

[0064] S102 Acquiring a multiphase flow image data set: using an image acquisition device to acquire images of a preset resolution in real time during the multiphase flow microfluidic visualization experiment at a preset acquisition frame rate to establish a multiphase flow image data set.

[0065] The specific process of the above steps S101-S102 can be specifically described by the following embodiments.

[0066] Build a microfluidic visualization experimental platform, which includes a light source, a high-precision camera, a computer, a syringe pump, a microfluidic chip, and an optical experimental stand;

[0067] Determine the structure of the microfluidic chip: determine the channel area s, channel depth h, and porosity of the pore structure Heterogeneity, wettability; determine the crack length L of the crack structure f , crack width W f , average crack opening a, roughness, wettability;

[0068] As a possible implementation, Figure 2 As shown in the figure, the long axis of the elliptical channel of the pore structure microfluidic chip is 19.95 mm, the short axis is 6.34 mm, and the channel area is 99.34 mm 2 , the channel depth is 0.05 mm, the porosity is 0.58, the cylinder in the ellipse represents the solid skeleton particles in the porous medium, and the cylinder diameter R follows a uniform distribution in is the average diameter λ determines the heterogeneity of the porous medium (λ = 0.25). The chip is made of glass and has a relatively hydrophilic wettability.

[0069] Conduct multiphase flow experiments: For oil-gas two-phase flow, oil-water two-phase flow, and oil-water-gas multiphase flow, determine the injection sequence of fluids, dye type, fluid preset RGB range, and injection flow rate v;

[0070] As a possible implementation method, a two-phase flow experiment of sodium dodecyl sulfate solution (SDS, surfactant) and trichloroethylene (non-aqueous phase liquid) can be carried out. After obtaining the residual state of trichloroethylene, SDS solution is injected with an injection flow rate of 10 μL / min. The dye used for trichloroethylene is Oil Red-O. The initial range of fluid RGB is [225, 170, 165] to [235, 180, 185], and the SDS solution is not stained.

[0071] Acquire multiphase flow image data set: Use a high-precision camera to collect preset resolution images of the multiphase flow process in real time, and record the image resolution δ and acquisition frame rate fps.

[0072] As a possible implementation method, a high-precision camera is used to collect preset resolution images of the multiphase flow process in real time. The image resolution is 11.3μm×1.3μm and the acquisition frame rate is 0.06Hz.

[0073] Furthermore, in an embodiment of the present application, the above step S2 specifically includes the following steps:

[0074] S201 used the imrotate function in MATLAB to rotate the original images at different times in the multiphase flow image dataset to the normalized position, and used the imcrop function to crop the rotated images to the normalized size;

[0075] S202 identifies the target fluid in the cropped and rotated original image according to a preset RGB range;

[0076] S203 determines whether the preset RGB range is accurate according to the recognition result, and if it is inaccurate, adjusts the preset RGB range until the recognition result is correct.

[0077] Furthermore, in an embodiment of the present application, the above step S3 specifically includes the following steps:

[0078] S301 marks the pixel points occupied by the target fluid in the target fluid area as white;

[0079] S302 counts the number of pixels N occupied by the target fluid;

[0080] S303 calculates the target fluid saturation S in the normalized image under the instantaneous state; for porous media, the target fluid saturation S is calculated as follows:

[0081]

[0082] Where N is the number of pixels occupied by the target fluid; δ is the image resolution; h is the channel depth of the microfluidic chip; s is the channel area of ​​the microfluidic chip, is the medium porosity;

[0083] For fractured media, the target fluid saturation S is calculated as:

[0084] S=Nδa / L f W f a=Nδ / L f W f (2)

[0085] Where a is the average opening of the crack; L f is the crack length; W f is the crack width;

[0086] Image resolution δ represents the area occupied by each pixel in the normalized image, and its calculation formula is:

[0087] δ=LW / mn (3)

[0088] Where, L is the real length of the multiphase flow experiment image; W is the real width of the multiphase flow experiment image; m is the lateral resolution of the camera in the multiphase flow experiment, that is, the number of pixels in the horizontal direction of the screen; n is the longitudinal resolution of the camera in the multiphase flow experiment, that is, the number of pixels in the vertical direction of the screen;

[0089] S304 generates target fluid saturation data in real time according to the target fluid saturation S in the normalized image in the instantaneous state.

[0090] In one embodiment of the present application, Figure 3 As shown, the target fluid is identified according to the preset RGB range, and the pixels occupied by the target fluid are marked as white; under this instantaneous condition, the saturation of trichloroethylene is 10.5%.

[0091] Furthermore, in an embodiment of the present application, the above step S4 specifically includes the following steps:

[0092] S401 counts the shooting time t and the target fluid saturation S of each image in the multiphase flow image data set;

[0093] S402 uses time t as the horizontal coordinate and the target fluid saturation S as the vertical coordinate to draw a multiphase flow experiment saturation evolution curve St.

[0094] In the embodiments of the present application, Figure 4 As shown, the multiphase flow image shooting time t is used as the horizontal coordinate and the target fluid saturation S is used as the vertical coordinate to draw the multiphase flow experiment saturation evolution curve St.

[0095] Furthermore, in an embodiment of the present application, after the above step S4, the following is further included:

[0096] Based on the saturation evolution curve St diagram, the saturation change rate is calculated to quantify the multiphase flow process. The saturation change rate includes the instantaneous change rate of the target fluid saturation and the overall change rate of the target fluid saturation:

[0097] The instantaneous change rate k of the target fluid saturation is used to quantify the instantaneous displacement efficiency of two-phase flow or multiphase flow. The calculation formula is:

[0098]

[0099] Where, S1 is the saturation of the target fluid at time t1; S2 is the saturation of the target fluid at time t2;

[0100] Optionally, in one embodiment of the present application, in this example, under the instantaneous condition of t=50s, the instantaneous rate of change of the saturation of trichloroethylene is calculated to be -2.29×10 -4 s -1 .

[0101] The overall change rate K of the target fluid saturation is used to quantify the overall displacement efficiency of two-phase flow or multiphase flow. The calculation formula is:

[0102]

[0103] In the formula, S end is the saturation of the target fluid at the end of the multiphase flow experiment; S init is the saturation of the target fluid at the beginning of the multiphase flow experiment; T is the duration of the multiphase flow experiment.

[0104] Optionally, in one embodiment of the present application, the overall rate of change of the saturation of trichloroethylene is calculated to be -1.37×10 -5 s -1 .

[0105] Further, in an embodiment of the present application, after calculating the saturation change rate based on the saturation evolution curve St diagram to quantify the multiphase flow process, it also includes:

[0106] When the target fluid is in a residual state and is no longer displaced by the invading phase fluid during the two-phase flow process, the saturation change is caused by mass transfer. The two-phase mass transfer rate coefficient K is calculated based on the saturation change.mf , the calculation formula is:

[0107]

[0108] In the formula, S l is the saturation of the residual fluid in the experiment; t is the time (T); ρ is the density of the residual fluid; is the porosity of the medium; c e is the equilibrium solubility of the residual fluid in the invading phase fluid; c is the concentration of the residual fluid in the invading phase fluid, where c is expressed as:

[0109]

[0110] Where s is the channel area of ​​the microfluidic chip; h is the channel depth of the microfluidic chip; v is the injection flow rate of the invading phase fluid.

[0111] Optionally, in one embodiment of the present application, the density of trichloroethylene is 1.46 g / mL, the porosity of the medium is 0.58, and the equilibrium solubility of trichloroethylene in the SDS solution is 2.03 g / L; under the instantaneous condition of t=50 s, the two-phase mass transfer rate coefficient of trichloroethylene and SDS solution is calculated to be 1.49 min -1 .

[0112] The present application provides a real-time calculation method for multiphase flow fluid saturation based on microfluidics technology, which first establishes a multiphase flow image data set, then crops the original images at different times in the multiphase flow image data set to the target size and rotates to the target position, identifies the target fluid in the cropped and rotated original image according to a preset RGB range, and adjusts the preset RGB range until the recognition result is accurate, the recognition result is the target fluid area, then generates the target fluid saturation data in real time based on the target fluid area, and finally draws the saturation evolution curve of the target fluid in the multiphase flow process based on the target fluid saturation data in real time. Thus, the accuracy of real-time calculation of fluid saturation in multiphase flow displacement and mass transfer processes is improved.

[0113] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0114] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0115] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A real-time calculation method for multiphase flow fluid saturation based on microfluidics technology, characterized in that: The following steps are involved: S1 establishes a multiphase flow image dataset; Carry out a porous medium or fracture medium multiphase flow microfluidic experiment according to actual needs, and acquire a preset resolution image of the multiphase flow process in real time through an image acquisition device to establish the multiphase flow image data set; S2 crops the original images at different times in the multiphase flow image data set into a target size and rotates them to a target position, identifies the target fluid in the cropped and rotated original images according to a preset RGB range, and adjusts the preset RGB range until the identification result is accurate, and the identification result is the target fluid area; S3 generates target fluid saturation data in real time based on the target fluid region of S2; S4 draws a saturation evolution curve of the target fluid in the multiphase flow process based on the target fluid saturation data in the real-time state obtained by S3.

2. According to the method for real-time calculation of multiphase flow fluid saturation based on microfluidics technology in claim 1, it is characterized in that: The step S1 specifically includes the following steps: S101 Conduct microfluidic visualization experiments of multiphase flow in porous media or fractured media: Prepare microfluidic transparent media with porous structures or fractured structures according to the research objectives, and dye different fluids and inject them into the microfluidic transparent media in sequence; S102 Acquiring a multiphase flow image data set: using an image acquisition device to acquire images of a preset resolution in real time during the multiphase flow microfluidic visualization experiment at a preset acquisition frame rate to establish a multiphase flow image data set.

3. The real-time calculation method of multiphase flow fluid saturation based on microfluidics technology according to claim 2 is characterized in that: The step S2 specifically includes the following steps: S201 uses the imrotate function in matlab to rotate the original images at different times in the multiphase flow image data set to normalized positions, and uses the imcrop function to crop the rotated images to a normalized size; S202 identifies the target fluid in the cropped and rotated original image according to a preset RGB range; S203 determines whether the preset RGB range is accurate according to the recognition result, and if it is inaccurate, adjusts the preset RGB range until the recognition result is correct.

4. The real-time calculation method of multiphase flow fluid saturation based on microfluidics technology according to claim 3 is characterized in that: The step S3 specifically comprises the following steps: S301 marks the pixel points occupied by the target fluid in the target fluid area as white; S302 counts the number N of pixels occupied by the target fluid; S303 calculates the target fluid saturation S in the normalized image under the instantaneous state; for porous media, the target fluid saturation S is calculated as follows: Where N is the number of pixels occupied by the target fluid; δ is the image resolution; h is the channel depth of the microfluidic chip; s is the channel area of ​​the microfluidic chip, is the medium porosity; For fractured media, the target fluid saturation S is calculated as: S=Nδa / L f W f a=Nδ / L f W f (2) Where a is the average opening of the crack; L f is the crack length; W f is the crack width; Image resolution δ represents the area occupied by each pixel in the normalized image, and the calculation formula is: δ=LW / mn (3) Where, L is the real length of the multiphase flow experiment image; W is the real width of the multiphase flow experiment image; m is the lateral resolution of the camera in the multiphase flow experiment, that is, the number of pixels in the horizontal direction of the screen; n is the longitudinal resolution of the camera in the multiphase flow experiment, that is, the number of pixels in the vertical direction of the screen; S304 generates target fluid saturation data in real time according to the target fluid saturation S in the normalized image in the instantaneous state.

5. The real-time calculation method of multiphase flow fluid saturation based on microfluidics technology according to claim 4 is characterized in that: The step S4 specifically comprises the following steps: S401 counts the shooting time t and the target fluid saturation S of each image in the multiphase flow image data set; S402 uses time t as the horizontal coordinate and the target fluid saturation S as the vertical coordinate to draw a multiphase flow experiment saturation evolution curve St.

6. The real-time calculation method of multiphase flow fluid saturation based on microfluidics technology according to claim 5 is characterized in that: After step S4, the method further includes: Based on the saturation evolution curve St diagram, the saturation change rate is calculated to quantify the multiphase flow process, and the saturation change rate includes the instantaneous change rate of the target fluid saturation and the overall change rate of the target fluid saturation: The instantaneous change rate k of the target fluid saturation is used to quantify the instantaneous displacement efficiency of two-phase flow or multiphase flow. The calculation formula is: Where, S1 is the saturation of the target fluid at time t1; S2 is the saturation of the target fluid at time t2; The overall change rate K of the target fluid saturation is used to quantify the overall displacement efficiency of two-phase flow or multiphase flow. The calculation formula is: In the formula, S end is the saturation of the target fluid at the end of the multiphase flow experiment; S init is the saturation of the target fluid at the beginning of the multiphase flow experiment; T is the duration of the multiphase flow experiment.

7. The real-time calculation method of multiphase flow fluid saturation based on microfluidics technology according to claim 6 is characterized in that: After calculating the saturation change rate based on the saturation evolution curve St diagram to quantify the multiphase flow process, the method further includes: When the target fluid is in a residual state and is no longer displaced by the invading phase fluid during the two-phase flow process, the saturation change is caused by mass transfer. The two-phase mass transfer rate coefficient K is calculated based on the saturation change. mf , the calculation formula is: In the formula, S l is the saturation of the residual fluid in the experiment; t is the time (T); ρ is the density of the residual fluid; is the porosity of the medium; c e is the equilibrium solubility of the residual fluid in the invading phase fluid; c is the concentration of the residual fluid in the invading phase fluid, where c is expressed as: Where s is the channel area of ​​the microfluidic chip; h is the channel depth of the microfluidic chip; v is the injection flow rate of the invading phase fluid.

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