A testing device and method for in-situ emulsification rate of thickened oil in a porous medium

Abstract

The present application relates to a kind of testing device and method of in-situ emulsification rate of thick oil viscosity reduction in porous medium, including displacement flow pump, cavity containing formation water, cavity containing thick oil, cavity containing viscosity reducer solution, multi-sampling point nested sand pack model, computer system;Displacement flow pump is used to provide the displacement power of fluid of high-precision preset flow;Cavity containing formation water is used to store experimental formation water, cavity containing thick oil is used to store experimental thick oil, cavity containing viscosity reducer solution is used to store experimental viscosity reducer solution;Multi-sampling point nested sand pack model is used to simulate formation porous medium environment, sampling point is used to collect the fluid in the interior of sand pack model;Computer system is used to record, analyze experimental monitoring data.The present application solves the problem that laboratory experiment is difficult to simulate mine injection water channeling and viscosity reducer emulsifies crude oil along water channeling channel and accurately evaluates the in-situ emulsification rate of thick oil in porous medium.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas field development technology, specifically relating to a testing device and method for the in-situ emulsification rate of heavy oil viscosity reduction in porous media. Background Technology

[0002] With the gradual depletion of global light oil resources, heavy oil, as an important alternative energy source, is receiving increasing attention for its development and utilization. Due to its high viscosity and poor fluidity, heavy oil faces significant technical challenges in its extraction. Currently, commonly used heavy oil extraction methods include steam injection and steam drive. While these methods have increased heavy oil production to some extent, they suffer from high energy consumption and large carbon emissions. Chemical viscosity reduction cold extraction technology is gaining increasing importance in heavy oil development. Its basic principle is to reduce the viscosity of heavy oil through chemical methods, thereby improving extraction efficiency. Therefore, it is necessary to accurately measure the in-situ emulsification rate of heavy oil under different spatiotemporal conditions in porous media, and then evaluate the development effect of heavy oil chemical viscosity reduction extraction technology.

[0003] Currently, crude oil emulsification rate testing mainly employs methods such as conductivity, optical microscopy, and volumetric analysis. The conductivity method determines the emulsification status of crude oil by measuring the change in conductivity of the solution in the aqueous phase from the start of emulsification to a certain point. The optical microscopy method uses a computer to extract the diameter of emulsified oil droplets and the total surface area of ​​crude oil from the micrograph using the principle of color tolerance, and then calculates the emulsification rate. The volumetric analysis method calculates the emulsification rate by measuring the volume change of the two-phase fluid in a test tube. It can be seen that the optical microscopy method is suitable for two-dimensional local analysis, and the conductivity and volumetric analysis methods have high accuracy in test tube analysis, but they are difficult to apply to the in-situ emulsification rate testing and analysis of heavy oil in porous media. Furthermore, the high viscosity and poor fluidity of heavy oil present another challenge in indoor core displacement experiments: how to achieve in-situ emulsification through contact between viscosity reducers and crude oil. Therefore, there is an urgent need to establish a testing device and method for the in-situ emulsification rate of heavy oil viscosity reduction in porous media. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a testing device for the in-situ emulsification rate of heavy oil viscosity reduction in porous media. A nested sand-filled model with multiple sampling points is established to expand the contact effect between the viscosity reducer and the heavy oil. Based on sampling and analysis inside the sand-filled model under different spatiotemporal conditions and injection parameters, the in-situ emulsification rate of heavy oil viscosity reduction in porous media is obtained.

[0005] This invention also provides a test method for the in-situ emulsification rate of heavy oil in porous media to reduce viscosity.

[0006] The technical solution adopted in this invention is as follows:

[0007] A testing device for the in-situ emulsification rate of heavy oil in porous media, comprising:

[0008] Displacement flow pump, cavity for containing formation water, cavity for containing heavy oil, cavity for containing viscosity reducer solution, nested sand-filled model with multiple sampling points, computer system;

[0009] The displacement flow pumps are all connected to the cavity containing formation water, the cavity containing heavy oil, and the cavity containing viscosity reducer solution; the cavity containing formation water, the cavity containing heavy oil, and the cavity containing viscosity reducer solution are all connected to the nested sand-filling model with multiple sampling points; the nested sand-filling model with multiple sampling points is connected to the computer system.

[0010] The displacement flow pump is used to provide displacement power for fluid with a high-precision preset flow rate; the cavity containing formation water is used to store experimental formation water, the cavity containing heavy oil is used to store experimental heavy oil, and the cavity containing viscosity reducer solution is used to store experimental viscosity reducer solution; the multi-sampling point nested sand-filled model is used to simulate the porous media environment of the formation, and the sampling points are used to collect fluid inside the sand-filled model; the computer system is used to record and analyze experimental monitoring data, including time, flow rate, pressure, produced fluid volume, and emulsification rate.

[0011] According to a preferred embodiment of the present invention, the nested sand-filling model with multiple sampling points includes a steel pipe, a solid steel column, several sampling ports, and several pressure measuring ports;

[0012] The solid steel column is installed inside the steel pipe. Several sampling ports are provided on the side of the steel pipe. Several pressure measuring ports are provided on the other side of the steel pipe at positions opposite to the sampling ports. Several pressure measuring ports are connected to several pressure sensors.

[0013] More preferably, both the inner wall of the steel pipe and the outer wall of the solid steel column are subjected to electrical discharge machining (EDM) texturing.

[0014] A method for testing the in-situ emulsification rate of heavy oil in porous media to reduce viscosity, implemented by a testing device, includes:

[0015] Conduct in-situ emulsification and displacement experiments for heavy oil viscosity reduction and perform real-time sampling;

[0016] The product liquid was allowed to stand and separate into layers, and the volume of the continuous oil phase was counted.

[0017] Demulsify the produced liquid and calculate the total volume of the oil phase.

[0018] Calculate the in-situ emulsification rate of heavy oil viscosity reduction in porous media;

[0019] By changing the experimental conditions and repeating the above steps, the in-situ emulsification rate of heavy oil viscosity reduction under different spatiotemporal conditions and injection parameters was obtained.

[0020] According to a preferred embodiment of the present invention, an in-situ emulsification and displacement experiment for heavy oil viscosity reduction is conducted and samples are taken in real time; including:

[0021] Heavy oil was injected and saturated in a nested sand-filled model with multiple sampling points. Formation water was then injected into the nested sand-filled model with multiple sampling points to displace the heavy oil. The heavy oil recovery rate was recorded during the displacement process. When the heavy oil recovery rate reached the recovery rate condition for injecting viscosity-reducing solution, the injection of formation water was stopped and the injection of viscosity-reducing solution was started. Produced fluid was collected at each sampling point at regular intervals and stored in a graduated cylinder for preservation.

[0022] According to a preferred embodiment of the present invention, quartz sand is segmentally filled and compacted into a nested sand-filling model with multiple sampling points using an annular sleeve and a semi-automatic compaction device to simulate porous formation conditions; including:

[0023] A preset volume of quartz sand is injected into the annulus between the steel pipe and the solid steel column of the nested sand-filling model with multiple sampling points; an annular sleeve is placed inside the annulus between the steel pipe and the solid steel column, with one end of the annular sleeve in contact with the quartz sand, and the other end of the annular sleeve is compacted by applying pressure through a semi-automatic compaction device.

[0024] Repeat the above steps until the annulus between the steel pipe and the solid steel column is filled with compacted quartz sand, ultimately forming a porous medium composed of many interconnected quartz sand skeletons and pores.

[0025] According to a preferred embodiment of the present invention, the produced liquid is allowed to settle and separate into layers, and the volume of the continuous oil phase is counted; including:

[0026] The graduated cylinder containing the product liquid was allowed to stand and separate into layers until the fluids of different densities in the graduated cylinder separated into layers and the volume of each part of the fluid no longer changed. The volume of the continuous oil phase at the top of the graduated cylinder and the total volume of the product liquid in the graduated cylinder were then read.

[0027] According to a preferred embodiment of the present invention, the demulsification of the produced liquid and the calculation of the total volume of the oil phase therein include:

[0028] Add the demulsifier to the product liquid in the graduated cylinder, centrifuge to separate the oil and water, let the fluid in the graduated cylinder stand until the oil and water stratification phenomenon appears in the product liquid, read the total volume of the lower water phase in the graduated cylinder, and calculate the total volume of the oil phase in the product liquid.

[0029] According to a preferred embodiment of the present invention, calculating the in-situ emulsification rate of heavy oil viscosity reduction in porous media includes:

[0030] Based on the obtained continuous oil phase volume and the obtained total oil phase volume, the in-situ emulsification rate of heavy oil viscosity reduction in porous media is calculated.

[0031] Further preferred, the mesh size of the quartz sand is one or more of 10-40 mesh, 40-70 mesh, 70-100 mesh, and 100-130 mesh, depending on the experimental requirements.

[0032] A further preferred method is to calculate the total volume of the oil phase in the produced liquid using the formula (1):

[0033] V o =V l -V w (1)

[0034] In equation (1), V o V is the total volume of the oil phase in the produced liquid. l V is the total volume of the produced liquid. w This represents the total volume of the aqueous phase in the produced liquid.

[0035] A further preferred formula for calculating the in-situ emulsification rate of heavy oil viscosity reduction is shown in equation (2):

[0036]

[0037] In equation (2), θ is the in-situ emulsification rate, and V o This represents the total volume of the oil phase in the produced liquid. This represents the total volume of the continuous oil phase in the produced liquid. This refers to the volume of oil contained in the emulsion in the produced liquid.

[0038] The beneficial effects of this invention are as follows:

[0039] 1. Compared with the traditional sand-filling model, the multi-sampling point nested sand-filling model adds a solid steel column in the center of the steel pipe. The annular space between the steel pipe and the solid steel column is filled with quartz sand. The injected formation water can easily flow along the surface of the solid steel column. After the viscosity reducer solution is injected, it is beneficial for the viscosity reducer to contact with the heavy oil and emulsify in situ. This solves the problem that it is difficult to simulate the flow of injected water in the mine and the emulsification of crude oil by the viscosity reducer along the water flow channel in indoor experiments.

[0040] 2. The method of testing the viscosity reduction emulsification rate of heavy oil by simulating internal sampling with sand filling is more effective than the traditional oil-water two-phase contact emulsification test based on test tubes. It can better reflect the influence of the two-phase flow process in the actual porous medium and solves the problem of testing the emulsification rate of heavy oil at different times and locations under in-situ conditions. It is helpful to analyze the viscosity reduction mining effect of heavy oil under real porous medium conditions. Attached Figure Description

[0041] Figure 1 A schematic diagram of the test method for in-situ emulsification rate of heavy oil in porous media to reduce viscosity;

[0042] Figure 2A schematic diagram of the structure of a test device for the in-situ emulsification rate of heavy oil viscosity reduction in porous media;

[0043] Figure 3 Photographs of in-situ emulsification sampling inside a nested sand-filling model with multiple sampling points at a certain moment;

[0044] Figure 4 A schematic diagram showing the change in in-situ emulsification rate of heavy oil viscosity reduction over time at different sampling locations;

[0045] Among them, 1. Displacement flow pump, 2. First valve, 3. Cavity containing formation water, 4. Second valve, 5. Third valve, 6. Cavity containing heavy oil, 7. Fourth valve, 8. Fifth valve, 9. Cavity containing viscosity reducer solution, 10. Sixth valve, 11. Nested sand-filled model with multiple sampling points, 12. First pressure sensor, 13. Second pressure sensor, 14. Third pressure sensor, 15. Fourth pressure sensor, 16. First sampling port, 17. Second sampling port, 18. Third sampling port, 19. Seventh valve, 20. First measuring cylinder, 21. Second measuring cylinder, 22. Third measuring cylinder, 23. Fourth measuring cylinder, 24. Computer system, 25. Solid steel column, 26. Steel pipe. Detailed Implementation

[0046] To make the above and other objects, features and advantages of the present invention more apparent and understandable, a further detailed description will be provided below in conjunction with the accompanying drawings and specific embodiments.

[0047] Example 1

[0048] A testing device for the in-situ emulsification rate of heavy oil in porous media, such as... Figure 2 As shown, it includes:

[0049] Displacement flow pump 1; cavity for containing formation water 3; cavity for containing heavy oil 6; cavity for containing viscosity reducer solution 9; nested sand-filled model with multiple sampling points 11; computer system 24.

[0050] Displacement flow pump 1 is connected to cavity 3 containing formation water, cavity 6 containing heavy oil, and cavity 9 containing viscosity reducer solution; cavity 3 containing formation water, cavity 6 containing heavy oil, and cavity 9 containing viscosity reducer solution are all connected to multi-sampling point nested sand filling model 11; multi-sampling point nested sand filling model 11 is connected to computer system 24.

[0051] Displacement flow pump 1 is used to provide displacement power for fluid with high-precision preset flow rate; cavity 3 for storing formation water is used to store experimental formation water, cavity 6 for storing experimental heavy oil is used to store experimental heavy oil, and cavity 9 for storing experimental viscosity reducer solution is used to store experimental viscosity reducer solution; multi-sampling point nested sand-filled model 11 is used to simulate the porous medium environment of the formation, and sampling points are used to collect fluid inside the sand-filled model; computer system 24 is used to record and analyze experimental monitoring data, including time, flow rate, pressure, produced fluid volume, and emulsification rate.

[0052] An in-situ emulsification experimental device was constructed using a cavity containing heavy oil, viscosity reducer solution, and formation water, a flow pump, a nested sand-filling model 11 with multiple sampling points, a pressure sensor, a computer system 24, a measuring cylinder, valves, and connecting pipelines. Quartz sand was filled and compacted in sections into the nested sand-filling model 11 with multiple sampling points through an annular sleeve and a semi-automatic compaction device to simulate the porous media conditions of the formation.

[0053] Example 2

[0054] The difference between the device for testing the in-situ emulsification rate of heavy oil in porous media according to Example 1 and the device described in Example 1 is that:

[0055] The nested sand-filling model 11 with multiple sampling points includes a steel pipe 26, a solid steel column 25, several sampling ports and several pressure measuring ports;

[0056] A solid steel column 25 is inserted through a steel pipe 26. Several sampling ports are provided on the side of the steel pipe 26, including a first sampling port 16, a second sampling port 17, and a third sampling port 18. Several pressure measuring ports are provided on the other side of the steel pipe 26, opposite to the sampling ports, and these pressure measuring ports are connected to several pressure sensors, including a second pressure sensor 13, a third pressure sensor 14, and a fourth pressure sensor 15.

[0057] The inner diameter of the steel pipe 26 is 2.5cm, the outer diameter of the solid steel column 25 is 1.7cm, the ring diameter between the steel pipe 26 and the solid steel column 25 is 0.4cm, the length is 60cm, the sampling points arranged on the side of the steel pipe 26 are spaced 15cm apart, the pressure measuring port is located on the side of the steel pipe 26 opposite to the sampling point, and the pressure measuring port and the sampling port are welded to the steel pipe 26.

[0058] The inner wall of steel pipe 26 and the outer wall of solid steel column 25 are both treated with electrical discharge machining (EDM) to improve roughness and prevent fluid from flowing along the wall surface.

[0059] The testing device also includes a first pressure sensor 12, which is located at one end of the nested sand-filling model 11 with multiple sampling points;

[0060] The testing device also includes several graduated cylinders, specifically a first graduated cylinder 20, a second graduated cylinder 21, a third graduated cylinder 22, and a fourth graduated cylinder 23; the first sampling port 16, the second sampling port 17, and the third sampling port 18 are respectively connected to the first graduated cylinder 20, the second graduated cylinder 21, and the third graduated cylinder 22.

[0061] The testing device also includes several valves, specifically valve 2, valve 4, valve 5, valve 7, valve 8, valve 10, and valve 19. The displacement flow pump 1 is connected to the cavity 3 containing formation water, the cavity 6 containing heavy oil, and the cavity 9 containing viscosity reducer solution through valves 2, 4, and 8, respectively. The cavity 3 containing formation water, the cavity 6 containing heavy oil, and the cavity 9 containing viscosity reducer solution are connected to the multi-sampling point nested sand-filling model 11 through valves 4, 7, and 10, respectively. The other end of the multi-sampling point nested sand-filling model 11 is connected to the fourth measuring cylinder 23 through valve 19.

[0062] Example 3

[0063] A method for testing the in-situ emulsification rate of heavy oil in porous media for viscosity reduction, implemented using the testing apparatus described in Example 1 or 2, as follows: Figure 1 As shown, it includes:

[0064] A test device was constructed to measure the in-situ emulsification rate of heavy oil viscosity reduction in porous media;

[0065] Conduct in-situ emulsification and displacement experiments for heavy oil viscosity reduction and perform real-time sampling;

[0066] The product liquid was allowed to stand and separate into layers, and the volume of the continuous oil phase was counted.

[0067] Demulsify the produced liquid and calculate the total volume of the oil phase.

[0068] Calculate the in-situ emulsification rate of heavy oil viscosity reduction in porous media;

[0069] By changing the experimental conditions and repeating the above steps, the in-situ emulsification rate of heavy oil viscosity reduction under different spatiotemporal conditions and injection parameters was obtained.

[0070] Conduct in-situ emulsification and displacement experiments for heavy oil viscosity reduction and perform real-time sampling; including:

[0071] Heavy oil was injected and saturated in a nested sand-filled model 11 with multiple sampling points. Formation water was injected into the nested sand-filled model 11 with multiple sampling points at a rate of 1 ml / min to displace the heavy oil. The heavy oil recovery rate was recorded during the displacement process. When the heavy oil recovery rate reached the recovery rate condition for injecting viscosity-reducing solution, the injection of formation water was stopped and the injection of viscosity-reducing solution was started. At each sampling port, the sampling port valve was opened at certain intervals to collect 2 ml of produced fluid and stored in a graduated cylinder for preservation.

[0072] Quartz sand is segmentally filled and compacted into the nested sand-filling model 11 with multiple sampling points using an annular casing and a semi-automatic compaction device to simulate porous formation conditions; including:

[0073] A preset volume of quartz sand is injected into the annulus between the steel pipe 26 and the solid steel column 25 of the nested sand-filling model 11 with multiple sampling points. An annular sleeve is placed inside the annulus between the steel pipe 26 and the solid steel column 25, with one end of the annular sleeve in contact with the quartz sand, and the other end of the annular sleeve is compacted by applying pressure through a semi-automatic compaction device. The mesh size of the quartz sand is one or more of 10-40 mesh, 40-70 mesh, 70-100 mesh, and 100-130 mesh, depending on the experimental requirements.

[0074] Repeat the above steps until the annulus between the steel pipe 26 and the solid steel column 25 is filled with compacted quartz sand, ultimately forming a porous medium composed of many interconnected quartz sand skeletons and pores.

[0075] The product liquid was allowed to settle and separate into layers, and the volume of the continuous oil phase was counted; including:

[0076] The graduated cylinder containing the product liquid was allowed to stand and separate into layers until the fluids of different densities in the graduated cylinder showed obvious stratification and the volume of each part of the fluid no longer changed. The volume of the continuous oil phase at the top of the graduated cylinder and the total volume of the product liquid in the graduated cylinder were then read.

[0077] Demulsify the produced liquid and calculate the total volume of the oil phase; including:

[0078] A demulsifier is added to the product liquid in a graduated cylinder. After centrifugation, the oil and water are separated. The fluid in the graduated cylinder is allowed to stand for a period of time until a clear oil-water stratification occurs in the product liquid. The total volume of the lower aqueous phase in the graduated cylinder is recorded, and the total volume of the oil phase in the product liquid is calculated. The formula for calculating the total volume of the oil phase in the product liquid is shown in equation (1):

[0079] V o =V l -V w (1)

[0080] In equation (1), V o V is the total volume of the oil phase in the produced liquid. l V is the total volume of the produced liquid. w This represents the total volume of the aqueous phase in the produced liquid.

[0081] Calculate the in-situ emulsification rate of heavy oil in porous media for viscosity reduction; including:

[0082] Based on the obtained continuous oil phase volume and the obtained total oil phase volume, the in-situ emulsification rate of heavy oil viscosity reduction in porous media is calculated.

[0083] The formula for calculating the in-situ emulsification rate of heavy oil viscosity reduction is shown in equation (2):

[0084]

[0085] In equation (2), θ is the in-situ emulsification rate, and V o This represents the total volume of the oil phase in the produced liquid. This represents the total volume of the continuous oil phase in the produced liquid. This refers to the volume of oil contained in the emulsion in the produced liquid.

[0086] Example 4

[0087] A method for testing the in-situ emulsification rate of heavy oil in porous media, implemented using the testing apparatus described in Example 1 or 2, includes:

[0088] A test device was constructed to measure the in-situ emulsification rate of heavy oil viscosity reduction in porous media. Quartz sand was segmentally filled and compacted into a nested sand-filled model 11 with multiple sampling points using an annular casing and a semi-automatic compaction device to simulate the porous media conditions of the formation. This included:

[0089] A preset volume of quartz sand is injected into the annular space between the steel pipe 26 and the solid steel column 25 of the multi-sampling point nested sand-filling model 11; an annular sleeve is placed inside the annular space between the steel pipe 26 and the solid steel column 25, with one end of the annular sleeve in contact with the quartz sand, and the other end of the annular sleeve is compacted by applying pressure through a semi-automatic compaction device; in this embodiment, the mesh size of the quartz sand is 70-100 mesh;

[0090] Repeat the above steps until the annulus between the steel pipe 26 and the solid steel column 25 is filled with compacted quartz sand, ultimately forming a porous medium composed of many interconnected quartz sand skeletons and pores.

[0091] Conduct in-situ emulsification and displacement experiments for heavy oil viscosity reduction and perform real-time sampling; including:

[0092] Heavy oil was injected and saturated into a nested sand-filled model 11 with multiple sampling points. Formation water was injected into the model 11 at a rate of 1 ml / min to displace the heavy oil. The heavy oil recovery rate was recorded during the displacement process. When the heavy oil recovery rate reached the recovery rate condition for injecting the viscosity-reducing solution, the injection of formation water was stopped and the injection of the viscosity-reducing solution began. At each sampling port, the sampling port valve was opened at regular intervals to collect 2 ml of produced fluid, which was then stored in a graduated cylinder. In this embodiment, the recovery rate condition for injecting the viscosity-reducing solution was 45%.

[0093] The product liquid was allowed to settle and separate into layers, and the volume of the continuous oil phase was counted; including:

[0094] The graduated cylinder containing the product liquid was allowed to stand and separate into layers until the fluids of different densities in the graduated cylinder showed obvious stratification and the volume of each part of the fluid no longer changed. The volume of the continuous oil phase at the top of the graduated cylinder and the total volume of the product liquid in the graduated cylinder were then read.

[0095] The liquid production rate at different locations and the volume of the continuous oil phase at the top of the measuring cylinder in this embodiment are shown in Tables 1 to 4. Figure 3 These are photos of the produced fluid at three locations under different injection times.

[0096] Table 1

[0097]

[0098] Table 2

[0099]

[0100]

[0101] Table 3

[0102]

[0103] Table 4

[0104]

[0105]

[0106] Demulsify the produced liquid and calculate the total volume of the oil phase; including:

[0107] A demulsifier is added to the product liquid in a graduated cylinder. After centrifugation, the oil and water are separated. The fluid in the graduated cylinder is allowed to stand for a period of time until a clear oil-water stratification occurs in the product liquid. The total volume of the lower aqueous phase in the graduated cylinder is recorded, and the total volume of the oil phase in the product liquid is calculated. The formula for calculating the total volume of the oil phase in the product liquid is shown in equation (1):

[0108] V o =V l -V w (1)

[0109] In equation (1), V o V is the total volume of the oil phase in the produced liquid. l V is the total volume of the produced liquid. w This represents the total volume of the aqueous phase in the product liquid. In this embodiment, the total volume of the aqueous phase and the total volume of the oil phase in the product liquid are shown in Tables 5 to 8.

[0110] Calculate the in-situ emulsification rate of heavy oil in porous media for viscosity reduction; including:

[0111] Based on the obtained continuous oil phase volume and the obtained total oil phase volume, the in-situ emulsification rate of heavy oil viscosity reduction in porous media is calculated.

[0112] The formula for calculating the in-situ emulsification rate of heavy oil viscosity reduction is shown in equation (2):

[0113]

[0114] In equation (2), θ is the in-situ emulsification rate, and V o This represents the total volume of the oil phase in the produced liquid. This represents the total volume of the continuous oil phase in the produced liquid. This refers to the volume of oil contained in the emulsion in the produced liquid.

[0115] By changing the experimental conditions and repeating the above steps, the in-situ emulsification rate of heavy oil viscosity reduction under different spatiotemporal conditions and injection parameters was obtained. In this embodiment, the calculated results of the in-situ emulsification rate of heavy oil viscosity reduction in porous media are shown in Tables 5 to 8. Figure 4 These are curves showing the change in in-situ emulsification rate of heavy oil viscosity reduction over time at different sampling locations. Among them, location 1 is at position 20 of the first graduated cylinder, location 2 is at position 21 of the second graduated cylinder, location 3 is at position 22 of the third graduated cylinder, and location 4 is at position 23 of the fourth graduated cylinder.

[0116] Table 5

[0117]

[0118] Table 6

[0119]

[0120] Table 7

[0121]

[0122] Table 8

[0123]

Claims

1. A testing device for the in-situ emulsification rate of heavy oil in porous media, characterized in that, include: Displacement flow pump, cavity for containing formation water, cavity for containing heavy oil, cavity for containing viscosity reducer solution, nested sand-filled model with multiple sampling points, computer system; The displacement flow pumps are all connected to the cavity containing formation water, the cavity containing heavy oil, and the cavity containing viscosity reducer solution; the cavity containing formation water, the cavity containing heavy oil, and the cavity containing viscosity reducer solution are all connected to the nested sand-filling model with multiple sampling points; the nested sand-filling model with multiple sampling points is connected to the computer system. The displacement flow pump is used to provide displacement power for fluid with a high-precision preset flow rate; the cavity containing formation water is used to store experimental formation water, the cavity containing heavy oil is used to store experimental heavy oil, and the cavity containing viscosity reducer solution is used to store experimental viscosity reducer solution; the multi-sampling point nested sand-filled model is used to simulate the porous media environment of the formation, and the sampling points are used to collect fluid inside the sand-filled model; the computer system is used to record and analyze experimental monitoring data, including time, flow rate, pressure, produced fluid volume, and emulsification rate; The nested sand-filling model with multiple sampling points includes a steel pipe, a solid steel column, several sampling ports, and several pressure measuring ports. The solid steel column is installed inside the steel pipe. Several sampling ports are provided on the side of the steel pipe. Several pressure measuring ports are provided on the other side of the steel pipe at the position opposite to the sampling ports. Several pressure measuring ports are connected to several pressure sensors. The inner wall of the steel pipe and the outer wall of the solid steel column are both treated with electrical discharge machining (EDM).

2. A method for testing the in-situ emulsification rate of heavy oil viscosity reduction in porous media, implemented using the testing device for the in-situ emulsification rate of heavy oil viscosity reduction in porous media as described in claim 1, characterized in that... include: Conduct in-situ emulsification and displacement experiments for heavy oil viscosity reduction and perform real-time sampling; The product liquid was allowed to stand and separate into layers, and the volume of the continuous oil phase was counted. Demulsify the produced liquid and calculate the total volume of the oil phase. Calculate the in-situ emulsification rate of heavy oil viscosity reduction in porous media; By changing the experimental conditions and repeating the above steps, the in-situ emulsification rate of heavy oil viscosity reduction under different spatiotemporal conditions and injection parameters was obtained.

3. The method for testing the in-situ emulsification rate of heavy oil in porous media according to claim 2, characterized in that, Conduct in-situ emulsification and displacement experiments for heavy oil viscosity reduction and perform real-time sampling; including: Heavy oil was injected and saturated in a nested sand-filled model with multiple sampling points. Formation water was then injected into the nested sand-filled model with multiple sampling points to displace the heavy oil. The heavy oil recovery rate was recorded during the displacement process. When the heavy oil recovery rate reached the recovery rate condition for injecting viscosity-reducing solution, the injection of formation water was stopped and the injection of viscosity-reducing solution was started. Produced fluid was collected at each sampling point at regular intervals and stored in a graduated cylinder for preservation.

4. The method for testing the in-situ emulsification rate of heavy oil in porous media according to claim 2, characterized in that, Quartz sand was segmentally filled and compacted into a nested sand-filling model with multiple sampling points using a ring casing and a semi-automatic compaction device to simulate porous formation conditions; including: A predetermined volume of quartz sand is injected into the annulus between the steel pipe and the solid steel column of the nested sand-filling model with multiple sampling points. An annular sleeve is placed inside the annulus between the steel pipe and the solid steel column, with one end of the annular sleeve in contact with the quartz sand, and the other end of the annular sleeve is compacted by applying pressure through a semi-automatic compaction device. The mesh size of the quartz sand is one or more of 10-40 mesh, 40-70 mesh, 70-100 mesh, and 100-130 mesh, depending on the experimental requirements. Repeat the above steps until the annulus between the steel pipe and the solid steel column is filled with compacted quartz sand, ultimately forming a porous medium composed of many interconnected quartz sand skeletons and pores.

5. The method for testing the in-situ emulsification rate of heavy oil in porous media according to claim 2, characterized in that, The product liquid was allowed to settle and separate into layers, and the volume of the continuous oil phase was counted; including: The graduated cylinder containing the product liquid was allowed to stand and separate into layers until the fluids of different densities in the graduated cylinder separated into layers and the volume of each part of the fluid no longer changed. The volume of the continuous oil phase at the top of the graduated cylinder and the total volume of the product liquid in the graduated cylinder were then read.

6. The method for testing the in-situ emulsification rate of heavy oil in porous media according to claim 2, characterized in that, Demulsify the produced liquid and calculate the total volume of the oil phase; including: Add the demulsifier to the product liquid in the graduated cylinder, centrifuge to separate the oil and water, let the fluid in the graduated cylinder stand until the oil and water stratification phenomenon appears in the product liquid, read the total volume of the lower water phase in the graduated cylinder, and calculate the total volume of the oil phase in the product liquid.

7. A method for testing the in-situ emulsification rate of heavy oil in porous media according to any one of claims 2-6, characterized in that, Calculate the in-situ emulsification rate of heavy oil in porous media for viscosity reduction; including: Based on the obtained continuous oil phase volume and the obtained total oil phase volume, the in-situ emulsification rate of heavy oil viscosity reduction in porous media is calculated.

8. The method for testing the in-situ emulsification rate of heavy oil in porous media according to claim 6, characterized in that, The formula for calculating the total volume of the oil phase in the produced liquid is shown in equation (1): （1） In equation (1), V o This represents the total volume of the oil phase in the produced liquid. V is the total volume of the produced liquid. w This represents the total volume of the aqueous phase in the produced liquid.

9. The method for testing the in-situ emulsification rate of heavy oil in porous media according to claim 7, characterized in that, The formula for calculating the in-situ emulsification rate of heavy oil viscosity reduction is shown in equation (2): （2） In equation (2), θ is the in-situ emulsification rate, and V o This represents the total volume of the oil phase in the produced liquid. This represents the total volume of the continuous oil phase in the produced liquid. This refers to the volume of oil contained in the emulsion in the produced liquid.

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