Visual experiment device and method for surfactant flooding residual oil

Abstract

The invention relates to the technical field of petroleum engineering, in particular to a visual experiment device and method for surfactant flooding residual oil, and the device comprises a three-dimensional transparent displacement model, an injector and a collection device; the three-dimensional transparent displacement model is provided with a plurality of inlets and outlets, each inlet is connected with an independent injector, and each outlet is connected with a waste liquid recovery device; silicone oil, pure water for dyeing and a surface active agent for dyeing are respectively filled in the injector; collecting devices are respectively arranged above and on the side edges of the three-dimensional transparent displacement model and are used for recording the flowing process of fluid in the three-dimensional transparent displacement model; each injector is mounted on a micro-flow pump, the three-dimensional transparent displacement model is saturated by silicone oil, and then the silicone oil is displaced by the dyed pure water and the dyed surface active agent, so that the improvement condition of the surface active agent solution on the displacement efficiency is obtained. The experiment process is visualized, displacement conditions can be adjusted and controlled, and the model body can be regenerated.

Description

Technical Field

[0001] The invention relates to the technical field of petroleum engineering, and in particular to a visualization experimental device and method for surfactant-driven residual oil. Background Art

[0002] As oil recovery technology continues to mature, oil recovery efficiency is also rising. Despite this, the remaining oil in the oil layer, reservoir, and oil field, as well as the crude oil remaining in the pores in the area affected by the oil recovery agent during the oil recovery process, have not been recovered, which in turn affects the oil recovery efficiency. The mobilization mechanism of residual oil in the pores during surfactant displacement is attributed to the existence of various microscopic forces, which further improves the sweep efficiency under the pores and the recovery efficiency of residual oil compared to water flooding.

[0003] A Chinese invention patent with publication number CN114320285A discloses a two-dimensional high-temperature and high-pressure macroscopic visualization displacement experimental device and its use method, and conducts a series of displacement experiments through a flat tempered glass macroscopic model. However, this type of two-dimensional displacement experiment is not guided by actual working conditions and has a significant gap with the actual rock sample morphology.

[0004] The Chinese utility model patent with patent number CN208239449U discloses a core displacement experimental device, which places the rock sample in a closed and opaque holder to conduct a series of displacement experiments. However, such non-visual displacement experiments usually do not provide direct visual information and rely on indirect measurements (such as pressure and flow data) to infer fluid flow conditions. Especially when complex flow phenomena are involved, such displacement experiments may not be able to provide complete information about the details of fluid flow, making the interpretation of experimental results complicated. In addition, such displacement experiments cannot provide a rapid feedback mechanism, and do not allow experimenters to quickly adjust experimental parameters based on observations, thereby adjusting and optimizing the experimental design. Summary of the invention

[0005] In order to solve the above problems, the present application provides a visualization experimental device and method for surfactant flooding of residual oil, which can visualize the experimental process, adjust and control the displacement conditions, and achieve regeneration of the model body.

[0006] The technical solution adopted by the present invention to solve the technical problem is:

[0007] The present invention provides a visualization experimental device for residual oil displacement by surfactant, comprising a three-dimensional transparent displacement model, a syringe and a collection device;

[0008] The three-dimensional transparent displacement model is provided with a plurality of inlets and outlets, each of the inlets is connected to a separate syringe, and the outlet is connected to a waste liquid recovery device; the syringes are respectively filled with silicone oil, dyed pure water and dyed surfactant;

[0009] The top and side of the three-dimensional transparent displacement model are respectively provided with acquisition devices for recording the process of fluid flow in the three-dimensional transparent displacement model;

[0010] Each of the syringes is mounted on a microfluidic pump, and the fluid in the syringe is injected into the three-dimensional transparent displacement model through the microfluidic pump.

[0011] As an improvement of the above scheme, there are three entrances, one of which is located at the upper end of the three-dimensional transparent displacement model, the other two entrances are located on the left side of the three-dimensional transparent displacement model, and the exit is located on the right side of the three-dimensional transparent displacement model.

[0012] As an improvement of the above scheme, the silicone oil is dimethyl silicone oil, which is loaded into the syringe connected to the inlet at the upper end, the dyed pure water is loaded into the syringe connected to one of the inlets on the left side, and the dyed surfactant solution is loaded into the syringe connected to the other inlet on the left side.

[0013] As an improvement of the above solution, each of the inlets is connected to one of the syringes via a hose, and the outlet is connected to the waste liquid recovery device via a hose, and a valve is installed on each of the hoses.

[0014] As an improvement of the above solution, the waste liquid recovery device is a storage tank.

[0015] As an improvement of the above solution, the acquisition device located at the top is a high-speed camera, the high-speed camera is connected to a computer, the computer includes a display, and the acquisition device located in the front is a CCD camera.

[0016] As an improvement of the above scheme, the process of making the three-dimensional transparent displacement model is as follows:

[0017] The real sandstone image is obtained by CT scanning, and a three-dimensional model of the sandstone morphology is constructed. A three-dimensional transparent displacement model is formed by 3D printing using transparent photosensitive resin. The three-dimensional transparent displacement model is divided into two parts: the sandstone entity and the pores.

[0018] The present invention also provides a visualization experimental method for residual oil flooding by surfactant, which is applied to any of the visualization experimental devices for residual oil flooding by surfactant described above, and the method comprises:

[0019] Step 1: weigh the three-dimensional transparent displacement model, and then weigh the three-dimensional transparent displacement model that is completely saturated with water to obtain the mass difference △m between the two, and calculate the pore volume V0 according to the density ρ of water;

[0020] Step 2: After drying and evacuating the three-dimensional transparent displacement model, the three-dimensional transparent displacement model is fixed on the displacement experimental platform;

[0021] Step 3: Dimethyl silicone oil is loaded into the syringe and connected to the inlet at the upper end. Dyed pure water and dyed surfactant solution are respectively loaded into the syringe and connected to the inlet on the left side. The outlet on the right side is then connected to the waste liquid recovery device. At this time, all valves are in a closed state.

[0022] Step 4: Turn on the switch of the acquisition device at the top, so that the three-dimensional transparent displacement model is located in the center of the field of view, then open the valve, turn on the microfluidic pump, and inject dimethyl silicone oil into the three-dimensional transparent displacement model from the inlet at the upper end until the dimethyl silicone oil is observed from the computer to completely saturate the entire three-dimensional transparent displacement model, turn off the microfluidic pump, and then close the valve;

[0023] Step 5: Turn on the switch of the acquisition device in front, so that the three-dimensional transparent displacement model is located in the center of the field of view, turn on the recording buttons of the two acquisition devices, then open the valve, turn on the microfluidic pump, and inject dyed pure water into the three-dimensional transparent displacement model from one of the inlets on the left until no dimethyl silicone oil is observed to flow out from the waste liquid recovery device, turn off the microfluidic pump, close the valve, and then close the recording button of the acquisition device;

[0024] Step 6: taking out the dimethyl silicone oil in the waste liquid recovery device and measuring its volume V1;

[0025] Step 7: Turn on the recording buttons of the two collection devices, then open the valve, turn on the microfluidic pump, and inject the dyed surfactant solution into the three-dimensional transparent displacement model from the other inlet on the left side until no dimethyl silicone oil is observed to flow out from the waste liquid recovery device, turn off the microfluidic pump, turn off the valve, and then turn off the recording button of the collection device;

[0026] Step 8: taking out the dimethyl silicone oil in the waste liquid recovery device and measuring its volume V2;

[0027] Step 9: The data of the dimethyl silicone oil volumes V1 and V2 measured in steps 6 and 8 are statistically analyzed to obtain the improvement of the displacement efficiency by the surfactant solution.

[0028] As an improvement of the above solution, in step 2, the three-dimensional transparent displacement model is fixed on the displacement experimental platform with a clamp.

[0029] The beneficial effects brought by the present invention are:

[0030] 1. The three-dimensional transparent displacement model formed by 3D printing of transparent photosensitive resin can build a model that is closer to the real rock sample morphology and realize the reproducibility of the same model;

[0031] 2. Through the acquisition device, the fluid state and flow process in the three-dimensional transparent displacement model can be observed and recorded in real time to prepare for subsequent analysis;

[0032] 3. First, a three-dimensional transparent displacement model saturated with silicone oil is used, and then dyed pure water and dyed surfactants are injected in sequence. The data of silicone oil volumes V1 and V2 are statistically analyzed to obtain the improvement of the displacement efficiency by the surfactant solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0034] Attached Figure 1 It is a structural schematic diagram of a visualization experimental device for surfactant flooding residual oil of the present application.

[0035] In the figure: A, three-dimensional transparent displacement model; 1-3, inlet; 4, outlet; 5-7, microfluidic pump; 8-10, syringe; 11-14, valve; 15, high-speed camera; 16, CCD camera; 17, computer; 18, storage tank. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] In the description of the present invention, it should be understood that the terms "upper side", "lower side", "upper end", "two ends", "width", "height", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0038] In the present invention, unless otherwise clearly specified and limited, the terms "set", "install", "connect", "connect", "connection", "communication" and the like should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection; it can be a mechanical connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] Example 1

[0040] Reference Figure 1 A visualization experimental device for surfactant flooding of residual oil includes a three-dimensional transparent displacement model A, a syringe and a collection device.

[0041] The three-dimensional transparent displacement model A is obtained by 3D printing using transparent photosensitive resin. The left side of the three-dimensional transparent displacement model A has two inlets 2 and 3, the upper end of the model has an inlet 1, and the right side of the model has an outlet 4. Each inlet 1, 2, 3 is connected to a syringe through a hose, and the outlet 4 is connected to a waste liquid recovery device through a hose. Specifically, the waste liquid recovery device is a storage tank 18. Each hose is provided with a valve 11, 12, 13, 14 for controlling the inflow and outflow of fluid.

[0042] The syringe 8 connected to the upper inlet 1 is filled with silicone oil, specifically dimethyl silicone oil, the syringe 9 connected to one of the left inlets 2 is filled with dyed pure water, and the syringe 10 connected to the other left inlet 3 is filled with dyed surfactant solution.

[0043] A microfluidic pump 5, 6, 7 is correspondingly arranged below each syringe 8, 9, 10, and the flow rate of the fluid in the syringe 8, 9, 10 is accurately controlled by the microfluidic pump 5, 6, 7 to ensure the generation of a stable phase flow.

[0044] A collection device is provided above the three-dimensional transparent displacement model A. Specifically, the collection device is a high-speed camera 15. The high-speed camera 15 is connected to a computer 17. The computer 17 includes a display to observe the fluid saturation inside the model in real time.

[0045] A collection device is also provided in front of the three-dimensional transparent displacement model A. Specifically, the collection device is a CCD camera 16 with a display screen, and the collection device is used for real-time photographing and analyzing the state or process of fluid movement.

[0046] According to the actual situation, the number and position of the inlet and outlet can be adjusted, and the number of syringes and microfluidic pumps can be changed accordingly. Different fluids can be injected into the syringes for different experiments.

[0047] Example 2

[0048] The present application also provides a visualization experiment of residual oil flooding by surfactant, which is applied to the visualization experiment device of residual oil flooding by surfactant in the above-mentioned embodiment 1, and comprises:

[0049] Step 1: Place the three-dimensional transparent displacement model A on a balance to weigh and record its mass. Then place the three-dimensional transparent displacement model A that has been completely saturated with water on a platform to weigh and record its mass. By comparing the two masses (the mass of the model in a dry state and the mass of the model in a saturated water state), the mass difference △m is obtained. The pore volume V0 can be obtained by calculating the mass difference △m, because the mass of water entering the pores of the model is directly related to its volume. According to the density of water ρ (usually about 1g / cm 3 ), the pore volume can be calculated by the following formula: V0 = △m / ρ.

[0050] Step 2: Place the three-dimensional transparent displacement model A in a vacuum drying oven for online drying to ensure that the moisture inside the model is removed, evacuate the model, and then fix the three-dimensional transparent displacement model A on the displacement experimental platform with a clamp.

[0051] Step 3: Fill the syringe 8 with dimethyl silicone oil and connect it to the upper inlet 1. Fill the syringes 9 and 10 with dyed pure water and dyed surfactant solution respectively and connect them to the left inlets 2 and 3 respectively. Then connect the right outlet 44 to the storage tank 18. At this time, valves 11, 12, 13 and 14 are in the closed state.

[0052] Step 4: Turn on the switch of the high-speed camera 15 above to place the three-dimensional transparent displacement model A in the center of the field of view, then open valves 11, 14, start the microfluidic pump 5, and inject dimethyl silicone oil into the three-dimensional transparent displacement model A until it is observed from the computer 17 that the dimethyl silicone oil completely saturates the entire three-dimensional transparent displacement model A, then turn off the microfluidic pump 5, and then close valves 11, 14.

[0053] Step 5: Turn on the switch of the CCD camera 16 in front so that the three-dimensional transparent displacement model A is located in the center of the field of view, turn on the record buttons of the high-speed camera 15 and the CCD camera 16, then open valves 12, 14, turn on the microfluidic pump 6, and inject dyed pure water into the three-dimensional transparent displacement model A until no dimethyl silicone oil is observed to flow out from the storage tank 18, turn off the microfluidic pump 6, close valves 12, 14, and then turn off the record buttons of the high-speed camera 15 and the CCD camera 16 to record the entire process of fluid flow for subsequent analysis.

[0054] Step 6: Take out the dimethyl silicone oil in the storage tank 18 and measure its volume V1.

[0055] Step 7: Turn on the record buttons of the high-speed camera 15 and the CCD camera 16, then open the valves 13 and 14, turn on the microfluidic pump 7, and inject the dyed surfactant solution into the three-dimensional transparent displacement model A until no dimethyl silicone oil is observed to flow out from the storage tank 18, turn off the microfluidic pump 7, close the valves 13 and 14, and then turn off the record buttons of the high-speed camera 15 and the CCD camera 16 to record the entire process of fluid flow;

[0056] Step 8: Take out the dimethyl silicone oil in the storage tank 18 and measure its volume V2.

[0057] Step 9: By statistically analyzing the data of the dimethyl silicone oil volumes V1 and V2 measured in steps 7 and 9, the improvement of the displacement efficiency by the surfactant solution can be obtained.

[0058] in,

[0059] The production process of the above three-dimensional transparent displacement model A is as follows: a real sandstone image is obtained by CT scanning, a three-dimensional model of the sandstone morphology is constructed using AVIZO software, and then the model is 3D printed using transparent photosensitive resin to form a three-dimensional transparent displacement model A. The above three-dimensional transparent displacement model A is divided into two parts: sandstone entity and pores.

[0060] In steps 3 and 4, at the saturation stage of the three-dimensional transparent displacement model A, it is necessary to ensure that the interior of the three-dimensional transparent displacement model A is fully filled with dimethyl silicone oil to increase its saturation, so it is selected to be introduced from the upper inlet 1 so as to utilize the effect of gravity to ensure that the silicone oil can be evenly distributed to all parts of the model. This method can minimize the formation of bubbles and ensure that the silicone oil flows downward to achieve a good saturation effect.

[0061] In steps 5 and 7, during the displacement experiment phase, injecting liquid from the left inlets 2 and 3 can construct a specific flow path and corresponding pressure gradient to better simulate the actual flow conditions. Injection from the left side can better control the flow field, reduce the impact of fluid vortex and uneven distribution, and facilitate observation and analysis of the distribution and interaction of liquids during the displacement process.

[0062] In step 4, when the saturation of the three-dimensional transparent displacement model A is preliminarily observed, the high-speed camera 15 directly above can directly show the distribution of the liquid in the entire three-dimensional transparent displacement model A. If the model structure is relatively simple, the viewing angle directly above is clear enough to see the saturation state inside the model. If the model structure is relatively complex, the CCD camera 16 in front can also be turned on at the same time to observe the saturation state inside the model at the same time.

[0063] In step 5, when displacement is performed, especially when it involves the interaction and flow between different liquids, a single top view may not be able to fully capture the dynamic and migration behavior of the liquid. Therefore, increasing the view angle of the front CCD camera 16 can help obtain more information about the flow and contact points and comprehensively analyze the displacement effect of the liquid. By observing from different angles, more data points can be obtained, which helps to improve the reliability of subsequent data analysis. Especially when comparing the displacement effects of dyed pure water and surfactants, sufficient image and data records must be made for comparison and analysis.

[0064] It should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A visualization experimental device for surfactant flooding of residual oil, characterized in that: It includes a three-dimensional transparent displacement model (A), a syringe and a collection device; The three-dimensional transparent displacement model (A) is provided with a plurality of inlets and outlets, each of the inlets is connected to a separate syringe, and the outlet is connected to a waste liquid recovery device; the syringes are respectively filled with silicone oil, dyed pure water and dyed surfactant; The top and side of the three-dimensional transparent displacement model (A) are respectively provided with acquisition devices for recording the flow process of the fluid in the three-dimensional transparent displacement model (A); Each of the syringes is mounted on a microfluidic pump, and the fluid in the syringe is injected into the three-dimensional transparent displacement model (A) through the microfluidic pump.

2. The visualization experimental device for surfactant flooding residual oil according to claim 1, characterized in that: The number of the inlets is three, the number of the outlet is one, one of the inlets (1) is located at the upper end of the three-dimensional transparent displacement model (A), the other two inlets (2, 3) are located on the left side of the three-dimensional transparent displacement model (A), and the outlet (4) is located on the right side of the three-dimensional transparent displacement model (A).

3. The visualization experimental device for surfactant flooding residual oil according to claim 2, characterized in that: The silicone oil is dimethyl silicone oil, which is loaded into the syringe (8) connected to the inlet (1) at the upper end, the dyed pure water is loaded into the syringe (9) connected to one of the inlets (2) on the left, and the dyed surfactant solution is loaded into the syringe (10) connected to the other inlet (3) on the left.

4. The visualization experimental device for surfactant flooding residual oil according to claim 1, characterized in that: Each of the inlets (1, 2, 3) is connected to a syringe (8, 9, 10) via a hose, and the outlet (4) is connected to the waste liquid recovery device via a hose. A valve (11, 12, 13, 14) is installed on each of the hoses.

5. The visualization experimental device for surfactant flooding residual oil according to claim 1, characterized in that: The waste liquid recovery device is a storage tank (18).

6. The visualization experimental device for surfactant flooding residual oil according to claim 1, characterized in that: The acquisition device located at the top is a high-speed camera (15), the high-speed camera (15) is connected to a computer (17), the computer (17) includes a display, and the acquisition device located at the front is a CCD camera (16).

7. The visualization experimental device for surfactant flooding residual oil according to claim 1, characterized in that: The preparation process of the three-dimensional transparent displacement model (A) is as follows: A real sandstone image is obtained by CT scanning, a three-dimensional model of the sandstone morphology is constructed, and a three-dimensional transparent displacement model (A) is formed by 3D printing using transparent photosensitive resin. The three-dimensional transparent displacement model (A) is divided into two parts: a sandstone entity and pores.

8. A visualization experiment method for residual oil flooding by surfactant, the method being applied to the visualization experiment device for residual oil flooding by surfactant according to any one of claims 1 to 7, characterized in that: The method comprises: Step 1: weigh the three-dimensional transparent displacement model (A), and then weigh the three-dimensional transparent displacement model (A) that is completely saturated with water to obtain the mass difference △m between the two, and calculate the pore volume V0 according to the density ρ of water; Step 2: After drying and evacuating the three-dimensional transparent displacement model (A), the three-dimensional transparent displacement model (A) is fixed on a displacement experimental platform; Step 3: Dimethyl silicone oil is loaded into the syringe (8) and connected to the inlet (1) at the upper end; dyed pure water and dyed surfactant solution are loaded into the syringes (9, 10) respectively and connected to the inlets (2, 3) on the left side respectively; and the outlet (4) on the right side is connected to the waste liquid recovery device; at this time, all valves (11, 12, 13, 14) are in a closed state; Step 4: Turn on the switch of the acquisition device above to make the three-dimensional transparent displacement model (A) located in the center of the field of view, then open the valves (11, 14), start the microfluidic pump (5), and inject dimethyl silicone oil into the three-dimensional transparent displacement model (A). Observe that the dimethyl silicone oil completely saturates the entire three-dimensional transparent displacement model (A), turn off the microfluidic pump (5), and then close the valves (11, 14); Step 5: Turn on the switch of the acquisition device in front so that the three-dimensional transparent displacement model (A) is located in the center of the field of view, turn on the recording buttons of the two acquisition devices, then open the valves (12, 14), turn on the microfluidic pump (6), and inject dyed pure water into the three-dimensional transparent displacement model (A) until no dimethyl silicone oil is observed to flow out from the waste liquid recovery device, turn off the microfluidic pump (6), close the valves (12, 14), and then turn off the recording buttons of the acquisition devices; Step 6: taking out the dimethyl silicone oil in the waste liquid recovery device and measuring its volume V1; Step 7: Turn on the recording buttons of the two acquisition devices, then open the valves (13, 14), turn on the microfluidic pump (7), and inject the dyed surfactant solution into the three-dimensional transparent displacement model (A) until no dimethyl silicone oil is observed to flow out from the waste liquid recovery device, turn off the microfluidic pump (7), turn off the valves (13, 14), and then turn off the recording button of the acquisition device; Step 8: taking out the dimethyl silicone oil in the waste liquid recovery device and measuring its volume V2; Step 9: The data of the dimethyl silicone oil volumes V1 and V2 measured in steps 6 and 8 are statistically analyzed to obtain the improvement of the displacement efficiency by the surfactant solution.

9. The visualization experimental method for residual oil flooding by surfactant according to claim 1, characterized in that: In the step 2, the three-dimensional transparent displacement model (A) is fixed on the displacement experimental platform by a clamp.

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