Multi-phase flow steam injection simulation experiment device for long horizontal well

Abstract

The invention discloses a multiphase flow steam injection simulation experiment device for a long horizontal well, which relates to the technical field of horizontal well exploitation and comprises N sections of reservoir box bodies arranged in sequence, horizontal steam injection pipe simulation devices arranged in the N sections of reservoir box bodies, and a steam injection simulation system communicated with the first section of horizontal steam injection pipe simulation device, the transparent visual observation section is arranged on a pipeline at an outlet of the horizontal steam injection pipe simulation device, the high-speed camera shooting system is used for shooting fluid in the transparent visual observation section at a high speed, and the control terminal is used for performing flow pattern analysis on information acquired by the high-speed camera shooting system. According to the method, the N sections of mutually independent reservoir box structures are adopted, differential geological parameters can be synchronously loaded to the boxes, the influences of different reservoir physical properties on the development effect can be synchronously compared, and the optimal mining scheme can be rapidly screened through parameter combination optimization. And a key theoretical basis and an engineering verification means are provided for refined regulation and control of a heavy oil thermal recovery process through flow pattern analysis.

Description

Technical Field

[0001] The present invention relates to the technical field of horizontal well exploitation, and particularly to a steam injection simulation experimental device for multiphase flow in long horizontal wells. Background Art

[0002] As a large energy-consuming country, the rapid development of China highly depends on the stable growth of oil and gas supply. China is rich in heavy oil resources, and thermal recovery will play an increasingly important role in future oil exploitation, with its proportion increasing significantly. Due to the characteristics of high viscosity and poor fluidity of heavy oil, the exploitation difficulty is very high. However, the viscosity of heavy oil is highly sensitive to temperature. Generally, for every 10°C increase in temperature, the viscosity decreases by about 50%. Therefore, for heavy oil exploitation, the most effective method at present is "thermal oil recovery", and among them, steam injection thermal recovery for heavy oil is the most widely used and mature thermal oil recovery method in each oilfield institution.

[0003] Currently, for multi-section long horizontal wells, there are problems such as poor steam injection effect, uneven utilization degree, and easy steam channeling in traditional general steam injection. Reasonable segmented steam injection is required to achieve the purpose of improving the steam absorption condition of the oil reservoir, increasing the utilization degree of the oil reservoir, and increasing the oil well production and recovery rate. Therefore, it is necessary to use a horizontal well steam injection model for experimental simulation. However, the existing horizontal well steam injection models have problems such as inability to simulate in segments, cumbersome simulation forms for heterogeneity in different horizontal sections, and difficulty in observing the flow state of the injected fluid, and further optimization is urgently needed. Summary of the Invention

[0004] The purpose of the present invention is to provide a steam injection simulation experimental device for multiphase flow in long horizontal wells to solve the above problems existing in the prior art, achieve segmented simulation, optimize the simulation scheme for heterogeneity in different horizontal sections, and reduce the difficulty of observing the fluid flow state.

[0005] To achieve the above purpose, the present invention provides the following solution:

[0006] A steam injection simulation experimental device for multiphase flow in long horizontal wells, comprising:

[0007] A reservoir box for filling experimental raw materials to simulate the geological conditions of an oil reservoir, and N sections of the reservoir boxes are arranged in sequence, where N is an integer greater than or equal to two;

[0008] A horizontal steam injection pipe simulation device is disposed through the inside of the reservoir box, and the horizontal steam injection pipe simulation devices in N sections of the reservoir boxes are connected in sequence through pipelines;

[0009] A steam injection simulation system is connected to the horizontal steam injection pipe simulation device in the first section for injecting steam into the horizontal steam injection pipe simulation device;

[0010] A flow pattern observation device, comprising a transparent visual observation section and a high-speed camera system. The transparent visual observation section is disposed on the pipeline at the outlet of the horizontal steam injection pipe simulation device, and the high-speed camera system is used to perform high-speed shooting on the fluid in the transparent visual observation section;

[0011] A control terminal, configured to perform flow pattern analysis on the information acquired by the high-speed camera system.

[0012] In an exemplary embodiment, the steam injection simulation system includes a steam generator, an air compressor, and a deionized water source. The steam generator is communicated with the horizontal steam injection pipe simulation device through a first pipeline. The air compressor is connected to a second pipeline, and the deionized water source is connected to a third pipeline. The second pipeline and the third pipeline converge through a gas-liquid two-phase mixer and then are communicated with the horizontal steam injection pipe simulation device.

[0013] In an exemplary embodiment, a water vapor flow control valve is disposed on the first pipeline, a pressure reducing valve and a gas flow control valve are disposed on the second pipeline connected to the air compressor, and a liquid flow control valve is disposed on the third pipeline connected to the deionized water source.

[0014] In an exemplary embodiment, a check valve is disposed at the outlet of the horizontal steam injection pipe simulation device in each section of the reservoir box body.

[0015] In an exemplary embodiment, a pressure monitoring element is disposed at the outlet of the horizontal steam injection pipe simulation device in each section of the reservoir box body.

[0016] In an exemplary embodiment, an injection fluid recovery device is connected to the outlet of the horizontal steam injection pipe simulation device in the last section of the reservoir box body.

[0017] In an exemplary embodiment, a temperature sensing element for monitoring the change of the simulated formation temperature is disposed inside the reservoir box body.

[0018] In an exemplary embodiment, the temperature sensing element is a thermocouple cluster, and a plurality of the thermocouple clusters are evenly arranged circumferentially around the horizontal steam injection pipe simulation device.

[0019] In an exemplary embodiment, an angle adjustment system for adjusting the inclination angle of the reservoir box body is further included.

[0020] In an exemplary embodiment, the angle adjustment system includes:

[0021] A movable plate, configured to support N sections of the reservoir box body;

[0022] A rotating shaft, rotatably disposed at the first end of the movable plate;

[0023] Support frames are arranged at both ends of the rotating shaft to support the rotating shaft;

[0024] A lifting device is arranged at the second end of the movable plate to lift the movable plate;

[0025] By driving the lifting device to move up and down, the first end of the movable plate is driven to rotate around the rotating shaft, so as to adjust the inclination angle of the reservoir box body.

[0026] The present invention has achieved the following technical effects compared with the prior art:

[0027] By adopting an N-section mutually independent reservoir box body structure, each box body can be synchronously loaded with different geological parameters (such as porosity, permeability, oil saturation), breaking through the limitation that the traditional steam injection model for horizontal wells needs to replace the simulation medium one by one, and significantly improving the experimental efficiency. This parallel simulation mechanism can not only synchronously compare the influence of different reservoir physical properties on the development effect, but also quickly screen the best exploitation scheme through parameter combination optimization, providing multi-dimensional data support for the development decision-making of complex heterogeneous shale oil reservoirs.

[0028] Through the synergistic effect of the transparent visible observation section and the high-speed camera system, the fluid dynamics at the outlet of the horizontal steam injection pipe simulation device are captured and analyzed in real time, and then the control terminal equipped with relevant software combines digital image processing technology to capture and analyze the multiphase flow dynamic characteristics in real time. Based on the ratio of the gas volume flow rate to the total volume flow rate, the two-phase flow is divided into three categories: separated flow, dispersed flow, and intermittent flow. Each flow pattern corresponds to different thermodynamic characteristics, flow laws, and heat transfer calculation formula systems. The research team systematically reveals the mechanism of action of key parameters such as steam injection temperature and pressure, steam quality, and reservoir permeability on the evolution of fluid flow patterns through experiments, quantitatively analyzes the variation characteristics of the effective injection volume under different flow patterns, and thus constructs a flow pattern-reservoir adaptability correlation model. This flow pattern analysis system not only provides an experimental benchmark for steam injection thermal recovery technology for flow pattern discrimination, but also guides the on-site optimization of steam injection pressure, temperature and other working conditions, and scientifically distributes the steam injection intensity of each layer section by establishing a dynamic matching mechanism between flow pattern prediction and steam injection parameters, thereby significantly suppressing the steam channeling phenomenon and improving the thermal energy utilization rate. This research paradigm that combines laboratory flow pattern observation technology with engineering applications can provide key theoretical basis and engineering verification means for the refined control of heavy oil thermal recovery technology.

[0029] The other technical solutions disclosed by the present invention also have the following technical advantages:

[0030] By setting up an angle adjustment system, the inclination angle of the reservoir box is dynamically adjusted in the horizontal well steam injection model, achieving accurate simulation of the heterogeneous structure and complex dip angles of the real formation, thereby reproducing the influence of the geometric heterogeneity of the underground reservoir on the fluid migration law in the experimental environment. By changing the formation dip angle parameter, researchers can systematically explore the flow pattern evolution law of gas-liquid two-phase flow in different inclined states, such as key dynamic characteristics such as gravity segregation effect, phase distribution characteristics, and velocity field changes. This controllable inclination condition provides an important experimental means for revealing the influence of formation dip angle on steam channeling path, heat wave propagation range, and effective injection efficiency during the steam injection process, and can also verify the accuracy of the dip correction coefficient in the numerical model. Through comparative experiments under multi-angle working conditions, a quantitative correlation model between the formation dip angle and the optimal steam injection parameters (such as steam injection pressure, injection rate) can be established, providing a scientific basis for the inclination adaptability optimization of the steam injection development plan for reservoirs with complex structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0032] Figure 1 Structural schematic diagram of a long horizontal well multiphase flow steam injection simulation experimental device disclosed in a specific embodiment of the present invention;

[0033] Figure 2 is Figure 1 Schematic cross-sectional view of the setting method of the horizontal steam injection pipe simulation device and the thermocouple cluster in the middle box;

[0034] Among them, 1. Air compressor; 2. Pressure reducing valve; 3. Gas flow control valve; 4. Deionized water source; 5. Liquid flow control valve; 6. Gas-liquid mixer; 7. First valve; 8. Steam flow control valve; 9. Steam generator; 10. Second valve; 11. Reservoir box; 12. Pressure monitoring element; 13. Check valve; 14. Transparent visual observation section; 15. Ball valve; 16. Control terminal; 17. Fluid recovery and statistics device; 18. Lifting device; 19. Angle adjustment system; 20. First pipeline; 21. Second pipeline; 22. Third pipeline; 23. Movable plate; 24. Rotating shaft; 25. Horizontal steam injection pipe simulation device; 26. Thermocouple cluster. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Those skilled in the art can easily understand the other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0036] The object of the present invention is to provide a simulation experimental device for multiphase flow steam injection in long horizontal wells to solve the problems existing in the prior art, achieve segmented simulation, optimize the simulation scheme for heterogeneity in different horizontal sections, and reduce the difficulty of observing the fluid flow state.

[0037] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0038] Please refer to Figures 1 to 2 , this embodiment provides a simulation experimental device for multiphase flow steam injection in long horizontal wells, including a reservoir box body 11, a horizontal steam injection pipe simulation device 25, a steam injection simulation system, a flow state observation device, and a control terminal 16. The reservoir box body 11 is used to fill experimental raw materials to simulate the reservoir geology of the oil reservoir. N reservoir box bodies 11 are arranged in sequence, and N is an integer greater than or equal to two. The horizontal steam injection pipe simulation device 25 is disposed through the inside of the reservoir box body 11, and the horizontal steam injection pipe simulation devices 25 in the N reservoir box bodies 11 are connected in sequence through pipelines.

[0039] The steam injection simulation system is connected to the first-stage horizontal steam injection pipe simulation device 25 and is used to inject steam into the horizontal steam injection pipe simulation device 25. Specifically, it includes a steam generator 9, an air compressor 1, and a deionized water source 4. The steam generator 9 is connected to the horizontal steam injection pipe simulation device 25 through a first pipeline 20. The air compressor 1 is connected to a second pipeline 21, and the deionized water source 4 is connected to a third pipeline 22. The second pipeline 21 and the third pipeline 22 are joined through a gas-liquid two-phase mixer 6 and then connected to the horizontal steam injection pipe simulation device 25.

[0040] Further, a water vapor flow control valve 8 is provided on the first pipeline 20, a pressure reducing valve 2 and a gas flow control valve 3 are provided on the second pipeline 21 connected to the air compressor 1, and a liquid flow control valve 5 is provided on the third pipeline 22 connected to the deionized water source 4. A first valve 7 is provided on the pipeline at the outlet of the gas-liquid two-phase mixer 6, and a second valve 10 is provided on the pipeline in front of the first-stage reservoir box body 11. A check valve 13, a pressure monitoring element 12, and a ball valve 15 are provided on the pipeline at the outlet of the horizontal steam injection pipe simulation device 25 in each reservoir box body 11.

[0041] The flow pattern observation device includes a transparent visible observation section 14 and a high-speed camera system (not shown in the figure). The transparent visible observation section 14 is arranged on the pipeline at the outlet of the horizontal steam injection pipe simulation device 25. The high-speed camera system is used to take high-speed pictures of the fluid in the transparent visible observation section 14, and the control terminal 16 is used to perform flow pattern analysis on the information obtained by the high-speed camera system.

[0042] As an optimization, the transparent visible observation section 14 in this embodiment uses a high light transmittance quartz glass tube (with a length of 100 mm and a diameter equal to that of the steam injection pipeline, 30 mm). Its physical properties have both high pressure resistance and wide spectral transmission. At the same time, anti-sand meshes are laid on the outer walls of the horizontal steam injection pipe simulation device 25 and each connecting piece to prevent reservoir sand from entering the pipeline. The anti-sand mesh can specifically adopt an iron wire mesh with an appropriate mesh number.

[0043] A temperature sensing element for monitoring the change of the simulated formation temperature is arranged inside the reservoir box 11. In this embodiment, the temperature sensing element adopts a thermocouple cluster 26, and a plurality of thermocouple clusters 26 are evenly arranged circumferentially around the horizontal steam injection pipe simulation device 25.

[0044] The above-mentioned pressure monitoring element 12 and temperature sensing element are both connected to the control terminal 16 in signal.

[0045] The pipeline at the outlet of the horizontal steam injection pipe simulation device 25 inside the last section of the reservoir box 11 is connected to an injection fluid recovery device 17. The injection fluid recovery device 17 is marked with scales and is used to collect the fluid injected by the steam injection simulation system. The recovered fluid is used for subsequent analysis.

[0046] The experimental process of this embodiment is as follows:

[0047] Preparation work: Open the box body sealing cover, and install the horizontal steam injection pipe simulation device 25 and the thermocouple cluster 26 inside the reservoir box 11 as shown in Figure 2 the figure. Then, fill sand into each section of the reservoir box 11 according to the set experimental parameters, and add an oil-water mixture to make the simulated formation reach a certain porosity and crude oil saturation. Close the box body sealing cover, open the ball valve 15, conduct an airtightness inspection on the whole system, turn on the high-speed camera system, and check the control terminal 16 to ensure normal data collection.

[0048] Experiment 1: Close the steam flow control valve 8 and the steam generator 9, turn on the air compressor 1 and adjust the pressure reducing valve 2 and the gas flow control valve 3. At the same time, adjust the deionized water source 4 and the liquid flow control valve 5 so that air and deionized water are mixed in the gas-liquid mixer 6 in a set ratio. Open the first valve 7 and the second valve 10, and inject the gas-liquid two-phase mixed fluid into the horizontal steam injection pipe simulation device 25.

[0049] Experiment 2: Turn off the air compressor 1, pressure reducing valve 2, gas flow control valve 3, deionized water source 4, and liquid flow control valve 5. Turn on the steam flow control valve 8 and steam generator 9 to make the steam generator 9 output wet steam with a set flow rate and dryness. Turn on the first valve 7 and the second valve 10 to inject wet steam into the horizontal steam injection pipe simulation device 25.

[0050] Here, an explanation of the term "dryness" is given: Dryness specifically refers to the proportion of the mass of dry saturated steam in wet steam (a state of coexistence of gas and liquid phases) to the total mass (steam + liquid water), and its value range is from 0 to 1. For example, a dryness of 0.8 means that 80% of the wet steam is dry saturated steam and 20% is liquid water droplets. In a steam thermal system (such as a boiler, steam injection for oil recovery, nuclear power plant), dryness is a core parameter, which directly affects the heat transfer efficiency (liquid water will reduce the enthalpy), the risk of pipeline erosion (water droplets hitting the pipe wall), and the operation stability of equipment. The "steam dryness" adjusted in Experiment 2 directly reflects the proportion of the available high-temperature enthalpy part in the steam and is a key indicator for analyzing steam injection efficiency and heat loss.

[0051] This embodiment designs two differential fluid experiments, aiming to simulate the actual steam displacement process and the gas-liquid two-phase flow characteristics under simplified conditions in the steam injection process respectively, so as to systematically reveal the influence mechanism of different media on the flow behavior. Experiment 1 uses a mixed fluid of air and deionized water. By precisely controlling the gas-liquid volume ratio, the evolution law, interfacial interaction, and flow stability of the basic flow patterns (such as separated flow, dispersed flow) of two-phase flow can be studied under normal temperature and pressure conditions. This simplified experimental environment helps to exclude complex interferences such as steam phase change and high-temperature thermal effects, and provides controllable data for establishing a basic flow model. Experiment 2 directly uses the wet steam output by the steam generator 9. By adjusting the steam dryness and flow rate, it truly reproduces the thermodynamic coupling process of high-temperature and high-pressure steam and reservoir fluid during the steam injection process, such as key phenomena as the dynamic of steam condensation-evaporation, the influence of heat loss on flow parameters, and the change of pipe wall wettability by high temperature. The two experiments complement each other: the former focuses on the theoretical verification of the essential laws of flow, and the latter focuses on the adaptability analysis of engineering actual working conditions. By comparing the differences in flow pattern characteristics, pressure drop gradient, and crossflow threshold under the two media, the parameter deviation of the theoretical model in the steam environment can be corrected, and at the same time, multi-dimensional experimental support can be provided for optimizing steam injection parameters (such as dryness adjustment range, injection rate control strategy), and finally achieving the overall research goal from the basic flow mechanism to the complex thermal recovery process.

[0052] The working principle of this embodiment is as follows:

[0053] By adopting the structure of N independent reservoir boxes 11, each box can be loaded with different geological parameters (such as porosity, permeability, and oil saturation) synchronously, breaking through the limitation of the traditional steam injection model for horizontal wells that requires successive replacement of simulation media, and significantly improving the experimental efficiency. This parallel simulation mechanism can not only compare the effects of different reservoir physical properties on the development effect synchronously, but also quickly screen the optimal exploitation plan through parameter combination optimization, providing multi-dimensional data support for the development decision-making of complex heterogeneous shale oil reservoirs.

[0054] During the steam injection experiment, through the coordinated action of the transparent visual observation section 14 and the high-speed camera system, the fluid dynamics at the outlet of the horizontal steam injection pipe simulation device 25 are captured and analyzed in real time. Then, the control terminal 16 equipped with relevant software combines digital image processing technology to capture and analyze the dynamic characteristics of multiphase flow in real time. Based on the ratio of gas volume flow to total volume flow, two-phase flow is divided into three categories: separated flow, dispersed flow, and intermittent flow. Each flow pattern corresponds to different thermodynamic characteristics, flow laws, and heat transfer calculation formula systems. The research team revealed the mechanism of action of key parameters such as steam injection temperature and pressure, steam dryness, and reservoir permeability on the evolution of fluid flow patterns through systematic experiments, and quantitatively analyzed the variation characteristics of effective injection volume under different flow patterns, thereby constructing a flow pattern-reservoir adaptability correlation model. This flow pattern analysis system not only provides an experimental benchmark for flow pattern discrimination in steam injection thermal recovery technology, but also guides the on-site optimization of steam injection pressure, temperature, and other operating conditions, and scientifically allocates the steam injection intensity of each layer section by establishing a dynamic matching mechanism between flow pattern prediction and steam injection parameters, thus significantly suppressing the steam channeling phenomenon and improving the thermal energy utilization rate. This research paradigm that combines laboratory flow pattern observation technology with engineering applications can provide key theoretical basis and engineering verification means for the refined control of heavy oil thermal recovery technology.

[0055] As a preferred solution of this embodiment, it further includes an angle adjustment system 19 for adjusting the inclination angle of the reservoir box 11. The angle adjustment system 19 specifically includes a movable plate 23, a rotating shaft 24, a support frame, and a lifting device 18. The movable plate 23 is used to support the N-section reservoir box 11. The rotating shaft 24 is rotatably arranged at the first end of the movable plate 23. The support frame is arranged at both ends of the rotating shaft 24 for supporting the rotating shaft 24. The lifting device 18 is arranged at the second end of the movable plate 23 for lifting the movable plate 23, and a jack, etc. can be specifically used.

[0056] During use, by driving the lifting device 18 to rise and fall, the first end of the movable plate 23 is driven to rotate around the rotating shaft 24, so as to realize the adjustment of the inclination angle of the reservoir box 11.

[0057] The angle adjustment system 19 in the steam injection model for horizontal wells precisely simulates the heterogeneous structure of the real formation and complex dip angles by dynamically adjusting the tilt angle of the reservoir box 11, thus reproducing the influence of the geometric heterogeneity of the underground reservoir on the fluid migration law in the experimental environment. By changing the formation dip angle parameter, researchers can systematically explore the flow pattern evolution law of gas-liquid two-phase flow in different tilted states, such as key dynamic characteristics like gravity segregation effect, phase distribution characteristics, and velocity field changes. This controllable tilting condition provides an important experimental means to reveal the influence of the formation dip angle on the steam channeling path, heat wave propagation range, and effective injection efficiency during the steam injection process, and can also verify the accuracy of the dip correction coefficient in the numerical model. Through comparative experiments under multi-angle conditions, a quantitative correlation model between the formation dip angle and the optimal steam injection parameters (such as steam injection pressure, injection rate) can be established, providing a scientific basis for the dip adaptability optimization of the steam injection development plan for reservoirs with complex structures.

[0058] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are all based on the orientation or positional relationship shown in the drawings, and are only used for facilitating the description of the present invention, rather than implying or requiring that the device or element referred to must have a specific orientation or structural form. Therefore, it should not be construed as a limitation to the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the described objects, and should not be construed as a limitation of importance or order, and the features defined by such terms may explicitly or implicitly include one or more of such features. Unless otherwise specified, "a plurality" in the description of the present invention means two or more.

[0059] For the terms "installed", "connected", and "connected", unless otherwise clearly defined, they should be understood in a broad sense, including but not limited to fixed connection, detachable connection, or integrally formed connection; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; and the communication inside two elements. Those skilled in the art can understand their meanings according to specific technical solutions. The fixed connection involved in the present invention, unless otherwise stated, includes both detachable fixed connections (such as bolt and screw connections) and non-detachable fixed connections (such as riveting and welding), and can also include an overall structure achieved through an integrally formed process (except for those that are obviously impossible to be integrally formed).

[0060] In any technical solution disclosed in the present invention, the terms used to represent the positional relationship or shape, unless otherwise stated, all cover states or shapes that are approximate, similar, or close to them.

[0061] Any component provided by the present invention can either be assembled from multiple separate components or be a single component manufactured by an integral forming process.

[0062] It should be noted that the structures, proportions, sizes, etc. depicted in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those skilled in this technology to understand and read, and are not used to limit the conditions under which the present invention can be implemented. Therefore, they do not have technical substantive significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope covered by the technical content disclosed in the present invention.

[0063] In the embodiments of this application, the same reference numeral is used to represent the same component or the same part.

[0064] Adaptations made according to actual needs are all within the protection scope of the present invention.

[0065] It should be noted that for those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference numeral in the claims should not be regarded as limiting the claimed right.

[0066] Specific examples are used in the present invention to elaborate on the principles and implementation manners of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, based on the idea of the present invention, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A multiphase flow steam injection simulation experimental device for long horizontal wells, characterized in that, Including: A reservoir box for filling experimental raw materials to simulate the geological conditions of an oil reservoir. N sections of the reservoir boxes are arranged in sequence, where N is an integer greater than or equal to two; A horizontal steam injection pipe simulation device is disposed through the interior of the reservoir box. The horizontal steam injection pipe simulation devices in N sections of the reservoir boxes are sequentially connected through pipelines; A steam injection simulation system is connected to the horizontal steam injection pipe simulation device of the first section for injecting steam into the horizontal steam injection pipe simulation device; A flow pattern observation device includes a transparent visual observation section and a high-speed camera system. The transparent visual observation section is disposed on the pipeline at the outlet of the horizontal steam injection pipe simulation device, and the high-speed camera system is used to perform high-speed shooting on the fluid in the transparent visual observation section; A control terminal is used to perform flow pattern analysis on the information obtained by the high-speed camera system.

2. The steam injection simulation experimental device for multiphase flow in long horizontal wells according to claim 1, wherein: The steam injection simulation system includes a steam generator, an air compressor, and a deionized water source. The steam generator is connected to the horizontal steam injection pipe simulation device through a first pipeline. The air compressor is connected to a second pipeline, and the deionized water source is connected to a third pipeline. The second pipeline and the third pipeline are merged through a gas-liquid two-phase mixer and then connected to the horizontal steam injection pipe simulation device.

3. The steam injection simulation experimental device for multiphase flow in long horizontal wells according to claim 2, characterized in that: A steam flow control valve is disposed on the first pipeline. A pressure reducing valve and a gas flow control valve are disposed on the second pipeline connected to the air compressor. A liquid flow control valve is disposed on the third pipeline connected to the deionized water source.

4. The steam injection simulation experimental device for multiphase flow in long horizontal wells according to claim 1, characterized in that: A check valve is disposed at the outlet of the horizontal steam injection pipe simulation device in each section of the reservoir box.

5. The steam injection simulation experimental device for multiphase flow in long horizontal wells according to claim 1, characterized in that: A pressure monitoring element is disposed at the outlet of the horizontal steam injection pipe simulation device in each section of the reservoir box.

6. The steam injection simulation experimental device for multiphase flow in long horizontal wells according to claim 1, wherein: An injection fluid recovery device is connected to the outlet of the horizontal steam injection pipe simulation device in the last section of the reservoir box.

7. The steam injection simulation experimental device for multiphase flow in long horizontal wells according to claim 1, characterized in that: A temperature sensing element for monitoring the change of the simulated formation temperature is disposed inside the reservoir box.

8. The steam injection simulation experimental device for multiphase flow in long horizontal wells according to claim 7, wherein: The temperature sensing element is a thermocouple cluster, and a plurality of the thermocouple clusters are evenly arranged circumferentially around the horizontal steam injection pipe simulation device.

9. The steam injection simulation experimental device for multiphase flow in long horizontal wells according to claim 1, characterized in that: It further includes an angle adjustment system for adjusting the tilt angle of the reservoir box.

10. The steam injection simulation experimental device for multiphase flow in long horizontal wells according to claim 9, characterized in that, The angle adjustment system includes: A movable plate for supporting N sections of the reservoir boxes; A rotating shaft rotatably disposed at the first end of the movable plate; A support frame disposed at both ends of the rotating shaft for supporting the rotating shaft; A lifting device disposed at the second end of the movable plate for lifting the movable plate; By driving the lifting device to lift and lower, the first end of the movable plate is driven to rotate around the rotating shaft, so as to realize the adjustment of the tilt angle of the reservoir box.

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