Two-dimensional visual model and oil-water displacement experiment equipment

Abstract

This application provides a two-dimensional visualization model and an oil-water displacement experimental device, relating to the fields of oil and gas field development engineering and seepage mechanics experimental technology. The two-dimensional visualization model includes a glass model composed of multiple microscopic photographs of thin-film castings. The glass model can be used to simulate the fluid seepage process in near-wellbore formations. The glass model has an injection end and a production end. The injection end has injection fractures extending towards the inside of the glass model, and the injection fractures extend towards the production end. The production end has production fractures extending towards the inside of the glass model, and the production fractures extend towards the injection end. The two-dimensional visualization model provided by this application can simulate the fluid seepage process within complex fracture networks, providing experimental basis for oilfield development.

Description

Technical Field

[0001] This application relates to the fields of oil and gas field development engineering and seepage mechanics experimental technology, and in particular to a two-dimensional visualization model and oil-water displacement experimental equipment. Background Technology

[0002] With the continuous development of oil and gas fields, low-permeability and ultra-low-permeability oil and gas reservoirs have become important exploration and development targets. Among them, beach-bar sand reservoirs, as a type of ultra-low-permeability reservoir, have strong reservoir heterogeneity, complex pore structure, and small micropore throats, resulting in high fluid flow resistance and low natural production capacity. In order to improve the recovery rate of such reservoirs, it is necessary to carry out multiple rounds of pressure drive on the near-wellbore formation to form a complex fracture network in the near-wellbore formation and improve the conductivity of the near-wellbore formation.

[0003] To gain a deeper understanding of the pressure drive development process, physical simulation experiments are typically used to study reservoir seepage patterns. Currently, the most commonly used experimental method is microfluidic experiments, which use image processing technology to extract pore boundaries and construct a microscopic visualization seepage model. Fluid is then injected into the microscopic visualization seepage model at a constant rate or with a constant pressure difference to simulate the fluid seepage patterns during actual near-wellbore formation pressure drive.

[0004] However, the aforementioned microscopic visualization seepage models have no cracks or have a single crack morphology, making it difficult to accurately simulate the seepage process of fluids within complex crack networks. Summary of the Invention

[0005] In view of this, this application provides a two-dimensional visualization model that can simulate the seepage process of fluids within a complex fracture network, providing experimental basis for oilfield development.

[0006] To achieve the above objectives, this application adopts the following technical solution:

[0007] One embodiment of this application provides a two-dimensional visualization model, including a glass model composed of multiple microscopic photographs of cast thin sections, which can be used to simulate the fluid seepage process in near-wellbore formations;

[0008] The glass model has an injection end and a extraction end, the injection end has an injection crack extending toward the inside of the glass model, and the injection crack extends toward the extraction end;

[0009] The extraction end has an extraction slit extending toward the inside of the glass model, and the extraction slit extends toward the injection end.

[0010] In one possible implementation, at least one of the injection fracture and the production fracture is configured as a single fracture;

[0011] And / or, at least one of the injection fracture and the extraction fracture is configured as an interleaved fracture.

[0012] In one possible implementation, the glass model is set as a square model, the square model having diagonals;

[0013] The injection end is located at one end of the diagonal, and the extraction end is located at the other end of the diagonal.

[0014] In one possible implementation, the length of the glass model is greater than or equal to 8 mm and less than or equal to 10 mm, and the width of the glass model is greater than or equal to 8 mm and less than or equal to 10 mm.

[0015] And / or, the micrograph of the cast sheet is set as a square unit, and multiple square units are arranged in multiple rows and columns.

[0016] In one possible implementation, the glass model includes a rock matrix structure, a rock pore structure, and a fracture structure, wherein the rock pore structure is interspersed within the rock matrix structure, and the fracture structure is located around the injection end and the extraction end of the two-dimensional visualization model.

[0017] Another aspect of this application provides an oil-water displacement experimental apparatus, including an experimental device and a two-dimensional visualization model as described in any of the preceding claims.

[0018] In one possible implementation, the experimental apparatus includes a base, an injection component, and a collection component;

[0019] The glass model is mounted on the base;

[0020] The injection component is disposed on the base, and the injection component can inject pressurized water into the injection end; the extraction component is disposed on the base, and the extraction component can be used to obtain crude oil discharged from the extraction end.

[0021] In one possible implementation, the base is provided with a receiving groove for accommodating the glass model;

[0022] The injection component and the extraction component are movably mounted on the base to be close to or away from the glass model located within the receiving groove.

[0023] In one possible implementation, the receiving slot is configured as a square receiving slot having diagonals;

[0024] The injection component is located at one end of the diagonal, and the extraction component is located at the other end of the diagonal.

[0025] In one possible implementation, a cover plate is also included, which is located above the base and is movable toward or away from the base in the height direction.

[0026] The base is provided with a clamping member, which can apply force to the cover plate to make the cover plate fit against the top surface of the glass model.

[0027] This application provides a two-dimensional visualization model, including a glass model composed of multiple microscopic photographs of cast thin sections. The glass model can be used to simulate the fluid seepage process in near-wellbore formations. The glass model has an injection end and a production end. The injection end has an injection fracture extending toward the inside of the glass model and the injection fracture extends toward the production end. The production end has a production fracture extending toward the inside of the glass model and the production fracture extends toward the injection end.

[0028] A glass model was designed and fabricated by stitching together multiple microscopic photographs of thin-film castings to simulate near-wellbore formations in actual oil reservoirs. By setting injection fractures and production fractures at the injection and production ends of the glass model respectively, and making them extend towards each other, a high-conductivity channel similar to a hydraulic fracturing fracture was physically constructed.

[0029] During the experiment, water was injected from the injection end at a high pressure and entered the glass model through the injection fracture. Due to the strong conductivity of the injection fracture, the injected water flowed rapidly along the injection fracture. Under the action of pressure difference, the injected water continued to seep into the interior of the glass model along the injection fracture to simulate the displacement process of the actual oil reservoir. After seepage, the injected water eventually converged into the produced fracture, which collected the injected water and guided it to the produced end, thus simulating the fluid seepage process within a complex fracture network.

[0030] Compared to existing microscopic visualization seepage models, this application constructs a large field of view by stitching together multiple microscopic images of cast thin sections and setting injection and production fractures, thus creating a "matrix-fracture" dual-medium model. This model can realistically simulate the complex fracture network formed in the near-wellbore formation after multiple rounds of pressure driving, overcoming the shortcomings of existing microscopic visualization seepage models that have no fractures or only a single fracture. Attached Figure Description

[0031] The specific implementation of the embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific implementation described herein is only for illustration and explanation of the embodiments of this application, and the embodiments of this application are not limited to the specific implementation described below.

[0032] Figure 1 Schematic diagram of the glass model provided in the embodiments of this application Figure 1 ;

[0033] Figure 2Schematic diagram of the glass model provided in the embodiments of this application Figure 2 ;

[0034] Figure 3 This is a front view of the oil-water displacement experimental apparatus provided in the embodiments of this application;

[0035] Figure 4 This is a top view of the oil-water displacement experimental apparatus provided in an embodiment of this application.

[0036] Explanation of reference numerals in the attached figures:

[0037] 100 - Injection end;

[0038] 110 - Injection crack;

[0039] 200 - Extraction end;

[0040] 210 - Extraction of fractures;

[0041] 300-Experimental Apparatus

[0042] 310 - Base;

[0043] 311-Receiving groove; 312-Clamping element;

[0044] 320 - Injection Component;

[0045] 330 - Extraction Component;

[0046] 340 - Cover plate;

[0047] 400-Glass Model.

[0048] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the embodiments of this application in any way, but rather to illustrate the concepts of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application and how the technical solutions of the embodiments of this application solve the above-mentioned technical problems will be clearly and completely described below with reference to specific embodiments and the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0050] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, an indirect connection through an intermediate medium, or the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0051] In the description of the embodiments of this application, it should be understood that the terms "upper", "lower", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0052] The terms "first," "second," "third," "fourth," etc. (if present) in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein.

[0053] In this application, the terms "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0054] Furthermore, the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion, such that a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or apparatus.

[0055] With the continuous development of oil and gas fields, low-permeability and ultra-low-permeability oil and gas reservoirs have become important exploration and development targets. Among them, beach-bar sand reservoirs, as a type of ultra-low-permeability reservoir, have strong reservoir heterogeneity, complex pore structure, and small micropore throats, resulting in high fluid flow resistance and low natural production capacity. In order to improve the recovery rate of such reservoirs, it is necessary to carry out multiple rounds of pressure drive on the near-wellbore formation to form a complex fracture network in the near-wellbore formation and improve the conductivity of the near-wellbore formation.

[0056] To gain a deeper understanding of the pressure drive development process, physical simulation experiments are typically used to study reservoir seepage patterns. Currently, the most commonly used experimental method is microfluidic experiments, which use image processing technology to extract pore boundaries and construct a microscopic visualization seepage model. Fluid is then injected into the microscopic visualization seepage model at a constant rate or with a constant pressure difference to simulate the fluid seepage patterns during actual near-wellbore formation pressure drive.

[0057] However, the aforementioned microscopic visualization seepage models have no cracks or have a single crack morphology, making it difficult to accurately simulate the seepage process of fluids within complex crack networks.

[0058] Based on this, the embodiments of this application provide a two-dimensional visualization model, including a glass model composed of multiple microscopic photographs of cast thin sections. The glass model can be used to simulate the fluid seepage process in near-wellbore formations. The glass model has an injection end and a production end. The injection end has an injection fracture extending toward the inside of the glass model and the injection fracture extends toward the production end. The production end has a production fracture extending toward the inside of the glass model and the production fracture extends toward the injection end.

[0059] A glass model was designed and fabricated by stitching together multiple microscopic photographs of thin-film castings to simulate near-wellbore formations in actual oil reservoirs. By setting injection fractures and production fractures at the injection and production ends of the glass model respectively, and making them extend towards each other, a high-conductivity channel similar to a hydraulic fracturing fracture was physically constructed.

[0060] During the experiment, the displacing phase, specifically water, was injected from the injection end under high pressure and entered the glass model through the injection fracture. Due to the high conductivity of the injection fracture, the injected water preferentially flowed rapidly along the injection fracture and, under the action of the pressure gradient, continuously seeped from the injection fracture into the rock pore structure inside the glass model, thereby simulating the displacement process in an actual oil reservoir. After seepage, the injected water eventually converged in the produced fracture and, through the guiding effect of the produced fracture, flowed to the produced end, thus realizing the physical simulation of the fluid seepage process within a complex fracture network.

[0061] Compared to existing microscopic visualization seepage models, this application constructs a large field of view by stitching together multiple microscopic images of cast thin sections and setting injection and production fractures, thus creating a "matrix-fracture" dual-medium model. This model can realistically simulate the complex fracture network formed in the near-wellbore formation after multiple rounds of pressure driving, overcoming the shortcomings of existing microscopic visualization seepage models that have no fractures or only a single fracture.

[0062] The technical solutions of the embodiments of this application will be described in detail below with reference to the accompanying drawings and specific examples. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0063] Reference Figure 1 and Figure 2 As shown, this application provides a two-dimensional visualization model, including a glass model 400 composed of multiple microscopic photographs of cast thin slices. The glass model 400 can be used to simulate the fluid seepage process in near-wellbore formations.

[0064] Furthermore, in some embodiments, the glass model 400 includes a rock matrix structure, a rock pore structure, and a fracture structure, with the rock pore structure interspersed within the rock matrix structure and the fracture structure located around the injection end 100 and the extraction end 200 of the two-dimensional visualization model.

[0065] In practical applications, cast thin sections are specialized thin sections used in petrology and reservoir geology research to observe rock pores or fractures. Specifically, cast thin sections are made by artificially filling primary and secondary pores and microfractures in the rock structure with a casting agent (such as ordinary or fluorescent resin materials) under high pressure or vacuum, followed by curing, cutting, grinding, and polishing to create standard rock thin sections. Cast thin sections produced by the above process allow the originally transparent and invisible pores or fractures to be revealed in solid form after being filled with the casting agent. Key characteristics such as the size, shape, distribution, and connectivity of pores or fractures can be clearly observed using polarizing microscopes and fluorescence microscopes.

[0066] In this application, the glass model 400 is used to replace the traditional cast thin film. The glass model 400 is made using high-precision photolithography equipment. The specific manufacturing process is as follows: (1) deposit a metal film on the glass substrate, coat it with photoresist and dry it; (2) cover the mask and expose it with ultraviolet light, develop it and remove some of the photoresist; (3) use hydrofluoric acid solution to etch the glass to a certain depth, clean it and harden the photoresist; (4) etch the glass a second time to a specified depth and remove the remaining photoresist and metal coating; (5) cut the glass substrate into a specified size, clean it and plasma treat it and then bond it; (6) vacuum, heat and pressurize it in the bonding machine to complete the bonding and finally take out the finished chip.

[0067] The glass model 400 has an injection end 100 and a extraction end 200. The injection end 100 has an injection crack 110 extending toward the inside of the glass model 400 and the injection crack 110 extending toward the extraction end 200.

[0068] In the actual implementation, before making the glass model 400, it is necessary to use drawing software (such as CAD) to copy a large number of electron microscope photos from the field to obtain the material drawing of the glass model 400. Based on the material drawing of the glass model 400, according to the actual situation, injection fracture 110 and extraction fracture 210 are respectively engraved at the injection end 100 and the extraction end 200. The two extend towards each other, physically constructing a high-conductivity channel similar to a fracturing fracture.

[0069] During the experiment, the displacement phase, specifically water, was injected from the injection end 100 under high pressure and entered the glass model 400 through the injection fracture 110. Due to the high conductivity of the injection fracture 110, the injected water preferentially flowed rapidly along the injection fracture 110 and, under the action of the pressure gradient, continuously seeped from the injection fracture 110 into the rock pore structure inside the glass model 400, thereby simulating the displacement process in an actual oil reservoir. After seepage, the injected water finally converged in the production fracture 210 and, through the guiding effect of the production fracture 210, flowed to the production end 200, thus realizing the physical simulation of the fluid seepage process in a complex fracture network.

[0070] Compared with existing microscopic visualization seepage models, this application constructs a large field of view by stitching together multiple microscopic photographs of cast thin sections and setting injection fracture 110 and production fracture 210, thus constructing a "matrix-fracture" dual-medium model. This model can realistically simulate the complex fracture network formed in the near-wellbore formation after multiple rounds of pressure driving, overcoming the shortcomings of existing microscopic visualization seepage models that have no fractures or only a single fracture.

[0071] Reference Figure 1 and Figure 2 As shown, in some embodiments, at least one of the injection fracture 110 and the extraction fracture 210 is configured as a single fracture; and / or, at least one of the injection fracture 110 and the extraction fracture 210 is configured as an interleaved fracture.

[0072] A single fracture can simulate the main fracture after fracturing of the near-wellbore formation, ensuring the stable establishment of the high-pressure field of the injected water and consolidating the basic seepage simulation effect of the "matrix-fracture" dual-medium model. Meanwhile, intersecting fractures can simulate the branched micro-fractures and complex fracture networks formed after multiple rounds of pressure driving in the near-wellbore formation, restoring the pressurized water seepage displacement process under complex fracture networks, and overcoming the shortcomings of existing microscopic visualization seepage models that have no fractures or only single fractures and cannot simulate complex fracture networks.

[0073] In practical implementation, both injection fracture 110 and production fracture 210 can be single fractures or staggered fractures, or one of injection fracture 110 and production fracture 210 can be a single fracture and the other a staggered fracture. Through the flexible combination of single fractures and staggered fractures, full coverage of different fracture scenarios in near-wellbore formations is achieved. This not only improves the imitation of actual reservoirs by the two-dimensional visualization model, but also takes into account the comprehensiveness of data acquisition. This enables the two-dimensional visualization model to more realistically and accurately simulate the pressurized water seepage displacement process in the complex fracture network of near-wellbore formations, providing more reliable experimental basis for the optimization of near-wellbore formation pressure drive schemes and the study of seepage laws.

[0074] Reference Figure 1 and Figure 2As shown, in some embodiments, the glass model 400 is configured as a square model with diagonals; the injection end 100 is located at one end of the diagonals, and the extraction end 200 is located at the other end of the diagonals.

[0075] In the specific implementation, the glass model 400 is set as a square model, and the injection end 100 and the extraction end 200 are respectively set at the two ends of the diagonal of the square. The square structure of the glass model 400 is adapted to the regular splicing of multiple cast thin-section micrographs, which improves the standardization of the preparation of two-dimensional visualization models.

[0076] Meanwhile, the diagonal of the square forms the longest straight seepage path inside. By placing the injection end 100 and the production end 200 at opposite ends of the square's diagonal, water can form the longest seepage displacement path after entering through the injection fracture 110. Whether it propagates along the injection fracture 110 towards the production end 200 or flows at a low speed into the glass pore area around the injection fracture 110, it accurately reproduces the long-distance seepage displacement process of pressurized water from near-well formation to deeper formations in actual oil reservoirs.

[0077] Compared to placing the injection end 100 and the production end 200 on the same side, adjacent side, or opposite corner of a square, the diagonal arrangement avoids the distortion of the seepage displacement process caused by an excessively short seepage displacement path. In the experiment, the seepage law of pressurized water under long path (such as velocity decay, displacement efficiency change, etc.) can be fully observed, making the experimental results more consistent with the actual seepage situation of the near-wellbore formation.

[0078] Furthermore, in some embodiments, the length of the glass model 400 is greater than or equal to 8 mm and less than or equal to 10 mm, and the width of the glass model 400 is greater than or equal to 8 mm and less than or equal to 10 mm; and / or, the micrograph of the cast sheet is set as a square unit, and multiple square units are arranged in multiple rows and columns.

[0079] In practice, the glass model 400 is constructed by welding together multiple cast thin-film micrographs arranged in multiple rows and columns. During the actual welding process, it is necessary to continuously flip each cast thin-film micrograph horizontally or vertically to make the crack orientations on each cast thin-film micrograph as related as possible. In this way, the large-size glass model 400 avoids the problem of distortion of the seepage displacement process caused by the small scale compared to a single cast thin-film micrograph, and realizes a complete and realistic simulation of the seepage law of pressurized water in near-wellbore formation at a microscale.

[0080] Meanwhile, the micrographs of the cast thin films are set as square units. The geometric regularity of the square units allows multiple micrographs of the cast thin films to be tightly spliced ​​and seamlessly fitted, greatly reducing the difficulty of splicing and ensuring the structural stability of the glass model 400.

[0081] This application also provides an oil-water displacement experimental apparatus, including an experimental device and a two-dimensional visualization model.

[0082] The two-dimensional visualization model in this application embodiment has the same structure as the two-dimensional visualization model provided in any of the above embodiments, and can bring the same or similar technical effects. It will not be described in detail here, but can be referred to the description of the above embodiments.

[0083] Reference Figure 3 and Figure 4 As shown, in some embodiments, the experimental apparatus 300 includes a base 310, an injection component 320, and a extraction component 330; a glass model 400 is disposed on the base 310; the injection component 320 is disposed on the base 310 and can inject pressurized water into the injection end 100; the extraction component 330 is disposed on the base 310 and can be used to obtain crude oil discharged from the extraction end 200.

[0084] In practice, the experiment is divided into two stages: 1. Saturation stage: crude oil is injected into the glass model 400 through the injection end 100 via the injection component 320. The crude oil can quickly fill the injection crack 110 of the glass model 400 and gradually seep into the pores or cracks of the glass model 400 under the action of seepage. After the crude oil is fully saturated, the injection is stopped and aging treatment is carried out to make the crude oil fully contact and adsorb onto the surface of the glass model 400. At this time, the crude oil is stably stored in the pores or cracks of the glass model 400 in various forms such as adsorbed state and free state, simulating the stable adsorption and bonding relationship between crude oil and rock matrix after long-term accumulation in actual oil reservoirs.

[0085] II. Displacement Stage: Displacement medium, specifically pressurized water, is injected into the glass model 400 through the injection component 320 and injection end 100. When the area affected by the pressurized water reaches 30% of the effective seepage area of ​​the glass model 400, the pressure of the pressurized water is slowly increased based on the initial pressure. When the area affected by the pressurized water reaches 50% of the effective seepage area of ​​the glass model 400, the pressure of the pressurized water is slowly decreased until the initial pressure of the pressurized water is reached. This is recorded as the first round of pressurized displacement. The above operation is repeated twice, which are recorded as the second round of pressurized displacement and the third round of pressurized displacement.

[0086] Reference Figure 3 and Figure 4 As shown, in some embodiments, the base 310 is provided with a receiving groove 311 for accommodating the glass model 400.

[0087] Furthermore, in some embodiments, the receiving groove 311 is configured as a square receiving groove with diagonals; the injection component 320 is disposed at one end of the diagonals, and the extraction component 330 is disposed at the other end of the diagonals.

[0088] As can be seen from the above, the glass model 400 is a square model, and the injection end 100 and the extraction end 200 are located at the two ends of the diagonal of the square. During the experiment, it is necessary to ensure that the seepage direction of the glass model 400 is completely coincident with the line connecting the injection end 100 and the extraction end 200. Therefore, in the specific implementation, a receiving groove 311 is provided. The size of the receiving groove 311 is adapted to the outer contour of the glass model 400, which can realize the precise embedding of the glass model 400. At the same time, the periphery of the receiving groove 311 forms a limiting and fixing effect on the glass model 400, avoiding the displacement of the glass model 400 caused by the impact of injection pressure or equipment vibration during the experiment, thus ensuring the stability of the experiment.

[0089] The injection component 320 and the extraction component 330 are movably mounted on the base 310 to be close to or away from the glass model 400 located in the receiving groove 311.

[0090] In practice, there will be slight dimensional tolerances between different batches of glass models 400. If experiments are to be conducted on glass models 400 of different sizes in the future, the injection component 320 and the extraction component 330 can be adjusted to meet the docking requirements of the injection end 100 and extraction end 200 of glass models 400 of different sizes by adjusting their own positions. There is no need to replace the base 310 or customize special components, which improves the structural versatility of the oil-water displacement experimental equipment and reduces the experimental cost.

[0091] Reference Figure 3 and Figure 4 As shown, in some embodiments, a cover plate 340 is also included, which is located above the base 310. The cover plate 340 can move closer to or further away from the base 310 along the height direction. The base 310 is provided with a clamping member 312, which can apply a force to the cover plate 340 so that the cover plate 340 is in contact with the top surface of the glass model 400.

[0092] During multiple rounds of pressure-driven experiments, the continuous high pressure at the injection end 100 will generate axial or radial thrust on the glass model 400. If only the circumferential restraint of the receiving groove 311 is used, the glass model 400 may move slightly within the receiving groove 311, damaging the sealing between the injection component 320 or the extraction component 330 and the glass model 400, or even changing the seepage path of the pressurized water. Therefore, in the above embodiment, a cover plate 340 and a clamping member 312 are added. The cover plate 340 is pressed against the top surface of the glass model 400 by the clamping member 312, and cooperates with the receiving groove 311 to form a fixed structure that clamps the glass model 400 from the top and bottom, completely fixing the glass model 400 within the receiving groove 311. This counteracts the pressure impact caused by high-pressure displacement, prevents the glass model 400 from moving or shifting, and ensures that the seepage direction of the glass model 400 is consistent with the line connecting the injection end 100 and the extraction end 200 throughout the experiment, thus ensuring the stability of the experimental process.

[0093] It should be understood that the various forms of processes shown above can be used to reorder, add, or delete steps. For example, the steps described in the embodiments of this application can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in the embodiments of this application can be achieved, and this document does not impose any restrictions.

[0094] The specific embodiments described above do not constitute a limitation on the scope of protection of the embodiments of this application. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the principles of the embodiments of this application should be included within the scope of protection of the embodiments of this application.

Claims

1. A two-dimensional visualization model, characterized in that, Includes a glass model (400) composed of multiple micrographs of cast thin sections, which can be used to simulate fluid seepage processes in near-wellbore formations; The glass model (400) has an injection end (100) and a extraction end (200), the injection end (100) having an injection crack (110) extending toward the inside of the glass model (400), the injection crack (110) extending toward the extraction end (200); The extraction end (200) has an extraction crack (210) extending toward the inside of the glass model (400) and the extraction crack (210) extending toward the injection end (100).

2. The two-dimensional visualization model according to claim 1, characterized in that, At least one of the injection fracture (110) and the production fracture (210) is configured as a single fracture; And / or, at least one of the injection fracture (110) and the extraction fracture (210) is configured as an interleaved fracture.

3. The two-dimensional visualization model according to claim 1, characterized in that, The glass model (400) is configured as a square model, the square model having diagonals; The injection end (100) is located at one end of the diagonal, and the extraction end (200) is located at the other end of the diagonal.

4. The two-dimensional visualization model according to claim 3, characterized in that, The length of the glass model (400) is greater than or equal to 8 mm and less than or equal to 10 mm, and the width of the glass model (400) is greater than or equal to 8 mm and less than or equal to 10 mm. And / or, the micrograph of the cast sheet is set as a square unit, and multiple square units are arranged in multiple rows and columns.

5. The two-dimensional visualization model according to claim 1, characterized in that, The glass model (400) includes a rock matrix structure, a rock pore structure and a fracture structure. The rock pore structure is interspersed inside the rock matrix structure, and the fracture structure is located around the injection end (100) and the extraction end (200) of the two-dimensional visualization model.

6. An oil-water displacement experimental apparatus, characterized in that, It includes an experimental setup and a two-dimensional visualization model as described in any one of claims 1-5.

7. The oil-water displacement experimental apparatus according to claim 6, characterized in that, The experimental apparatus (300) includes a base (310), an injection component (320), and a collection component (330). The glass model (400) is disposed on the base (310); The injection component (320) is disposed on the base (310), and the injection component (320) can inject pressurized water into the injection end (100); the extraction component (330) is disposed on the base (310), and the extraction component (330) can be used to obtain crude oil discharged from the extraction end (200).

8. The oil-water displacement experimental apparatus according to claim 7, characterized in that, The base (310) is provided with a receiving groove (311) for accommodating the glass model (400). The injection assembly (320) and the extraction assembly (330) are movably disposed on the base (310) to be close to or away from the glass model (400) located in the receiving groove (311).

9. The oil-water displacement experimental apparatus according to claim 8, characterized in that, The receiving groove (311) is configured as a square receiving groove, and the square receiving groove has a diagonal; The injection component (320) is located at one end of the diagonal, and the extraction component (330) is located at the other end of the diagonal.

10. The oil-water displacement experimental apparatus according to claim 7, characterized in that, It also includes a cover plate (340) located above the base (310), the cover plate (340) being able to move closer to or further away from the base (310) in the height direction. The base (310) is provided with a clamping member (312), which can apply force to the cover plate (340) so that the cover plate (340) fits against the top surface of the glass model (400).

Images