Visual underground river karst type fracture-cavity oil reservoir physical experiment model and manufacturing method

Abstract

The invention discloses a visual underground river karst type fracture-cavity oil reservoir physical experiment model and a manufacturing method. The visual underground river karst type fracture-cavity oil reservoir physical experiment model comprises a matrix, and a karst cave, a fracture, an injection well and a production well are wrapped in the matrix; the karst cave, the crack, the injection well and the production well are communicated in sequence; ports of the injection wells and the production wells are communicated with the outside, karst caves, cracks, the injection wells and the production wells are arranged in the matrix, distribution of a reservoir structure is set according to actual underground river karst type fracture-cavity oil reservoir characteristics, accurate carving of the karst caves is guaranteed, and the underground river karst type fracture-cavity oil reservoir is formed. On the basis, physical experiments such as water drive, gas drive and foam drive of underground river karst type fracture-cavity oil reservoirs are carried out, the migration law of fluids such as oil-gas-water foam is macroscopically represented, and a basis is provided for the forming mechanism and the using mechanism of remaining oil.

Description

Technical Field

[0001] The invention belongs to the technical field of oil extraction and relates to a physical experimental model of a visualized underground river karst fracture-cavern oil reservoir and a manufacturing method thereof. Background Art

[0002] The reservoir characteristics of fracture-cavity oil reservoirs are complex and diverse, with matrix, caves and fractures discretely distributed, showing extremely strong heterogeneity. According to the karst characteristics, fracture-cavity oil reservoirs can be divided into surface karst, fault-controlled karst and underground river karst reservoirs.

[0003] Caves and fractures are the primary oil storage spaces within fracture-vuggy reservoirs. The connectivity between caves and fractures within different reservoir layers is complex, the filling characteristics within caves vary, and the scales within fractures vary significantly. These reservoir characteristics lead to high initial production but rapid decline in fracture-vuggy reservoirs; significant impacts of bottom and edge water on production; and the high risk of water (gas) channeling during water (gas) injection, resulting in low recovery rates. These issues severely restrict the high-yield and efficient development of fracture-vuggy reservoirs, necessitating urgent research into the migration patterns of oil, gas, and water within these reservoirs, as well as the mechanisms of residual oil formation and utilization.

[0004] Physical experiments are the main method to reveal the exploitation mechanism of fracture-cavity reservoirs. Current physical experimental models of fracture-cavity reservoirs mainly use full-diameter cores, 3D printing, glass water tanks, and spliced ​​plexiglass. However, these methods are difficult to simultaneously meet the requirements of precise carving, visualization, and simulated filling characteristics of fractures and caves, thus limiting the implementation of water drive, gas drive, and foam drive experiments in fracture-cavity reservoirs. Summary of the Invention

[0005] The purpose of the present invention is to solve the problem that the existing technology is difficult to simultaneously meet the requirements of precise carving, visualization, and simulated filling characteristics of fractures and caves, thereby limiting the implementation of water drive, gas drive, and foam drive experiments in fracture-cavity oil reservoirs. A visual physical experimental model and production method of a dark river karst fracture-cavity oil reservoir are provided, which can be used to carry out physical experiments such as water drive, gas drive, and foam drive in dark river karst fracture-cavity oil reservoirs, macroscopically characterize the migration laws of fluids such as oil, gas, water, and foam, provide a basis for the formation mechanism and utilization mechanism of residual oil, explore efficient development methods for dark river karst fracture-cavity oil reservoirs, and achieve high-yield and efficient development of oil reservoirs.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A physical experimental model of a visualized underground river karst fracture-cavity reservoir, comprising a matrix, wherein the matrix encloses caves, fractures, injection wells, and production wells;

[0008] The cave, fracture, injection well and production well are connected in sequence;

[0009] The ports of the injection well and the production well are in communication with the outside.

[0010] The further improvement of the present application is that:

[0011] The material of the substrate is acrylic plate.

[0012] The cave includes unfilled cave, fully filled cave and semi-filled cave.

[0013] A method for manufacturing a visualized underground river karst-type fracture-cave oil reservoir physical experiment model, comprising the following steps:

[0014] Obtaining a base plate;

[0015] Etching caves and fractures on the base plate, wherein the caves include unfilled caves, fully filled caves and semi-filled caves, and the interiors of the fully filled caves and the semi-filled caves are filled;

[0016] Drilling holes on the base plate, wherein the holes are used as injection wells and production wells, and a sealing pipeline structure is connected to the wellhead position;

[0017] Sealing the side of the base plate on which the caves and fractures are engraved.

[0018] The further improvement of the present method is that:

[0019] The filling material for filling the fully filled caves and the semi-filled caves is epoxy resin glue and quartz sand.

[0020] The mass ratio of the epoxy resin glue and the quartz sand is 5:100.

[0021] The fracture width is 0.3mm-2mm, and the depth is 1cm.

[0022] The depth of the cave is 1cm.

[0023] The diameter of the injection well and the production well is 0.5cm.

[0024] The base plate and the cover plate are both acrylic plates.

[0025] Compared with the prior art, the present application has the following beneficial effects:

[0026] The present application discloses a visualized underground river karst-type fracture-cave oil reservoir physical experiment model, which is characterized in that caves, fractures, injection wells and production wells are arranged in the interior of a substrate, the distribution of the reservoir structure is set according to the actual underground river karst-type fracture-cave oil reservoir reservoir characteristics, the accurate engraving of the caves is ensured, and on this basis, the physical experiments of the underground river karst-type fracture-cave oil reservoir such as water drive, gas drive and foam drive are carried out, the migration law of the oil, gas and water foam fluids is macroscopically characterized, and the basis for the formation mechanism and the production mechanism of the remaining oil is provided.

[0027] Further, in the present application, the material of the substrate is acrylic plate, and the transparent acrylic plate meets the internal fluid movement visualization, and the migration and distribution law of each phase fluid can be observed in real time.

[0028] Further, in the present application, the cave includes unfilled cave, fully filled cave and semi-filled cave, and by simulating different fracture-cave media, the flow capacity of fluid in the cave with different filling modes and different scale fractures can be observed, and the recovery mechanism of the fracture-cave reservoir, especially the underground river type fracture-cave reservoir, is provided with basis.

[0029] The application discloses a manufacturing method of a visual underground river karst type fracture-cave reservoir physical experiment model.

[0030] Further, in the present application, the bottom plate and the cover plate are both acrylic plates, and the flow capacity of fluid in the cave with different filling modes and different scale fractures can be observed, and the recovery mechanism of the fracture-cave reservoir, especially the underground river type fracture-cave reservoir, is provided with basis. BRIEF DESCRIPTION OF DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation to the scope, and for those skilled in the art, other related drawings can also be obtained without creative labor.

[0032] Fig. 1 The present application is an experiment model design profile;

[0033] Fig. 2 The present application is an experiment model structure schematic diagram;

[0034] 1-First production well; 2-First external pipeline; 3-Injection well; 4-Injection well external pipeline; 5-Second production well; 6-Second external pipeline; 7-Bottom plate; 8-Cover plate; 9-Fracture; 10-Cave; 11-Screw; 12-Substrate. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the following will combine the drawings in the embodiments of the present application to clearly and completely describe the technical scheme in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments.

[0036] The components of the embodiments of the present application generally described and illustrated in the drawings herein can be arranged and designed in a wide variety of different configurations.

[0037] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of the application.

[0038] All other embodiments obtained by persons of ordinary skill in the art based on the embodiments in the present application without creative work shall fall within the scope of protection of the present application.

[0039] It should be noted that: similar numbers and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0040] In the description of the embodiments of the present application, it should be noted that if the terms "upper", "lower", "horizontal", "inner" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship when the product of the present application is used, only for the convenience of describing the present application and simplifying the description, and it is not intended to indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, therefore, it cannot be understood as a limitation on the present application.

[0041] In addition, the terms "first", "second", and the like are only used to distinguish description, and cannot be understood as indicating or implying relative importance.

[0042] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly inclined. For example, "horizontal" only means that its direction is relatively more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0043] In the description of the embodiments of the present application, it should also be noted that unless otherwise explicitly specified and limited, if the terms "set", "mount", "connected", "connected" appear, they should be understood in a broad sense, for example, they can be fixedly connected, or detachably connected, or integrally connected; can be mechanically connected, or electrically connected; can be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements.

[0044] For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0045] The present application will be described in further detail below in conjunction with the accompanying drawings:

[0046] Reference Figs. 1-2The application discloses a visual underground river karst fracture-cave oil reservoir physical experiment model and a manufacturing method.

[0047] The application is used for researching oil and gas and water migration rules, residual oil formation mechanism and exploitation mechanism in the underground river karst fracture-cave oil reservoir, and designs a reservoir structure according to oilfield field logging and seismic data, and uses an acrylic plate as raw material, and adopts a laser etching method to manufacture the visual underground river karst fracture-cave oil reservoir physical experiment model.

[0048] The model comprises the following structures:

[0049] Embodiment 1

[0050] The embodiment discloses a visual underground river karst fracture-cave oil reservoir physical experiment model, and is characterized by comprising a matrix 12, wherein the matrix 12 internally wraps a cave 10, a fracture 9, an injection well 3 and a production well; the cave 10, the fracture 9, the injection well 3 and the production well are sequentially communicated; and the ports of the injection well 3 and the production well are communicated with the outside.

[0051] In the embodiment, the positions of the cave 10, the fracture 9, the injection well 3 and the production well are arranged according to field logging, seismic data and the like.

[0052] In the embodiment, the matrix 12 is a main part of the model.

[0053] In the embodiment, the cave 10 and the fracture 9 are completely wrapped in the inside of the matrix 12 and are not communicated with the outside.

[0054] In the embodiment, the inlet end of the injection well 3 and the production well is directly communicated with the outside, and a sealing pipeline joint and a pipeline are externally connected at the position close to the port of the injection well 3 and the production well.

[0055] Specifically, in the embodiment, two production wells are arranged, which are a first production well 1 and a second production well 5; the port of the first production well 1 is connected with a first external pipeline 2, the port of the second production well 5 is connected with a second external pipeline 6, and the port of the injection well 3 is externally connected with an injection well external pipeline 4.

[0056] In this embodiment, the inside of the matrix is provided with a solution cave, a fracture, an injection well and a production well, the distribution of the reservoir structure is set according to the actual underground river karst type fracture-cave reservoir characteristics, the accurate carving of the solution cave is ensured, and on this basis, the physical experiments such as water drive, gas drive and foam drive of the underground river karst type fracture-cave reservoir are carried out, the migration law of the oil-gas-water foam and other fluids is macroscopically characterized, and a basis is provided for the formation mechanism and exploitation mechanism of the remaining oil.

[0057] Embodiment 2

[0058] The embodiment discloses a visual underground river karst type fracture-cave reservoir physical experiment model, and has the characteristics that the model comprises a matrix 12, the inside of the matrix 12 is wrapped with a solution cave 10, a fracture 9, an injection well 3 and a production well; the solution cave 10, the fracture 9, the injection well 3 and the production well are sequentially communicated; the ports of the injection well 3 and the production well are communicated with the outside. The material of the matrix 12 is an acrylic plate.

[0059] In this embodiment, the matrix 12 comprises two mutually adhered acrylic plates as raw materials, which are a bottom plate 7 and a cover plate 8.

[0060] The solution cave 10, the fracture 9, the injection well 3 and the production well are etched on the bottom plate 7, and the cover plate 8 seals the etched structure.

[0061] In this embodiment, the two acrylic plates are tightly adhered together by using epoxy resin glue and screws. Screws 11 are further arranged between the bottom plate 7 and the cover plate 8.

[0062] Further, the thickness of the bottom plate 7 is greater than the thickness of the cover plate 8.

[0063] The length of the bottom plate 7 is 50 cm, the width is 25 cm, and the thickness is 2 cm.

[0064] The length of the cover plate 8 is 50 cm, the width is 25 cm, and the thickness is 1 cm.

[0065] In this embodiment, the material of the matrix in the present application is an acrylic plate, and the transparent acrylic plate satisfies the visualization of the internal fluid movement, so that the migration and distribution law of each phase fluid can be observed in real time.

[0066] Embodiment 3

[0067] The embodiment discloses a visual underground river karst type fracture-cave reservoir physical experiment model, and has the characteristics that the model comprises a matrix 12, the inside of the matrix 12 is wrapped with a solution cave 10, a fracture 9, an injection well 3 and a production well; the solution cave 10, the fracture 9, the injection well 3 and the production well are sequentially communicated; the ports of the injection well 3 and the production well are communicated with the outside. The solution cave comprises an unfilled solution cave, a fully filled solution cave and a semi-filled solution cave.

[0068] In the embodiment, the un-filled karst cave is engraved on the base plate 7 by laser etching, and the morphological characteristics are determined according to actual mine data, and the engraving depth is generally 1 cm.

[0069] The full-filled karst cave is filled with filling medium in the engraved karst cave, and the filling medium is made of epoxy resin glue and quartz sand cement mixture, and the mixing mass ratio of epoxy resin glue and quartz sand is generally 5:100, and the particle size of the quartz sand is generally 120-140 mesh.

[0070] The semi-filled karst cave is filled with a part of the filling medium in the engraved karst cave.

[0071] In the embodiment, the crack 9 involves different widths, and the crack 9 is engraved on the base plate 7 by laser etching, and different width cracks are engraved by setting laser width and intensity, and the crack width is generally 0.3-2 mm, and the depth is 1 cm.

[0072] The embodiment also discloses a manufacturing method of a visualized underground river karst-type fracture-cave oil reservoir physical experiment model.

[0073] Obtaining a base plate;

[0074] Etching karst caves and cracks on the base plate, the karst caves including un-filled karst caves, full-filled karst caves and semi-filled karst caves, and filling the inside of the full-filled karst caves and the semi-filled karst caves;

[0075] Drilling holes on the base plate, the holes serving as water injection wells and production wells, and connecting sealing pipeline structures and pipelines to wellhead positions;

[0076] Sealing a cover plate on one side of the engraved karst caves and cracks of the base plate, and the cover plate and the base plate forming a matrix of the model.

[0077] Further, in the embodiment, the base plate 7 and the cover plate are both acrylic plates.

[0078] The specific steps of etching the un-filled karst caves, the full-filled karst caves and the semi-filled karst caves are as follows:

[0079] Cutting a cuboid acrylic plate with a length of 50 cm, a width of 25 cm and a thickness of 2 cm as the base plate 7;

[0080] Etching the karst caves 10 on the base plate 7 by laser etching, wherein the depth of the karst caves 10 is 1 cm.

[0081] Etching a plurality of cracks 9 with different widths on the base plate 7 by laser etching, wherein the width of the cracks 9 is between 0.3 mm and 2 mm, and the depth is 1 cm.

[0082] Drilling holes with a diameter of 0.5 cm on the base plate 7 by using an electric drill.

[0083] Further, the step of filling the solution cavity in need of filling comprises the following steps:

[0084] For the solution cavity and the half-filled solution cavity, without considering the permeability difference of the filling medium, 120-140 mesh quartz sand is mixed with epoxy resin glue in a mass ratio of 5:100 for 5 minutes, and then filled into the solution cavity and compacted to make the filling medium adhere to the acrylic plate.

[0085] For the solution cavity, the fracture, the injection well and the production well, no treatment is performed.

[0086] The model can perform physical experiments such as water drive, gas drive and foam drive on the dark river karst fracture-cavity reservoir by using the physical experiment model, and macroscopically represents the migration law of oil, gas and water foam and the like, thereby providing a basis for the formation mechanism and the production mechanism of the remaining oil, exploring efficient development means for the dark river karst fracture-cavity reservoir, and realizing high-yield and efficient development of the reservoir.

[0087] The embodiment also discloses a specific embodiment, and specifically comprises the following steps:

[0088] Step 1: designing the experiment model according to logging, seismic and the like, and the specific steps are as follows:

[0089] (1) drawing a geological profile according to logging, seismic and the like of the oilfield, wherein the profile shows the position, number, size and filling characteristics of the solution cavity, the density, width and position of the fracture, and the position and depth of the injection well and the production well;

[0090] (2) according to the geological profile, the solution cavity contour and the positions of the injection well, the production well and the fracture are outlined by using CAD software, and the solution cavity, the fracture, the injection well and the production well are scaled according to a suitable proportion within a range of 50 cm in length and 25 cm in width.

[0091] Step 2: engraving the fracture 9 and the solution cavity 10 on the acrylic plate, and drilling the injection well and the production well, and the specific steps are as follows:

[0092] (1) cutting a cuboid thick acrylic plate with a length of 50 cm, a width of 25 cm and a thickness of 2 cm as a bottom plate;

[0093] (2) according to the position, contour and size of the solution cavity in the experiment model design drawing, the solution cavity is engraved on the bottom plate by using a laser etching method, wherein the depth of the solution cavity is 1 cm;

[0094] (3) according to the position and width of the fracture in the experiment model design drawing, a plurality of fractures with different widths are engraved on the bottom plate by using a laser etching method, wherein the width of the fracture is between 0.3 mm and 2 mm, and the depth is 1 cm.

[0095] (4) According to the injection well and position in the experimental model design drawing, a hole with a diameter of 0.5 cm is drilled on the bottom plate by using an electric drill.

[0096] Step 3: According to the filling characteristics of the mine field cave, the filling medium is added in the full filling and half filling caves, and the specific steps are as follows:

[0097] (1) According to the geological profile, the filling characteristics in all caves are analyzed, wherein the filling characteristics include the permeability of the filling medium and the filling degree;

[0098] (2) For the filling caves and half filling caves, 120-140 mesh quartz sand is used without considering the permeability difference of the filling medium, and is mixed and stirred for 5 minutes according to the mass ratio of epoxy resin glue to quartz sand 5:100, and then is filled into the caves and is compacted to make the filling medium adhere to the acrylic plate;

[0099] (3) For the unfilled caves, cracks, injection wells and production wells, no treatment is performed.

[0100] Step 4: The model cover plate is added, and the packaging and encryption processing are performed, and the specific steps are as follows:

[0101] (1) A long rectangular thin acrylic plate with a length of 50 cm, a width of 25 cm and a thickness of 1 cm is cut as a cover plate;

[0102] (2) A number of threads are engraved in the thick acrylic plate bottom plate and the thin acrylic plate cover plate, and a layer of epoxy resin glue with a thickness of 0.2 mm is applied on the surface of the thin acrylic plate cover plate;

[0103] (3) The thick acrylic plate bottom plate and the thin acrylic plate cover plate are pasted together, and are adhered together under the adhesion of the epoxy resin glue;

[0104] (4) The thick acrylic plate bottom plate and the thin acrylic plate cover plate are fixed by using screws to ensure that the caves and cracks are not directly connected with the outside world;

[0105] (5) The injection well and the production well are connected with the sealing pipeline joint and the pipeline at the wellhead position.

[0106] The device can monitor the migration and distribution law of each phase fluid in the oil displacement simulation experiment in real time, the flow capacity of the fluid through different fracture-cave media (including different scale cracks, different filling mode caves and the like), and provides a basis for the recovery mechanism of the fracture-cave reservoir, especially the underground river type fracture-cave reservoir.

[0107] The above is only a preferred embodiment of the present application, and is not used to limit the present application, and the present application can have various changes and variations for those skilled in the art.

[0108] Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A physical experimental model of a visual underground river karst fracture-cavity reservoir, characterized by: The invention comprises a matrix (12), wherein the matrix (12) internally encloses a cave (10), a fracture (9), an injection well (3) and a production well; The cave (10), fracture (9), injection well (3) and production well are connected in sequence; The ports of the injection well (3) and the production well are in communication with the outside.

2. A visual underground river karst fracture-cavern reservoir physical experimental model according to claim 1, characterized in that: The material of the matrix (12) is an acrylic plate.

3. A visualized underground river karst fracture-cavern reservoir physical experimental model according to claim 1, characterized in that: The caves include unfilled caves, fully filled caves and semi-filled caves.

4. A method for making a visual physical experimental model of a dark river karst fracture-cavern reservoir, characterized in that: The following steps are involved: Get the base plate (7); Etching caves (10) and cracks (9) on a bottom plate (7), wherein the caves (10) include unfilled caves, fully filled caves, and semi-filled caves, and filling the interiors of the fully filled caves and semi-filled caves; Drill holes on the bottom plate (7), the holes are used as water injection wells (3) and production wells, and a sealing pipeline structure is connected to the wellhead; A sealing cover plate (8) is carved on one side of the bottom plate (7) to form a cavities (10) and cracks (9).

5. The method for making a visualized underground river karst fracture-cavern reservoir physical experimental model according to claim 4 is characterized in that: The fillers used in the fully filled cave and the semi-filled cave are epoxy resin glue and quartz sand.

6. The method for making a visualized underground river karst fracture-cavern reservoir physical experimental model according to claim 5, characterized in that: The mass ratio of the epoxy resin glue to the quartz sand is 5:

100.

7. The method for making a visualized physical experimental model of a dark river karst fracture-cavern reservoir according to claim 4 is characterized in that: The crack (9) has a width of 0.3 mm to 2 mm and a depth of 1 cm.

8. The method for making a visualized physical experimental model of a dark river karst fracture-cavern reservoir according to claim 4 is characterized in that: The depth of the cave (10) is 1 cm.

9. The method for making a visualized physical experimental model of a dark river karst fracture-cavern reservoir according to claim 4, characterized in that: The diameters of the water injection well (3) and the production well are both 0.5 cm.

10. The method for making a visualized physical experimental model of a dark river karst fracture-cavern reservoir according to claim 4, characterized in that: The bottom plate (7) and the cover plate (8) are both acrylic plates.

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