Supplemental compaction device and compaction method for three-dimensional sand filling experimental model

Abstract

The invention provides a supplementing and compacting device for a three-dimensional sand filling experimental model, which comprises a model main body for placing sand filling bodies with different permeability, a model cover plate arranged above the model main body, and an adjusting mechanism, the liquid cavity is formed in the model body, the piston is connected with the inner circumferential surface of the liquid cavity in a sealed mode so as to divide the liquid cavity into an upper space and a lower space containing oil, and the connecting rod is connected with the upper end face of the piston. And the free end of the connecting rod extends out of the model main body and is fixed on the model cover plate. In addition, the invention further provides a method for compacting the sand filling body.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas field development, and in particular to a supplementary compaction device for a three-dimensional sand filling experimental model, and a method for compacting a sand filling body. Background Art

[0002] Reservoir physical simulation experiment is one of the important means and methods to study the seepage law of oil and gas reservoirs during the exploitation process, development effect evaluation, and evaluation of the effect of improving the recovery rate. The sand filling physical model is the basis of the oil and gas reservoir physical simulation experiment. It simulates the physical properties of underground oil and gas reservoirs, such as permeability, and produces the required sand filling physical model according to the actual situation of the oil and gas reservoir and the experimental requirements of the physical simulation research.

[0003] In the existing technology, the three-dimensional sand filling model has attracted much attention due to its intuitiveness, easy operation, simulation of well types and well patterns, and has been widely used in reservoir physical simulation experiments. When making the three-dimensional sand filling physical model, in order to be closer to the diagenesis process of the actual oil and gas reservoir and simulate the multi-stage compaction in the real diagenesis process, the filling sand needs to be fully compacted. At the same time, in order to avoid the phenomenon of displacement fluid channeling during the displacement experiment, the sand filled in the three-dimensional sand filling physical model must also be fully compacted.

[0004] At present, the conventional method of compacting a three-dimensional physical model is to compact the sand by hammering it while filling the sand model, cover the top cover after the sand filling is completed, and then tighten the nut on the flange of the cover. When the physical model made by this sand filling and compaction method is used for physical simulation displacement experiments, as the displacement pressure increases, the displacement fluid sometimes flows out of the three-dimensional sand filling model, resulting in the failure of the physical simulation experiment of the oil and gas reservoir.

[0005] Therefore, in order to improve the success rate of the three-dimensional sand filling physical simulation experiment, it is necessary to further strengthen and supplement the compaction effect to prevent the displacement fluid from flowing between the model cover, the main frame and the sand body, and inside the sand body during the displacement experiment, thereby failing to achieve the effect of displacing the inside.

[0006] Therefore, it is desirable in the art to provide a supplementary compaction device for a three-dimensional sand filling experimental model to solve the above technical problems. Summary of the invention

[0007] The purpose of the present invention is to provide a supplementary compaction device for a three-dimensional sand filling experimental model, which can enable the three-dimensional sand filling experimental model to perform supplementary compaction on the sand filling body on the basis of traditional sand filling and compaction, so that the sand filling body can be compacted more firmly and more evenly.

[0008] According to a first aspect of the present invention, there is provided a supplementary compaction device for a three-dimensional sand filling experimental model, comprising a model body for placing sand filling bodies of different permeabilities,

[0009] a model cover plate disposed above the model body, and

[0010] The adjusting mechanism comprises a liquid cavity arranged in the model body, a piston sealingly connected to the inner peripheral surface of the liquid cavity to divide the liquid cavity into an upper space and a lower space containing oil, and a connecting rod connected to the upper end surface of the piston, wherein the free end of the connecting rod extends through the model body and is fixed to the model cover.

[0011] In one embodiment, the model body is configured in a cylindrical form, and a plurality of the adjustment mechanisms are provided at intervals along the circumference of the model body.

[0012] In one embodiment, the regulating mechanism further includes a first pipeline connected to the upper space and used to input oil, a second pipeline connected to the lower space and used to output oil, and an oil pool respectively connecting the free ends of the first pipeline and the second pipeline.

[0013] In one embodiment, the regulating mechanism further includes a commutator disposed between the first pipeline and the second pipeline, and a pump body disposed on the first pipeline.

[0014] Among them, the oil in the oil pool can enter the upper space of the liquid chamber through the first pipeline under the action of the pump body, so that the piston moves downward; the reversing device is configured to change the flow direction of the oil in the first pipeline and the second pipeline, thereby allowing the oil in the upper space to flow back into the oil pool, so that the piston moves upward.

[0015] In one embodiment, the regulating mechanism further includes a relief valve disposed on the first pipeline and arranged in parallel with the pump body, and a throttle valve disposed on the first pipeline and between the reversing device and the pump body.

[0016] In one embodiment, the model cover plate includes a main body portion, and an extension portion extending axially downward from the main body portion and used to form a sealed connection with the inner circumferential surface of the model body, wherein a cross-section of the main body portion and a cross-section of the extension portion have a consistent shape, and a cross-sectional area of ​​the main body portion is larger than a cross-sectional area of ​​the extension portion.

[0017] In one embodiment, a seal is provided at the junction of the extension portion and the model body.

[0018] In one embodiment, a plurality of reserved holes for forming a threaded connection with the connecting rod are arranged at intervals along the circumference of the main body portion, and the supplementary compaction device further comprises a nut fixed at the free end of the connecting rod.

[0019] In one embodiment, the supplementary compaction device further comprises a first wellbore arranged longitudinally on the model cover plate and used for water injection, and a second wellbore arranged transversely on the model body and used for oil production.

[0020] According to a second aspect of the present invention, there is provided a method for compacting a sand fill body using the supplementary compaction device as described above, comprising the following steps:

[0021] S1, placing two sand filling bodies with different permeabilities in the main body of the model and preliminarily compacting them;

[0022] S2. The oil in the oil pool is pumped into the upper space of the liquid chamber through the first pipeline by the pump body, and the piston and the connecting rod move downward under the action of the hydraulic pressure so that the extended part of the model cover plate compacts the sand filling body.

[0023] Compared with the prior art, the advantages of the present invention are:

[0024] First, the present invention enables the three-dimensional sand filling experimental model to perform additional compaction on the sand filling body on the basis of the traditional sand filling and compaction, so that the sand filling body can be compacted more solidly and more evenly. Since there is good sealing between the model body and the model cover plate, during the compaction process, the sand filling body has a high degree of tightness with the model body and the model cover plate, thereby reducing the occurrence of fluid crossflow during the physical simulation displacement experiment, and further improving the success rate of the three-dimensional sand filling physical model during the experiment.

[0025] Secondly, the hydraulic pressure generated by the adjustment mechanism of the present invention not only ensures that the sand filling body in the model body can be fully compacted, but also ensures that each part of the sand filling body can be compacted more evenly. In addition, since the present invention sets a plurality of adjustment mechanisms arranged at intervals along the circumference of the model body, the four sides of the model cover plate can be simultaneously subjected to the hydraulic pressure brought by the adjustment mechanism, so as to ensure that the four sides of the model cover plate can obtain the same downward pressure at the same time. In this way, not only the sand filling body in the model body can be fully compacted, but also each part of the sand filling body can be compacted more evenly. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present invention will be described in detail below in conjunction with the accompanying drawings, in which:

[0027] Figure 1The structure of the supplementary compaction device for the three-dimensional sand filling experimental model according to the present invention is schematically shown;

[0028] Figure 2 A partial schematic diagram of a supplementary compaction device for a three-dimensional sand filling experimental model according to the present invention is schematically shown, which shows a partial structure of an adjustment mechanism;

[0029] Figure 3 A cross-sectional view of a model cover plate in a supplementary compaction device for a three-dimensional sand filling experimental model according to the present invention;

[0030] Figure 4 A cross-sectional view of a model body in a supplementary compaction device for a three-dimensional sand filling experimental model according to the present invention;

[0031] Figure 5 A schematic diagram of a simulation experiment of a supplementary compaction device for a three-dimensional sand filling experimental model according to the present invention is schematically shown.

[0032] In the drawings, the same reference numerals are used for the same components. The drawings are not drawn to scale. DETAILED DESCRIPTION

[0033] In order to make the technical solutions and advantages of the present invention more clearly understood, the exemplary embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than an exhaustive list of all the embodiments. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0034] In the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0035] In the present invention, unless otherwise clearly stipulated and limited, terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal connection of two elements.

[0036] For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] The present invention will be further described below in conjunction with the accompanying drawings.

[0038] Figure 1 The structure of the supplementary compaction device 100 for the three-dimensional sand filling experimental model according to the present invention is schematically shown;

[0039] Figure 2 A partial schematic diagram of a supplementary compaction device 100 for a three-dimensional sand filling test model according to the present invention is schematically shown, which shows a partial structure of an adjustment mechanism;

[0040] Figure 3 A cross-sectional view of a model cover plate 20 in a supplementary compaction device 100 for a three-dimensional sand filling experimental model according to the present invention;

[0041] Figure 4 A cross-sectional view of a model body 10 in a supplementary compaction device 100 for a three-dimensional sand filling experimental model according to the present invention;

[0042] Figure 5 The schematic diagram of a simulation experiment of a supplementary compaction device 100 for a three-dimensional sand filling experimental model according to the present invention is schematically shown.

[0043] like Figure 1 As shown, according to a first aspect of the present invention, a supplementary compaction device 100 for a three-dimensional sand filling experimental model is provided, which includes a model body 10 and a model cover plate 20. The model body 10 is configured in a cylindrical form, and a sand filling body 101 with different permeabilities can be placed inside it for use in simulation experiments. The model cover plate 20 can be installed on the top of the model body 10, so as to form a sealed connection with the model body 10.

[0044] Preferably, at least two sand packing bodies 101 with different permeabilities are included in each simulation experiment.

[0045] According to the present invention, the supplementary compaction device 100 for the three-dimensional sand filling experimental model further includes an adjustment mechanism. Figure 1 and 4 As shown, the adjustment mechanism includes a liquid chamber 31 disposed in the model body 10, a piston 32 disposed in the liquid chamber 31, and a connecting rod 33 fixedly connected to the upper end surface of the piston 32. Preferably, the outer peripheral surface of the piston 32 is sealedly connected to the inner peripheral surface of the liquid chamber 31, so that the liquid chamber 31 can be divided into an upper space 311 and a lower space 312.

[0046] Preferably, the liquid chamber 31 in the present invention is configured as a cylindrical cavity; the connecting rod 33 in the present invention is made of stainless steel.

[0047] In one embodiment, Figure 1As shown, the free end of the connecting rod 33 is configured to extend through the model body 10, so as to be fixed on the model cover plate 20. In the initial state, the lower space 312 of the liquid cavity 31 is filled with oil so that the piston 32 abuts against the top of the liquid cavity 31, and a gap is left between the model cover plate 20 and the model body 10.

[0048] In one embodiment, Figure 1 and 2 As shown, the regulating mechanism further includes a first pipeline 34, a second pipeline 35 and an oil pool 36. The first pipeline 34 is connected to the upper space 311 of the liquid chamber 31, the second pipeline 35 is connected to the lower space 312 of the liquid chamber 31, and the free ends of the first pipeline 34 and the second pipeline 35 extend into the oil pool 36 respectively.

[0049] In the initial state, the first pipeline 34 can transport the oil in the oil pool 36 to the upper space 311 of the liquid chamber 31 through the pump body 341 (introduced below). At the same time, the oil in the lower space 312 of the liquid chamber 31 will be squeezed out under the action of hydraulic pressure, thereby flowing back to the oil pool 36 through the second pipeline 35.

[0050] In the above process, the piston 32 will move downward in the liquid chamber 31 under the action of hydraulic pressure. At the same time, the connecting rod 33 and the model cover plate 20 will move downward together with the piston 32, so that the model cover plate 20 blocks the model body 10 to achieve the purpose of compacting the sand body 101 filled in the model body 10.

[0051] Preferably, a plurality of adjustment mechanisms are arranged at intervals along the circumference of the model body 10. In this way, the four sides of the model cover plate 20 can be simultaneously subjected to the hydraulic pressure brought by the adjustment mechanism, so as to ensure that the four sides of the model cover plate 20 can simultaneously obtain the same downward pressure. In this way, not only can the sand filling body 101 in the model body 10 be fully compacted, but also each part of the sand filling body 101 can be compacted more evenly.

[0052] Preferably, each first pipeline 34 can simultaneously inject the same oil into the corresponding liquid cavity 31, and prompt each piston 32 to generate the same liquid pressure in the liquid cavity 31, thereby prompting the piston 32 to move the same distance. Therefore, the model cover plate 20, driven by the piston 32 and the connecting rod 33, can make the sand filling body 101 subject to the same force at all locations, so as to achieve the purpose of uniform compaction.

[0053] In one embodiment, Figure 2 As shown, the regulating mechanism further includes a reversing device 37 disposed between the first pipeline 34 and the second pipeline 35 , and a pump body 341 disposed on the first pipeline 34 .

[0054] Preferably, the oil in the oil pool 36 can enter the upper space 311 of the liquid chamber 31 through the first pipeline 34 under the action of the pump body 341. At the same time, the oil in the lower space 312 of the liquid chamber 31 will be squeezed out under the action of the hydraulic pressure, and then flow back to the oil pool 36 through the second pipeline 35, so as to achieve the purpose of downward movement of the piston 32 in the liquid chamber 31.

[0055] Accordingly, the movement stroke of the piston 32 in the liquid chamber 31 is controlled by the hydraulic pressure, so as to further control the downward movement of the model cover plate 20 through the connecting rod 33. It is easy to understand that the model cover plate 20 closes the model body 10 under the action of the hydraulic pressure, which can not only fully compact the sand filling body 101 placed in the model body 10, but also make the sand filling body 101 compacted more uniformly, thereby preventing the phenomenon of displacement fluid flowing from the three-dimensional sand filling model, and further improving the success rate of the three-dimensional sand filling model.

[0056] Preferably, the reversing device 37 is configured to change the flow direction of the oil in the first pipeline 34 and the second pipeline 35. In other words, the oil in the upper space 311 of the liquid chamber 31 will flow back to the oil pool 36 through the first pipeline 34 under the action of the pump body 341, thereby prompting the piston 32 to move upward in the liquid chamber 31. At the same time, the oil in the oil pool 36 will enter the lower space 312 of the liquid chamber 31 through the second pipeline 35 under the action of the pressure difference, thereby achieving the purpose of resetting the model cover plate 20, thereby facilitating the subsequent disassembly of the model cover plate 20.

[0057] In one embodiment, Figure 2 As shown, the regulating mechanism further includes an overflow valve 342 disposed on the first pipeline 34. Preferably, the overflow valve 342 is arranged in parallel with the pump body 341, so as to stabilize the flow of the oil and further stabilize the working pressure of the regulating mechanism to improve the success rate of the three-dimensional sand filling model.

[0058] In one embodiment, Figure 2 As shown, the regulating mechanism further includes a throttle valve 343 disposed on the first pipeline 34. Preferably, the throttle valve 343 is located between the reversing device 37 and the pump body 341, so as to adjust the flow rate of the oil, and further play the effect of controlling the supplementary compaction.

[0059] According to the present invention, Figure 3As shown, the model cover plate 20 includes a main body 21 and an extension portion 22 extending axially downward from the main body 21. The extension portion 22 is configured to form a sealed connection with the inner peripheral surface of the model body 10. In this way, it is ensured that the model cover plate 20 can prevent the sand filling body 101 from leaking out during the compaction process, and it is also ensured that the sand filling body 101 in the model body 10 can be compacted more solidly and more evenly, thereby improving the success rate of the three-dimensional sand filling model.

[0060] In one embodiment, the cross-section of the main body 21 and the cross-section of the extension 22 have the same shape, and the cross-sectional area of ​​the main body 21 is larger than that of the extension 22. In addition, the cross-sectional area of ​​the extension 22 is the same as the upper top area of ​​the sand pack 101, so that the extension 22 can obtain a larger contact area with the sand pack 101, thereby facilitating subsequent compaction work.

[0061] In a preferred embodiment, a seal is provided at the joint between the extension part 22 and the model body 10. The seal is, for example, a sealing ring. In this way, a better sealing relationship can be achieved between the extension part 22 and the model body 10. Thus, it is ensured that the model cover plate 20 can prevent the sand filling body 101 from leaking out during the compaction process, and it is also ensured that the sand filling body 101 in the model body 10 can be compacted more solidly and more evenly, thereby improving the success rate of the three-dimensional sand filling model.

[0062] In a preferred embodiment, Figure 1 and 3 As shown, a plurality of reserved holes 211 for forming a threaded connection with the connecting rod 33 are arranged at intervals along the circumference of the main body 21. In this way, not only the firmness between the connecting rod 33 and the main body 21 is improved, but also the model cover plate 20 can always move with the connecting rod 33 to achieve the purpose of compacting the sand filling body 101 in the model main body 10.

[0063] In a preferred embodiment, Figure 1 As shown, the supplementary compaction device 100 for the three-dimensional sand filling experimental model further includes a nut 40 fixed at the free end of the connecting rod 33. In this way, the connection relationship between the connecting rod 33 and the model cover plate 20 is further strengthened, thereby ensuring that the model cover plate 20 can always move with the connecting rod 33 to achieve the purpose of compacting the sand filling body 101 in the model main body 10.

[0064] According to the present invention, Figure 5As shown, the supplementary compaction device 100 for the three-dimensional sand filling experimental model also includes a first well hole 51 arranged longitudinally on the model cover plate 20, and a second well hole 52 arranged transversely on the model body 10. The first well hole 51 is constructed as a vertical well and is used to inject water into the sand filling body 101; the second well hole 52 is constructed as a horizontal well and is used to take the oil in the sand filling body 101.

[0065] According to a second aspect of the present invention, there is provided a method for compacting a sand fill body using the supplementary compaction device as described above, comprising the following steps:

[0066] First, two sand filling bodies 101 with different permeabilities are placed in the model body 10 and preliminarily compacted;

[0067] Then, the oil in the oil pool 36 is pumped into the upper space 311 of the liquid chamber 31 through the first pipeline 34 by the pump body 341 , and the piston 32 and the connecting rod 33 move downward under the action of the hydraulic pressure to compact the extended portion 22 of the model cover plate 20 to the sand filling body 101 .

[0068] The hydraulic pressure generated by the regulating mechanism not only ensures that the sand-filled body 101 in the model body 10 can be fully compacted, but also ensures that each part of the sand-filled body 101 can be compacted more evenly.

[0069] Combine the following Figure 5 Introduce the specific simulation experiment plan.

[0070] Experimental plan: The well pattern is designed as 1 injection and 1 production, that is, 1 vertical well for water injection (first wellbore 51) and 1 horizontal well for oil production (second wellbore 52). The reservoir condition is designed as a two-layer heterogeneous reservoir with permeabilities of K1 and K2 (two sand filling bodies 101 with different permeabilities).

[0071] (1) Well pattern arrangement: The well pattern is designed as 1 injection and 1 production: 1 vertical well for water injection (first well hole 51) and 1 horizontal well for oil production (second well hole 52). The well pattern is arranged as follows: Figure 5 shown.

[0072] (2) Filling with sand: According to the physical model design of the two-layer heterogeneous reservoir, the permeabilities are K1 and K2 respectively, and the sand to be filled into the model is prepared. According to the permeability requirements of K1 and K2, the sand filling model is configured with sand of different particle sizes, and the sand is first filled and compacted using the traditional method.

[0073] (3) Supplementary compaction: The pump body 341 and the throttle valve 343 are opened, and the oil in the oil pool 36 is pumped into the upper space 311 of the liquid chamber 31 through the first pipeline 34 through the pump body 341, thereby generating hydraulic pressure. The piston 32 in the liquid chamber 31 moves downward under the action of the hydraulic pressure, thereby driving the connecting rod 33 and the model cover plate 20 to move downward together. At the same time, the extension part 22 of the model cover plate 20 contacts the sand filling body 101, and the sand filling body 101 is further compacted until the model cover plate 20 can no longer move downward.

[0074] Thereafter, the movement direction of the oil in the first pipeline 34 and the second pipeline 35 is changed by the reversing device 37 , and the piston 32 and the connecting rod 33 move upward under the action of the hydraulic pressure to reset the mold cover plate 20 .

[0075] Compared with the prior art, the present invention has the following advantages:

[0076] First, the present invention enables the three-dimensional sand filling experimental model to perform additional compaction on the sand filling body 101 on the basis of the traditional sand filling and compaction, so that the sand filling body 101 can be compacted more compactly and more evenly. Since there is good sealing between the model main body 10 and the model cover plate 20, during the compaction process, there is a high degree of tightness between the sand filling body 101 and the model main body 10 and the model cover plate 20, thereby reducing the occurrence of fluid crossflow during the physical simulation displacement experiment, and further improving the success rate of the three-dimensional sand filling physical model during the experiment.

[0077] Secondly, the hydraulic pressure generated by the adjustment mechanism of the present invention not only ensures that the sand filling body 101 in the model body 10 can be fully compacted, but also ensures that each part of the sand filling body 101 can be compacted more evenly. In addition, since the present invention provides a plurality of adjustment mechanisms arranged at intervals along the circumference of the model body 10, the four sides of the model cover plate 20 can be simultaneously subjected to the hydraulic pressure brought by the adjustment mechanism, so as to ensure that the four sides of the model cover plate 20 can simultaneously obtain the same downward pressure. In this way, not only the sand filling body 101 in the model body 10 can be fully compacted, but also each part of the sand filling body 101 can be compacted more evenly.

[0078] The above are only preferred embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art can easily make changes or modifications within the disclosure scope of the present invention, and such changes or modifications should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A supplementary compaction device for a three-dimensional sand filling experimental model, comprising: A model body (10) for placing sand filling bodies (101) of different permeabilities, a model cover plate (20) disposed above the model body (10), and The regulating mechanism comprises a liquid chamber (31) arranged in the model body (10), a piston (32) sealedly connected to the inner peripheral surface of the liquid chamber (31) so as to divide the liquid chamber (31) into an upper space (311) and a lower space (312) containing oil, and a connecting rod (33) connected to the upper end surface of the piston (32), wherein the free end of the connecting rod (33) extends out of the model body (10) and is fixed on the model cover plate (20).

2. The supplementary compaction device for a three-dimensional sand filling experimental model according to claim 1, characterized in that: The model body (10) is configured in a cylindrical form, and a plurality of the adjustment mechanisms are arranged at intervals along the circumference of the model body (10).

3. The supplementary compaction device for a three-dimensional sand filling experimental model according to claim 2, characterized in that: The regulating mechanism further comprises a first pipeline (34) connected to the upper space (311) and used for inputting oil, a second pipeline (35) connected to the lower space (312) and used for outputting oil, and an oil pool (36) respectively connecting the free ends of the first pipeline (34) and the second pipeline (35).

4. The supplementary compaction device for a three-dimensional sand filling experimental model according to claim 3, characterized in that: The regulating mechanism further comprises a commutator (37) arranged between the first pipeline (34) and the second pipeline (35), and a pump body (341) arranged on the first pipeline (34). Wherein, the oil in the oil pool (36) can enter the upper space (311) of the liquid chamber (31) through the first pipeline (34) under the action of the pump body (341), so that the piston (32) moves downward; the reversing device (37) is configured to change the flow direction of the oil in the first pipeline (34) and the second pipeline (35), thereby allowing the oil in the upper space (311) to flow back into the oil pool (36), so that the piston (32) moves upward.

5. The supplementary compaction device for a three-dimensional sand filling experimental model according to claim 4, characterized in that: The regulating mechanism further comprises an overflow valve (342) provided on the first pipeline (34) and arranged in parallel with the pump body (341), and a throttle valve (343) provided on the first pipeline (34) and between the reversing device (37) and the pump body (341).

6. The supplementary compaction device for a three-dimensional sand filling test model according to claim 5, characterized in that: The model cover plate (20) comprises a main body portion (21), and an extension portion (22) extending axially downward from the main body portion (21) and used to form a sealed connection with the inner peripheral surface of the model body (10), wherein the cross-section of the main body portion (21) and the cross-section of the extension portion (22) have the same shape, and the cross-sectional area of ​​the main body portion (21) is larger than the cross-sectional area of ​​the extension portion (22).

7. The supplementary compaction device for a three-dimensional sand filling test model according to claim 6, characterized in that: A sealing member is provided at the joint between the extension portion (22) and the model body (10).

8. The supplementary compaction device for a three-dimensional sand filling test model according to claim 7, characterized in that: A plurality of reserved holes (211) for forming a threaded connection with the connecting rod (33) are arranged at intervals along the circumference of the main body portion (21), and the supplementary compaction device also includes a nut (40) fixed at the free end of the connecting rod (33).

9. The supplementary compaction device for a three-dimensional sand filling experimental model according to claim 8, characterized in that: The supplementary compaction device also includes a first well hole (51) arranged longitudinally on the model cover plate (20) and used for water injection, and a second well hole (52) arranged transversely on the model body (10) and used for oil production.

10. A method for compacting a sand filling body using the supplementary compaction device according to any one of claims 1 to 9, comprising the following steps: S1, placing two sand filling bodies with different permeabilities in the model body (10) and preliminarily compacting them; S2. The oil in the oil pool (36) is pumped into the upper space (311) of the liquid chamber (31) through the first pipeline (34) by the pump body (341), and the piston (32) and the connecting rod (33) move downward under the action of hydraulic pressure so that the extension part (22) of the model cover plate (20) compacts the sand filling body.

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