Method and device for fine reconstruction of water tank sediment structure

Abstract

The present invention discloses a method and apparatus for finely reconstructing the sediment structure of a water tank. The apparatus comprises several localized freezing tanks, each comprising a rectangular tank body with an open bottom and a hollow interior; at least two channels located on the top surface of the tank body, communicating with the hollow interior; one channel for the entry of a refrigerant medium and the other for the exit of the refrigerant after use; and three metal particles of varying diameters located on the top surface of the tank body at locations distinct from the two channels. This method significantly improves the accuracy and efficiency of finely reconstructing the sediment structure of a water tank without significantly disrupting the experimental results.

Description

Technical Field

[0001] The present invention relates to the technical field of a method for finely reconstructing a water tank sediment structure. Background Art

[0002] Current oil exploration and development relies primarily on drilling, logging, and supplemented by seismic data to predict the distribution of underground oil and gas reservoirs. However, drilling and logging data can only extract geological information within a very small area, approximately 1-3 meters, around the borehole and its surroundings. In areas with sparse well spacing, typically greater than 100 meters, interwell reservoir characteristics are highly uncertain and difficult to determine using drilling or logging data. Further sedimentation model analysis is required.

[0003] On the other hand, since the vertical resolution of seismic data is usually below 30 m, and the thickness of sand bodies in medium-thin reservoirs is less than 30 m, predicting the distribution characteristics of sand bodies in thin reservoirs with sparse wells is also of great significance for oil and gas exploration and development. Sedimentation pattern analysis is the key to predicting the distribution characteristics of sand bodies between wells.

[0004] Sedimentation flume experiments are a method for conducting sedimentation experiments in experimental flumes using water media and artificial ore body models to obtain or verify theoretical curves and process field data. Based on the principle of similarity, the small-scale sedimentary structures of sedimentary flume experiments can be used to study the sedimentary structures of macro-scale sedimentary bodies and construct sedimentary models that can be applied to large-scale reservoir prediction, thereby serving oilfield exploration and development. The sedimentary structure refers to the overall characteristics of the spatial distribution and arrangement of the components of sedimentary rocks, or that is, the sum of the relationships between the particles that make up the rock. It is the primary structure formed during or after sedimentation and before consolidation, including bedding and layer structures.

[0005] After obtaining the experimental results from a sediment flume, they need to be analyzed to determine the structural characteristics of the sedimentary body. The most important step is to obtain a three-dimensional model of the overall configuration of the sedimentary structure, formed by the planar docking relationships and vertical stacking relationships of the individual sedimentary structures. By reconstructing this three-dimensional model, the distribution characteristics of the sedimentary sand bodies can be reproduced. The process of obtaining this three-dimensional model is known as the fine reconstruction of the flume sedimentary structure.

[0006] The existing method for fine reconstruction of flume sediment structure is mainly the continuous slicing method, which uses a series of parallel planes to parallel cut the model after the flume experiment is completed and dried, obtaining the internal and contour information of the cross-section. Then, based on this, computer image processing technology is used to link the information of each cross-section one by one to obtain a three-dimensional stereo image.

[0007] However, the continuous sectioning method has the following disadvantages: (1) High destructiveness: The continuous sectioning method needs to be advanced layer by layer, which will destroy the previous sedimentary structure and make the model unable to be used for other research; (2) Low precision: The continuous sectioning method uses a mechanical cutting method, and the cutting accuracy is limited by the cutter. In addition, the mechanical stress generated during the cutting process will destroy part of the sedimentary structure, which will lead to the loss of analysis accuracy; (3) Time-consuming: The continuous sectioning method needs to wait for the model to dry before it can be carried out, which takes a long time; (4) Easy to deform: When the continuous sectioning method is advanced layer by layer, the sedimentary body is peeled off, and a fresh cutting surface is formed, because the sand body on one side is removed, the stress environment changes, which will cause the cutting surface to deform, part of the sand body to fall off, and the original sedimentary structure to be destroyed. Summary of the Invention

[0008] In view of the defects of the prior art, the purpose of the present invention is to provide a new method and device for fine reconstruction of water tank sediment structure, which can significantly improve the accuracy and efficiency of fine reconstruction of water tank sediment structure without causing high destructiveness to the post-experimental model.

[0009] The technical solutions of the present invention are as follows:

[0010] A device for fine reconstruction of a water tank sediment structure, comprising: a combined bottom plate and a combined freezing tank, wherein the combined bottom plate is formed by flatly splicing a number of rectangular base bottom plates of equal thickness, with a splicing gap between adjacent base bottom plates, the splicing gap being filled with an elastic adhesive, and the filled splicing gap being of the same thickness as the base bottom plate; the combined freezing tank comprises a number of local freezing tanks; the local freezing tank comprises: a rectangular tank body with an open bottom and a hollow interior, at least two channels located on the top surface of the tank body and connected to the hollow interior thereof, wherein any one of the channels is connected to the hollow interior thereof; One channel is for the freezing medium to enter, the other channel is for the freezing medium to flow out after use, and three metal particles with different diameters are located on the top surface of the trough body at different positions from the two channels; wherein, any basic bottom plate has a local freezing trough matched with it, and the local freezing trough satisfies: its trough body thickness is sw / 2, length is LL+sw / 2, and width is LW+sw / 2, wherein sw represents the width of the splicing gap between any basic bottom plate and its adjacent basic bottom plate, LL represents the length of any basic bottom plate, and LW represents the width of any basic bottom plate.

[0011] In the above solution, the channel can be a structure protruding from the top surface of the trough body, such as a pipe extending upward, or a structure recessed into the trough body, such as a pipe extending inward, or an opening on the top without a specific shape.

[0012] According to some specific embodiments of the present invention, in the combined base plate, the sizes of the basic base plates are the same; correspondingly, in the combined freezing tank, the sizes of the tank bodies of the local freezing tanks are the same.

[0013] According to some specific embodiments of the present invention, the joint gaps between adjacent basic slabs have the same width, and their widths sw satisfy: 0<sw<2mm.

[0014] According to some specific embodiments of the present invention, the diameters of the three metal particles with different diameters satisfy: if the diameter of any one of the metal particles is pw, the diameters of the other two metal particles are 2*pw and 4*pw, respectively.

[0015] According to some specific embodiments of the present invention, the elastic coefficient of the elastic adhesive satisfies: when the thickness of the sediment thereon reaches the maximum thickness of the water tank, the elastic deformation of the elastic adhesive is less than 0.0001.

[0016] The present invention further discloses a method for finely reconstructing a water tank sediment structure using the above-mentioned device, which comprises:

[0017] The local freezing tank is used to divide the sediment body located on the combined bottom plate and having completed the water tank sedimentation experiment, thereby obtaining a plurality of independent sediment bodies located on the basic bottom plate and covered by the tank body of the local freezing tank;

[0018] In a unified coordinate system, the position of each independent deposit on the combined base plate, i.e., the first positional relationship, and the spatial position of the three metal particles on its local freezing tank, i.e., the second positional relationship, are recorded;

[0019] The independent sediment body is subjected to a quick freezing process by the local freezing tank to obtain a frozen sediment body;

[0020] Obtaining CT scan data of the frozen deposit at different rotation angles, and forming a slice data set of the frozen deposit from all CT scan data within a rotation angle range of 0-360 degrees;

[0021] Obtaining three-dimensional sedimentary structure data of any of the frozen sedimentary bodies by performing a Jordan transformation on a slice data set;

[0022] identifying, from the three-dimensional structural data, the spatial positions of three metal particles on a local freezing tank of the frozen deposit, i.e., a third positional relationship;

[0023] Obtaining correspondence between each three-dimensional sedimentary structure data and the frozen sedimentary body on the base plate by aligning the second positional relationship with the third positional relationship;

[0024] According to the first positional relationship, the three-dimensional sedimentary structure data corresponding to different frozen sediment bodies are spliced to obtain a three-dimensional flume experimental sedimentary structure.

[0025] Among them, CT scanning (computed tomography) is a computerized tomography imaging technology that uses precisely collimated X-rays and extremely sensitive detectors to perform continuous tomographic scanning around the object being measured and form a three-dimensional image. According to the different physical resolutions of the imaging, CT scanning methods can be roughly divided into millimeter CT, micrometer CT and nanometer CT. Among them, the resolution scale of a single pixel of micrometer CT can reach 1-10 microns.

[0026] Preferably, the CT scan of the present invention is a micron CT scan.

[0027] According to some specific embodiments of the present invention, the fine reconstruction method specifically includes:

[0028] The local freezing tank is used to divide the sediment body located on the combined bottom plate and having completed the water tank sedimentation experiment, thereby obtaining a plurality of independent sediment bodies located on the basic bottom plate and covered by the tank body of the local freezing tank;

[0029] A freezing medium is injected through one channel of the local freezing tank to rapidly freeze the post-experimental sediment in the independent sediment to obtain a frozen sediment. All frozen sediments are labeled as follows:

[0030] Using laser three-dimensional positioning technology, in a rectangular coordinate system, the spatial positions of the marking points formed by the three metal particles on the local freezing tank Pi of the i-th frozen sediment are recorded, where the straight edge of the tank is the origin, the vertical direction is the Z direction, and the other two sides are the X and Y directions. The spatial position of the TD marking point is recorded as Di = {Pi_DX, Pi_DY, Pi_DZ}, the spatial position of the TE marking point is recorded as Ei = {Pi_EX, Pi_EY, Pi_EZ}, and the spatial position of the TF marking point is recorded as Fi = {Pi_FX, Pi_FY, Pi_FZ}, where Pi_DX, Pi_EX, and Pi_FX are the coordinates of the three marking points in the X direction, Pi_DY, Pi_EY, and Pi_FY are the coordinates of the three marking points in the Y direction, and Pi_DZ, Pi_EZ, and Pi_FZ are the coordinates of the three marking points in the Z direction;

[0031] The spatial positions of the three marking points Di, Ei and Fi of the i-th local freezing tank Pi constitute the coordinate information set Ci = {Di, Ei, Fi} of the i-th local freezing tank; the set of spatial position information of the marking points of all N local freezing tanks constitutes the spatial coordinate annotation set S = {Ci|i = 1...N};

[0032] The i-th frozen sediment body after the marking is placed in a rotating CT scanner. The frozen sediment body is irradiated once every rotation of theta angle to obtain scanning data Tk under each irradiation, i.e., slice data at different rotation angles. After completing 360° rotation, a total of 360 / theta slices of data are obtained, which are sequentially composed into a slice information set {Tk|k=1…360 / theta};

[0033] Based on the obtained slice information set, Jordan transformation is used to obtain the three-dimensional sedimentary structure data CTi of the i-th frozen sediment body;

[0034] Identify the coordinate data corresponding to the three marking points from the obtained three-dimensional sedimentary structure data CTi, wherein the Di point is the origin, the Di-TE side is the X-axis, and the Di-TF side is the Y-axis;

[0035] The coordinate information set Ci = {Di, Ei, Fi} of the i-th local freezing tank is extracted from the spatial coordinate annotation set S = {Ci|i = 1…N}, and the coordinate information Di = {Pi_DX, Pi_DY, Pi_DZ} and TE point coordinates Ei = {Pi_EX, Pi_EY, Pi_EZ} of the marked point TD in the i-th frozen sediment body are extracted therefrom to form a coordinate system. At the same time, according to the local coordinates CT_Di = {CTi_DX, CTi_DY, CTi_DZ} of the TD point in CTi and the local coordinates CT_Ei = {CTi_EX, CTi_EY, CTi_EZ} of the TE point in CTi identified from the three-dimensional sedimentary structure data CTi, the three-dimensional sedimentary structure CTi is spliced to obtain the three-dimensional reconstructed volume data F of the water tank sedimentary structure.

[0036] The present invention has the following beneficial effects: the method for fine reconstruction of the water tank sediment structure of the present invention can combine CT scanning and local freezing, and can significantly improve the accuracy and efficiency of the fine reconstruction of the water tank sediment structure without causing excessive destructive damage to the experimental results. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic diagram of the laying structure of the sink bottom plate involved in the specific implementation method.

[0038] Figure 2 It is a structural schematic diagram of the local freezing tank involved in the specific implementation method.

[0039] Figure 3 It is a schematic diagram of the process of dividing and freezing the sediment body by the local freezing tank involved in the specific implementation method.

[0040] Figure 4 Schematic diagram of the frozen deposit CT scanning process involved in the specific implementation method.

[0041] Figure 5 Schematic diagram of stitching micron CT scanning data for a local cryotank involved in a specific implementation method. DETAILED DESCRIPTION

[0042] The present invention is described in detail below with reference to the embodiments and accompanying drawings. However, it should be understood that the embodiments and accompanying drawings are merely exemplary descriptions of the present invention and do not constitute any limitation on the scope of protection of the present invention. All reasonable variations and combinations within the scope of the inventive concept of the present invention fall within the scope of protection of the present invention.

[0043] According to the technical solution of the present invention, some specific implementations of the method for fine reconstruction of the water tank sediment structure include the following steps:

[0044] Step 1: Refer to the attached Figure 1 Before the sink deposition experiment begins, several rectangular sink bottom plates FB (i.e., the aforementioned basic bottom plates) of equal thickness are laid on the rectangular sink base FA of the experimental sink. Each sink bottom plate FB only covers a local area of the sink base FA, and after being spliced together, they cover the entire area of the sink base FA, i.e., the entire base surface of the sink base FA, with equal thickness to form the combined bottom plate. There is a splicing gap FC between adjacent sink bottom plates FB, and the splicing gap FC is bonded using an elastic adhesive such as soft rubber. A sedimentation sink experiment is conducted in the sink after the laying is completed.

[0045] In some preferred embodiments, the shapes and sizes of the sink bottom plates FB are the same.

[0046] In some preferred embodiments, the shapes and sizes of the joint gaps between adjacent sink bottom plates FB are the same. Further preferably, the width sw of the joint gap satisfies: 0<sw<2mm.

[0047] In some preferred embodiments, the elastic coefficient of the elastic adhesive satisfies that when the thickness of the sediment thereon reaches the maximum thickness of the water tank, the elastic deformation of the elastic adhesive is less than 0.0001, so as to avoid the elastic adhesive having an essential impact on the deposition process.

[0048] Step 2: Before or during the water tank sedimentation experiment, prepare several Figure 2 The local freezing tank shown includes: a rectangular tank body TG with an open bottom and a hollow interior, three channels TA, TB, and TC located on the top surface of the tank body TG and connected to the hollow interior, and three metal particles TD, TE, and TF with different diameters located on the top surface of the tank body TG.

[0049] In the above steps, one of the three channels, TA, TB, and TC, is used to inject a freezing medium, such as liquid nitrogen, while the other two channels, TB and TC, are used to allow the freezing medium to enter the tank and exit after use. Three metal particles are used for position marking, forming clear marking points in subsequent micron CT scan images.

[0050] In some preferred embodiments, the tank body TG is made of high-strength plastic.

[0051] In some preferred embodiments, the diameters of the three metal particles are pw, 2*pw, and 4*pw, respectively.

[0052] In some preferred embodiments, the local freezing tank satisfies: the thickness of the tank body TG is sw / 2, the length is LL+sw / 2, the width is LW+sw / 2, and the height is LH. The height LH needs to be higher than the maximum thickness of the sediment in the tank, wherein sw represents the width of the aforementioned splicing gap, LL represents the length of the aforementioned tank bottom plate FB, and LW represents the width of the aforementioned tank bottom plate FB.

[0053] Step 3: Refer to the attached Figure 3 After the sedimentation tank experiment is completed, it is not necessary to dry it. While keeping the sediment in the tank moist, place the local freezing tank on the tank bottom plate FB loaded with the post-experiment sediment S, and align one side of the local freezing tank with the edge of the tank bottom plate FB. Then press the local freezing tank to slowly cut down until the tank bottom plate FB loaded with the post-experiment sediment S filling the bottom surface of the local freezing tank is completely cut out to obtain an independent sediment. A freezing medium such as liquid nitrogen is injected through a channel of the local freezing tank to quickly freeze the post-experiment sediment in the independent sediment to obtain a frozen sediment, thereby maintaining the sediment structure characteristics and maintaining its morphological stability.

[0054] Repeat the above process and use multiple local freezing tanks to obtain frozen sediments corresponding to all the water tank bottom plates FB. Each local freezing tank corresponds to a frozen sediment. The following labeling process is performed on all frozen sediments:

[0055] Using laser three-dimensional positioning technology, in a rectangular coordinate system, the spatial positions of the marking points formed by the three metal particles on the local freezing tank Pi of the i-th frozen sediment are recorded, where the straight edge of the tank is the origin, the vertical direction is the Z direction, and the other two sides are the X and Y directions. The spatial position of the TD marking point is recorded as Di = {Pi_DX, Pi_DY, Pi_DZ}, the spatial position of the TE marking point is recorded as Ei = {Pi_EX, Pi_EY, Pi_EZ}, and the spatial position of the TF marking point is recorded as Fi = {Pi_FX, Pi_FY, Pi_FZ}, where Pi_DX, Pi_EX, and Pi_FX are the coordinates of the three marking points in the X direction, Pi_DY, Pi_EY, and Pi_FY are the coordinates of the three marking points in the Y direction, and Pi_DZ, Pi_EZ, and Pi_FZ are the coordinates of the three marking points in the Z direction;

[0056] The spatial positions of the three marking points Di, Ei and Fi of the i-th local freezing tank Pi constitute the coordinate information set Ci = {Di, Ei, Fi} of the i-th local freezing tank; the set of spatial position information of the marking points of all N local freezing tanks constitutes the spatial coordinate annotation set S = {Ci|i = 1…N}.

[0057] In some preferred embodiments, step three further includes: transferring each frozen sediment body to a flat plate of equal thickness according to its arrangement relationship on the water tank bottom plate FB, and then performing the marking process.

[0058] Step 4: Refer to the attached Figure 4 , through a CT imaging system composed of CTA: radiation source, CTB: turntable, CTC: imaging plate, CTD: computer, etc., the frozen sediment body T after the annotation process is rotated CT scanned at a rotation angle of 0-360° to obtain CT scan data at different rotation angles. Based on the CT scan data at different rotation angles, Jordan transformation is used to obtain three-dimensional sedimentary structure data CTi of the frozen sediment body.

[0059] In some embodiments, step four may include:

[0060] placing the i-th frozen deposited body after the labeling process is completed into a rotary CT scanner;

[0061] Each time the frozen deposit is rotated by theta angle, the frozen deposit is irradiated once, and the scan data Tk obtained by each irradiation, i.e., the slice data at the corresponding rotation angle, is stored in a data processor such as a scanning computer;

[0062] After completing the 360° rotation, a total of 360 / theta slice data are obtained, which are sequentially composed into a slice information set {Tk|k=1…360 / theta};

[0063] Based on the obtained slice information set, Jordan transformation is used to obtain the three-dimensional sedimentary structure data CTi of the i-th frozen sediment body;

[0064] The data corresponding to the three marking points are identified from the obtained three-dimensional sedimentary structure data CTi, wherein the Di point is the origin, the Di-TE edge is the X-axis, and the Di-TF edge is the Y-axis, that is, in the scanning data, Di_x0, Di_y0, and Di_z0 are used as the origins, and the relative position coordinates of the three marking points are recorded. For example, the relative coordinates of the TD point in CTi are CT_Di = {CTi_DX, CTi_DY, CTi_DZ}, the relative coordinates of the TE point in CTi are CT_Ei = {CTi_EX, CTi_EY, CTi_EZ}, and the relative coordinates of the TF point in CTi are CT_Fi = {CTi_FX, CTi_FY, CTi_FZ}. The identification of the three marking points can be achieved by showing that the three marking points all present high-density phases in the CT scan image and have different sizes.

[0065] Step 5: Extract the coordinate information set Ci = {Di, Ei, Fi} of the i-th local freezing tank from the spatial coordinate annotation set S = {Ci|i = 1…N} in step 3, and extract the coordinate information Di = {Pi_DX, Pi_DY, Pi_DZ} and TE point coordinates Ei = {Pi_EX, Pi_EY, Pi_EZ} of the annotation point TD in the i-th frozen sediment body from the slice information set in step 5 to form a coordinate system. At the same time, from the three-dimensional scanning data Di obtained in step 5, the local coordinates CT_Di = {CTi_DX, CTi_DY, CTi_DZ} of the TD point and the local coordinates CT_Ei = {CTi_EX, CTi_EY, CTi_EZ} of the TE point in CTi can be clarified according to the relative size of the imaged metal particles. According to the above information, CTi is spliced to obtain the three-dimensional reconstructed volume data F of the water tank sediment structure.

[0066] Example 1

[0067] According to a specific implementation method, the process of steps one to six is used to finely reconstruct the water tank sediment structure, wherein the water tank base is a square with a side length of 200.18 cm, the water tank bottom plate FB laid thereon is a square with a side length of 20 cm, and the width of the filling seam embedded between the water tank bottom plates FB is 2 mm. The water tank experiment was carried out for 12 hours, and the thickest sediment formed was 2 cm. After the experiment is completed, the sediment is cut using a square local freezing tank. The side length of the local freezing tank is 20 cm, the shell thickness is 1 mm, and the height is 6 cm. The diameter of the metal particles at the marked points TD on the local freezing tank is 0.5 mm, the diameter of the metal particles at the TE point is 1.0 mm, and the diameter of the metal particles at the TF point is 2.0 mm. After that, liquid nitrogen is injected through the liquid nitrogen injection port of the local freezing tank. Each local freezing tank is injected with 1 L of liquid nitrogen. After waiting for 5 minutes, the sediment in each local freezing tank reaches a highly frozen solidified state.

[0068] Using a laser locator, the coordinate information of all local cryotank markers was recorded. Then, micron CT scanning and data splicing were performed on each local cryotank, and finally a 3D reconstruction model of the sediment body with an accuracy of 10 μm was synthesized. Figure 5 , which shows examples of images before and after stitching. Meanwhile, the frozen sediments in each local freezing tank are placed in an insulated box for future use.

[0069] The above embodiments are merely preferred embodiments of the present invention, and the scope of protection of the present invention is not limited to the above embodiments. All technical solutions that fall within the scope of protection of the present invention are within the scope of protection of the present invention. It should be noted that improvements and modifications that can be made by a person skilled in the art without departing from the principles of the present invention are also considered to be within the scope of protection of the present invention.

Claims

1. A device for fine reconstruction of a water tank sediment structure, characterized in that: It includes: A combined bottom plate and a combined freezing tank, wherein the combined bottom plate is formed by a plurality of rectangular basic bottom plates of equal thickness being laid flat and spliced together, with a splicing gap between adjacent basic bottom plates, the splicing gap being filled with an elastic adhesive, and the filled splicing gap being of the same thickness as the basic bottom plate; the combined freezing tank comprises a plurality of local freezing tanks; the local freezing tank comprises: a rectangular tank body with an open bottom and a hollow interior, at least two channels located on the top surface of the tank body and connected to the hollow interior thereof, wherein any one channel is for the freezing medium to enter and the other channel is for the freezing medium to flow out after use, and three channels of different diameters located on the top surface of the tank body at different positions from the two channels Metal particles; wherein, any basic bottom plate has a local freezing groove matched with it, and the local freezing groove satisfies: the groove body thickness is sw / 2, the length is LL+sw / 2, and the width is LW+sw / 2, wherein sw represents the width of the splicing gap between any basic bottom plate and its adjacent basic bottom plate, LL represents the length of any basic bottom plate, and LW represents the width of any basic bottom plate; the splicing gaps between the adjacent basic bottom plates are of equal width, and their widths sw satisfy: 0<sw<2mm; the elastic coefficient of the elastic adhesive satisfies: when the thickness of the sediment thereon reaches the maximum thickness of the water tank, the elastic deformation of the elastic adhesive is less than 0.0001.

2. The device according to claim 1, characterized in that In the combined bottom plate, the sizes of the basic bottom plates are the same; correspondingly, in the combined freezing tank, the sizes of the tank bodies of the local freezing tanks are the same.

3. The device according to claim 1, characterized in that The diameters of the three metal particles with different diameters satisfy the following condition: if the diameter of any one of the metal particles is pw, the diameters of the other two metal particles are 2*pw and 4*pw respectively.

4. A method for finely reconstructing a water tank sediment structure using the device according to any one of claims 1 to 3, characterized in that: It includes: The local freezing tank is used to divide the sediment body located on the combined bottom plate and having completed the water tank sedimentation experiment, thereby obtaining a plurality of independent sediment bodies located on the basic bottom plate and covered by the tank body of the local freezing tank; In a unified coordinate system, the position of each independent deposit on the combined base plate, i.e., the first positional relationship, and the spatial position of the three metal particles on its local freezing tank, i.e., the second positional relationship, are recorded; The independent sediment body is subjected to a quick freezing process by the local freezing tank to obtain a frozen sediment body; Obtaining CT scan data of the frozen deposit at different rotation angles, and forming a slice data set of the frozen deposit from all CT scan data within a rotation angle range of 0-360 degrees; Obtaining three-dimensional sedimentary structure data of any of the frozen sedimentary bodies by performing a Jordan transformation on a slice data set; identifying, from the three-dimensional sedimentary structure data, the spatial positions of three metal particles on a local freezing tank of the frozen sedimentary body, i.e., a third positional relationship; Obtaining correspondence between each three-dimensional sedimentary structure data and the frozen sedimentary body on the base plate by aligning the second positional relationship with the third positional relationship; According to the first positional relationship, the three-dimensional sedimentary structure data corresponding to different frozen sediment bodies are spliced to obtain a three-dimensional flume experimental sedimentary structure.

5. The method for fine reconstruction of the water tank sediment structure according to claim 4, characterized in that: The quick freezing treatment is achieved by liquid nitrogen.

6. The method for fine reconstruction of a water tank sediment structure according to claim 4, characterized in that: Specifically include: The local freezing tank is used to divide the sediment body located on the combined bottom plate and having completed the water tank sedimentation experiment, thereby obtaining a plurality of independent sediment bodies located on the basic bottom plate and covered by the tank body of the local freezing tank; A freezing medium is injected through one channel of the local freezing tank to rapidly freeze the post-experimental sediment in the independent sediment to obtain a frozen sediment. All frozen sediments are labeled as follows: Using laser three-dimensional positioning technology, in a rectangular coordinate system, the spatial positions of the marking points formed by the three metal particles on the local freezing tank Pi of the i-th frozen sediment are recorded. The straight edge of the tank is taken as the origin, the vertical direction is the Z direction, and the other two sides are the X and Y directions. The spatial position of the TD marking point is recorded as Di={Pi_DX,Pi_DY,Pi_DZ}, the spatial position of the TE marking point is recorded as Ei={Pi_EX,Pi_EY,Pi_EZ}, and the spatial position of the TF marking point is recorded as Fi={Pi_FX,Pi_FY,Pi_FZ}, where Pi_DX, Pi_EX, and Pi_FX are the coordinates of the three marking points in the X direction, Pi_DY, Pi_EY, and Pi_FY are the coordinates of the three marking points in the Y direction, and Pi_DZ, Pi_EZ, and Pi_FZ are the coordinates of the three marking points in the Z direction. The spatial positions of the three marking points Di, Ei and Fi of the i-th local freezing tank Pi constitute the coordinate information set Ci={Di,Ei,Fi} of the i-th local freezing tank; the set of spatial position information of the marking points of all N local freezing tanks constitutes the spatial coordinate annotation set S={Ci|i=1…N}; The i-th frozen sediment body after the marking is placed in a rotating CT scanner. The frozen sediment body is irradiated once every rotation of theta angle to obtain scanning data Tk under each irradiation, i.e., slice data at different rotation angles. After completing 360° rotation, a total of 360 / theta slices of data are obtained, which are sequentially formed into a slice information set {Tk|k=1…360 / theta}; Based on the obtained slice information set, Jordan transformation is used to obtain the three-dimensional sedimentary structure data CTi of the i-th frozen sediment body; Identify the coordinate data corresponding to the three marking points from the obtained three-dimensional sedimentary structure data CTi, wherein the Di point is the origin, the Di-TE side is the X-axis, and the Di-TF side is the Y-axis; The coordinate information set Ci={Di,Ei,Fi} of the i-th local freezing tank is extracted from the spatial coordinate annotation set S={Ci|i=1…N}, and the coordinate information Di={Pi_DX,Pi_DY,Pi_DZ} of the marked point TD in the i-th frozen sediment body and the TE point coordinates Ei={Pi_EX,Pi_EY,Pi_EZ} are extracted therefrom to form a coordinate system. At the same time, according to the local coordinates CT_Di={CTi_DX, CTi_DY, CTi_DZ} of the TD point in CTi and the local coordinates CT_Ei={CTi_EX, CTi_EY, CTi_EZ} of the TE point in CTi identified from the three-dimensional sedimentary structure data CTi, the three-dimensional sedimentary structure CTi is spliced to obtain the three-dimensional reconstructed volume data F of the water tank sedimentary structure.

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