A method and apparatus for evaluating fault seal

Abstract

The present application belongs to the field of oil and gas geophysical prospecting and well logging, and discloses a fault sealing evaluation method and device, wherein the method comprises: extracting wave bands for comparison from seismic waveform information on both sides of the fault, taking one wave band on the left side of the fault and one wave band on the right side of the fault as a comparison group; determining the mapping relationship of the sampling points of the two wave bands; obtaining the distance of the two wave bands; normalizing the similarity values of all comparison groups to obtain the normalization coefficient of the two wave bands in each comparison group; and determining the fault sealing according to the normalization coefficient of the two wave bands in each comparison group. The present application directly uses seismic data to evaluate the fault sealing without carrying out lithology or shale content inversion of seismic data, thereby avoiding the limitation that lithology inversion is difficult to carry out in well-free areas and areas with complex geological conditions, reducing the intermediate process and adjustable parameters in the evaluation, and thus being more applicable, avoiding the influence of human factors, and being more reliable in evaluation.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of oil and gas geophysical prospecting and well logging, and particularly relates to a fault sealing evaluation method and device. BACKGROUND

[0002] The opening or closure of the fault also affects whether the oil and gas in the reservoir can reach the target area along the fault plane and the channel therein, and further realize the search and development of oil and gas field. At this time, the analysis of fault sealing plays a role of a bridge. Through the connection of fault sealing and actual data and target area characteristics, the oil and gas distribution can be inferred, and therefore it is particularly important to use seismic data to evaluate the sealing of the fault.

[0003] At present, the qualitative and quantitative evaluation of fault transverse sealing is mainly carried out by using seismic data, and the following methods are mainly used. Bouvier proposed a clay smear potential (CSP), also known as clay smear potential or clay contamination potential, which is represented by CSP. Lindsay et al. proposed a parameter, shale smear factor (SSF), to represent the continuity of shale smear layer based on statistical analysis of actual data. After Yielding proposed the shale gouge ratio (SGR) algorithm, SGR was used by scholars to verify the fault sealing, which is called a mainstream method.

[0004] The above methods all need to carry out lithology inversion on the basis of seismic data to evaluate the transverse sealing of the fault. In actual production, it is difficult to carry out accurate lithology inversion by using seismic data, especially in deep strata. Due to strong compaction, the difference between the longitudinal wave impedance of mudstone and sandstone is small, and it is difficult to obtain the lithology profile and shale content by using post-stack seismic data. On the other hand, due to the influence of the algorithm of seismic inversion, it involves intermediate links such as time-depth calibration, seismic wavelet extraction, low-frequency model establishment, and in the area without well, due to the lack of well data, the low-frequency model cannot be constructed, and further the lithology inversion and fault transverse sealing evaluation cannot be carried out. SUMMARY

[0005] In view of the above problems, the present application provides a fault sealing evaluation method and device, which adopts the following technical scheme:

[0006] The application discloses a fault sealing evaluation method, which comprises the following steps: extracting seismic waveform information on both sides of a fault from seismic data of a target layer, extracting wave bands for comparison from the seismic waveform information on both sides of the fault respectively, taking one wave band on the left side of the fault and one wave band on the right side of the fault as a comparison group, and obtaining a plurality of comparison groups; comparing the two wave bands in each comparison group to determine the mapping relationship of the sampling points of the two wave bands; summing the distance between the sampling points with the mapping relationship in the two wave bands of each comparison group to obtain the distance sum of the two wave bands; taking the distance sum of the two wave bands of each comparison group as the similarity value of the two wave bands in each comparison group, and performing normalization processing on the similarity values of all the comparison groups to obtain the normalization coefficient of the two wave bands in each comparison group; and determining the fault sealing property according to the normalization coefficient of the two wave bands in each comparison group.

[0007] Further, the step of extracting wave bands for comparison from the seismic waveform information on both sides of the fault respectively comprises the following steps:

[0008] Taking the time derivative of the seismic amplitude in the seismic waveform information on both sides of the fault, finding the point with the minimum change in the seismic waveform, and extracting the wave band for comparison horizontally.

[0009] Further, the step of comparing the two wave bands in each comparison group to determine the mapping relationship of the sampling points of the two wave bands comprises the following steps:

[0010] Constructing a cumulative distance matrix, taking the column of the matrix as the first wave band in the comparison group, taking the row of the matrix as the second wave band in the comparison group, and taking the element in the grid of the matrix as the cumulative distance between the two sampling points of the first wave band and the second wave band.

[0011] Calculating the cumulative distance represented by the element in each grid of the cumulative distance matrix.

[0012] Determining the shortest path between the comparison points of the first wave band and the second wave band according to the cumulative distance represented by the element in each grid of the matrix, and obtaining the shortest distance between the comparison points of the first wave band and the second wave band.

[0013] Determining the mapping relationship of the sampling points of the two wave bands according to the shortest path between the comparison points of the first wave band and the second wave band.

[0014] Further, the step of calculating the cumulative distance represented by the element in each grid of the cumulative distance matrix comprises the following steps:

[0015] For the leftmost column of grids of the matrix, the cumulative distance represented by the element in each grid is calculated from the upper right grid, the distance between the two sampling points of the first wave band and the second wave band is calculated from top to bottom along the first column of grids, the distance between the two sampling points of the first wave band and the second wave band is summed with the distance of the adjacent grids above and below to obtain the cumulative distance represented by the element in the grid.

[0016] For the uppermost row of the matrix, the distance between the two sample points of the first and second bands is summed with the distance of the left adjacent grid, and the cumulative distance represented by the element in the grid is obtained by calculating from left to right in the first row of the matrix.

[0017] For the remaining grids in the matrix, the distance between the two sample points of the first and second bands is summed with the minimum cumulative distance value between the three sample points above and left of the first and second bands, and the cumulative distance represented by the element in the grid is obtained.

[0018] Further, according to the cumulative distance represented by the element in each grid in the matrix, the shortest path between the contrast points of the first and second bands is determined, and the shortest distance between the contrast points of the first and second bands is obtained, including the following steps:

[0019] Starting from the lower right corner of the matrix, the point with the minimum cumulative distance between the three sample points above and left of the first and second bands is found, and the shortest path between the contrast points of the first and second bands is found by backtracking, and the shortest distance between the contrast points of the first and second bands is obtained, wherein the starting point of the shortest path is the point at the top left corner of the matrix.

[0020] Further, the similarity values of all contrast groups are normalized to obtain the normalization coefficients of the two bands in each contrast group, including the following steps:

[0021] The similarity values of the two bands of all contrast groups are sorted to determine the minimum and maximum similarity values of the two bands of the contrast group.

[0022] The similarity values of all contrast groups are normalized according to the minimum and maximum similarity values of the two bands of the contrast group to obtain the normalization coefficients of the two bands in each contrast group.

[0023] Further, according to the normalization coefficients of the two bands in each contrast group, the fault sealing property is determined, including the following steps:

[0024] The normalization coefficients of the two bands in each contrast group are assigned to the fault according to the time period, and the size of the normalization coefficient is represented by color, and the larger the normalization coefficient, the stronger the fault sealing property.

[0025] Further, it further includes the following steps:

[0026] The top and bottom of the target layer are determined, and the seismic data of the target layer is extracted.

[0027] The application also provides a fault sealing property evaluation device, comprising:

[0028] The data acquisition module is configured to extract seismic waveform information on both sides of the fault from seismic data of the target layer section, extract wave bands for comparison from the seismic waveform information on both sides of the fault respectively, take one wave band on the left side of the fault and one wave band on the right side of the fault as one comparison group, and obtain a plurality of comparison groups;

[0029] The first calculation module is configured to compare the two wave bands in each comparison group to determine a mapping relationship of sampling points of the two wave bands.

[0030] The second calculation module is configured to sum distances between the sampling points having the mapping relationship in the two wave bands of each comparison group to obtain a distance sum of the two wave bands.

[0031] The third calculation module is configured to represent a similarity value of the two wave bands in each comparison group by the distance sum of the two wave bands of each comparison group, and normalize the similarity values of all comparison groups to obtain a normalization coefficient of the two wave bands in each comparison group.

[0032] The fourth calculation module is configured to determine the fault sealing property according to the normalization coefficient of the two wave bands in each comparison group.

[0033] Further, the data acquisition module is specifically configured to:

[0034] Take a time derivative of seismic amplitudes in the seismic waveform information on both sides of the fault, find out points with the smallest change in the seismic waveform, and extract wave bands for comparison horizontally.

[0035] Further, the first calculation module is specifically configured to:

[0036] Construct a cumulative distance matrix, take columns of the matrix to correspond to the first wave bands in the comparison groups, take rows of the matrix to correspond to the second wave bands in the comparison groups, and represent cumulative distances of two sampling points that are mapped to each other between the first wave band and the second wave band by elements in grids of the matrix.

[0037] Calculate the cumulative distances represented by the elements in the grids of the cumulative distance matrix.

[0038] Determine the shortest path between comparison points of the first wave band and the second wave band according to the cumulative distances represented by the elements in the grids of the matrix, and obtain the shortest distance between the comparison points of the first wave band and the second wave band.

[0039] Determine the mapping relationship of the sampling points of the two wave bands according to the shortest path between the comparison points of the first wave band and the second wave band.

[0040] Further, the third calculation module is specifically configured to:

[0041] Sort the similarity values of the two wave bands of all comparison groups to determine a minimum similarity value and a maximum similarity value of the two wave bands of the comparison groups.

[0042] According to the minimum similarity value and the maximum similarity value of the two wave bands of the contrast group, the similarity values of all the contrast groups are normalized to obtain the normalized coefficients of the two wave bands in each contrast group.

[0043] The present application has the advantages that: the present application directly uses seismic data to evaluate fault sealing property without carrying out lithology or shale content inversion of seismic data, avoids the limitation that lithology inversion is difficult to carry out in well-free areas and areas with complex geological conditions, is directly driven by seismic data, does not need the participation of wells, has few intermediate processes and adjustable parameters, and therefore has stronger applicability, avoids the influence of human factors, and has higher reliability of fault sealing property evaluation.

[0044] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent to those skilled in the art from the following description, or can be learned by practice of the present application. The objects and other advantages of the present application will be realized and achieved by means of the structures particularly pointed out in the description and appended claims. BRIEF DESCRIPTION OF DRAWINGS

[0045] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor based on these drawings.

[0046] Figure 1 A flowchart of a fault sealing property evaluation method according to an embodiment of the present application is shown;

[0047] Figure 2 A cumulative distance matrix and a best path display schematic diagram according to an embodiment of the present application are shown;

[0048] Figure 3 A mapping relationship schematic diagram of sampling points in the two wave bands of each contrast group according to an embodiment of the present application is shown;

[0049] Figure 4 A fault sealing property evaluation result schematic diagram according to an embodiment of the present application is shown;

[0050] Figure 5 A structure schematic diagram of a fault sealing property evaluation device according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0051] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0052] It should be noted that the terms "first," "second," etc., used in this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0053] This invention provides a method and apparatus for evaluating fault sealing performance. Starting directly from seismic data, it directly compares the seismic data characteristics on both sides of the fault for quantitative evaluation of fault sealing performance. Since this method does not require the participation of well data, it is also applicable in exploration areas without wells, while avoiding indirect errors introduced during the inversion process.

[0054] like Figure 1 As shown, a fault sealing performance evaluation method includes the following steps:

[0055] S1. Determine the top and bottom of the target segment and extract the seismic data of the target segment. For example, based on the stratigraphy and faults provided by seismologists, determine the top and bottom of the target segment and extract the seismic data of the target segment.

[0056] S2. Extract seismic waveform information from both sides of the fault from the seismic data of the target segment. Extract bands for comparison from the seismic waveform information on both sides of the fault. Take one band on the left side of the fault and one band on the right side of the fault as a comparison group to obtain multiple comparison groups.

[0057] The process of extracting bands for comparison from the seismic waveform information on both sides of the fault includes the following steps: taking the time derivative of the seismic amplitude in the seismic waveform information on both sides of the fault, finding the point with the smallest change in the seismic waveform, and extracting the bands for comparison laterally.

[0058] S3. Compare the two bands in each comparison group to determine the mapping relationship between the sampling points of the two bands.

[0059] Since traditional point-to-point Euclidean distance methods cannot effectively compare the similarity of seismic waveforms of varying lengths, this invention employs an algorithm to find the optimal comparison path. Specific step S3 includes:

[0060] S31, construct a cumulative distance matrix, the column of the matrix corresponds to the first wave band in the contrast group, the row of the matrix corresponds to the second wave band in the contrast group, and the element in the grid of the matrix represents the cumulative distance of two sampling points of the first wave band and the second wave band.

[0061] For example, first we form an N*M grid, where the column corresponds to the first wave band A, the row corresponds to the second wave band B, N is the number of sampling points of the first wave band A, M is the number of sampling points of the second wave band B, and each element in the grid represents the cumulative distance of two sampling points of the first wave band A and the second wave band B.

[0062] Wherein, the specific calculation method of cumulative distance is as follows:

[0063] dis(x, y) = |x-y| (1)

[0064] In the formula, x and y are the numerical values corresponding to each waveform sampling point, and dis(x, y) represents the Euclidean distance between two sampling points.

[0065] For the elements in the leftmost column of the matrix:

[0066] D[i, 0] = dis(A i , B0) + D[i-1, 0] (2)

[0067] In the formula, unless otherwise specified, the row and column subscripts of the element are from 0. D[i, 0] represents the cumulative distance corresponding to the element in the ith row and the 0th column, dis(A i , B0) represents the distance between the two sampling points in the ith row and the 0th column calculated by formula 1, and D[i-1, 0] represents the cumulative distance corresponding to the (i-1)th row and the 0th column.

[0068] For the elements in the top row of the matrix:

[0069] D[0, j] = dis(A0, B j ) + D[0, j-1] (3)

[0070] In the formula, D[0, j] represents the cumulative distance corresponding to the element in the 0th row and the jth column, dis(A0, B j ) represents the distance between the two sampling points in the 0th row and the jth column calculated by formula 1, and D[0, j-1] represents the cumulative distance corresponding to the 0th row and the (j-1)th column.

[0071] For the elements in other positions of the matrix:

[0072] D[i, j] = dis(A i , B j)+min(D[i-1,j],D[i,j-1],D[i-1,j-1]) (4)

[0073] In the formula, D[i,j] represents the cumulative distance corresponding to the element in the i-th row and j-th column, and dis(A i B j ) represents the distance between two sample points in the i-th row and j-th column calculated using Equation 1.

[0074] S32. Calculate the cumulative distance represented by each element in the cumulative distance matrix, as follows:

[0075] S321. For the leftmost column of the matrix, start the calculation from the top right corner grid and proceed from top to bottom along the first column of the grid. Sum the distance between the two sampling points that are mapped to each other in the first band and the second band with the distance between the adjacent grids above and below to obtain the cumulative distance represented by the elements in the grid. The calculation formula is shown in Equation 2.

[0076] S322. For the top row of the matrix, calculate from left to right from the first row of the matrix, summing the distance between the two sampling points that are mapped to each other in the first band and the second band with the distance of the adjacent grid on the left, to obtain the cumulative distance represented by the elements in the grid. The calculation formula is shown in Equation 3.

[0077] S323. For the remaining grids in the matrix, the distance between two sampling points that are mapped to each other in the first band and the second band is summed with the minimum cumulative distance between the three sampling points in the upper left of the first band and the second band to obtain the cumulative distance represented by the elements in the grid. The calculation formula is shown in Equation 4.

[0078] S33. Based on the cumulative distance represented by the elements in each grid of the matrix, determine the shortest path between the comparison points of the first and second bands, and obtain the shortest distance between the comparison points of the first and second bands as follows:

[0079] Starting from the bottom right corner of the matrix, find the point with the smallest cumulative distance among the three sampling points in the upper left corner of the first and second bands. Repeat this process, using backtracking to find the shortest path between the comparison points of the first and second bands, thus obtaining the shortest distance between them. The starting point of the shortest path is the point in the upper left corner of the matrix.

[0080] S34. Determine the mapping relationship between the sampling points of the two bands based on the shortest path between the comparison points of the first and second bands.

[0081] like Figure 2 As shown, Figure 2The calculated cumulative distance matrix and shortest path are displayed. The gray value represents the cumulative distance of each element. The smaller the gray value, the smaller the distance. The red line in the figure represents the shortest path found.

[0082] S4. Sum the distances between the sampling points with a mapping relationship in the two bands of each comparison group to obtain the distance sum between the two bands.

[0083] For example, such as Figure 3 As shown, the 0th sampling point of the first band A is compared with the 0th, 1st, and 2nd sampling points of the second band B. The distances between the 0th sampling point of waveform A and the 0th, 1st, and 2nd sampling points of the second band B are summed to obtain the final distance sum D.

[0084] S5. Using the distance between the two bands in each comparison group and the similarity value representing the two bands in each comparison group, normalize the similarity values ​​of all comparison groups to obtain the normalization coefficients for the two bands in each comparison group, as follows:

[0085] S51. Sort the similarity values ​​of the two bands in all comparison groups and determine the minimum and maximum similarity values ​​of the two bands in the comparison groups.

[0086] The distance between two bands in the comparison group indicates similarity; the smaller the distance, the more similar the waveforms of the two bands are.

[0087] S52. Based on the minimum and maximum similarity values ​​of the two bands in each comparison group, normalize the similarity values ​​of all comparison groups to obtain the normalization coefficient c for the two bands in each comparison group, as follows:

[0088]

[0089] In the formula, D max D min These are the minimum and maximum similarity values ​​for the two bands in the comparison group, respectively.

[0090] S6. Determine the fault sealing performance based on the normalization coefficients of the two bands in each comparison group.

[0091] For example, the normalization coefficient c of the two bands in each comparison group is assigned to the fault according to the time period, and the size of the normalization coefficient c is represented by color. The larger the normalization coefficient c, the stronger the fault sealing effect, and vice versa.

[0092] Actual seismic data demonstrates that the fault sealing evaluation method of this invention has good operability and predictive power. For example... Figure 4 As shown, Figure 4For the application of the present application in the actual work area, the gray value is the intuitive display of the sealing property of the fault, and the smaller gray value in the figure indicates that the waveform difference is large, and then indicates that the fault sealing property is strong.

[0093] Based on the above fault sealing property evaluation method, as shown in the figure, Figure 5 The present application also provides a fault sealing property evaluation device, which comprises a data acquisition module, a first calculation module, a second calculation module, a third calculation module and a fourth calculation module.

[0094] The data acquisition module is used for extracting the seismic waveform information of the two sides of the fault from the seismic data of the target layer section, extracting the wave bands for comparison from the seismic waveform information of the two sides of the fault respectively, taking one wave band on the left side of the fault and one wave band on the right side of the fault as one comparison group, and obtaining a plurality of comparison groups. The first calculation module is used for comparing the two wave bands in each comparison group and determining the mapping relationship of the sampling points of the two wave bands. The second calculation module is used for summing the distances between the sampling points with the mapping relationship in the two wave bands of each comparison group and obtaining the distance sum of the two wave bands. The third calculation module is used for representing the similarity value of the two wave bands in each comparison group through the distance sum of the two wave bands of each comparison group, and performing normalization processing on the similarity values of all the comparison groups to obtain the normalization coefficient of the two wave bands in each comparison group. The fourth calculation module is used for determining the fault sealing property according to the normalization coefficient of the two wave bands in each comparison group.

[0095] The existing fault sealing property evaluation needs to be based on the lithology or shale content inversion of seismic data to carry out the evaluation, the intermediate process is more, the parameters to be adjusted are numerous, the result of the sealing property evaluation is different for different people, and the multi-solution is very strong.

[0096] The present application does not need to carry out the lithology or shale content inversion of seismic data, directly uses the seismic data to evaluate the fault sealing property, avoids the limitation that the lithology inversion is difficult to carry out in the well area and the geological condition complex area, the present application is directly driven based on the seismic data, does not need the participation of the well, the intermediate process is less, the adjustable parameters are less, therefore, the applicability is stronger, the influence of the artificial factor is avoided, and the fault sealing property evaluation is more reliable.

[0097] Although the present application is described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method of evaluating fault seal potential, characterized by, The method comprises the following steps: extracting seismic waveform information on both sides of a fault from seismic data of a target layer, extracting wave segments for comparison from the seismic waveform information on both sides of the fault respectively, taking one wave segment on the left side of the fault and one wave segment on the right side of the fault as a comparison group, and obtaining a plurality of comparison groups; comparing the two wave segments in each comparison group to determine the mapping relationship between the sampling points of the two wave segments, including the following steps: constructing a cumulative distance matrix, taking the columns of the matrix to correspond to the first wave segment in the comparison group, taking the rows of the matrix to correspond to the second wave segment in the comparison group, and taking the elements in the grid of the matrix to represent the cumulative distance between the two sampling points that are mutually mapped by the first wave segment and the second wave segment; calculating the cumulative distance represented by each element in the grid of the matrix; determining the shortest path between the comparison points of the first wave segment and the second wave segment according to the cumulative distance represented by each element in the grid of the matrix, and obtaining the shortest distance between the comparison points of the first wave segment and the second wave segment; and determining the mapping relationship between the sampling points of the two wave segments according to the shortest path between the comparison points of the first wave segment and the second wave segment; summing the distances between the sampling points with the mapping relationship in the two wave segments of each comparison group to obtain the distance sum of the two wave segments; representing the similarity value of the two wave segments in each comparison group by the distance sum of the two wave segments of each comparison group, normalizing the similarity values of all comparison groups to obtain the normalization coefficient of the two wave segments in each comparison group, including the following steps: sorting the similarity values of the two wave segments of all comparison groups to determine the minimum similarity value and the maximum similarity value of the two wave segments of the comparison group; and normalizing the similarity values of all comparison groups according to the minimum similarity value and the maximum similarity value of the two wave segments of the comparison group to obtain the normalization coefficient of the two wave segments in each comparison group; determining the fault sealing property according to the normalization coefficient of the two wave segments in each comparison group.

2. The fault seal evaluation method of claim 1, wherein, extracting the wave segments for comparison from the seismic waveform information on both sides of the fault respectively, including the following steps: taking the time derivative of the seismic amplitude in the seismic waveform information on both sides of the fault, finding the point with the smallest change in the seismic waveform, and extracting the wave segments for comparison horizontally.

3. The fault seal evaluation method of claim 1, wherein, calculating the cumulative distance represented by each element in the grid of the matrix, including the following steps: for the leftmost column of grids in the matrix, starting from the top-right grid, calculating along the first column of grids from top to bottom, summing the distance between the two sampling points that are mutually mapped by the first wave segment and the second wave segment and the distance of the adjacent grids above and below to obtain the cumulative distance represented by the element in the grid; for the top row of grids in the matrix, starting from the first row of grids in the matrix from left to right, summing the distance between the two sampling points that are mutually mapped by the first wave segment and the second wave segment and the distance of the adjacent grid on the left to obtain the cumulative distance represented by the element in the grid; for the remaining grids in the matrix, summing the distance between the two sampling points that are mutually mapped by the first wave segment and the second wave segment and the minimum cumulative distance value among the three sampling points above and to the left of the first wave segment and the second wave segment to obtain the cumulative distance represented by the element in the grid.

4. The fault seal evaluation method of claim 1, wherein, According to the cumulative distance represented by each element in the matrix, the shortest path between the contrast points of the first wave band and the second wave band is determined, and the shortest distance between the contrast points of the first wave band and the second wave band is obtained, including the following steps: Starting from the lower right corner of the matrix, the point with the minimum cumulative distance between the three sampling points above and left of the first wave band and the second wave band is found, and the shortest path between the contrast points of the first wave band and the second wave band is found in turn by backtracking, and the shortest distance between the contrast points of the first wave band and the second wave band is obtained, wherein the starting point of the shortest path is the point at the top left corner of the matrix.

5. The fault seal evaluation method of claim 1, wherein, According to the normalized coefficients of the two wave bands in each contrast group, the fault sealing property is determined, including the following steps: The normalized coefficients of the two wave bands in each contrast group are assigned to the fault according to the time period, and the size of the normalized coefficient is represented by color, and the larger the normalized coefficient, the stronger the fault sealing property.

6. The method of fault seal evaluation according to any one of claims 1 to 5, characterized in that, Further comprising the following steps: Determine the top and bottom of the target interval and extract the seismic data of the target interval.

7. A fault seal evaluation apparatus, characterized by It includes: The data acquisition module is used to extract the seismic waveform information of the two sides of the fault from the seismic data of the target interval, extract the wave bands used for comparison from the seismic waveform information of the two sides of the fault respectively, take one wave band on the left side of the fault and one wave band on the right side of the fault as a contrast group, and obtain a plurality of contrast groups; The first calculation module is used to compare the two wave bands in each contrast group to determine the mapping relationship of the sampling points of the two wave bands, including the following steps: constructing a cumulative distance matrix, the columns of the matrix correspond to the first wave band in the contrast group, the rows of the matrix correspond to the second wave band in the contrast group, and the elements in the grid of the matrix represent the cumulative distance of the two sampling points of the first wave band and the second wave band; calculate the cumulative distance represented by each element in the cumulative distance matrix; according to the cumulative distance represented by each element in the matrix, the shortest path between the contrast points of the first wave band and the second wave band is determined, and the shortest distance between the contrast points of the first wave band and the second wave band is obtained; according to the shortest path between the contrast points of the first wave band and the second wave band, the mapping relationship of the sampling points of the two wave bands is determined; The second calculation module is used to sum the distances between the sampling points with the mapping relationship in the two wave bands of each contrast group, and obtain the distance sum of the two wave bands; The third calculation module is used to represent the similarity value of the two wave bands in each contrast group through the distance sum of the two wave bands of each contrast group, and normalize the similarity values of all contrast groups to obtain the normalized coefficient of the two wave bands in each contrast group, including the following steps: sorting the similarity values of the two wave bands of all contrast groups to determine the minimum similarity value and the maximum similarity value of the two wave bands of the contrast group; according to the minimum similarity value and the maximum similarity value of the two wave bands of the contrast group, the similarity values of all contrast groups are normalized to obtain the normalized coefficient of the two wave bands in each contrast group; The fourth calculation module is used to determine the fault sealing property according to the normalized coefficients of the two wave bands in each contrast group.

8. The fault seal evaluation apparatus of claim 7, wherein, The data acquisition module is specifically used for: The time derivative of the seismic amplitude in the seismic waveform information on both sides of the fault is taken, and the point with the least change in the seismic waveform is found, and the wave band used for comparison is extracted horizontally.

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