Seabed fan description method and system based on general spectrum decomposition and multi-attribute fusion

Abstract

The invention provides a seabed fan description method and system based on general spectral decomposition and multi-attribute fusion, and belongs to the field of petroleum and natural gas exploration and development. Comprising the steps that firstly, a target horizon and seabed fan development top and bottom interfaces are determined, a three-dimensional age stratigraphic framework is established with the top and bottom interfaces as constraints, and three-dimensional automatic tracking is conducted on an internal stratum of the three-dimensional age stratigraphic framework; performing correlation calculation on the seismic original data to obtain a main frequency value, and performing frequency division processing on the main frequency value by adopting a wavelet frequency division technology to obtain a series of single-frequency-band frequency division data volumes; and utilizing the stratum subjected to three-dimensional automatic tracking and identification to extract a horizon stratum slice of a sensitive attribute body from the frequency division data body, and finally fusing and displaying results to describe a seabed sector boundary. According to the method, the precision of boundary description is improved through spectral decomposition and multi-attribute fusion, and meanwhile, when the stratum interface is tracked, a method of combining automatic tracking and manual intervention is adopted, so that the interpretation workload is reduced, and the interface tracking accuracy is ensured.

Description

Technical Field

[0001] The present invention belongs to the field of oil and gas exploration and development, and in particular relates to a submarine fan characterization method and system based on general spectral decomposition and multi-attribute fusion. Background Art

[0002] Submarine fans are usually composite sand bodies such as channels and sheet sands formed by sediment gravity flow in deep-sea environments.

[0003] At present, the commonly used method for submarine fan characterization is mainly to use the technology of seismic attribute analysis, such as:

[0004] 1) Using conventional amplitude attributes (maximum amplitude, root mean square, etc.), the fan boundary is characterized according to the sensitive attributes of the submarine fan;

[0005] 2) Using isochronous stratigraphic slicing technology and impedance fusion to track submarine fans, the principle is that the resolution of submarine fans in the vertical direction is better than that in the horizontal direction; Chinese patent publication CN113341480A discloses a sandy hydrate reservoir prediction method based on frequency-divided RGB slicing and multi-attribute fusion. First, based on the "source-channel-sink" guiding ideology, the research target area is selected, and the bottom boundary of the hydrate stability zone in the research area is calculated based on temperature data. On the basis of the chronostratigraphic framework, a chronostratigraphic framework is established; then, on the basis of the three-dimensional stratigraphic framework, the strata from the seabed to the set range are quantified. , automatically track the three-dimensional strata; secondly, the seismic data body is frequency-divided into low-medium-high frequency data bodies; then the maximum amplitude, minimum amplitude, root mean square amplitude and coherence attribute body are calculated for the three sets of data, and the attributes of each layer are extracted along the layer; the four layer attributes are fused and analyzed according to the three primary colors principle, and the hydrate geological elements and the superposition of various abnormal areas are identified to circle the areas with the most abnormal areas; finally, the elastic parameters such as hydrate impedance and longitudinal wave velocity are inverted by software and deterministic inversion technology, and then the hydrate saturation body is inverted to realize the prediction of hydrate-enriched areas.

[0006] 3) The submarine fan is tracked by combining the curvature of the survey line dip angle with the RGB attribute fusion technology. The principle is to track different stratum morphologies based on the positive or negative curvature when the stratum is uplifted or depressed;

[0007] 4) Characterization of fans of each period based on high-resolution reservoir prediction technology.

[0008] Submarine fans are often laterally distributed composite channel sand bodies with complex contact relationships between sand bodies and multi-stage evolution. Conventional wave impedance inversion has low resolution, and conventional single attribute extraction is only sensitive to specific sand bodies. Conventional attribute fusion technology is sensitive to sand bodies at specific frequencies, and has low accuracy in dividing the boundaries and internal stages of single sand bodies, which cannot meet current exploration and development needs. Summary of the invention

[0009] The purpose of the present invention is to solve the above-mentioned problems existing in the prior art and to provide a method and system for submarine fan characterization based on general spectral decomposition and multi-attribute fusion.

[0010] The present invention is achieved through the following technical solutions:

[0011] A first aspect of the present invention provides a method for characterizing a submarine fan based on general spectral decomposition and multi-attribute fusion, comprising the following steps:

[0012] The first step is to use the well logging, geological and original seismic data of the three-dimensional target reservoir area to combine well and seismic data and determine the target layer and the top interface H1 and bottom interface H2 of the submarine fan development;

[0013] The second step is to establish a three-dimensional chronostratigraphic framework using interfaces H1 and H2 as constraints;

[0014] The third step is to automatically track the strata within the 3D chronostratigraphic framework in 3D.

[0015] Step 4: Use correlation calculation to obtain the main frequency value of the original seismic data, and then use wavelet frequency division technology to divide the main frequency value to obtain a series of single-band frequency division data bodies;

[0016] Step 5: Using the strata identified by three-dimensional automatic tracking, extract the stratigraphic slices along the layers of the sensitive attribute body from the frequency-divided data volume;

[0017] Step 6: Fusion and display the results of the frequency-divided data volume to depict the boundary of the submarine fan.

[0018] A further improvement of the present invention is:

[0019] The first step of well-seismic integration is as follows:

[0020] Based on the surrounding wells and sedimentary background information, the period of submarine fan development was determined, and then two isochronous sedimentary interfaces were determined as the top interface H1 and the bottom interface H2.

[0021] A further improvement of the present invention is:

[0022] In the second step, the three-dimensional chronostratigraphic framework is established with interfaces H1 and H2 as constraints. The specific operations include:

[0023] Based on the seismic data, the H1 and H2 interfaces are interpreted and tracked to obtain a three-dimensional chronostratigraphic framework.

[0024] A further improvement of the present invention is:

[0025] In the third step, the strata within the 3D chronostratigraphic framework are automatically tracked in 3D. The specific operations include:

[0026] For the strata within the top and bottom limits of the 3D chronostratigraphic framework, a global automatic seismic interpretation method based on an automatic stratigraphic model and a manually modified model is used to automatically track the strata in the study area in 3D.

[0027] During 3D automatic tracking, the layer slicing technology is used to divide the strata between H1 and H2 into N1, N2, N3...Nm stratigraphic interfaces, so as to accurately reflect the geological characteristics of each inclined stratum and the characteristics of sedimentary reservoir changes, and determine the extension direction of the submarine fan sedimentary body, where m is greater than 100;

[0028] Among them, the tracking features are wave crests, wave troughs or zero value points. The selection of tracking features needs to be based on logging data to clarify the post-stack seismic response characteristics of the reservoir, so as to determine whether the final tracking is a wave crest, wave trough, zero value point or any combination.

[0029] A further improvement of the present invention is:

[0030] In the fourth step, the main frequency value is obtained by using correlation calculation on the original seismic data. The specific operations include:

[0031] Different wavelet parameters are designed for the original seismic data, and the negative correlation between the wavelet and the seismic trace is removed by correlation calculation to obtain different main frequency values. The wavelet parameters include frequency, number of cycles and phase.

[0032] The specific correlation calculation is: calculate the correlation coefficient between the wavelet and the seismic trace. The principle is to use the correlation coefficient between the two variables, whose value is equal to the covariance between the wavelet and the seismic trace divided by the standard deviation of the wavelet and the standard deviation of the seismic trace, that is, the Pearson correlation coefficient, with a range of -1 to 1. When the correlation coefficient is negative, it is removed and only positive correlation is retained.

[0033] A further improvement of the present invention is:

[0034] In the fourth step, the wavelet frequency division technology is used to divide the main frequency value to obtain a series of single-band frequency division data bodies. The specific operations include:

[0035] The frequency division processing function is constructed using wavelet transformation. is the mother wavelet of wavelet transform,

[0036]

[0037] Where: t is the time corresponding to the target sampling point; a is the scale factor, which controls the signal transformation frequency; b is the translation factor, which controls the time position of the signal analysis. The wavelet function is obtained by changing the values ​​of the two.

[0038]

[0039] Where: for Fourier transform of

[0040] According to the convolution formula, the wavelet transform formula of the signal f(t) is defined as follows:

[0041]

[0042]

[0043] Applying wavelet frequency division technology, the original seismic data is decomposed and inversely transformed according to the center frequencies of x~y Hz and (yx) / z, and a series of single-band frequency division data volumes F1, F2...F are obtained. (y-x) / z , where x is the low-frequency end of the seismic data, y is the high-frequency end of the seismic data, the spacing is z Hz, and the selection of x, y, and z is based on experience.

[0044] A further improvement of the present invention is:

[0045] In the fifth step, the stratigraphic slices along the layers of the sensitive attribute bodies are extracted from the frequency-divided data volume by using the stratigraphic layers identified by three-dimensional automatic tracking. The specific operations include:

[0046] First select the sensitive attribute g, and then calculate the amplitude value of this sensitive attribute as the corresponding attribute body F 1g 、F 2g ……F (y-x) / z g, the amplitude body at this time is the selected frequency division data body F1, F2...F (y-x) / z The sensitive attributes extracted from the above data are as follows: each amplitude body reflects or highlights the sedimentary facies in the submarine fan of different periods;

[0047] Extract F along the N1, N2, N3...Nm stratum interfaces divided during 3D automatic tracking 1g 、F 2g ……F (y-x) / z g The layer properties of the attribute body.

[0048] A further improvement of the present invention is:

[0049] In the sixth step, the results of the frequency-divided data volume are fused and displayed to depict the boundary of the submarine fan more clearly. The specific operations include:

[0050] The attribute body F of multiple outputs 1g 、F 2g ……F (y-x) / z g is mixed and displayed in a three-dimensional window, ultimately showing submarine fans of different periods more intuitively.

[0051] The second aspect of the present invention provides a submarine fan characterization system based on general spectral decomposition and multi-attribute fusion, comprising:

[0052] The interface determination unit is used to combine well logging, geology and original seismic data of the three-dimensional target reservoir area to determine the target layer and the top interface H1 and bottom interface H2 of the submarine fan development;

[0053] The stratigraphic framework establishment unit is connected to the interface determination unit and is used to establish a three-dimensional chronostratigraphic framework with interfaces H1 and H2 as constraints;

[0054] A three-dimensional automatic tracking unit is connected to a stratigraphic framework establishment unit and is used for three-dimensional automatic tracking of the strata within the three-dimensional chronostratigraphic framework;

[0055] The frequency division data volume acquisition unit is used to obtain the main frequency value by using the correlation calculation on the original seismic data, and then use the wavelet frequency division technology to perform frequency division processing on the main frequency value to obtain a series of single-band frequency division data volumes;

[0056] The rock formation stratigraphic slice extraction unit is connected to the three-dimensional automatic tracking unit and the frequency division data volume acquisition unit respectively, and is used to extract stratigraphic slices of sensitive attribute bodies along the layers from the frequency division data volume by using the strata identified by the three-dimensional automatic tracking;

[0057] The fusion display unit is connected to the rock stratum slice extraction unit and is used to fuse and display the results of the frequency division data volume to depict the boundary of the submarine fan more clearly.

[0058] According to a third aspect of the present invention, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores at least one computer-executable program, and when the at least one program is executed by the computer, the computer executes the steps in the above-mentioned submarine fan characterization method based on general spectral decomposition and multi-attribute fusion.

[0059] Compared with the prior art, the present invention has the following beneficial effects:

[0060] (1) Conventional submarine fan characterization often uses isochronous sections or layer-by-layer slices when extracting seismic attributes. Isochronous slices can select any time value to extract attribute slices, and scan the data body from shallow to deep. This technology is only applicable to sheet-like and flat parallel strata. Although isochronous stratigraphic slices can extract seismic attributes along the layer, the number of strata tracked is limited, and it is impossible to track from the top to the bottom of the target layer. The present invention uses the layer-by-layer slice technology to accurately divide the target layer into m isochronous strata, and can scan the data body from shallow to deep. At the same time, it can extract isochronous interface attribute information applicable to sedimentary bodies with strong heterogeneity such as submarine fans.

[0061] (2) The present invention adopts a method combining automatic tracking and manual intervention when there are N1, N2, N3 ... Nm formation interfaces, which reduces the workload of interpretation and ensures the accuracy of formation interface tracking;

[0062] (3) Submarine fans usually have multiple stages and multiple sand bodies. The present invention uses general spectral decomposition to perform frequency division processing on seismic data. Geological targets of different scales have different sensitivities to different frequency components of seismic signals. After frequency division processing, the clarity of geological phenomena displayed by data in different frequency bands is obviously different. Therefore, different spectrum amplitude bodies are selected to reflect or highlight different submarine fan sedimentary bodies. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 It is a flow chart of a submarine fan characterization method based on general spectral decomposition and multi-attribute fusion in an embodiment of the present invention;

[0064] Figure 2 It is a schematic diagram of the general spectral decomposition technique;

[0065] Figure 3a It is a schematic diagram of isochronous stratigraphic slices;

[0066] Figure 3b It is a schematic diagram of stratigraphic slices along the layer;

[0067] Figure 4 It is the top and bottom interface of the submarine fan development in the study area;

[0068] Figure 5 It is a submarine fan characterized by a single seismic attribute based on the original seismic data;

[0069] Figure 6a It is a submarine fan characterized by a single seismic attribute based on the frequency-divided data volume F1;

[0070] Figure 6b It is a submarine fan characterized by a single seismic attribute based on the frequency-divided data volume F2;

[0071] Figure 6c It is a submarine fan characterized by a single seismic attribute based on the frequency-divided data volume F3;

[0072] Figure 7 It is the submarine fan characterization effect using general spectral decomposition and multi-attribute fusion. DETAILED DESCRIPTION

[0073] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0074] The present invention solves the problem of complex submarine fan boundary characterization and internal phase division, and has the following purposes:

[0075] 1) In the process of submarine fan boundary characterization, the problem of low boundary characterization accuracy caused by single attribute and single method is solved. The sensitive attributes and sensitive amplitude ranges of sand bodies vary in different regions, and different frequency data bodies and multiple attributes need to be used for prediction;

[0076] 2) Solve the problem of multi-stage sand body superposition in the characterization of submarine fans. On the basis of fully respecting the original seismic data, the data body after frequency division processing is used as the carrier to conduct seismic attribute and stratigraphic slice analysis. After giving different main frequency values, the corresponding tuning amplitude is output. Different amplitude bodies highlight and characterize different periods of submarine fan deposition.

[0077] The present invention determines the top interface H1 and the bottom interface H2 of the submarine fan in the target layer based on seismic and well logging data, establishes a three-dimensional chronostratigraphic framework with the interfaces H1 and H2 as constraints, and performs three-dimensional automatic tracking on it; obtains the main frequency value based on the original seismic data, performs frequency division processing on the main frequency value, and obtains a series of single-band frequency division data bodies; utilizes the strata identified by three-dimensional automatic tracking to extract stratigraphic slices of sensitive attribute bodies along the layers of the frequency division data body, and finally fuses and displays the results of the frequency division data body to depict the boundary of the submarine fan more clearly.

[0078] The present invention improves the accuracy of boundary characterization caused by a single attribute and a single method through spectral decomposition and multi-attribute fusion. At the same time, when tracking the formation interface, a method combining automatic tracking and manual intervention is adopted, which not only reduces the workload of interpretation, but also ensures the accuracy of interface tracking. Ultimately, the present invention improves the accuracy of submarine fan prediction and promotes the efficient exploration and development of deep-sea and semi-deep-sea oil and gas reservoirs.

[0079] The present invention provides a submarine fan characterization method based on general spectral decomposition and multi-attribute fusion, and the embodiments of the method are as follows:

[0080] [Example 1]

[0081] like Figure 1 As shown, the method includes:

[0082] The first step is to use the well logging, geological and original seismic data of the three-dimensional target reservoir area to combine well and seismic data and determine the target layer and the top interface H1 and bottom interface H2 of the submarine fan development;

[0083] By combining well and seismic data, that is, based on the surrounding wells and sedimentary background information, the period of submarine fan development can be determined, and two isochronous sedimentary interfaces can be determined as the top interface H1 and the bottom interface H2.

[0084] The second step is to establish a three-dimensional chronostratigraphic framework using interfaces H1 and H2 as constraints;

[0085] Specific operations include:

[0086] By interpreting and tracking the H1 and H2 interfaces in seismic data, a three-dimensional chronostratigraphic framework can be obtained.

[0087] The third step is to automatically track the strata within the 3D chronostratigraphic framework in 3D.

[0088] For the strata within the top and bottom limits of the 3D chronostratigraphic framework, a global automatic seismic interpretation method based on an automatic stratigraphic model and a manually modified model is used to automatically track the study area in 3D. The tracking features are peaks, troughs or zero value points. The selection of tracking features needs to be based on logging data to clarify the post-stack seismic response characteristics of the reservoir, so as to determine whether the final tracked features are peaks, troughs, zero value points or any combination.

[0089] During 3D automatic tracking, the layer slicing technology is used to divide the strata between H1 and H2 into N1, N2, N3...Nm stratigraphic interfaces, so as to accurately reflect the geological characteristics of each inclined stratum and the characteristics of sedimentary reservoir changes, and determine the extension direction of the submarine fan sedimentary body, where m is generally greater than 100. In addition, during 3D automatic tracking, on the basis of automatic stratigraphic model tracking, the rationality of sequence tracking is monitored in real time using seismic profiles, and timely adjustments are made to achieve a combination of automatic tracking and manual modification;

[0090] The automatic formation model is based on the H1 and H2 interfaces as constraints, tracking H1 and H2 layer by layer to track all the peaks and troughs between H1 and H2. The tracking mode is shown in Figure 2 Right: Manually modifying the model means that when there is an unconformable contact between the upper and lower strata, such as onlap, downcut, top overlap, etc., the automatic tracking interface cannot intelligently identify this contact relationship and can be adjusted through manual modification.

[0091] Step 4: Use correlation calculation to obtain the main frequency value of the original seismic data, and then use wavelet frequency division technology to divide the main frequency value to obtain a series of single-band frequency division data bodies;

[0092] Among them, the main frequency value is obtained by using correlation calculation on the original seismic data. The specific operations include:

[0093] Different wavelet parameters are designed for the original seismic data, and the negative correlation between the wavelet and the seismic trace is removed by correlation calculation to obtain different main frequency values. The wavelet parameters include frequency, number of cycles and phase.

[0094] The specific correlation calculation is: calculate the correlation coefficient between the wavelet and the seismic trace. The principle is to use the correlation coefficient between the two variables, whose value is equal to the covariance between the wavelet and the seismic trace divided by the standard deviation of the wavelet and the standard deviation of the seismic trace, that is, the Pearson correlation coefficient, with a range of -1 to 1. When the correlation coefficient is negative, it is removed and only positive correlation is retained.

[0095] The wavelet frequency division technology is used to divide the main frequency value to obtain a series of single-band frequency division data bodies. The specific operations include:

[0096] The frequency division processing function is constructed using wavelet transformation. is the mother wavelet of wavelet transform,

[0097]

[0098] In the formula: t is the time corresponding to the target sampling point; a is the scale factor, which controls the signal transformation frequency; b is the translation factor, which controls the time position of the signal analysis. The wavelet function is obtained by changing the values ​​of the two.

[0099]

[0100] Where: for Fourier transform of

[0101] According to the convolution formula, the wavelet transform formula of the signal f(t) is defined as follows:

[0102]

[0103]

[0104] Applying wavelet frequency division technology, the original seismic data is decomposed and inversely transformed according to the center frequencies of x~y Hz and (yx) / z, and a series of single-band frequency division data volumes F1, F2...F are obtained. (y-x) / z , where x is the low-frequency end of the seismic data, y is the high-frequency end of the seismic data, and the spacing is z Hz. The selection of x, y, and z can also be selected based on experience.

[0105] Step 5: Using the strata identified by three-dimensional automatic tracking, extract the stratigraphic slices along the layers of the sensitive attribute body from the frequency-divided data volume;

[0106] Specific operations include:

[0107] First, select the sensitive attribute g (such as amplitude, RMS, sweet spot attribute, etc.), and then calculate the amplitude value of this sensitive attribute (such as maximum amplitude, maximum root mean square amplitude, maximum sweet spot, etc.) as the corresponding attribute body F 1g 、F 2g ……F (y-x) / z g, the amplitude body at this time is the selected frequency division data body F1, F2...F (y-x) / z The sensitive attributes extracted from the above (the determined sensitive attributes g), each amplitude body reflects or highlights the sedimentary facies in the submarine fan of different periods;

[0108] Extract F along the N1, N2, N3...Nm stratum interfaces divided during 3D automatic tracking 1g 、F 2g ……F (y-x) / z g The layer properties of the attribute body.

[0109] Step 6: The results of the frequency-divided data volume are fused and displayed to depict the boundary of the submarine fan more clearly;

[0110] Specific operations include:

[0111] The attribute body F of multiple outputs 1g 、F 2g ……F (y-x) / z g is mixed and displayed in a three-dimensional window, ultimately showing submarine fans of different periods more intuitively.

[0112] The embodiments of the method of the present invention are as follows:

[0113] [Example 2]

[0114] Affected by multiple factors such as provenance in different directions, paleo-geomorphology, and time of hydrodynamic changes, submarine fans in the study area are developed in multiple stages in the target strata, with complex distribution and superposition of sand bodies and strong lateral heterogeneity of reservoirs. This geological reason also directly leads to the formation of isochronous bodies and lithologic transchronous bodies on seismic profiles. Due to the different thickness of sand bodies and cyclic combinations, the frequencies of seismic signals of submarine fans of different stages will also be different, and their tuning amplitudes will also be different. Therefore, when describing the boundaries and stages of submarine fans, if only a single-frequency, single-attribute seismic body is selected, its understanding is often limited.

[0115] In the embodiment, a general spectral decomposition method ( Figure 2 ) Spectral decomposition of the original seismic data is performed, and three different frequency amplitude bodies (F1 (10HZ), F2 (20HZ), F3 (30HZ)) are selected. Multi-attribute fusion technology is used to fuse F1 (10HZ), F2 (20HZ), and F3 (30HZ). Then, the characteristics of the sedimentary body are analyzed on the stratigraphic time section of the fused data body. There are two commonly used methods for making stratigraphic slices, namely isochronous stratigraphic slices and stratigraphic slices along the layer ( Figure 3a and Figure 3b In this embodiment, the stratigraphic slices along the layer are selected, and the top and bottom interfaces H1 and H2 of the submarine fan development are defined by artificial interpretation method ( Figure 4 ), on this basis, the software is used to automatically track the internal layers of the submarine fan, and combined with manual intervention, the interpretation of each internal layer is completed. The root mean square amplitude attributes of each layer are extracted from the aforementioned frequency-divided data body, and the fusion analysis is performed layer by layer. Figure 5As shown in , the result is a submarine fan characterized by a single seismic attribute based on the original seismic data. The fan boundary is fuzzy and the internal sedimentary body has poor continuity. Figure 6a , Figure 6b and Figure 6c The comparison of the submarine fans depicted by single seismic attributes based on the frequency-divided data volumes F1 (10 Hz), F2 (20 Hz), and F3 (30 Hz) shows that the fan boundaries are clearer, but there are certain differences in the inner parts. The fusion of the results of the frequency-divided data volumes shows that the contour boundaries of the submarine fans are more clearly depicted ( Figure 7 ).

[0116] The present invention also provides a submarine fan characterization system based on general spectral decomposition and multi-attribute fusion, and the embodiments of the system are as follows:

[0117] [Example 3]

[0118] The system comprises:

[0119] The interface determination unit is used to combine well logging, geology and original seismic data of the three-dimensional target reservoir area to determine the target layer and the top interface H1 and bottom interface H2 of the submarine fan development;

[0120] The stratigraphic framework establishment unit is connected to the interface determination unit and is used to establish a three-dimensional chronostratigraphic framework with interfaces H1 and H2 as constraints;

[0121] A three-dimensional automatic tracking unit is connected to a stratigraphic framework establishment unit and is used for three-dimensional automatic tracking of the strata within the three-dimensional chronostratigraphic framework;

[0122] The frequency division data volume acquisition unit is used to obtain the main frequency value by using the correlation calculation on the original seismic data, and then use the wavelet frequency division technology to perform frequency division processing on the main frequency value to obtain a series of single-band frequency division data volumes;

[0123] The rock formation stratigraphic slice extraction unit is connected to the three-dimensional automatic tracking unit and the frequency division data volume acquisition unit respectively, and is used to extract stratigraphic slices of sensitive attribute bodies along the layers from the frequency division data volume by using the strata identified by the three-dimensional automatic tracking;

[0124] The fusion display unit is connected to the rock stratum slice extraction unit and is used to fuse and display the results of the frequency division data volume to depict the boundary of the submarine fan more clearly.

[0125] The present invention also provides a computer-readable storage medium, and an embodiment of the computer-readable storage medium is as follows:

[0126] [Example 4]

[0127] The computer-readable storage medium stores at least one computer-executable program, and when the at least one program is executed by the computer, the computer executes the steps in the above-mentioned submarine fan characterization method based on general spectral decomposition and multi-attribute fusion.

[0128] The above technical solution is only one implementation mode of the present invention. For those skilled in the art, it is easy to make various types of improvements or modifications based on the principles disclosed in the present invention, and it is not limited to the technical solution described in the above specific embodiments of the present invention. Therefore, the above description is only preferred and does not have a restrictive meaning.

Claims

1. A submarine fan characterization method based on general spectral decomposition and multi-attribute fusion, characterized in that: The following steps are involved: The first step is to use the well logging, geological and original seismic data of the three-dimensional target reservoir area to combine well and seismic data and determine the target layer and the top interface H1 and bottom interface H2 of the submarine fan development; The second step is to establish a three-dimensional chronostratigraphic framework using interfaces H1 and H2 as constraints; The third step is to automatically track the strata within the 3D chronostratigraphic framework in 3D. Step 4: Use correlation calculation to obtain the main frequency value of the original seismic data, and then use wavelet frequency division technology to divide the main frequency value to obtain a series of single-band frequency division data bodies; Step 5: Using the strata identified by three-dimensional automatic tracking, extract the stratigraphic slices along the layers of the sensitive attribute body from the frequency-divided data volume; Step 6: Fusion and display the results of the frequency-divided data volume to depict the boundary of the submarine fan.

2. The submarine fan characterization method based on general spectral decomposition and multi-attribute fusion according to claim 1 is characterized in that: The first step of well-seismic integration is as follows: Based on the surrounding wells and sedimentary background information, the period of submarine fan development was determined, and then two isochronous sedimentary interfaces were determined as the top interface H1 and the bottom interface H2.

3. The submarine fan characterization method based on general spectral decomposition and multi-attribute fusion according to claim 2 is characterized in that: In the second step, the three-dimensional chronostratigraphic framework is established with interfaces H1 and H2 as constraints. The specific operations include: Based on the seismic data, the H1 and H2 interfaces are interpreted and tracked to obtain a three-dimensional chronostratigraphic framework.

4. The submarine fan characterization method based on general spectral decomposition and multi-attribute fusion according to claim 3 is characterized in that: In the third step, the strata within the 3D chronostratigraphic framework are automatically tracked in 3D. The specific operations include: For the strata within the top and bottom limits of the 3D chronostratigraphic framework, a global automatic seismic interpretation method based on an automatic stratigraphic model and a manually modified model is used to automatically track the strata in the study area in 3D. During 3D automatic tracking, the layer slicing technology is used to divide the strata between H1 and H2 into N1, N2, N3...Nm stratigraphic interfaces, so as to accurately reflect the geological characteristics of each inclined stratum and the characteristics of sedimentary reservoir changes, and determine the extension direction of the submarine fan sedimentary body, where m is greater than 100; Among them, the tracking features are wave crests, wave troughs or zero value points. The selection of tracking features needs to be based on logging data to clarify the post-stack seismic response characteristics of the reservoir, so as to determine whether the final tracking is a wave crest, wave trough, zero value point or any combination.

5. The submarine fan characterization method based on general spectral decomposition and multi-attribute fusion according to claim 4 is characterized in that: In the fourth step, the main frequency value is obtained by using correlation calculation on the original seismic data. The specific operations include: Different wavelet parameters are designed for the original seismic data, and the negative correlation between the wavelet and the seismic trace is removed by correlation calculation to obtain different main frequency values. The wavelet parameters include frequency, number of cycles and phase. The specific correlation calculation is: calculate the correlation coefficient between the wavelet and the seismic trace. The principle is to use the correlation coefficient between the two variables, whose value is equal to the covariance between the wavelet and the seismic trace divided by the standard deviation of the wavelet and the standard deviation of the seismic trace, that is, the Pearson correlation coefficient, with a range of -1 to 1. When the correlation coefficient is negative, it is removed and only positive correlation is retained.

6. The submarine fan characterization method based on general spectral decomposition and multi-attribute fusion according to claim 5 is characterized in that: In the fourth step, the wavelet frequency division technology is used to divide the main frequency value to obtain a series of single-band frequency division data bodies. The specific operations include: The frequency division processing function is constructed using wavelet transformation. is the mother wavelet of wavelet transform, Where: t is the time corresponding to the target sampling point; a is the scale factor, which controls the signal transformation frequency; b is the translation factor, which controls the time position of the signal analysis. The wavelet function is obtained by changing the values ​​of the two. Where: for Fourier transform of According to the convolution formula, the wavelet transform formula of the signal f(t) is defined as follows: Applying wavelet frequency division technology, the original seismic data is decomposed and inversely transformed according to the center frequencies of x~y Hz and (yx) / z, and a series of single-band frequency division data volumes F1, F2...F are obtained. (y-x) / z , where x is the low-frequency end of the seismic data, y is the high-frequency end of the seismic data, the spacing is z Hz, and the selection of x, y, and z is based on experience.

7. The submarine fan characterization method based on general spectral decomposition and multi-attribute fusion according to claim 6 is characterized in that: In the fifth step, the stratigraphic slices along the layers of the sensitive attribute bodies are extracted from the frequency-divided data volume by using the stratigraphic slices identified by three-dimensional automatic tracking. The specific operations include: First select the sensitive attribute g, and then calculate the amplitude value of this sensitive attribute as the corresponding attribute body F 1g 、F 2g ……F (y-x) / z g, the amplitude body at this time is the selected frequency division data body F1, F2...F (y-x) / z The sensitive attributes extracted from the above data are as follows: each amplitude body reflects or highlights the sedimentary facies in the submarine fan of different periods; Extract F along the N1, N2, N3...Nm stratum interfaces divided during 3D automatic tracking 1g 、F 2g ……F (y-x) / zg Layer properties of the attribute body.

8. The submarine fan characterization method based on general spectral decomposition and multi-attribute fusion according to claim 7 is characterized in that: In the sixth step, the results of the frequency-divided data volume are fused and displayed to depict the boundary of the submarine fan more clearly. The specific operations include: The attribute body F of multiple outputs 1g 、F 2g ……F (y-x) / z g is mixed and displayed in a three-dimensional window, ultimately showing submarine fans of different periods more intuitively.

9. A submarine fan characterization system based on general spectral decomposition and multi-attribute fusion, characterized in that: include: The interface determination unit is used to combine well logging, geology and original seismic data of the three-dimensional target reservoir area to determine the target layer and the top interface H1 and bottom interface H2 of the submarine fan development; The stratigraphic framework establishment unit is connected to the interface determination unit and is used to establish a three-dimensional chronostratigraphic framework with interfaces H1 and H2 as constraints; A three-dimensional automatic tracking unit is connected to a stratigraphic framework establishment unit and is used for three-dimensional automatic tracking of the strata within the three-dimensional chronostratigraphic framework; The frequency division data volume acquisition unit is used to obtain the main frequency value by using the correlation calculation on the original seismic data, and then use the wavelet frequency division technology to perform frequency division processing on the main frequency value to obtain a series of single-band frequency division data volumes; The rock formation stratigraphic slice extraction unit is connected to the three-dimensional automatic tracking unit and the frequency division data volume acquisition unit respectively, and is used to extract stratigraphic slices of sensitive attribute bodies along the layers from the frequency division data volume by using the strata identified by the three-dimensional automatic tracking; The fusion display unit is connected to the rock stratum slice extraction unit and is used to fuse and display the results of the frequency division data volume to depict the boundary of the submarine fan more clearly.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores at least one computer-executable program, and when the at least one program is executed by the computer, the computer executes the steps in the submarine fan characterization method based on general spectral decomposition and multi-attribute fusion as described in any one of claims 1 to 8.

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