Exogenous diffraction suppression method and device, electronic equipment and storage medium

Abstract

The invention provides an exogenous diffraction suppression method and device, electronic equipment and a storage medium. The method comprises the following steps: according to time curve distribution of an exogenous diffraction signal, determining space coordinates of an offshore obstacle in a target ocean area; and travel time difference correction is carried out on the exogenous diffraction signals of the XYZ components according to the determined space coordinates of the marine obstacles. Performing quaternion vector representation on the exogenous diffraction signal after travel time difference correction, and then constructing a block Hankel matrix in a quaternion frequency domain; and according to the quaternion singular value distribution conforming to the exogenous diffraction signal, carrying out rank reduction processing on the block Hankel matrix so as to separate the exogenous diffraction signal from a rank reduction processing result. And according to the separated exogenous diffraction signals, suppressing the exogenous diffraction signals for the multi-component common detection point gather corresponding to the target ocean area.

Description

Technical Field

[0001] The present application relates to the field of marine seismic exploration, and in particular to an external source diffraction suppression method, device, electronic equipment and storage medium. Background Art

[0002] With the development of marine resource exploration, the application of marine seismic exploration has become increasingly prominent. Due to the special construction environment of the ocean, the collected seismic data are often affected by various noises, such as multiple waves, surge noise and external diffraction interference. In particular, external diffraction interference, which is caused by the energy excited by the airgun source, encounters obstacles when propagating in the water body, and then is received by the detector and forms an interference signal. This phenomenon is similar to a secondary source. In the real environment, there are many facilities at sea, such as seawater platforms, submarine pipelines, submarine obstacles, etc., which may become the source of external diffraction interference. Compared with other noises, the morphology and spectral characteristics of external diffraction interference are close to those of effective waves, and due to the weak energy attenuation in the water body, its interference signal usually has strong energy, which has a significant impact on seismic data, especially for effective signals in medium and deep layers.

[0003] At present, the hot spots of marine resource exploration are mainly human activity areas, and the dense offshore facilities make the external diffraction signal noise particularly significant. Therefore, when processing shallow sea seismic data, it is particularly important to suppress the external diffraction interference. Summary of the invention

[0004] The purpose of the present application is to provide a method, device, electronic equipment and storage medium for suppressing external source diffraction, which can effectively suppress external source diffraction on common detection point gathers in ocean areas.

[0005] In order to achieve the above purpose, the embodiment of the present application is implemented as follows:

[0006] In a first aspect, a method for suppressing external diffraction is provided, comprising:

[0007] Determine the spatial coordinates of the marine obstacles in the target ocean area based on the spatial characteristics of the time-distance curve of the external source diffraction signal;

[0008] According to the determined spatial coordinates of the marine obstacles, the travel time difference of the XYZ component external source diffraction signal is corrected;

[0009] The XYZ component diffraction waves after travel time correction are represented by quaternion vectors, and a block Hankel matrix is ​​constructed in the quaternion frequency domain;

[0010] According to the singular value distribution that conforms to the external source diffraction signal, the block Hankel matrix external source diffraction signal is subjected to rank reduction processing to separate the external source diffraction signal from the rank reduction processing result;

[0011] According to the extracted external source diffraction signal, external source diffraction suppression is performed on the common detection point gathers corresponding to the multi-component of the target ocean area.

[0012] In a second aspect, a processing device for marine seismic gathers is provided, comprising:

[0013] The obstacle coordinate determination module is used to determine the spatial coordinates of the marine obstacles in the target ocean area according to the spatial characteristics of the time-distance curve of the external source diffraction signal;

[0014] A travel time difference correction module is used to correct the travel time difference of the XYZ component external source diffraction signal according to the determined spatial coordinates of the marine obstacle;

[0015] A Hankel matrix building module is used to represent the XYZ component external diffraction waves after travel time correction by quaternion vectors to build a block Hankel matrix in the quaternion frequency domain;

[0016] An exogenous diffraction signal extraction module is used to perform rank reduction processing on the block Hankel matrix according to the singular value distribution that conforms to the exogenous diffraction signal, so as to separate the exogenous diffraction signal from the rank reduction processing result;

[0017] The external source diffraction suppression module is used to suppress the external source diffraction of the common detection point gathers corresponding to the multi-component of the target ocean area according to the extracted external source diffraction signal.

[0018] In a third aspect, an embodiment of the present application provides an electronic device, comprising: a processor; and a memory configured to store computer-executable instructions, wherein the computer-executable instructions, when executed, cause the processor to execute the method described in the first aspect.

[0019] According to a fourth aspect, a computer-readable storage medium is provided, wherein the computer-readable storage medium is used to store computer-executable instructions, and the computer-executable instructions implement the method described in the first aspect when executed by a processor.

[0020] The embodiment of the present application first locates the diffraction point according to the time-distance curve characteristics of the external diffraction signal, determines the position of the offshore obstacle, and prepares for further suppression of the external diffraction signal. Then, based on the frequency domain block Hankel matrix represented by the quaternion, combined with the kinematic and dynamic characteristics of the external diffraction signal, the external diffraction signal in the multi-component seismic record is separated and suppressed by an adaptive rank reduction method to retain the vector characteristics of the seismic wave field. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 Schematic diagram of the diffraction wave path on the common detection gather.

[0023] Figure 2 Schematic diagram of the process of suppressing external source diffraction according to an embodiment of the present application.

[0024] Figure 3 Schematic diagram of the three-dimensional model of marine seismic data.

[0025] Figure 4 This is a comparison chart before and after separation of X-component diffraction waves.

[0026] Figure 5 This is a comparison chart before and after the Y component diffraction wave separation.

[0027] Figure 6 This is a comparison chart before and after the Z component diffraction wave separation.

[0028] Figure 7 Comparison of the arrow ends before and after external diffraction signal suppression.

[0029] Figure 8 This is a comparison chart between the theoretical time-distance curve calculated by locating the external source diffraction point and the actual curve.

[0030] Fig. 9 This is a comparison chart before and after separation of X-component diffraction waves.

[0031] Fig.10 This is a comparison chart before and after the Y component diffraction wave separation.

[0032] Fig.11 This is a comparison chart before and after the Z component diffraction wave separation.

[0033] Fig.12 Comparison of the sagittal end diagrams before and after suppression of the external diffraction signal.

[0034] Fig.13 This is a comparison chart between the time-distance curve calculated by locating the external source diffraction point and the actual curve.

[0035] Fig.14 Schematic diagram of the structure of the external source diffraction suppression device in an embodiment of the present application.

[0036] Fig.15 A schematic diagram of the structure of an electronic device according to an embodiment of the present application. DETAILED DESCRIPTION

[0037] External diffraction signals often appear as coherent noise with continuous event axes and clear waveform characteristics, so they are regarded as a major interference factor in seismic exploration. With the continuous advancement of marine seismic acquisition technology, PXYZ components have gradually replaced traditional PZ components and become the main method for marine seismic data acquisition. Compared with traditional seismic methods, multi-component seismic exploration can simultaneously obtain longitudinal wave (P wave) and converted shear wave (S wave) data, providing comprehensive information of the full wave field of underground elastic waves, thereby further improving exploration accuracy. However, the current main method for processing multi-component seismic data is to process each component separately. This independent processing method ignores the relationship between different components and may affect the vector characteristics of the seismic wave field. When processing multi-component seismic data, it is crucial to maintain the relative amplitude relationship between the components, so this requires joint processing as much as possible.

[0038] To this end, this application aims to propose an exogenous diffraction suppression scheme. First, the diffraction point is located according to the time-distance curve characteristics of the exogenous diffraction signal, the position of the offshore obstacle is determined, and preparations are made for further suppression of the exogenous diffraction signal. Then, based on the frequency domain block Hankel matrix represented by quaternion, combined with the kinematic and dynamic characteristics of the exogenous diffraction signal, the exogenous diffraction signal in the multi-component seismic record is separated and suppressed by an adaptive rank reduction method to retain the vector characteristics of the seismic wave field.

[0039] In order to enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are only part of the embodiments of this specification, not all of the embodiments. Based on the embodiments in this specification, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of this specification.

[0040] The external source diffraction suppression scheme of the present application mainly includes two main contents: positioning of the external source diffraction point and suppression of the external source diffraction signal.

[0041] 1. Location of source diffraction point

[0042] During the seismic data acquisition process, the construction team usually records the spatial position of offshore obstacles. For the primary diffraction wave caused by external interference, by combining the spatial positions of the shot point, the detection point and the obstacle, the distribution of the external diffraction signal (signal) can be accurately calculated by the following equations (1) and (2). Given that the common detection point gather usually has a high signal-to-noise ratio, the external diffraction signal is located on the common detection gather to improve the accuracy of the positioning result.

[0043] Figure 1 Schematic diagram of the diffraction wave path on the common detection gather in the ocean area, showing the path diagram of the shot point (red figure) propagating to the diffraction point on the seabed (gray circle) with the seabed layer and the seabed sediment layer. Assume that the coordinates of the seabed diffraction point are (x, y, z) and the coordinates of the shot point are (x i ,y i ,z i ), the seawater velocity is V water At the same time, it is assumed that the travel time from the diffraction point to the detection point is T r , the travel time from the shot point to the diffraction point and then to the detection point is T, then the three-dimensional diffraction wave time-distance curve on the common detection gather can be expressed as:

[0044]

[0045] Further assume that the travel time at the vertex of the diffraction wave time-distance curve is T0, and the corresponding shot point coordinates are (x0, y0, z0). Therefore, according to formula (1), each point on the diffraction time-distance curve can be subtracted from the vertex to obtain:

[0046]

[0047] In formula (2), T i represents the corresponding travel time on the diffraction time-distance curve, (x i ,y i ,z i ) represents the shot point coordinates corresponding to this point.

[0048] Further transforming formula (2), we can get:

[0049]

[0050] By solving the nonlinear equation system of equation (3), the coordinate position (x, y, z) of the diffraction point can be obtained.

[0051] By solving equation (3), the spatial coordinates of the external source diffraction point can be determined, and the spatial distribution characteristics of the external source diffraction signal can be further analyzed. The travel time t of each theoretical diffraction wave can be calculated using equation (4): i The actual diffraction wave travel time T i When the error is within the preset threshold range, it can be considered that the time-distance curve of the diffraction wave obtained by theoretical calculation can effectively approximate the spatial distribution characteristics of the actual diffraction wave in this area.

[0052]

[0053] Where Φ represents the theoretical diffraction wave travel time t i The actual diffraction wave travel time T i The error between them; F represents the Frobenius norm; s represents the position function of the shot point; r represents the position function of the detector point; d represents the position function of the external source diffraction point.

[0054] 2. External diffraction signal separation

[0055] Quaternions are the extension of complex numbers to higher dimensions. They consist of a real part and three imaginary parts. Their Cartesian form is shown in equation (5). The unique four-dimensional structure of quaternions provides an effective means for characterizing and processing multi-component seismic data.

[0056] q=a+bi+cj+dk (5)

[0057] Among them, i, j, k are the imaginary units of the quaternion, and i 2 =j 2 =k 2 =ijk=-1, ij=k=-ji, jk=i=-kj, ki=j=-ik. If a=0, q is a pure quaternion. A pure quaternion corresponds to a three-dimensional space in a geometric sense, and the imaginary units i, j, k correspond to the X, Y and Z rectangular coordinate axes of the three-dimensional space.

[0058] Marine seismographs (such as OBN, OBS and OBC) usually collect four components, namely, pressure component P and velocity or acceleration components X, Y, Z. The seismic wave field recorded by the X, Y, and Z components simultaneously can effectively reflect the propagation characteristics of seismic waves in the underground three-dimensional space. The geometric characteristics of pure quaternions can be used to place the three components X, Y, and Z in the imaginary parts b, c, and d of the quaternion respectively, so as to perform vector representation, that is, expressed as:

[0059] Q(s,r,t)=D X (s,r,t)i+D Y (s,r,t)j+D Z (s,r,t)k (6)

[0060] Among them, D X (s,r,t),D Y (s,r,t),D Z (s, r, t) represent the seismic records of X, Y and Z components respectively; Q(s, r, t) represents the vector representation result of the common detection point gather.

[0061] The external source diffraction signal separation algorithm is performed in the frequency domain, so it is necessary to transform the quaternion in equation (6) into the frequency domain.

[0062] The matrix data singular values ​​can be used to evaluate the extent of different types of linear events in seismic data. The stronger the energy of the linear signal, the larger the corresponding singular value. Specifically, after the travel time difference correction of the exogenous diffraction signal, the first few larger singular values ​​are associated with the exogenous diffraction signal, while the remaining singular values ​​are more related to reflection waves and other noise. Therefore, by reducing the rank of the matrix, the exogenous diffraction signal can be effectively separated from the seismic data.

[0063] Because the positioning of the external diffraction point may be biased. This deviation makes it impossible to conform to the linear assumption even if the travel time correction of the external diffraction signal is performed. In order to solve this problem, the residual time difference correction is performed on the data Q(s,r,t0) after the travel time correction. The core idea is that when the diffraction point is accurately positioned, the diffraction wave phase axis after the travel time correction should tend to be flat. When superimposed along the time-distance curve, its energy value will also be the largest. Therefore, by time-shifting the data Q(s,r,t0) after the travel time correction, its energy value is maximized, thereby confirming the residual time difference, which is specifically expressed as:

[0064]

[0065] Where t0 represents the time variable after travel time correction; Δt max Indicates the maximum threshold value of time shift; N r represents the total number of seismic traces of the reference trace; E(Δt) represents the waveform misalignment;

[0066] After the residual time difference correction, the exogenous diffraction signal is converted from the time domain to the frequency domain and represented by a block Hankel matrix. In order to extract the exogenous diffraction signal, a small number of singular values ​​and their corresponding singular vectors can be used to approximate the matrix to achieve the purpose of signal separation. In this study, the three-component seismic data are vectorized according to quaternions, so the quaternion singular value decomposition (QSVD) algorithm is used for low-rank approximation. The low-rank approximation based on the rank constraint can be formalized as an optimization problem:

[0067]

[0068] Where W(f) represents the low-rank approximation matrix after QSVD in the frequency domain, l represents the optimal rank parameter, X(f) represents the block Hankel matrix composed of observation data in the frequency domain, and the specific expression is shown in formula (9); F represents the Frobenius norm.

[0069]

[0070] in, N xIndicates the total number of channels in the X and Y directions; H i represents the Hankel matrix constructed from the i-th data slice along the Y direction:

[0071]

[0072] in, Q(x,y,f) represents the frequency domain data obtained by Q(x,y,t) through QFT.

[0073] Since the distinction between linear and nonlinear signals in the singular spectrum will be manifested as a sharp drop in singular values, according to the linear characteristics of the external diffraction signal after time difference correction, the rank corresponding to the point where the singular value drops sharply can be determined as the optimal rank l. In order to determine this optimal rank, equation (11) is used for calculation:

[0074]

[0075] Among them, σ i represents the i-th singular value point in the singular value spectrum, and N represents the length of the singular value spectrum.

[0076] According to the above reasoning process, an embodiment of the present application proposes a method for suppressing external source diffraction. Figure 2 : is a flow chart of the external source diffraction suppression method, comprising the following steps:

[0077] S202, determining the spatial coordinates of the marine obstacles in the target ocean area according to the spatial characteristics of the time-distance curve of the external source diffraction signal.

[0078] The external source diffraction signal of this embodiment comes from the common detection point gather in the target ocean area. Specifically, the coordinate position of the external source diffraction point can be determined according to formula (3), and the coordinate position of the external source diffraction point is determined as the spatial coordinate of the marine obstacle.

[0079] It should be noted that determining the time-distance curve of the external source diffraction signal belongs to the function of the existing seismic exploration data processing software, which will not be described in detail here. S204, correcting the travel time difference of the external source diffraction signal of the XYZ component according to the determined spatial coordinates of the marine obstacle.

[0080] It should be noted that, when the spatial coordinates of the marine obstacle are determined, the travel time difference correction of the external source diffraction signal of the XYZ component belongs to the existing technology and will not be described in detail in this text.

[0081] S206, performing quaternion vector representation on the XYZ component diffraction waves after travel time correction, and constructing a block Hankel matrix in the quaternion frequency domain;

[0082] Specifically, this embodiment determines a theoretical time-distance curve of an external source diffraction signal and a theoretical travel time of each diffraction wave of the theoretical time-distance curve according to the coordinates of the external source diffraction point being located; then, when the error between the travel time of each theoretical diffraction wave and the actual travel time of the diffraction wave is less than a preset error threshold, the theoretical time-distance curve is used as a spatial distribution feature of the external source diffraction signal to determine a block Hankel matrix of the external source diffraction signal in the quaternion frequency domain.

[0083] Among them, the error formula between each theoretical diffraction wave travel time Ti and the actual diffraction wave travel time Ti is: Φ represents the sum of the errors between the theoretical diffraction wave travel time ti and the actual diffraction wave travel time Ti; F represents the Frobenius norm; s represents the position function of the shot point; r represents the position function of the detector point; and d represents the position function of the external source diffraction point.

[0084] In addition, before taking the theoretical time-distance curve as the spatial distribution feature of the external source diffraction signal to determine the block Hankel matrix of the external source diffraction signal in the quaternion frequency domain, the present embodiment can also construct a reference track that conforms to the time-distance curve of the external source diffraction signal; then determine the waveform misalignment amount of the time-distance curve of the external source diffraction signal according to formula (7), and perform waveform misalignment correction on the time-distance curve of the external source diffraction signal based on the waveform misalignment amount.

[0085] S208, performing rank reduction processing on the block Hankel matrix according to the singular value distribution that conforms to the external source diffraction signal, so as to separate the external source diffraction signal from the rank reduction processing result.

[0086] As mentioned above, this embodiment constructs a low-rank approximate optimization problem for the rank reduction processing result according to the quaternion singular value decomposition algorithm, that is, formula (8). Then, using formula (11) as the rank constraint, the low-rank approximate optimization problem is solved to separate the external source diffraction signal from the rank reduction processing result.

[0087] In marine seismic data acquisition, a three-dimensional observation method is usually used. In order to verify the effectiveness of the external diffraction signal, a three-dimensional observation method is designed. Figure 3 The three-dimensional model shown in the figure. The designed model is 3000m long and 1000m deep, with the obstacle inserted into the seabed at a depth of 7m and a width of 8m. The specific parameters are shown in Table 1. In the forward modeling process, the elastic wave finite difference method was used for forward simulation, and the 50Hz Ricker wavelet was selected. The seawater depth was set to 50m, the source position was located at x=1200m, and the immersion depth was 5m at the seawater depth. Free boundary conditions were set, the track spacing was 20m, and the gun spacing was 50m.

[0088] The model parameters are as follows:

[0089] Strata name Depth m P-wave velocity m / s Shear wave velocity m / s <![CDATA[Density kg / m 3 > Seawater layer 0～50 1500 0 1000 Stratum ① 51～400 1600～2340 200～750 1978～2142 Stratum ② 401～530 2500 831 2200 Stratum ③ 531～700 2700 1066 2200 Stratum ④ 701～800 3000 1537 2200 Stratum ⑤ 701～1000 3500 2007 2275 diffracting body 0～57 4000 2310 2550

[0090] According to the above technical process, the data obtained by the 3D model forward modeling was suppressed by the external diffraction signal to verify the effectiveness of the proposed method. The XYZ component results before and after suppression are shown in the figure. Figures 4 to 6 shown. Figure 4 This is a comparison chart of the X-component diffraction wave before and after separation. Figure 5 This is a comparison chart of the Y component diffraction wave before and after separation. Figure 6 Comparison of Z-component diffraction waves before and after separation. Figures 4 to 6 In the figure, (a) indicates before suppression; (b) indicates after suppression; (c) indicates the suppressed noise. Figure 7 , Figure 7 This is a comparison of the endograms before and after the external source diffraction, (a) before suppression; (b) after suppression. The suppression process not only effectively filters out the external source diffraction interference noise, but also keeps the polarization characteristics of the seismic wave field stable before and after suppression.

[0091] In addition, the actual time-range curve and the theoretical external source diffraction signal pickup curve calculated based on the positioning results are shown, e.g. Figure 8 shown. Figure 8 It is shown in the figure that the calculated time-distance curve is highly consistent with the manually picked time-distance curve, indicating that the method can accurately obtain the spatial distribution characteristics of the external source diffraction signal, which further verifies the accuracy of the method.

[0092] The method of this embodiment is applied to the processing of OBN multi-component seismic data in a shallow sea area. A large amount of external diffraction interference is developed in the collected data, which drowns the effective reflection signal. The external diffraction interference on the XYZ component is vector-suppressed. The results before and after suppression are shown in the figure below. Figures 9-11 As shown in Figure 2. Comparative analysis shows that after external diffraction suppression, the common detection gathers almost completely remove external diffraction interference. At the same time, the suppressed noise data contains almost no effective signals, which verifies the significant effect of the proposed method in suppressing external diffraction interference waves. In addition, in order to verify the effectiveness of the algorithm in maintaining vector features, a point was randomly selected to draw the vector end diagram before and after suppression. The results are shown in Figure 2. Fig.12 It can be observed from the figure that the polarization characteristics before and after the suppression process remain basically unchanged, which further proves that the algorithm successfully retains the signal vector characteristics while suppressing the external diffraction interference.

[0093] In addition, the effective suppression of external diffraction signals requires accurate acquisition of the spatial position of the external diffraction point, and this positioning process must be based on the characteristics of the diffraction wave time-distance curve. Fig.13The figure shows the comparison between the time-distance curve of the actual diffraction wave picked up manually (yellow line) and the time-distance curve calculated by the positioning result (green line). As can be seen from the figure, the calculated time-distance curve is highly consistent with the time-distance curve picked up manually, which shows the effectiveness of the method used in accurately describing the spatial distribution characteristics of the external diffraction signal.

[0094] External diffraction signal

[0095] In addition, another embodiment of this embodiment further provides an external source diffraction suppression device, Fig.14 1 is a schematic structural diagram of the external source diffraction suppression device 1400, comprising:

[0096] The obstacle coordinate determination module 1410 is used to determine the spatial coordinates of the marine obstacles in the target marine area according to the spatial characteristics of the time-distance curve of the external source diffraction signal;

[0097] The travel time difference correction module 1420 is used to correct the travel time difference of the external source diffraction signal of the XYZ component according to the determined spatial coordinates of the marine obstacle;

[0098] A Hankel matrix construction module 1430 is used to perform quaternion vector representation on the XYZ component external diffraction waves after travel time correction to construct a block Hankel matrix in the quaternion frequency domain;

[0099] An exogenous diffraction signal extraction module 1440 is used to perform rank reduction processing on the block Hankel matrix according to a singular value distribution that conforms to the exogenous diffraction signal, so as to separate the exogenous diffraction signal from the rank reduction processing result;

[0100] The external source diffraction suppression module 1450 is used to suppress the external source diffraction on the common detection point gathers corresponding to the multi-component of the target ocean area based on the extracted external source diffraction signal.

[0101] Optionally, before determining the spatial coordinates of the marine obstacles in the target marine area according to the spatial characteristics of the time-distance curve of the external source diffraction signal, the obstacle coordinate determination module 1410 is further configured to:

[0102] Based on the formula: Determine the coordinate position of the external source diffraction point, and determine the coordinate position of the external source diffraction point as the spatial coordinate of the marine obstacle;

[0103] Where x, y, and z represent the coordinates of the external source diffraction point; T i represents the corresponding travel time on the diffraction time-distance curve; x i ,y i ,、z i Respectively represent T iThe corresponding shot point coordinates; T0 represents the travel time at the vertex of the time-distance curve of the external diffraction signal; x0, y0, and z0 represent the shot point coordinates corresponding to T0; V water Indicates the speed of sea water.

[0104] Optionally, the Hankel matrix construction module 1430 constructs a block Hankel matrix in the quaternion frequency domain including:

[0105] Based on the coordinates of the external source diffraction point, a theoretical time-distance curve of the external source diffraction signal and the theoretical travel time of each diffraction wave of the theoretical time-distance curve are determined; when the error between the travel time of each theoretical diffraction wave and the actual travel time of the diffraction wave is less than a preset error threshold, the theoretical time-distance curve is used as the spatial distribution feature of the external source diffraction signal to determine the block Hankel matrix of the external source diffraction signal in the quaternion frequency domain.

[0106] Optionally, the exogenous diffraction signal extraction module 1440 performs rank reduction processing on the block Hankel matrix according to a singular value distribution that conforms to the exogenous diffraction signal, including:

[0107] The common detection point gathers are vectorized by using quaternions, so as to perform rank reduction processing of singular value decomposition on the block Hankel matrix, and obtain a rank reduction processing result including a plurality of singular value distributions.

[0108] Optionally, the quaternion vector of the external source diffraction signal is characterized as:

[0109] Q(s,r,t)=D X (s,r,t)i+D Y (s,r,t)j+D Z (s,r,t)k; where D X (s,r,t),D Y (s,r,t),D Z (s,r,t) points

[0110] They respectively represent the seismic records of X, Y and Z components; Q(s, r, t) represents the vector characterization result of the common detection point gather.

[0111] Optionally, before using the theoretical time-distance curve as the spatial distribution feature of the external source diffraction signal to determine the block Hankel matrix of the external source diffraction signal in the quaternion frequency domain, the Hankel matrix construction module 1430 is further used to:

[0112] Constructing a reference track that conforms to the time-distance curve of the external source diffraction signal;

[0113] Based on the formula: Determine the waveform misalignment of the time-distance curve of the external source diffraction wave; wherein t0 represents the time variable after travel time correction; Δt max Indicates the maximum threshold value of time shift; N r represents the total number of seismic traces of the reference trace; E(Δt) represents the waveform misalignment;

[0114] Based on the waveform misalignment amount, waveform misalignment correction is performed on the time-distance curve of the external source diffraction signal.

[0115] Optionally, the exogenous diffraction signal extraction module 1440 separates the exogenous diffraction signal from the rank reduction processing result according to the singular value distribution of the frequency domain quaternion block Hankel matrix of the exogenous diffraction wave, including:

[0116] According to the quaternion singular value decomposition algorithm, a low-rank approximate optimization problem for the rank reduction processing result is constructed: And l=2,3,L,N-1 is the rank constraint, and the low-rank approximate optimization problem is solved to separate the external source diffraction signal from the rank reduction processing result;

[0117] Where W represents the external diffraction signal; l represents the optimal rank parameter; σ i represents the i-th singular value point in the singular value spectrum, and N represents the length of the singular value spectrum.

[0118] It should be noted that the external source diffraction suppression device of this embodiment can be used as Figure 2 The execution subject of the method shown can thus realize Figure 2 The steps and functions in the method shown.

[0119] Fig.15 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. Fig.15 At the hardware level, the electronic device includes a processor, and optionally also includes an internal bus, a network interface, and a memory. The memory may include a memory, such as a high-speed random access memory (RAM), and may also include a non-volatile memory (non-volatile memory), such as at least one disk storage. Of course, the electronic device may also include hardware required for other services.

[0120] The processor, network interface and memory can be interconnected through an internal bus, which can be an ISA (Industry Standard Architecture) bus, a PCI (Peripheral Component Interconnect) bus or an EISA (Extended Industry Standard Architecture) bus. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Fig.15 Only one bidirectional arrow is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0121] The memory is used to store the computer program. Specifically, the computer program may include a program code, and the program code includes a computer operation instruction. The memory may include a memory and a non-volatile memory, and provides the computer program to the processor.

[0122] The processor reads the corresponding computer program from the non-volatile memory into the memory and then runs it, forming the above-mentioned Fig.14 The external source diffraction suppression device shown. Correspondingly, the processor executes the program stored in the memory and is specifically used to perform the following operations:

[0123] According to the spatial characteristics of the time-distance curve of the external source diffraction signal, the spatial coordinates of the marine obstacles in the target ocean area are determined.

[0124] According to the determined spatial coordinates of the marine obstacles, the travel time difference of the external source diffraction signal of the XYZ components is corrected.

[0125] The XYZ component diffraction waves after travel time correction are represented by quaternion vectors, and a block Hankel matrix is ​​constructed in the quaternion frequency domain.

[0126] According to the singular value distribution that conforms to the external source diffraction signal, the block Hankel matrix is ​​rank reduced to separate the external source diffraction signal from the rank reduced result.

[0127] Based on the extracted external source diffraction signal, external source diffraction suppression is performed on the common detection point gathers corresponding to the multi-component of the target ocean area.

[0128] The above is as in this manual Figure 2The method disclosed in the illustrated embodiment can be applied to a processor and implemented by the processor. The processor may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method can be completed by an integrated logic circuit of hardware in the processor or an instruction in the form of software. The above processor can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The methods, steps and logic block diagrams disclosed in the embodiments of the present application can be implemented or executed. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc. The steps of the method disclosed in the embodiments of the present application can be directly embodied as a hardware decoding processor for execution, or a combination of hardware and software modules in the decoding processor for execution. The software module can be located in a mature storage medium in the field such as random access memory, flash memory, read-only memory, programmable read-only memory or electrically erasable programmable memory, register, etc. The storage medium is located in the memory, and the processor reads the information in the memory and completes the steps of the above method in combination with its hardware.

[0129] Of course, in addition to software implementation, the electronic device of this specification does not exclude other implementation methods, such as logic devices or a combination of software and hardware, etc., that is to say, the execution subject of the following processing flow is not limited to each logic unit, but can also be hardware or logic devices.

[0130] In addition, an embodiment of the present application also proposes a computer-readable storage medium, which stores one or more computer programs, and the one or more computer programs include instructions.

[0131] When the above instructions are executed by a portable electronic device including multiple application programs, the portable electronic device can execute Figure 2 The steps in the method shown include:

[0132] According to the spatial characteristics of the time-distance curve of the external source diffraction signal, the spatial coordinates of the marine obstacles in the target ocean area are determined.

[0133] According to the determined spatial coordinates of the marine obstacles, the travel time difference of the external source diffraction signal of the XYZ components is corrected.

[0134] The XYZ component diffraction waves after travel time correction are represented by quaternion vectors, and a block Hankel matrix is ​​constructed in the quaternion frequency domain.

[0135] According to the singular value distribution that conforms to the external source diffraction signal, the block Hankel matrix is ​​rank reduced to separate the external source diffraction signal from the rank reduced result.

[0136] Based on the extracted external source diffraction signal, external source diffraction suppression is performed on the common detection point gathers corresponding to the multi-component of the target ocean area.

[0137] Those skilled in the art will appreciate that the embodiments of this specification may be provided as methods, systems or computer program products. Therefore, this specification may take the form of a complete hardware embodiment, a complete software embodiment or an embodiment combining software and hardware. Moreover, this specification may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0138] The above is a description of a specific embodiment of the specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in an order different from that in the embodiments and still achieve the desired results. In addition, the processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0139] The above are only embodiments of this specification and are not intended to limit this specification. For those skilled in the art, this specification may be subject to various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this specification shall be included in the scope of the claims of this specification. In addition, all other embodiments obtained by ordinary technicians in this field without creative work shall fall within the scope of protection of this document.

Claims

1. A method for suppressing external diffraction, characterized in that: include: Determine the spatial coordinates of the marine obstacles in the target ocean area based on the spatial characteristics of the time-distance curve of the external source diffraction signal; According to the determined spatial coordinates of the marine obstacles, the travel time difference correction of the external source diffraction signal of the XYZ components is performed; The external diffraction signal after travel time correction is represented by quaternion vector, and a block Hankel matrix is ​​constructed in the quaternion frequency domain; According to the singular value distribution that conforms to the external diffraction signal, the block Hankel matrix is ​​subjected to rank reduction processing to separate the external diffraction signal from the rank reduction processing result; According to the extracted external source diffraction signal, external source diffraction suppression is performed on the common detection point gathers corresponding to the multi-component of the target ocean area.

2. The method according to claim 1, characterized in that Before determining the spatial coordinates of the marine obstacles in the target marine area according to the spatial characteristics of the time-distance curve of the external source diffraction signal, the method further includes: Based on the formula: Determine the coordinate position of the external source diffraction point, and determine the coordinate position of the external source diffraction point as the spatial coordinate of the marine obstacle; Where x, y, and z represent the coordinates of the external source diffraction point; T i represents the corresponding travel time on the diffraction time-distance curve; x i ,y i ,、z i Respectively represent T i The corresponding shot point coordinates; T0 represents the travel time at the vertex of the time-distance curve of the external diffraction signal; x0, y0, and z0 represent the shot point coordinates corresponding to T0; V water Indicates the speed of sea water.

3. The method according to claim 2, characterized in that Construct a block Hankel matrix in the quaternion frequency domain, including: According to the coordinates of the external source diffraction point, the theoretical time-distance curve of the external source diffraction signal and the travel time of each theoretical diffraction wave of the theoretical time-distance curve are determined; When the error between the travel time of each theoretical diffraction wave and the actual travel time of the diffraction wave is less than a preset error threshold, the theoretical time-distance curve is used as the spatial distribution feature of the external source diffraction signal to determine the block Hankel matrix of the external source diffraction signal in the quaternion frequency domain.

4. The method according to claim 3, characterized in that: The quaternion vector representation of the external diffraction signal is: Q(s,r,t) = D X (s,r,t)i + D Y (s,r,t)j + D Z (s,r,t)k; where D X (s,r,t), D Y (s,r,t), D Z (s,r,t) points They respectively represent the seismic records of X, Y and Z components; Q(s, r, t) represents the vector characterization result of the common detection point gather.

5. The method according to claim 3, characterized in that: Before using the theoretical time-distance curve as the spatial distribution feature of the external source diffraction signal to determine the block Hankel matrix of the external source diffraction signal in the quaternion frequency domain, the method includes: Construct a reference trace that matches the time-distance curve of the external diffraction signal; According to the formula: Determine the waveform misalignment of the time-distance curve of the external diffraction signal; where t0 represents the time variable after travel time correction; Δt max Indicates the maximum threshold value of time shift; N r represents the total number of seismic traces of the reference trace; E(Δt) represents the waveform misalignment; According to the waveform misalignment amount, waveform misalignment correction is performed on the time-distance curve of the external source diffraction signal.

6. The method according to claim 5, characterized in that According to the singular value distribution that conforms to the external diffraction signal, the block Hankel matrix is ​​subjected to rank reduction processing to separate the external diffraction signal from the rank reduction processing result, including: According to the quaternion singular value decomposition algorithm, a low-rank approximate optimization problem for the rank reduction processing result is constructed: And l=2,3,L,N-1 is the rank constraint, and the low-rank approximate optimization problem is solved to separate the external source diffraction signal from the rank reduction processing result; Where W represents the external diffraction signal; l represents the optimal rank parameter, σ i represents the i-th singular value point in the singular value spectrum, and N represents the length of the singular value spectrum.

7. An external source diffraction suppression device, characterized in that: include: The obstacle coordinate determination module is used to determine the spatial coordinates of the marine obstacles in the target ocean area according to the spatial characteristics of the time-distance curve of the external source diffraction signal; A travel time difference correction module is used to correct the travel time difference of the XYZ component external source diffraction signal according to the determined spatial coordinates of the marine obstacle; Hankel matrix building module, used to represent the XYZ component external diffraction wave after travel time correction by quaternion vector to build block Hankel matrix in quaternion frequency domain; An exogenous diffraction signal extraction module is used to perform rank reduction processing on the block Hankel matrix according to the singular value distribution that conforms to the exogenous diffraction signal, so as to separate the exogenous diffraction signal from the rank reduction processing result; The external source diffraction suppression module is used to suppress the external source diffraction of the common detection point gathers corresponding to the multi-component of the target ocean area according to the extracted external source diffraction signal.

8. An electronic device, comprising a processor; and a memory configured to store computer executable instructions, wherein when the computer executable instructions are executed, the processor executes the method according to any one of claims 1 to 7.

9. A computer-readable storage medium, wherein the computer-readable storage medium is used to store computer-executable instructions, wherein the computer-executable instructions, when executed by a processor, implement the method according to any one of claims 1 to 7.

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