Shot gather seismic diffracted wave separation method and device

Abstract

The invention provides a shot gather seismic diffracted wave separation method and device, and relates to the technical field of seismic exploration, and the method comprises the steps: obtaining two-dimensional single-shot seismic data of a designated geographic region; processing the two-dimensional single-shot seismic data by using a plane wave method to obtain a space coordinate of a virtual seismic source point; based on the two-dimensional single-shot seismic data and the space coordinates of the virtual seismic source point, seismic data and a target reflected wave extraction function in a virtual seismic source space are determined; the target reflected wave extraction function is a continuous function; based on the space coordinates of the virtual seismic source point, the seismic data in the virtual seismic source space and the target reflected wave extraction function, target reflected wave field data are determined; target reflection wave field data are removed from the two-dimensional single-shot seismic data, and diffracted wave field data are obtained. The application of the target reflected wave extraction function effectively avoids the loss of the diffracted wave and the residue of the reflected wave in the separation process, so that the technical problem of poor diffracted wave separation effect in the existing diffracted wave separation method is effectively relieved.

Description

Technical Field

[0001] The invention relates to the technical field of seismic exploration, and in particular to a shot gather seismic diffraction wave separation method and device. Background Art

[0002] When seismic waves propagate underground, they will be reflected when encountering the stratum interface to form reflection waves, which can accurately reflect the continuous interface information. Smaller geological discontinuities do not have continuous reflection interfaces and do not produce reflection waves, but instead serve as secondary seismic sources to form diffraction waves. Therefore, seismic diffraction waves are the seismic response of small-scale geological discontinuities, carrying rich small-scale geological body information, and have the potential for high-resolution exploration and important research value.

[0003] However, the diffraction wave is affected by geometric diffusion attenuation, and its energy is one to two orders of magnitude lower than that of the reflected wave. It will be shielded by the strong signal of the reflected wave and cannot exert its high-resolution detection potential. Therefore, it is necessary to separate the diffraction wave, eliminate the shielding effect of the reflected wave, and realize high-resolution detection of the diffraction wave. It is difficult to realize the pre-stack diffraction wave signal extraction in the existing technology. The existing diffraction wave extraction technology is mainly concentrated in the post-stack domain. Before the diffraction wave extraction, the signal is first corrected and superimposed according to the propagation law of the reflected wave. Therefore, the diffraction wave has been damaged to a certain extent during the signal superposition process, which affects the integrity and richness of the diffraction wave signal. Therefore, the method of diffraction wave extraction based on post-stack data has the technical problem of poor separation effect. Summary of the invention

[0004] The object of the present invention is to provide a shot gather seismic diffraction wave separation method and device to alleviate the technical problem of poor diffraction wave separation effect existing in the existing diffraction wave separation method.

[0005] In a first aspect, the present invention provides a shot-gather seismic diffraction wave separation method, comprising: acquiring two-dimensional single-shot seismic data of a specified geographical area; processing the two-dimensional single-shot seismic data using a plane wave method to obtain the spatial coordinates of a virtual source point; wherein the virtual source point represents a mirror point of the shot point with respect to a stratum; based on the two-dimensional single-shot seismic data and the spatial coordinates of the virtual source point, determining the seismic data in the virtual source space and a target reflection wave extraction function; wherein the target reflection wave extraction function is a continuous function; based on the spatial coordinates of the virtual source point, the seismic data in the virtual source space and the target reflection wave extraction function, determining the target reflection wave wave field data; and removing the target reflection wave wave field data from the two-dimensional single-shot seismic data to obtain the diffraction wave wave field data.

[0006] Optionally, based on the two-dimensional single-shot seismic data and the spatial coordinates of the virtual seismic source point, the seismic data and the target reflection wave extraction function in the virtual seismic source space are determined, including: focusing the two-dimensional single-shot seismic data based on the spatial coordinates of the virtual seismic source point to obtain the seismic data in the virtual seismic source space; determining the initial reflection wave extraction function based on the two-dimensional single-shot seismic data and the spatial coordinates of the virtual seismic source point; determining the target reflection wave extraction function based on the seismic data in the virtual seismic source space, the initial reflection wave extraction function and the spatial coordinates of the virtual seismic source point.

[0007] Optionally, based on the two-dimensional single-shot seismic data and the spatial coordinates of the virtual seismic source points, an initial reflection wave extraction function is determined, including: calculating the number of illumination times of each virtual seismic source point in the underground space of a specified geographical area based on the two-dimensional single-shot seismic data and the spatial coordinates of the virtual seismic source points; and constructing an initial reflection wave extraction function based on a preset upper limit of the number of illumination times and the number of illumination times of all virtual seismic source points in the underground space.

[0008] Optionally, based on the seismic data in the virtual seismic source space, the initial reflection wave extraction function and the spatial coordinates of the virtual seismic source point, a target reflection wave extraction function is determined, including: constructing a first reflection wave model in the virtual seismic source space based on the seismic data in the virtual seismic source space and the initial reflection wave extraction function; performing anti-focusing processing on the first reflection wave model based on the spatial coordinates of the virtual seismic source point to obtain initial reflection wave wavefield data; performing focusing processing on the initial reflection wave wavefield data based on the spatial coordinates of the virtual seismic source point to obtain a second reflection wave model in the virtual seismic source space; and constructing a target reflection wave extraction function based on the second reflection wave model in the virtual seismic source space and the seismic data in the virtual seismic source space.

[0009] Optionally, based on the spatial coordinates of the virtual seismic source point, the seismic data in the virtual seismic source space and the target reflection wave extraction function, the target reflection wave wavefield data is determined, including: constructing a target reflection wave model in the virtual seismic source space based on the seismic data in the virtual seismic source space and the target reflection wave extraction function; and performing anti-focusing processing on the target reflection wave model based on the spatial coordinates of the virtual seismic source point to obtain the target reflection wave wavefield data.

[0010] In a second aspect, the present invention provides a shot-gather seismic diffraction wave separation device, comprising: an acquisition module, used to acquire two-dimensional single-shot seismic data of a specified geographical area; a processing module, used to process the two-dimensional single-shot seismic data using a plane wave method to obtain the spatial coordinates of a virtual source point; wherein the virtual source point represents a mirror point of the shot point about a stratum; a first determination module, used to determine the seismic data and a target reflection wave extraction function in the virtual source space based on the two-dimensional single-shot seismic data and the spatial coordinates of the virtual source point; wherein the target reflection wave extraction function is a continuous function; a second determination module, used to determine the target reflection wave field data based on the spatial coordinates of the virtual source point, the seismic data in the virtual source space and the target reflection wave extraction function; and a removal module, used to remove the target reflection wave field data from the two-dimensional single-shot seismic data to obtain the diffraction wave field data.

[0011] Optionally, the first determination module includes: a focusing unit, used to focus the two-dimensional single-shot seismic data based on the spatial coordinates of the virtual seismic source point to obtain the seismic data in the virtual seismic source space; a first determination unit, used to determine the initial reflection wave extraction function based on the two-dimensional single-shot seismic data and the spatial coordinates of the virtual seismic source point; and a second determination unit, used to determine the target reflection wave extraction function based on the seismic data in the virtual seismic source space, the initial reflection wave extraction function and the spatial coordinates of the virtual seismic source point.

[0012] Optionally, the first determination unit is specifically used to: calculate the illumination times of each virtual seismic source point in the underground space of a specified geographical area based on two-dimensional single-shot seismic data and the spatial coordinates of the virtual seismic source points; and construct an initial reflection wave extraction function based on a preset upper limit of the illumination times and the illumination times of all virtual seismic source points in the underground space.

[0013] In a third aspect, the present invention provides an electronic device including a memory and a processor, wherein the memory stores a computer program executable on the processor, and when the processor executes the computer program, the shot gather seismic diffraction wave separation method of any one of the aforementioned implementation modes is implemented.

[0014] In a fourth aspect, the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer instructions, and when the computer instructions are executed by a processor, the shot gather seismic diffraction wave separation method of any one of the aforementioned implementation modes is implemented.

[0015] The present invention provides a shot-gather seismic diffraction wave separation method. After acquiring two-dimensional single-shot seismic data, the method first determines the spatial coordinates of a virtual source point, then uses the virtual source theory to focus the reflection wave at the virtual source, and uses a continuous target reflection wave extraction function to achieve effective extraction and suppression of reflection wave field data, so as to separate diffraction wave field data from the two-dimensional single-shot seismic data. The application of the target reflection wave extraction function can effectively avoid the loss of diffraction waves and the residue of reflection waves during the separation process, thereby effectively alleviating the technical problem of poor diffraction wave separation effect in the existing diffraction wave separation method. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 A flow chart of a shot gather seismic diffraction wave separation method provided by an embodiment of the present invention;

[0018] Figure 2 A flowchart of determining seismic data and target reflection wave extraction function in a virtual source space based on two-dimensional single-shot seismic data and the spatial coordinates of a virtual source point provided by an embodiment of the present invention;

[0019] Figure 3 A functional module diagram of a shot gather seismic diffraction wave separation device provided by an embodiment of the present invention;

[0020] Figure 4 A schematic diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0022] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] Some embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0024] Embodiment 1

[0025] Figure 1 A flow chart of a shot gather seismic diffraction wave separation method provided in an embodiment of the present invention is as follows: Figure 1 As shown, the method specifically comprises the following steps:

[0026] Step S102, obtaining two-dimensional single-shot seismic data of a specified geographical area.

[0027] The method provided by the embodiment of the present invention is applicable to the two-dimensional single shot seismic data U(x s ,x r ,t) (i.e., seismic shot data) for diffraction wave separation. Two-dimensional single-shot seismic data is seismic data recorded by a seismic exploration system consisting of a single shot point S and multiple detection points R. The shot point and all the detection points are arranged on the x-axis, and the depth is 0, that is, the coordinates of the shot point and all the detection points in the y direction and the coordinates in the z direction are all 0. s represents the coordinates of the shot point, x r represents the coordinates of the detection point, and t represents the earthquake recording time.

[0028] Step S104, using a plane wave method to process the two-dimensional single-shot seismic data to obtain the spatial coordinates of the virtual earthquake source point.

[0029] Among them, the virtual source point represents the mirror point of the shot point with respect to the stratum.

[0030] Specifically, according to the reflection law, the reflection time corresponding to the geological interface can be regarded as the time from the virtual source point to the detection point. The virtual source point is the mirror image point of the shot point with respect to the stratum, and its coordinates are (X(x s ,x r ,t), Z(x s ,x r ,t)), that is, there is a mapping relationship between the seismic shot data and the location of the virtual source point. Each sample point in the seismic shot data (that is, seismic record sample point) corresponds to a virtual source point coordinate. s Under the premise of being fixed, the above mapping relationship can be understood as: a set of determined (x r ,t) corresponds to a virtual earthquake source point coordinate (X(x r ,t), Z(x r ,t)),(X(x r ,t), Z(x r,t)) can also be written as (X(x s ,x r ,t), Z(x s ,x r ,t)).

[0031] Based on the fact that the earthquake recording time at the detection point is equal to the distance between the underground virtual source point and the surface detection point divided by the seismic longitudinal wave velocity, the earthquake recording time t can be expressed as: Where v represents the seismic longitudinal wave velocity, t(x r ) indicates that the coordinate is x r The earthquake recording time of the detection point at .

[0032] The plane wave method processes two-dimensional single-shot seismic data, which is essentially the following process:

[0033] ① Taking partial derivative of the above formula (1), we get:

[0034] ② Multiply both sides of equation (2) by t and take the partial derivative again to obtain: A set of determined (x r ,t) into formula (3), we can get the seismic longitudinal wave velocity v.

[0035] ③ Substitute the seismic P-wave velocity v and (x r ,t) into the above formula (2), we can get (x r ,t) is the coordinate X(x s ,x r ,t),

[0036] ④Replace the (x r ,t) and the calculated X(xs,xr,t) are put into equation (1) to obtain (x r ,t) is the coordinate Z(xs,xr,t) of the virtual source point in the z direction, that is, the depth Z(xs,xr,t).

[0037] So far, a set of determined (x r ,t) corresponds to the spatial coordinates of the virtual source point (X(x s ,x r ,t), Z(x s ,x r ,t)) has been obtained, and it is known that each seismic record sample point corresponds to a virtual source point coordinate. Therefore, by referring to the above process to process each sample point in the ground shot data, the coordinates of all virtual source points in the underground space of the specified geographical area can be obtained.

[0038] Step S106, based on the two-dimensional single-shot seismic data and the spatial coordinates of the virtual seismic source point, determine the seismic data and target reflection wave extraction function in the virtual seismic source space.

[0039] Among them, the target reflection wave extraction function is a continuous function.

[0040] Specifically, the two-dimensional single-shot seismic data is focused using the spatial coordinates of the virtual source point to obtain the seismic data in the virtual source space, that is, all seismic signal intensities are returned and superimposed on the reflection point position of the corresponding stratum.

[0041] From the description above, we know that each seismic record sample point will correspond to a virtual source position, and some virtual source positions will have multiple seismic record sample points corresponding to them. If a virtual source position can correspond to multiple seismic record sample points, it means that the virtual source position is the position where the reflection wave is generated; if a virtual source position can only correspond to a small number of seismic record sample points, it means that the virtual source position is the position where the diffraction wave is generated. Therefore, according to the two-dimensional single-shot seismic data and the spatial coordinates of all virtual source points, the number of illuminations of each virtual source point can be calculated. By setting the limit of the number of illuminations, the discrete reflection wave extraction function (that is, the initial reflection wave extraction function) can be preliminarily determined, and the function value is 0 or 1. Among them, the number of illuminations of a virtual source point refers to the number of seismic record sample points that have a corresponding relationship with the virtual source point.

[0042] In combination with the seismic data in the virtual source space and the initial reflection wave extraction function, the reflection wave model in the virtual source space can be preliminarily determined. However, if the data at the reflection wave focus point in the virtual source space is directly cut out based on the current reflection wave model, since the current cutting operation is not smooth (because the initial reflection wave extraction function is a discrete function), it will inevitably lead to residual reflection waves and energy loss of diffraction waves, which is not conducive to subsequent diffraction wave processing. Therefore, after determining the initial reflection wave extraction function, the embodiment of the present invention performs a reverse focusing-focusing process of the reflection wave again to update the reflection wave model in the virtual source space, and then combines the seismic data in the virtual source space to construct a continuous reflection wave extraction function, that is, a target reflection wave extraction function.

[0043] Step S108, determining the target reflection wave field data based on the spatial coordinates of the virtual source point, the seismic data in the virtual source space and the target reflection wave extraction function.

[0044] The target reflection wave extraction function is used to process the seismic data in the virtual source space to obtain the target reflection wave model in the virtual source space. Then, the target reflection wave field data can be obtained by performing anti-focusing processing on it in combination with the spatial coordinates of the virtual source point.

[0045] Step S110 , removing target reflection wave field data from the two-dimensional single-shot seismic data to obtain diffraction wave field data.

[0046] The diffraction wave field data is expressed as: U dif (x s ,x r ,t)=U(x s ,x r ,t)-U ref (x s ,x r ,t). Among them, U(x s ,x r ,t) represents the two-dimensional single-shot seismic data, U ref (x s ,x r ,t) represents the target reflection wave field data, U dif (x s ,x r ,t) represents the diffraction wave field data.

[0047] The embodiment of the present invention provides a shot-gather seismic diffraction wave separation method. After acquiring two-dimensional single-shot seismic data, the method first determines the spatial coordinates of a virtual source point, then uses the virtual source theory to focus the reflection wave at the virtual source, and uses a continuous target reflection wave extraction function to achieve effective extraction and suppression of reflection wave field data, so as to separate diffraction wave field data from the two-dimensional single-shot seismic data. The application of the target reflection wave extraction function can effectively avoid the loss of diffraction waves and the residue of reflection waves during the separation process, thereby effectively alleviating the technical problem of poor diffraction wave separation effect in the existing diffraction wave separation method.

[0048] In an optional embodiment, if Figure 2 As shown, the above step S106, based on the two-dimensional single-shot seismic data and the spatial coordinates of the virtual source point, determines the seismic data and the target reflection wave extraction function in the virtual source space, specifically including the following steps:

[0049] Step S1061, focusing processing is performed on the two-dimensional single-shot seismic data based on the spatial coordinates of the virtual seismic source point to obtain seismic data in the virtual seismic source space.

[0050] Focusing the 2D single-shot seismic data can also be understood as converting the seismic wave field into the virtual source space as follows: Where δ represents the Dirac function, (x im ,z im ) represents the spatial coordinates of the target virtual seismic source point, and the target virtual seismic source point represents any virtual seismic source point among all virtual seismic source points. im ,z im) represents the seismic data in the virtual source space.

[0051] Step S1062, determining an initial reflection wave extraction function based on the two-dimensional single-shot seismic data and the spatial coordinates of the virtual source point.

[0052] According to the two-dimensional single-shot seismic data and the spatial coordinates of the virtual seismic source points, the illumination times of each virtual seismic source point in the underground space can be calculated, and then the reflection wave focal point can be determined from all the virtual seismic source points according to the number of illumination times, and then a discrete initial reflection wave extraction function can be constructed.

[0053] Step S1063, determining a target reflection wave extraction function based on the seismic data in the virtual source space, the initial reflection wave extraction function and the spatial coordinates of the virtual source point.

[0054] From the description above, it can be seen that only the initial reflection wave model can be obtained according to the initial reflection wave extraction function and the seismic data in the virtual source space, and the model cannot be used directly. Therefore, after obtaining the initial reflection wave model, it is also necessary to perform defocusing and focusing processing in combination with the spatial coordinates of the virtual source point to update the reflection wave model and then construct the target reflection wave extraction function.

[0055] In an optional implementation, the above step S1062, based on the two-dimensional single-shot seismic data and the spatial coordinates of the virtual source point, determines the initial reflection wave extraction function, which specifically includes the following steps:

[0056] Step S10621, based on the two-dimensional single-shot seismic data and the spatial coordinates of the virtual seismic source points, calculate the number of illumination times of each virtual seismic source point in the underground space of the specified geographical area.

[0057] Step S10622: construct an initial reflection wave extraction function based on a preset upper limit of the number of illumination times and the number of illumination times of all virtual seismic source points in the underground space.

[0058] The illumination times of a known virtual source point refers to the number of seismic record sample points corresponding to the virtual source point. Therefore, the embodiment of the present invention uses the following formula to calculate the target virtual source point (x im ,z im ) lighting times, Among them, ε represents a very small number used to improve the stability of division, δ represents the Dirac function, T(x im ,z im ) represents the target virtual source point (x im ,z im ) lighting times.

[0059] After determining the number of illumination times for each virtual earthquake source point, the initial reflection wave extraction function can be constructed in combination with the preset upper limit of illumination times: Where K represents the preset upper limit of illumination times. According to the expression of the initial reflection wave extraction function, if the illumination times of the virtual source point reaches this upper limit, the function value of the initial reflection wave extraction function is 1, otherwise it is 0.

[0060] In an optional implementation, the above step S1063, based on the seismic data in the virtual source space, the initial reflection wave extraction function and the spatial coordinates of the virtual source point, determines the target reflection wave extraction function, which specifically includes the following steps:

[0061] Step S10631, constructing a first reflection wave model in the virtual source space based on the seismic data in the virtual source space and the initial reflection wave extraction function.

[0062] Step S10632: Defocusing the first reflection wave model based on the spatial coordinates of the virtual seismic source point to obtain initial reflection wave field data.

[0063] Step S10633, focusing processing is performed on the initial reflection wave field data based on the spatial coordinates of the virtual source point to obtain a second reflection wave model in the virtual source space.

[0064] Step S10634, constructing a target reflection wave extraction function based on the second reflection wave model in the virtual source space and the seismic data in the virtual source space.

[0065] The seismic data in the virtual source space are multiplied by the initial reflection wave extraction function to obtain the first reflection wave model in the virtual source space (that is, the above-mentioned initial reflection wave model). It is expressed as: Based on the spatial coordinates of the virtual source point, the first reflection wave model in the virtual source space is converted to the seismic wave field space to obtain the initial reflection wave field data.

[0066]

[0067] Furthermore, the initial reflection wave field data is transformed into the virtual source space according to the spatial coordinates of the virtual source point, and the second reflection wave model in the virtual source space can be obtained: The second reflection wave model is divided by the complete seismic data and then the square root is taken to construct the target reflection wave extraction function: Among them, ε represents a very small number used to improve the stability of division, M′(x im ,z im ) represents the target reflection wave extraction function.

[0068] In an optional implementation, the above step S108, based on the spatial coordinates of the virtual source point, the seismic data in the virtual source space and the target reflection wave extraction function, determines the target reflection wave field data, specifically including the following steps:

[0069] Step S1081, based on the seismic data in the virtual source space and the target reflection wave extraction function, a target reflection wave model in the virtual source space is constructed. The target reflection wave model is expressed as:

[0070]

[0071] Step S1082: Defocusing the target reflection wave model based on the spatial coordinates of the virtual seismic source point to obtain target reflection wave field data.

[0072] The target reflection wave field data is expressed as:

[0073]

[0074] The shot-gather seismic diffraction wave separation method proposed in the embodiment of the present invention is a technical means for pre-stack diffraction wave separation. The method uses travel time information to construct a mapping relationship between seismic shot-gather data and virtual source points, and uses the virtual source theory to focus the reflection wave at the virtual source. Based on the continuity of the target reflection wave extraction function, the reflection wave and the diffraction wave in the virtual source space can be effectively separated, and the reflection wave residue and diffraction wave loss can be avoided, so as to achieve the purpose of improving the diffraction wave separation effect and separation quality. That is, the present invention has the ability to obtain weak signals of seismic diffraction waves, can be used for pre-stack shot-gather and diffraction wave field extraction under complex geological conditions, can serve the detection of small-scale geological anomalies in seismic exploration, and accurately locate geological discontinuities, such as faults, collapse columns, etc.

[0075] Embodiment 2

[0076] An embodiment of the present invention further provides a shot gather seismic diffraction wave separation device, which is mainly used to execute the shot gather seismic diffraction wave separation method provided in the above-mentioned embodiment 1. The shot gather seismic diffraction wave separation device provided in the embodiment of the present invention is specifically introduced below.

[0077] Figure 3 A functional module diagram of a shot gather seismic diffraction wave separation device provided by an embodiment of the present invention, such as Figure 3 As shown, the device mainly includes: an acquisition module 10, a processing module 20, a first determination module 30, a second determination module 40, and a rejection module 50, wherein:

[0078] The acquisition module 10 is used to acquire two-dimensional single-shot seismic data of a specified geographical area.

[0079] The processing module 20 is used to process the two-dimensional single-shot seismic data using a plane wave method to obtain the spatial coordinates of a virtual source point; wherein the virtual source point represents a mirror point of the shot point with respect to the stratum.

[0080] The first determination module 30 is used to determine the seismic data and the target reflection wave extraction function in the virtual source space based on the two-dimensional single-shot seismic data and the spatial coordinates of the virtual source point; wherein the target reflection wave extraction function is a continuous function.

[0081] The second determination module 40 is used to determine the target reflection wave field data based on the spatial coordinates of the virtual source point, the seismic data in the virtual source space and the target reflection wave extraction function.

[0082] The elimination module 50 is used to eliminate the target reflection wave field data from the two-dimensional single-shot seismic data to obtain the diffraction wave field data.

[0083] The embodiment of the present invention provides a shot-gather seismic diffraction wave separation device, which first determines the spatial coordinates of a virtual source point after acquiring two-dimensional single-shot seismic data, then focuses the reflection wave at the virtual source using the virtual source theory, and uses a continuous target reflection wave extraction function to effectively extract and suppress the reflection wave field data, so as to separate the diffraction wave field data from the two-dimensional single-shot seismic data. The application of the target reflection wave extraction function can effectively avoid the loss of diffraction waves and the residue of reflection waves during the separation process, thereby effectively alleviating the technical problem of poor diffraction wave separation effect in the existing diffraction wave separation method.

[0084] Optionally, the first determining module 30 includes:

[0085] The focusing unit is used to perform focusing processing on the two-dimensional single-shot seismic data based on the spatial coordinates of the virtual seismic source point to obtain seismic data in the virtual seismic source space.

[0086] The first determination unit is used to determine the initial reflection wave extraction function based on the two-dimensional single-shot seismic data and the spatial coordinates of the virtual source point.

[0087] The second determination unit is used to determine the target reflection wave extraction function based on the seismic data in the virtual source space, the initial reflection wave extraction function and the space coordinates of the virtual source point.

[0088] Optionally, the first determining unit is specifically configured to:

[0089] Based on the two-dimensional single-shot seismic data and the spatial coordinates of the virtual source points, the illumination times of each virtual source point in the underground space of the specified geographical area are calculated.

[0090] Based on the preset upper limit of illumination times and the illumination times of all virtual seismic source points in the underground space, an initial reflection wave extraction function is constructed.

[0091] Optionally, the second determining unit is specifically configured to:

[0092] Based on the seismic data in the virtual source space and the initial reflection wave extraction function, a first reflection wave model in the virtual source space is constructed.

[0093] The first reflection wave model is defocused based on the spatial coordinates of the virtual seismic source point to obtain the initial reflection wave field data.

[0094] The initial reflection wave field data is focused based on the spatial coordinates of the virtual source point to obtain the second reflection wave model in the virtual source space.

[0095] Based on the second reflection wave model in the virtual source space and the seismic data in the virtual source space, a target reflection wave extraction function is constructed.

[0096] Optionally, the second determining module 40 is specifically configured to:

[0097] Based on the seismic data in the virtual source space and the target reflection wave extraction function, a target reflection wave model in the virtual source space is constructed.

[0098] The target reflection wave model is defocused based on the spatial coordinates of the virtual seismic source point to obtain the target reflection wave field data.

[0099] Embodiment 3

[0100] See also Figure 4 An embodiment of the present invention provides an electronic device, which includes: a processor 60, a memory 61, a bus 62 and a communication interface 63, the processor 60, the communication interface 63 and the memory 61 are connected through the bus 62; the processor 60 is used to execute an executable module stored in the memory 61, such as a computer program.

[0101] The memory 61 may include a high-speed random access memory (RAM), and may also include a non-volatile memory, such as at least one disk memory. The communication connection between the system network element and at least one other network element is realized through at least one communication interface 63 (which may be wired or wireless), and the Internet, wide area network, local area network, metropolitan area network, etc. may be used.

[0102] The bus 62 may be an ISA bus, a PCI bus, or an EISA bus. The bus may be divided into an address bus, a data bus, a control bus, and the like. For ease of representation, Figure 4 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.

[0103] Among them, the memory 61 is used to store programs, and the processor 60 executes the program after receiving the execution instruction. The method executed by the device defined by the process disclosed in any embodiment of the above-mentioned embodiment of the present invention can be applied to the processor 60 or implemented by the processor 60.

[0104] The processor 60 may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method can be completed by the hardware integrated logic circuit or software instructions in the processor 60. The above processor 60 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 invention can be implemented or executed. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor. The steps of the method disclosed in the embodiments of the present invention can be directly embodied as a hardware decoding processor to be executed, or the hardware and software modules in the decoding processor can be executed. The software module can be located in a mature storage medium in the field such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. The storage medium is located in the memory 61, and the processor 60 reads the information in the memory 61 and completes the steps of the above method in combination with its hardware.

[0105] A computer program product of a shot gather seismic diffraction wave separation method and apparatus provided in an embodiment of the present invention includes a computer-readable storage medium storing a non-volatile program code executable by a processor. The instructions included in the program code can be used to execute the method in the previous method embodiment. The specific implementation can be found in the method embodiment, which will not be repeated here.

[0106] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0107] If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a non-volatile computer-readable storage medium that is executable by a processor. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0108] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0109] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0110] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0111] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0112] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A shot gather seismic diffraction wave separation method, characterized in that: include: Acquire 2D single-shot seismic data for a specified geographic area; The two-dimensional single-shot seismic data is processed by plane wave method to obtain the spatial coordinates of a virtual source point; wherein the virtual source point represents a mirror image point of the shot point with respect to the stratum; Based on the two-dimensional single-shot seismic data and the spatial coordinates of the virtual seismic source point, determining the seismic data and the target reflection wave extraction function in the virtual seismic source space; wherein the target reflection wave extraction function is a continuous function; Determining target reflection wave field data based on the spatial coordinates of the virtual seismic source point, the seismic data in the virtual seismic source space, and the target reflection wave extraction function; The target reflection wave field data is removed from the two-dimensional single-shot seismic data to obtain diffraction wave field data.

2. The shot gather seismic diffraction wave separation method according to claim 1, characterized in that: Based on the two-dimensional single-shot seismic data and the spatial coordinates of the virtual seismic source point, determining the seismic data and the target reflection wave extraction function in the virtual seismic source space includes: Focusing the two-dimensional single-shot seismic data based on the spatial coordinates of the virtual seismic source point to obtain seismic data in the virtual seismic source space; Determining an initial reflection wave extraction function based on the two-dimensional single-shot seismic data and the spatial coordinates of the virtual seismic source point; A target reflection wave extraction function is determined based on the seismic data in the virtual source space, the initial reflection wave extraction function and the spatial coordinates of the virtual source point.

3. The shot gather seismic diffraction wave separation method according to claim 2, characterized in that: Based on the two-dimensional single-shot seismic data and the spatial coordinates of the virtual seismic source point, determining an initial reflection wave extraction function includes: Calculating the illumination times of each virtual seismic source point in the underground space of the designated geographical area based on the two-dimensional single-shot seismic data and the spatial coordinates of the virtual seismic source point; Based on a preset upper limit of the number of illumination times and the number of illumination times of all virtual seismic source points in the underground space, an initial reflection wave extraction function is constructed.

4. The shot gather seismic diffraction wave separation method according to claim 2, characterized in that: Determining a target reflection wave extraction function based on the seismic data in the virtual source space, the initial reflection wave extraction function and the spatial coordinates of the virtual source point includes: Based on the seismic data in the virtual seismic source space and the initial reflection wave extraction function, constructing a first reflection wave model in the virtual seismic source space; Defocusing the first reflection wave model based on the spatial coordinates of the virtual seismic source point to obtain initial reflection wave field data; Focusing the initial reflection wave field data based on the spatial coordinates of the virtual seismic source point to obtain a second reflection wave model in the virtual seismic source space; The target reflection wave extraction function is constructed based on the second reflection wave model in the virtual seismic source space and the seismic data in the virtual seismic source space.

5. The shot gather seismic diffraction wave separation method according to claim 1, characterized in that: Determining target reflection wave field data based on the spatial coordinates of the virtual seismic source point, the seismic data in the virtual seismic source space, and the target reflection wave extraction function includes: Based on the seismic data in the virtual source space and the target reflection wave extraction function, construct a target reflection wave model in the virtual source space; The target reflection wave model is subjected to anti-focusing processing based on the spatial coordinates of the virtual seismic source point to obtain target reflection wave field data.

6. A shot gather seismic diffraction wave separation device, characterized in that: include: An acquisition module for acquiring two-dimensional single-shot seismic data of a specified geographical area; A processing module, used to process the two-dimensional single-shot seismic data using a plane wave method to obtain the spatial coordinates of a virtual source point; wherein the virtual source point represents a mirror image point of the shot point with respect to the stratum; A first determination module is used to determine the seismic data and the target reflection wave extraction function in the virtual source space based on the two-dimensional single-shot seismic data and the spatial coordinates of the virtual source point; wherein the target reflection wave extraction function is a continuous function; A second determination module is used to determine target reflection wave field data based on the spatial coordinates of the virtual seismic source point, the seismic data in the virtual seismic source space and the target reflection wave extraction function; The elimination module is used to eliminate the target reflection wave field data from the two-dimensional single-shot seismic data to obtain diffraction wave field data.

7. The shot gather seismic diffraction wave separation device according to claim 6, characterized in that: The first determining module comprises: A focusing unit, used for performing focusing processing on the two-dimensional single-shot seismic data based on the spatial coordinates of the virtual seismic source point to obtain seismic data in the virtual seismic source space; A first determining unit is used to determine an initial reflection wave extraction function based on the two-dimensional single-shot seismic data and the spatial coordinates of the virtual source point; The second determining unit is used to determine a target reflection wave extraction function based on the seismic data in the virtual source space, the initial reflection wave extraction function and the spatial coordinates of the virtual source point.

8. The shot gather seismic diffraction wave separation device according to claim 7, characterized in that: The first determining unit is specifically configured to: Calculating the illumination times of each virtual seismic source point in the underground space of the designated geographical area based on the two-dimensional single-shot seismic data and the spatial coordinates of the virtual seismic source point; Based on a preset upper limit of the number of illumination times and the number of illumination times of all virtual seismic source points in the underground space, an initial reflection wave extraction function is constructed.

9. An electronic device comprising a memory and a processor, wherein the memory stores a computer program that can be run on the processor, wherein: When the processor executes the computer program, the shot gather seismic diffraction wave separation method according to any one of claims 1 to 5 is implemented.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and when the computer instructions are executed by a processor, the shot gather seismic diffraction wave separation method according to any one of claims 1 to 5 is implemented.

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