Method, device, equipment and medium for simulating seismic profile of horizontal sand layer surface

Abstract

The present invention proposes a method, device, equipment and medium for simulating seismic profiles on the surface of horizontal sand layers. The seismic profile simulation method includes: generating a single-channel dune ringing multiple wave signal; calculating a time domain reflection coefficient sequence based on a depth domain layer velocity model; convolving the time domain reflection coefficient model with the single-channel dune ringing multiple wave signal one by one to synthesize a seismic profile under horizontal sand layer surface conditions. The scheme of the present invention can be used to obtain seismic profiles under conditions of different sand layer thicknesses, which is convenient for analyzing and identifying desert ringing. The seismic profile data of the horizontal sand layer surface conditions can be quickly obtained from the underground velocity model, providing support for dune ringing analysis and identification.

Description

Technical Field

[0001] The invention belongs to the field of seismic data acquisition and processing, and specifically relates to a seismic profile simulation method for a horizontal sand layer surface, which can be used for multiple wave characteristic analysis, multiple wave identification and suppression under sand layer surface conditions. Background Art

[0002] One of the most important tasks in seismic processing is to suppress the multiple wave energy in the data. This is a problem that actually exists for all seismic data. The ability to process unwanted multiple waves is very important for subsequent imaging and amplitude analysis. Seismic imaging methods generally assume that the input data does not contain multiple waves. Violating this assumption will lead to a decrease in the quality of imaging and amplitude. Multiple wave processing is an important topic in seismic processing. The problem of multiple waves is common in seismic exploration, especially in desert areas. As a coherent noise, multiple waves reduce the signal-to-noise ratio of seismic data and restrict the improvement of resolution. If they cannot be effectively suppressed, multiple waves will affect the authenticity and reliability of seismic imaging, and interfere with the interpretation of seismic data.

[0003] The multiple wave problem is the bottleneck that restricts the accuracy of seismic data processing in desert surface exploration areas. Multiple waves can be divided into free surface multiple waves and interlayer multiple waves. Wang Zhengjun et al. [1] analyzed the mechanism of interlayer multiple waves in the Jurassic coal seams in the central Junggar Basin, and Wang Gonghuai et al. [2] introduced the method of suppressing interlayer multiple waves of low signal-to-noise ratio seismic data in the Bachu uplift of the Tarim Basin. For desert surface multiple waves, Bai Junhui et al. [3] conducted a study on surface ghost reflections in the vertical seismic profile excitation in the Tazhong area, and analyzed the characteristics of surface multiple waves through vertical seismic profile (VSP) acquisition records. Ling Yun et al. [4] proposed a variable step-size prediction deconvolution technique to suppress dune rumble multiple waves. Wang Lixin et al. [5] used the Radon method to suppress dune rumble multiple waves.

[0004] However, there are few studies on dune rumbling forward modeling and dune rumbling seismic profile characteristics. The reason is that dune rumbling forward modeling requires the use of variable density wave equation method, while the air density is very small. In order to maintain calculation stability, the calculation grid must be very dense, resulting in a very large amount of calculation, high cost, and not feasible. Summary of the invention

[0005] In order to solve the problems that dune rumbling forward simulation has large computational complexity, is difficult to implement, and cannot effectively analyze the seismic profile characteristics of dune rumbling, the present invention proposes a seismic profile simulation method for the surface of horizontal sand layers. The method can quickly obtain seismic profile data of the surface conditions of horizontal sand layers based on the underground velocity model, thus providing support for dune rumbling analysis and identification.

[0006] According to one aspect of the present invention, a method for simulating a seismic profile of a horizontal sand layer surface is provided, comprising:

[0007] Generate a single-channel dune rumble multiple wave signal;

[0008] Calculate the time domain reflection coefficient sequence based on the depth domain layer velocity model;

[0009] The time domain reflection coefficient model is convolved with the single-channel dune rumble multiple wave signals one by one to synthesize the seismic profile under the surface conditions of the horizontal sand layer.

[0010] Furthermore, a single-channel dune-containing rumbling multiple wave signal is generated from the sand layer thickness, sand layer velocity, water surface reflection coefficient, seismic wave amplitude attenuation factor and primary wave signal.

[0011] Furthermore, the single-channel dune rumble multiple wave signal is:

[0012] X(t)=X s (t)+(-1)rαX s (t-τ)+(-1) 2 r 2 α 2 X s (t-2τ)+(-1) 3 r 3 α 3 X s (t-3τ)+… (2)

[0013] Among them, the free surface reflection coefficient is approximately -1, the water surface reflection coefficient is r, the seismic wave amplitude attenuation factor in a multiple wave cycle is α, the primary wave signal is f(t), and X s (t) represents the primary and multiple wave signals at the source end, and:

[0014] X s (t) = f(t) + (-1)(1-r) 2 αf(t-τ)+(-1) 2 (1-r) 2 rα 2 f(t-2τ)+(-1) 3 (1-r) 2 r 2 α 3 f(t-3τ)+… (3)

[0015] Where τ is the multiple wave period.

[0016] Furthermore, the multiple wave period is:

[0017] τ=2h / c (1)

[0018] Where h is the thickness of the sand layer and c is the velocity of the sand layer.

[0019] Further, the calculating of the time domain reflection coefficient sequence comprises:

[0020] Performing deep-time conversion on the depth domain layer velocity model, converting the depth domain layer velocity model into a time domain layer velocity model;

[0021] The time domain reflection coefficient series is calculated from the time domain layer velocity model.

[0022] Furthermore, the reflection coefficient of a certain point (i, j) in the time domain reflection coefficient sequence is:

[0023]

[0024] Among them, v i,j represents the velocity of point (i,j), v i,j+1 Indicates the speed of the next point (i,j+1) in the time direction of point (i,j).

[0025] Furthermore, the time domain reflection coefficient model is convolved with the single-channel dune rumble signal channel by channel and expressed as:

[0026] S(x,t)=R(x,t)*X(t) (5)

[0027] Where R(x,t) represents the underground reflection coefficient sequence at space x.

[0028] According to another aspect of the present invention, there is provided a seismic profile simulation device for a horizontal sand layer surface, comprising:

[0029] Signal unit, generating single-channel dune rumble multiple wave signals;

[0030] A calculation unit, which calculates a time domain reflection coefficient sequence based on a depth domain layer velocity model;

[0031] The synthesis unit convolves the time domain reflection coefficient model with the single-channel dune rumble multiple wave signals one by one to synthesize the seismic profile under the surface conditions of the horizontal sand layer.

[0032] According to another aspect of the present invention, there is provided an electronic device, the electronic device comprising:

[0033] A memory storing executable instructions;

[0034] A processor runs the executable instructions in the memory to implement the seismic profile simulation method of the horizontal sand layer surface.

[0035] According to another aspect of the present invention, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method for simulating a seismic profile of a horizontal sand layer surface is implemented.

[0036] The present invention aims to solve the problem that the dune rumbling forward simulation has a large amount of calculation, is difficult to implement, and cannot effectively analyze the characteristics of the dune rumbling seismic profile. A method for simulating the seismic profile of the horizontal sand layer surface is proposed. The method mainly includes the steps of single-channel dune rumbling signal simulation, time domain reflection coefficient sequence calculation, and time domain seismic profile synthesis. The seismic profile data of the horizontal sand layer surface conditions can be quickly obtained from the underground velocity model, providing support for dune rumbling analysis and identification. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The above and other objects, features and advantages of the present disclosure will become more apparent through a more detailed description of exemplary embodiments of the present disclosure in conjunction with the accompanying drawings, wherein like reference numerals generally represent like components in the exemplary embodiments of the present disclosure.

[0038] Figure 1 The present invention is a flow chart of the method for simulating seismic profiles of horizontal sand layers.

[0039] Figure 2 Schematic diagram of the Shunbei underground velocity model according to an embodiment of the present invention.

[0040] Figure 3 This is a partial enlarged view of the target area of ​​the Shunbei underground velocity model according to an embodiment of the present invention.

[0041] Figure 4 4 is a time domain reflection coefficient profile diagram of a target area according to an embodiment of the present invention.

[0042] Figure 5 4 is a primary wave seismic profile diagram according to an embodiment of the present invention.

[0043] Figure 6 This is a seismic profile (including primary waves and multiple waves) when the sand layer thickness is 2m according to an embodiment of the present invention.

[0044] Figure 7 This is a seismic profile diagram (including primary waves and multiple waves) when the sand layer thickness is 5m according to an embodiment of the present invention.

[0045] Figure 8 This is a seismic profile (including primary waves and multiple waves) when the sand layer thickness is 10m according to an embodiment of the present invention.

[0046] Fig. 9 This is a seismic profile (including primary waves and multiple waves) when the sand layer thickness is 15 m according to an embodiment of the present invention. DETAILED DESCRIPTION

[0047] The preferred embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the preferred embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to make the present disclosure more thorough and complete, and to fully convey the scope of the present disclosure to those skilled in the art.

[0048] The present invention aims to solve the problems that dune rumbling forward simulation has large computational complexity, is difficult to implement, and cannot effectively analyze the characteristics of dune rumbling seismic profiles, and proposes a method for simulating seismic profiles on the surface of horizontal sand layers. The implementation scheme is: a single-channel signal containing multiple dune rumbling waves is generated based on the sand layer thickness, sand layer velocity, water table reflection coefficient, seismic wave amplitude attenuation factor, and primary wave signal f(t); then the time domain reflection coefficient sequence is calculated based on the depth domain layer velocity model; finally, the time domain reflection coefficient model is convolved with the single dune rumbling signal channel by channel to synthesize the seismic profile under the condition of horizontal sand layer surface. The present invention can obtain seismic profiles under different sand layer thickness conditions, which is convenient for analyzing and identifying desert rumbling.

[0049] The present disclosure proposes a method for simulating a seismic profile of a horizontal sand layer surface, comprising:

[0050] Generate a single-channel dune rumble multiple wave signal;

[0051] Calculate the time domain reflection coefficient sequence based on the depth domain layer velocity model;

[0052] The time domain reflection coefficient model is convolved with the single-channel dune rumble multiple wave signals one by one to synthesize the seismic profile under the surface conditions of the horizontal sand layer.

[0053] Firstly, a single-channel dune rumbling signal simulation is carried out to generate a single-channel dune rumbling multiple wave signal.

[0054] For a single-channel seismic record, the earthquake source is located below the water table and the receiving point is located on the surface. During the propagation of the seismic wave, multiple oscillations occur between the surface and the water table to generate dune rumble multiple waves, including multiple waves at the earthquake source and multiple waves at the receiving end. The multiple waves are periodic, and their period is:

[0055] τ=2h / c (1)

[0056] Where h is the thickness of the sand layer and c is the velocity of the sand layer.

[0057] Specifically, the free surface reflection coefficient is approximated as -1, the water surface reflection coefficient is recorded as r, the seismic wave amplitude attenuation factor in a multiple wave cycle is α, and the primary wave signal is f(t). Then, the dune ringing signal after the superposition of multiple waves is:

[0058] X(t)=X s (t)+(-1)rαX s (t-τ)+(-1) 2 r 2 α 2 X s (t-2τ)+(-1) 3 r 3 α 3 X s (t-3τ)+… (2)

[0059] Among them, X s (t) represents the primary and multiple wave signals at the source end, and:

[0060] X s (t) = f(t) + (-1)(1-r) 2 αf(t-τ)+(-1) 2 (1-r) 2 rα 2 f(t-2τ)+(-1) 3 (1-r) 2 r 2 α 3 f(t-3τ)+… (3)

[0061] At the same time, the time domain reflection coefficient sequence is calculated. The depth domain layer velocity model is converted into the time domain layer velocity model by deep-time conversion, and then the time domain reflection coefficient sequence is calculated from the time domain layer velocity model, where the reflection coefficient of a certain point (i, j) is:

[0062]

[0063] Among them, v i,j represents the velocity of point (i,j), v i,j+1 Indicates the speed of the next point (i,j+1) in the time direction of point (i,j).

[0064] Finally, the time domain seismic profile synthesis is performed.

[0065] Specifically, the time domain reflection coefficient model is convolved with the single-channel dune rumble multiple wave signal one by one to synthesize the seismic profile under the horizontal sand layer surface condition, which can be expressed as:

[0066] S(x,t)=R(x,t)*X(t) (5)

[0067] Where R(x,t) represents the underground reflection coefficient sequence at space x.

[0068] To facilitate understanding of the solutions and effects of the embodiments of the present invention, a specific application example is given below. Those skilled in the art should understand that the example is only for facilitating understanding of the present invention, and any specific details thereof are not intended to limit the present invention in any way.

[0069] Example 1

[0070] This embodiment will refer to Figure 2-Figure 9 , a specific application example of the present invention is described in detail.

[0071] Referring to the underground structure of Shunbei area, the following is established: Figure 2 The velocity model shown has a grid number of 9001*5001 and a grid size of 2m. In order to show the seismic profile characteristics more clearly, the fault-karst target area is enlarged ( Figure 3 ), Figure 4 is the corresponding time domain reflection coefficient profile. Take the sand layer velocity c as 600m / s, the water surface reflection coefficient r as 0.6, the attenuation coefficient α as 1, and the primary wave f(t) as 30hz Ricker wavelet. Figure 5 It is a seismic profile without multiple waves obtained by convolution of the time domain reflection coefficient series and the Ricker wavelet. Figure 6-Figure 9 These are the seismic profiles when the sand layer thickness is 2m, 5m, 10m, and 15m, respectively. It can be seen that as the sand layer thickness increases, the time difference between the primary wave and the multiple waves gradually increases, and the multiple waves become more and more obvious.

[0072] Example 2

[0073] This embodiment provides a seismic profile simulation device for a horizontal sand layer surface, characterized by comprising:

[0074] Signal unit, generating single-channel dune rumble multiple wave signals;

[0075] A calculation unit, which calculates a time domain reflection coefficient sequence based on a depth domain layer velocity model;

[0076] The synthesis unit convolves the time domain reflection coefficient model with the single-channel dune rumble multiple wave signals one by one to synthesize the seismic profile under the surface conditions of the horizontal sand layer.

[0077] The signal unit and the calculation unit are respectively connected to the synthesis unit for communication, and are used to send the generated single-channel dune-ringing multiple wave signals and the calculated time domain reflection coefficient sequence to the synthesis unit. The synthesis unit performs convolution operation on the time domain reflection coefficient model with the single-channel dune-ringing multiple wave signals one by one to synthesize the seismic profile under the surface conditions of the horizontal sand layer.

[0078] Example 3

[0079] This embodiment provides an electronic device, which includes: a memory storing executable instructions; a processor running the executable instructions in the memory to implement the above-mentioned method for simulating seismic profiles of horizontal sand layers.

[0080] An electronic device according to an embodiment of the present disclosure includes a memory and a processor.

[0081] The memory is used to store non-temporary computer-readable instructions. Specifically, the memory may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may, for example, include random access memory (RAM) and / or cache memory (cache), etc. The non-volatile memory may, for example, include read-only memory (ROM), hard disk, flash memory, etc.

[0082] The processor may be a central processing unit (CPU) or other forms of processing units having data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device to perform desired functions. In one embodiment of the present disclosure, the processor is used to run the computer-readable instructions stored in the memory.

[0083] Those skilled in the art should be able to understand that in order to solve the technical problem of how to obtain a good user experience, the present embodiment may also include well-known structures such as a communication bus and an interface, and these well-known structures should also be included in the protection scope of the present disclosure.

[0084] For detailed description of this embodiment, reference may be made to the corresponding descriptions in the aforementioned embodiments, which will not be repeated here.

[0085] Example 4

[0086] This embodiment provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the seismic profile simulation method of the horizontal sand layer surface is implemented.

[0087] According to the computer-readable storage medium of the embodiment of the present disclosure, non-transitory computer-readable instructions are stored thereon. When the non-transitory computer-readable instructions are executed by a processor, all or part of the steps of the method of each embodiment of the present disclosure are executed.

[0088] The above-mentioned computer-readable storage media include, but are not limited to: optical storage media (e.g., CD-ROM and DVD), magneto-optical storage media (e.g., MO), magnetic storage media (e.g., magnetic tape or mobile hard disk), media with built-in rewritable non-volatile memory (e.g., memory card) and media with built-in ROM (e.g., ROM box).

[0089] Those skilled in the art should understand that the purpose of the above description of the embodiments of the present invention is only to exemplarily illustrate the beneficial effects of the embodiments of the present invention, and is not intended to limit the embodiments of the present invention to any given examples.

[0090] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A method for simulating a seismic profile of a horizontal sand layer surface, characterized in that: include: A single-channel dune-contained multiple-wave signal is generated based on the sand layer thickness, sand layer velocity, water surface reflection coefficient, seismic wave amplitude attenuation factor and primary wave signal; Calculate the time domain reflection coefficient sequence based on the depth domain layer velocity model; The time domain reflection coefficient model is convolved with the single-channel dune rumble multiple wave signals one by one to synthesize the seismic profile under the surface conditions of the horizontal sand layer. The single-channel dune rumble multiple wave signal is: X(t)=X s (t)+(-1)rαX s (t-τ)+(-1) 2 r 2 α 2 X s (t-2τ)+(-1) 3 r 3 α 3 X s (t-3τ)+…(2) Among them, the free surface reflection coefficient is approximately -1, the water surface reflection coefficient is r, the seismic wave amplitude attenuation factor in a multiple wave cycle is α, the primary wave signal is f(t), and X s (t) represents the primary and multiple wave signals at the source end, and: X s (t)=f(t)+(-1)(1-r) 2 αf(t-τ)+(-1) 2 (1-r) 2 rα 2 f(t-2τ)+(-1) 3 (1-r) 2 r 2 α 3 f(t-3τ)+…(3) Where τ is the multiple wave period.

2. The method for simulating a seismic profile of a horizontal sand layer surface according to claim 1, characterized in that: The multiple wave period is: τ=2h / c (1) Where h is the thickness of the sand layer and c is the velocity of the sand layer.

3. The method for simulating a seismic profile of a horizontal sand layer surface according to claim 1, characterized in that: The calculation of the time domain reflection coefficient sequence comprises: Performing deep-time conversion on the depth domain layer velocity model, converting the depth domain layer velocity model into a time domain layer velocity model; The time domain reflection coefficient series is calculated from the time domain layer velocity model.

4. The method for simulating seismic profiles of horizontal sand layers according to claim 3, characterized in that: The reflection coefficient of a point (i, j) in the time domain reflection coefficient sequence is: Among them, v i,j represents the velocity of point (i,j), v i,j+1 Indicates the speed of the next point (i,j+1) in the time direction of point (i,j).

5. The method for simulating a seismic profile of a horizontal sand layer surface according to claim 4, characterized in that: The time domain reflection coefficient model is convolved with the single-channel dune rumble signal one by one and is expressed as: S(x,t)=R(x,t)*X(t) (5) Where R(x,t) represents the underground reflection coefficient sequence at space x.

6. A seismic profile simulation device for a horizontal sand layer surface, characterized in that: include: The signal unit generates a single-channel dune-contained multiple-wave signal based on the sand layer thickness, sand layer velocity, water surface reflection coefficient, seismic wave amplitude attenuation factor and primary wave signal; A calculation unit, which calculates a time domain reflection coefficient sequence based on a depth domain layer velocity model; The synthesis unit convolves the time domain reflection coefficient model with the single-channel dune rumble multiple wave signals one by one to synthesize the seismic profile under the surface conditions of the horizontal sand layer; The single-channel dune rumble multiple wave signal is: X(t)=X s (t)+(-1)rαX s (t-τ)+(-1) 2 r 2 α 2 X s (t-2τ)+(-1) 3 r 3 α 3 X s (t-3τ)+…(2) Among them, the free surface reflection coefficient is approximately -1, the water surface reflection coefficient is r, the seismic wave amplitude attenuation factor in a multiple wave cycle is α, the primary wave signal is f(t), and X s (t) represents the primary and multiple wave signals at the source end, and: X s (t)=f(t)+(-1)(1-r) 2 αf(t-τ)+(-1) 2 (1-r) 2 rα 2 f(t-2τ)+(-1) 3 (1-r) 2 r 2 α 3 f(t-3τ)+…(3) Where τ is the multiple wave period.

7. An electronic device, characterized in that: The electronic device comprises: A memory storing executable instructions; A processor, wherein the processor runs the executable instructions in the memory to implement the seismic profile simulation method for a horizontal sand layer surface according to any one of claims 1-5.

8. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method for simulating a seismic profile of a horizontal sand layer surface according to any one of claims 1 to 5 is implemented.

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