Method, device, equipment and medium for determining the sinking depth of an air gun seismic source-cable combination

Abstract

The present invention belongs to the field of seismic exploration technology applications, and provides a method, device, equipment and medium for determining the sinking depth of an air gun seismic source - cable combination. The method for determining the sinking depth of an ocean air gun seismic source - cable combination includes: establishing a velocity model and an absorption model for the work area; conducting numerical simulations of the excitation of the air gun seismic source wavelet; and selecting the sinking depth of the seismic source and the sinking depth of the cable based on the simulation results. By carrying out simulations of the excitation of the ocean air gun seismic source wavelet on the basis of the velocity and absorption models of the work area, the present invention quantitatively determines the optimal sinking depths of the seismic source and the cable under specific air gun volume conditions according to the simulation results, improves the quality of ocean seismic acquisition data, saves the cost of excitation tests, and at the same time provides a theoretical basis for the optimization design of field air gun seismic source excitation and cable sinking depth parameters.

Description

Technical Field

[0001] The present invention belongs to the technical application field of seismic exploration. It is a determination method, a determination device, an electronic device, and a storage medium for simulating the excitation of a marine air gun source wavelet based on the velocity and absorption models in a work area, and quantitatively determining the optimal sinking depths of the source and the cable under specific air gun volume conditions according to the simulation results. Background Art

[0002] With the in-depth development of oil and gas exploration, seismic exploration has been increasingly related to the ocean. The marine oil and gas exploration ability has also made great progress. The acquisition technology has developed from traditional towed cable two-dimensional to towed cable three-dimensional, from single-ship narrow azimuth to multi-ship wide azimuth, and from towed cable to OBN acquisition, etc., all of which mark the development of marine acquisition technology, aiming to improve the quality of marine acquisition data.

[0003] During the acquisition process, many factors affect the data quality. Among them, environmental factors include tides, ocean currents, seawater temperature, and salinity, etc.; there are also acquisition factors such as source spacing, trace interval, azimuth angle, cable length, cable spacing, coverage times, and course, etc. Environmental factors are not changeable by humans. For acquisition factors, due to cost and technical means limitations, the air gun capacity, cable length, trace interval, course, etc. are generally relatively fixed. Only the sinking depths of the source and the cable are factors that can be controlled by humans and directly affect the data quality. Therefore, it is particularly important to design the optimal sinking depths of the air gun and the cable to improve the data quality.

[0004] Through literature review, it can be seen that most current research discusses the air gun source and the cable receiver separately. There are also a small number of articles involving comprehensive analysis of the two, but the pertinence is insufficient and the consideration is not comprehensive. Based on this problem, the field needs a determination method for the optimal matching sinking depths of excitation and reception for a specific air gun capacity for a marine air gun source-cable combination. Summary of the Invention

[0005] The present invention conducts numerical simulation of the air gun source wavelet recording excitation through the velocity model and absorption model in the work area, quantitatively demonstrates and analyzes the frequency, energy, and signal-to-noise ratio characteristics of the hydrate reservoir reflection signal under specific air gun capacity conditions with different source sinking depths, different cable sinking depths, etc. through the simulation results, and then combines the specific geological task requirements to determine the optimal matching sinking depths of excitation and reception for a specific air gun capacity, improve the data quality, and at the same time provide a theoretical basis for the optimization design of the field air gun source excitation and cable sinking depth parameters.

[0006] According to one aspect of the present invention, there is provided a determination method for the optimal matching sinking depths of a marine air gun source-cable combination, including:

[0007] Establish a velocity model and an absorption model for the work area;

[0008] Conduct numerical simulation of the excitation of the air gun source wavelet record;

[0009] Based on the simulation results, select the sinking depth of the source and the sinking depth of the cable.

[0010] Furthermore, analyze the frequency, energy, and signal-to-noise ratio characteristics of the reservoir reflection signals under different source sinking depths and different cable sinking depths through the simulation results. Combining with the specific geological task requirements, determine the optimal matching sinking depths for excitation and reception with a specific air gun capacity.

[0011] Furthermore, the establishment of the velocity model for the work area includes:

[0012] By collecting the previous exploration data of the work area, use the interpretation profile to establish the structural model of the work area, and determine the target layer and the spatial position relationship;

[0013] Use well data to determine the longitudinal wave velocity, transverse wave velocity, and density attribute values of the formation corresponding to different target layers.

[0014] Furthermore, the establishment of the absorption model includes:

[0015] Establish an initial absorption model;

[0016] Conduct numerical simulation of the viscoelastic medium for the excitation of the air gun source wavelet, compare the error between the frequency band of the target layer in the simulated data and the actual data, and modify the absorption model until the error between the frequency band of the simulated data and the actual data is minimized, and establish the final absorption model.

[0017] Furthermore, conducting numerical simulation of the excitation of the air gun source wavelet record includes:

[0018] Establish a viscoelastic wave equation;

[0019] Complete the simulation source loading by loading the actual air gun far-field wavelet function in the field into the external force term of the viscoelastic wave equation.

[0020] Furthermore, the selection of the source sinking depth includes:

[0021] For the determined air gun volume wavelet, select different source sinking depths for excitation simulation;

[0022] Keep the receiving depth constant and analyze the target layer of single-shot excitation at different depths;

[0023] On the premise of meeting the geological task requirements, determine the source sinking depth parameters based on the frequency, energy, and signal-to-noise ratio of the target layer in the excitation depth data.

[0024] Furthermore, the selection of the cable sinking depth includes:

[0025] For a determined air gun volume wavelet, different single-shot simulations of cable deployment are carried out based on the source sinking depth parameter.

[0026] Analyze the single-shot data corresponding to different cable deployment depths, and determine the cable deployment depth parameter according to the frequency, amplitude, and signal-to-noise ratio, combined with the geological task.

[0027] According to another aspect of the present invention, there is provided a device for determining the optimal matching sinking depth of an ocean air gun source-cable combination, comprising:

[0028] A construction unit for establishing a velocity model and an absorption model of the work area;

[0029] A simulation unit for performing numerical simulation of the excitation of the air gun source wavelet record;

[0030] A selection unit for selecting the source sinking depth and the cable sinking depth based on the simulation results.

[0031] According to another aspect of the present invention, there is provided an electronic device, which includes:

[0032] A memory storing executable instructions;

[0033] A processor that runs the executable instructions in the memory to implement the method for determining the sinking depth of the ocean air gun source-cable combination.

[0034] According to another aspect of the present invention, there is provided a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the method for determining the sinking depth of the ocean air gun source-cable combination.

[0035] The present invention establishes a suitable velocity and absorption model for the work area, conducts numerical simulation of the air gun source wavelet loading in a viscoelastic medium, and quantitatively demonstrates the optimal source-cable combination sinking depth based on the analysis results of key parameters such as the target layer frequency, energy, and signal-to-noise ratio of the simulation data under different source sinking depths and different cable sinking depths, solves the blindness and test costs of field tests, meets the high-resolution exploration requirements of marine reservoirs, and also provides a theoretical basis for the optimization design of field air gun source excitation and cable sinking depth parameters. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] By describing the exemplary embodiments of the present disclosure in more detail in conjunction with the accompanying drawings, the above and other objects, features, and advantages of the present disclosure will become more apparent. Among them, in the exemplary embodiments of the present disclosure, the same reference numerals generally represent the same components.

[0037] Figure 1 It is a flowchart of the method for determining the optimal matching sinking depth of the ocean air gun source-cable combination of the present invention.

[0038] Figure 2 is the air gun source wavelet signal according to an embodiment of the present invention.

[0039] Figure 3 is the two-dimensional velocity model according to an embodiment of the present invention.

[0040] Figure 4 is the comparison chart of the frequency characteristics curves of the viscoelastic and elastic target layers with different Q models according to an embodiment of the present invention.

[0041] Figure 5a is for the 1160in 3 seafloor reflection spectrum at different source depths in the comparison analysis chart of the spectra and energies of different target layers.

[0042] Figure 5b is for the 1160in 3 hydrate free gas reservoir reflection spectrum at different source depths in the comparison analysis chart of the spectra and energies of different target layers.

[0043] Figure 5c is for the 1160in 3 bedrock reflection spectrum at different source depths in the comparison analysis chart of the spectra and energies of different target layers.

[0044] Figure 5d is for the 1160in 3 energy comparison of different target layers at different source depths in the comparison analysis chart of the spectra and energies of different target layers.

[0045] Figure 6a is for the 1160in 3 spectrum comparison of data at different cable lowering depths in the comparison analysis of the single-shot spectra and signal-to-noise ratios received at different cable depths.

[0046] Figure 6b is for the 1160in 3 signal-to-noise ratio comparison of data at different cable lowering depths in the comparison analysis of the single-shot spectra and signal-to-noise ratios received at different cable depths. Detailed implementation manners

[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 drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth 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 belongs to the field of seismic exploration technology applications, and relates to a method for optimizing the best sinking depths of a seismic source and a cable. First, by establishing a velocity model and an absorption model for the work area, numerical simulations of air gun seismic source wavelet recording excitation are carried out. Through the analysis of the simulation results, the frequency, energy, and signal-to-noise ratio characteristics of reservoir reflection signals under different seismic source sinking depths, different cable sinking depths, etc. are obtained. Then, combined with the specific geological task requirements, the best matching sinking depths for excitation and reception with a specific air gun capacity are determined, aiming to improve the data quality, save the excitation test cost, and at the same time provide a theoretical basis for the optimization design of field air gun seismic source excitation and cable sinking depth parameters.

[0049] Based on the velocity model and the absorption model, the present invention conducts air gun wavelet excitation simulations, and quantitatively analyzes indexes such as the frequency, energy, and signal-to-noise ratio of the reflection signals of the target layer in the data under different excitation depths and cable reception depths according to the simulation results, and quantitatively determines the best sinking depths of the seismic source and the cable, aiming to improve the data quality.

[0050] As Figure 1 shown, the present invention provides a method for determining the best matching sinking depths of an ocean air gun seismic source - cable combination, including:

[0051] Establishing a velocity model and an absorption model for the work area;

[0052] Conducting numerical simulations of air gun seismic source wavelet recording excitation;

[0053] Selecting the seismic source sinking depth and the cable sinking depth based on the simulation results.

[0054] Specifically, first, a velocity model and an absorption model for the work area are established.

[0055] 1) Establishment of the velocity model

[0056] By collecting the previous exploration data of the work area (interpretation profiles, well data, etc.), using the interpretation profiles to complete the establishment of the structural model of the work area, and determining the main target layer and its spatial position relationship; then using the well data to determine the longitudinal wave velocity, transverse wave velocity, and density attribute values of the corresponding strata for different target layers.

[0057] 2) Establishment of the modified absorption model

[0058] By comparing the dominant frequency and frequency bandwidth of the wavelet excited by the air gun source with those of the target layer in the actual data, it can be seen that there are differences between the two, and the former parameters are higher than the latter. Therefore, it is necessary to construct an absorption model that conforms to the actual work area, and it is meaningful to carry out the demonstration of excitation and reception depths. The specific construction idea is to first propose an initial absorption model corresponding to the structural model according to the empirical formula of Academician Li Qingzhong, and conduct numerical simulations of viscoelastic media for the excitation of the air gun source wavelet. Compare the frequency band of the target layer in the simulated data with the actual data, and modify the absorption model until the error between the frequency band of the simulated data and the actual data is minimized, that is, the establishment of the absorption model is completed.

[0059] (2) Implementation of the numerical simulation technology for loading viscoelastic media with air gun source wavelets

[0060] The following gives the first-order stress-velocity equation of two-dimensional viscoelastic waves based on the Kelvin-Voigt viscoelastic model.

[0061] 1) Establish the finite-difference formula for the viscoelastic wave equation

[0062] The basic behavior of viscosity is the inelastic property of the medium, which is mainly manifested as the medium having the characteristic of permanent deformation over time. There are generally three ideas and methods for dealing with viscoelastic problems:

[0063] A. Add the viscous factor of the medium to the constitutive equation. The stress and strain are no longer a simple transient relationship, but must include the derivative term of time. The medium models such as Kelvin and linear viscoelasticity. The main idea of establishing the constitutive equation is to consider the medium model as a system. The most typical ones are the differential constitutive relationship introduced by the device combination method and the integral constitutive relationship introduced by the cumulative memory method.

[0064] B. Add a damping factor to the motion equation, such as the d'Alembert viscoelastic medium.

[0065] C. The method of combining the two.

[0066] For example, the first method can be adopted. The Kelvin viscoelastic body is also called the Stocks viscoelastic body and the voigt viscoelastic body. This model is composed of a spring-type elastic element and a damping-type viscous element in parallel. At all times, the elongation of the two elements is always the same. The two elements are in parallel, and the total stress is equal to the sum of the stresses of the two unit bodies.

[0067] The Meyer-voigt stress-strain relationship is:

[0068]

[0069]

[0070]

[0071] where λ and μ are Lame constants, λ' and μ' are viscosity coefficients; e is the normal strain; θ = e x + e z is the relative volume change; γ is the shear strain; σ is the normal stress; τ is the shear stress.

[0072] The geometric equations are as follows:

[0073]

[0074]

[0075] The motion equations are as follows:

[0076]

[0077]

[0078] Substituting several equations into the Kelvin viscoelastic constitutive equation and combining with the motion equation (elastic dynamics equation), the first-order viscoelastic wave equation system can be derived:

[0079]

[0080]

[0081]

[0082]

[0083]

[0084] Using finite differences to replace derivatives as in Equation (5)

[0085]

[0086] The explicit staggered-grid finite-difference discretization formula for the Kelvin first-order viscoelastic wave equation is obtained as follows:

[0087]

[0088]

[0089] where v is the velocity, ρ is the density, τ is the stress, F is the external force, and other finite-difference formulas are similar.

[0090] 2) Source model

[0091] The airgun source is different from the Ricker wavelet and controllable vibrator signal. The simulation source is loaded by loading the actual airgun far-field wavelet function into the external force term F of the wave equation. The airgun source signal is as follows Figure 2 shown.

[0092] (3) Implementation of the excitation-receiving combined sinking depth optimization technology

[0093] 1) Demonstration of earthquake source placement depth

[0094] For a determined airgun volume wavelet, different source placement depths are selected for excitation simulation, the receiving depth is kept constant, and then the target layer of a single shot excited at different depths is analyzed to find the best excitation depth data. The target layer frequency, energy and signal-to-noise ratio are optimal and still meet the requirements of the geological task.

[0095] 2) Cable laying depth demonstration

[0096] For the determined airgun volume wavelet, under the above-mentioned source sinking depth demonstration parameters, different cable sinking single-shot simulations are carried out. Similarly, the single-shot corresponding to different cable sinking depths is analyzed to analyze the frequency, amplitude and signal-to-noise ratio, and the optimal cable sinking depth parameters are determined in combination with the geological task.

[0097] 3) Based on a comprehensive analysis of the source and cable depth, the optimal source-cable combination depth under specific airgun volume conditions is determined to improve data quality.

[0098] The present invention proposes a numerical simulation excitation and reception parameter optimization technology based on airgun source loading, which systematically considers the effects of excitation, reception and wave propagation. The frequency, energy and signal-to-noise ratio characteristics of the hydrate reservoir reflection signal of a specific airgun capacity under different seismic source and cable sinking depth conditions are quantitatively demonstrated and analyzed through simulation results. Combined with the specific geological task requirements, the optimal matching sinking depth of excitation and reception of the specific airgun capacity is determined to meet the needs of high-resolution exploration of marine reservoirs. At the same time, it also provides a theoretical basis for the optimization design of field airgun source excitation and cable sinking depth parameters.

[0099] 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.

[0100] Example 1

[0101] Taking a certain sea area work area in the ocean as an example, the entire technical process and implementation method are explained in detail below.

[0102] Step 1: Establish the work area velocity model and absorption model

[0103] The velocity model is established according to the interpretation profile of the work area. The main target layers include the seawater layer, the subsea mud layer, the sediment layer, the bedrock layer, and the reservoir, as Figure 3 shown. The volume of the air gun wavelet used in this work area is 1160 in 3 . The main frequency and frequency bandwidth of the wavelet are 66 Hz and 120 Hz respectively, while the main frequency and frequency bandwidth of the target layer in the actual data are 52 Hz and 110 Hz. Therefore, it is necessary to establish a suitable absorption model to ensure the rationality and correctness of the subsequent demonstration. Through different iterative processes, the final corrected absorption model is determined, as shown in Table 1.

[0104] Table 1 Corrected absorption model

[0105]

[0106]

[0107] It is very different from the absorption model established by Li Qingzhong's original empirical formula. The main frequency and frequency bandwidth of the corrected absorption model for simulating a single shot are 52 Hz and 105 Hz respectively, which are close to the actual situation, proving that the absorption model meets the requirements, as shown in Figure 4 shown. Figure 4 Among them, from top to bottom, the first and second curves represent the spectra of the seabed and the hydrate target layer corresponding to the elastic simulation results. It can be seen that the main frequency and frequency bandwidth are consistent with the excitation wavelet; the third and fourth curves represent the results of viscoelastic simulation based on the corrected Q model. The main frequency and frequency bandwidth of the seabed and hydrate are not much different, with the main frequency being 52 Hz and the frequency bandwidth being 105 Hz, only the energy is different, which is basically consistent with the analysis results of the actual data; the fifth and sixth curves represent the simulation results corresponding to the Q model established according to Academician Li Qingzhong's empirical formula. It can be analyzed that the Q model is inaccurate, resulting in excessive absorption and a large difference from the actual data.

[0108] Step 2: Demonstration of different source sinking depths and cable sinking depths

[0109] 1) Demonstration of source sinking depth

[0110] Through the simulation of the wavelets of four source depths (4 m, 5 m, 7 m, and 10 m) of 1160 in 3 while keeping the cable depth consistent, select the corresponding single-shot analysis, and at the same time extract the spectra of the reflection signals of the main target layers (seabed, hydrate reservoir, bedrock) for analysis, as Figures 5a - 5dAs shown in the figure. The analysis of simulation data shows that as the source depth increases, the dominant frequency of the target layer (seabed, reservoir, bedrock) decreases while the energy increases; at the same source depth, the dominant frequency differences among different target layers are not significant, but the energy differences are relatively large; as the sinking depth increases, the notch point moves towards the low frequency, affecting the frequency band width. The corresponding dominant frequencies of the seabed layer under different source depth conditions are 52Hz, 51Hz, 40Hz, and 28Hz; those of the hydrate reservoir are 50Hz, 48Hz, 38Hz, and 28Hz; and those of the bedrock layer are 45Hz, 40Hz, 38Hz, and 28Hz.

[0111] By comparison, when the source is sunk by 5m, the dominant frequency is relatively high, the energy in the dominant frequency band is strong, and the resolution limit is 11m, which is much smaller than the minimum thickness of the hydrate reservoir, 15m. In terms of energy, it is superior to the case of 4m sinking. Therefore, a source sinking depth of 5m is more conducive to the high-resolution exploration requirements of hydrate reservoirs.

[0112] 2) Demonstration of cable sinking depth

[0113] Single-shot analyses of different cable depths are carried out using the wavelet with a source depth of 5m. The cable depths are 0m, 6m, 10m, 15m, and 20m respectively. Through the spectral and signal-to-noise ratio analyses of single shots, it can be seen that as the cable depth increases, the notch point frequency becomes lower and lower, and low-frequency notch points appear accordingly, affecting the frequency band width. Since the sea surface swell in the field cannot be described, the signal-to-noise ratio of the data with a sinking depth of 0m does not match the actual data, so no analysis will be done here. From the overall trend analysis of the simulation data, it can be seen that as the cable sinking depth increases, the signal-to-noise ratio shows an improving trend. When the cable is sunk to a depth of 6m, the dominant frequency band is the widest and the energy in the dominant frequency band is the strongest. When the depth reaches 15m, the increase in the signal-to-noise ratio is not obvious, as shown in Figures 6a - 6b As shown. Considering the single-shot appearance, data spectrum, and signal-to-noise ratio analysis comprehensively, a cable sinking depth of 6m is more appropriate.

[0114] Combining the demonstration results of the source sinking depth and the cable sinking depth, it is considered that for a 1160in 3 it is more appropriate to use a gas gun excitation parameter with a source sinking depth of 5m and a cable sinking depth of 6m, which can meet the high-resolution seismic exploration of hydrates.

[0115] Example 2

[0116] This embodiment provides a device for determining the combined sinking depth of a marine air gun source and a cable, including:

[0117] A construction unit for establishing a velocity model and an absorption model of the work area;

[0118] A simulation unit for carrying out numerical simulation of the excitation of the air gun source wavelet recording;

[0119] A selection unit for selecting different source sinking depths and cable sinking depths based on the simulation results.

[0120] The building unit, the simulation unit, and the selection unit are connected in sequence. Based on the work area velocity model and absorption model established by the building unit, the simulation unit performs numerical simulation of the excitation of the air gun source wavelet recording. The selection unit selects the best-matched source sinking depth and cable sinking depth based on the simulation results provided by the simulation unit.

[0121] Example 3

[0122] This embodiment provides an electronic device, which includes: a memory storing executable instructions; a processor that runs the executable instructions in the memory to implement the above-mentioned method for determining the combined sinking depth of the marine air gun source and cable.

[0123] The electronic device according to an embodiment of the present disclosure includes a memory and a processor.

[0124] The memory is used to store non-temporary computer-readable instructions. Specifically, the memory may include one or more computer program products, and the computer program products may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may include, for example, random access memory (RAM) and / or cache memory, etc. The non-volatile memory may include, for example, read-only memory (ROM), hard disk, flash memory, etc.

[0125] The processor may be a central processing unit (CPU) or other forms of processing units with data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device to perform desired functions. In an embodiment of the present disclosure, the processor is used to run the computer-readable instructions stored in the memory.

[0126] Those skilled in the art should understand that, in order to solve the technical problem of how to obtain good user experience effects, this embodiment may also include well-known structures such as communication buses and interfaces, and these well-known structures should also be included in the protection scope of the present disclosure.

[0127] For the detailed description of this embodiment, reference may be made to the corresponding descriptions in the foregoing embodiments, and details will not be repeated here.

[0128] Example 4

[0129] An embodiment of the present disclosure provides a computer-readable storage medium storing a computer program, and when the computer program is executed by a processor, it implements the method for determining the combined sinking depth of the marine air gun source and cable.

[0130] A computer-readable storage medium according to an embodiment of the present disclosure stores non-transitory computer-readable instructions. When the non-transitory computer-readable instructions are run by a processor, all or part of the steps of the methods of the various embodiments of the present disclosure described above are executed.

[0131] The above computer-readable storage medium includes, but is not limited to: optical storage media (such as CD-ROMs and DVDs), magneto-optical storage media (such as MOs), magnetic storage media (such as magnetic tapes or external hard drives), media with built-in rewritable non-volatile memories (such as memory cards), and media with built-in ROMs (such as ROM cartridges).

[0132] 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 of the examples given.

[0133] The various embodiments of the present invention have been described above. The above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A method for determining the sinking depth of a marine air gun seismic source - cable combination, characterized in that Including: Establish a velocity model and an absorption model for the work area; Conduct numerical simulation of the excitation of the air gun source wavelet record; Select the sinking depth of the source and the sinking depth of the cable based on the simulation results; Among them, the establishment of the absorption model includes: Establish an initial absorption model; Conduct numerical simulation of viscoelastic medium for the excitation of the air gun source wavelet, compare the error between the frequency band of the target layer in the simulated data and the actual data, modify the absorption model until the error between the frequency band of the simulated data and the actual data is minimized, and establish the final absorption model; Among them, the numerical simulation of the excitation of the air gun source wavelet record includes: Establish a viscoelastic wave equation; Complete the loading of the simulated source by loading the actual far-field wavelet function of the air gun in the field into the external force term of the viscoelastic wave equation.

2. The method for determining the sinking depth of the marine air gun seismic source-cable combination according to claim 1, characterized in that, Analyze the frequency, energy, and signal-to-noise ratio characteristics of the reservoir reflection signal under different source sinking depths and different cable sinking depths through the simulation results, and determine the optimal matching sinking depths for excitation and reception with a specific air gun capacity in combination with the specific geological task requirements.

3. The method for determining the sinking depth of the marine air gun seismic source-cable combination according to claim 1, wherein The establishment of the velocity model for the work area includes: Collect the previous exploration data of the work area, establish a structural model of the work area using the interpretation profile, and determine the target layer and its spatial position relationship; Use well data to determine the longitudinal wave velocity, transverse wave velocity, and density attribute values of the formation corresponding to different target layers.

4. The method for determining the sinking depth of the marine air gun seismic source-cable combination according to claim 1, wherein Selecting the sinking depth of the source includes: For the determined air gun volume wavelet, select different source sinking depths for excitation simulation; Keep the reception depth constant and analyze the single-shot target layer at different excitation depths; Based on the frequency, energy, and signal-to-noise ratio of the target layer in the excitation depth data, determine the source sinking depth parameters on the premise of meeting the geological task requirements.

5. The method for determining the sinking depth of the marine air gun seismic source-cable combination according to claim 4, wherein Selecting the sinking depth of the cable includes: For the determined air gun volume wavelet, conduct single-shot simulations with different cable sinkings based on the source sinking depth parameters; Analyze the single shots corresponding to different cable sinking depths, and determine the cable sinking depth parameters according to the frequency, amplitude, and signal-to-noise ratio in combination with the geological task.

6. An apparatus for determining the sinking depth of a marine air gun seismic source-cable combination, characterized in that, Including: A construction unit that establishes a velocity model and an absorption model for the work area; A simulation unit that conducts numerical simulation of the excitation of the air gun source wavelet record; A selection unit that selects the source sinking depth and the cable sinking depth based on the simulation results; Among them, the establishment of the absorption model includes: Establish an initial absorption model; Conduct numerical simulation of viscoelastic medium for the excitation of the air gun source wavelet, compare the error between the frequency band of the target layer in the simulated data and the actual data, modify the absorption model until the error between the frequency band of the simulated data and the actual data is minimized, and establish the final absorption model; Among them, the numerical simulation of the excitation of the air gun source wavelet record includes: Establish a viscoelastic wave equation; Complete the loading of the simulated source by loading the actual far-field wavelet function of the air gun in the field into the external force term of the viscoelastic wave equation.

7. An electronic device, characterized in that, The electronic device includes: A memory that stores executable instructions; A processor that runs the executable instructions in the memory to implement the method for determining the combined sinking depth of an ocean air gun source and a cable 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, it implements the method for determining the combined sinking depth of an ocean air gun source and a cable according to any one of claims 1-5.

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