Method and device for determining the number of combinations of vibratory source and the number of coverages

Abstract

The present disclosure provides a method and device for determining the number of controlled source excitation combinations and the number of coverages, belonging to the field of energy development exploration. The determination method comprises: obtaining test data by performing multiple seismic exploration tests using a controlled source excitation combination arranged in the work area; determining a signal-to-noise ratio function of a seismic wave corresponding to the use of different numbers of controlled sources to excite the seismic wave in the seismic exploration test based on a velocity curve of the seismic wave, the test data, and a viscous acoustic wave equation of seismic wave propagation; and determining a target combination number and a target coverage number based on the signal-to-noise ratio function. The present disclosure can effectively improve the quality of seismic acquisition data while reducing the cost of seismic acquisition work.

Description

TECHNICAL FIELD

[0001] The present disclosure belongs to the field of energy development and exploration, and particularly relates to a method and device for determining the number of combined vibrators and the number of coverages of a vibroseis. BACKGROUND

[0002] In the process of seismic data acquisition, the vibroseis gradually becomes the most important excitation method due to its safety, environmental protection, high efficiency and controllable excitation parameters. The vibroseis is a mechanical vibrator that generates seismic waves by continuously impacting the ground through a vibrator installed on a special vehicle, also known as a continuous vibration vibrator. The vibration time and frequency range of the seismic waves generated by the vibroseis can be artificially controlled.

[0003] In order to increase the excitation energy, multiple vibrators are often used to generate seismic waves simultaneously. These multiple vibrators form a vibroseis excitation combination. In order to improve the signal-to-noise ratio of seismic data, multiple repeated observations of the same part of the underground interface are required, and the number of repeated observations is referred to as the number of coverages. In the process of seismic data acquisition, the number of combined vibrators and the number of coverages directly affect the quality, efficiency and exploration cost of seismic data.

[0004] The quality of seismic data improves with the increase of the number of combined vibrators, and also improves with the increase of the number of coverages. However, the exploration cost also increases with the increase of the number of combined vibrators or the number of coverages. Therefore, in the process of seismic data acquisition, it is necessary to scientifically and reasonably design the number of combined vibrators and the number of coverages to achieve the purpose of obtaining high-performance seismic acquisition data.

[0005] In related technologies, the number of combined vibrators and the number of coverages are determined in the following way: first, multiple test groups are selected in a certain area of the work area for seismic exploration, and the number of combined vibrators used by different test groups is different. Then, by processing the test data obtained by each test group, corresponding seismic profile maps are obtained, and the quality of each seismic profile map is observed and compared by naked eye, and finally the number of combined vibrators and the number of coverages are determined.

[0006] However, by observing the seismic profile map with the naked eye, the observation result is not accurate enough and has strong subjectivity, so the corresponding relationship determined may not be scientific, which leads to poor quality of seismic data or increases the cost of seismic acquisition work. SUMMARY

[0007] The present disclosure provides a method for determining the number of combined vibrators and the number of coverages of a vibroseis, which can effectively improve the quality of seismic acquisition data while reducing the cost of seismic acquisition work. The technical solution is as follows:

[0008] The embodiment of the present disclosure provides a method for determining a controllable source excitation combination number and a coverage number, the method comprising:

[0009] A plurality of seismic exploration tests are performed by using a controllable source excitation combination arranged in a work area to obtain test data, and the controllable source excitation combination comprises different numbers of controllable sources in any two of the plurality of seismic exploration tests.

[0010] Based on a velocity curve of a seismic wave, the test data, and a viscous acoustic wave equation of seismic wave propagation, a signal-to-noise ratio function of the seismic wave corresponding to the seismic wave excited by using different numbers of controllable sources in the seismic exploration test is determined, the velocity curve is used to express a relationship between a propagation velocity of the seismic wave and a stratum depth, and the signal-to-noise ratio function is used to express a relationship between a signal-to-noise ratio, a frequency of the seismic wave, the stratum depth, and a coverage number.

[0011] Based on the signal-to-noise ratio function, a target combination number and a target coverage number are determined, and the target combination number and the target coverage number are used to perform seismic exploration on the work area.

[0012] In another implementation manner of the present disclosure, the method for determining the signal-to-noise ratio function of the seismic wave corresponding to the seismic wave excited by using different numbers of controllable sources in the seismic exploration test based on the velocity curve of the seismic wave, the test data, and the viscous acoustic wave equation of seismic wave propagation comprises:

[0013] Based on the velocity curve and the viscous acoustic wave equation, a wave field function is obtained, and the wave field function is used to express a relationship between a wave field value of the seismic wave propagating in space, a frequency of the seismic wave, and a stratum depth.

[0014] Based on the test data, a first signal-to-noise ratio of each excitation point is determined, and the excitation point is a position of the controllable source.

[0015] A second signal-to-noise ratio of each excitation point after being attenuated based on a spherical divergence effect is determined.

[0016] Based on the second signal-to-noise ratio and the wave field function, the signal-to-noise ratio function of the seismic wave is determined.

[0017] In another implementation manner of the present disclosure, the method for determining the first signal-to-noise ratio of each excitation point based on the test data comprises:

[0018] The first signal-to-noise ratio of each excitation point is determined by the following formula:

[0019]

[0020] R1=A1 / di, wherein R1 is a first signal-to-noise ratio of the excitation point, A1 is an amplitude of an effective wave of the excitation point, and di is an amplitude of an i-th noise sample recorded by each receiver before the seismic wave reaches the receiver.

[0021] In another implementation manner of the present disclosure, the first signal-to-noise ratio of each excitation point is determined as a second signal-to-noise ratio after being attenuated based on a spherical divergence effect.

[0022] The second signal-to-noise ratio is obtained by the following formula:

[0023]

[0024] wherein R2 is the second signal-to-noise ratio, z is a stratum depth, and R1 is the first signal-to-noise ratio of the excitation point.

[0025] In another implementation manner of the present disclosure, the signal-to-noise ratio function of the seismic wave is determined based on the second signal-to-noise ratio and the wave field function.

[0026] The signal-to-noise ratio function of the seismic wave is obtained by the following formula:

[0027]

[0028] wherein R is the signal-to-noise ratio of the seismic wave, r0 is a closest distance between a receiver and an excitation point in seismic exploration, R2 is the second signal-to-noise ratio, and z is the stratum depth. is a wave field function, and n is a number of coverages.

[0029] In another implementation manner of the present disclosure, the target number of combined stations and the target number of coverages are determined based on the signal-to-noise ratio function.

[0030] A plurality of preset numbers of coverages are obtained.

[0031] A plurality of signal-to-noise ratio graphs are drawn based on the plurality of preset numbers of coverages and the signal-to-noise ratio function.

[0032] In each of the plurality of signal-to-noise ratio graphs, a maximum frequency of the seismic wave corresponding to the stratum depth of the target layer of the work area when the signal-to-noise ratio is greater than 1 is determined.

[0033] The target number of combined stations and the target number of coverages are determined according to the maximum frequency.

[0034] In another implementation manner of the present disclosure, the target number of combined stations and the target number of coverages are determined according to the maximum frequency.

[0035] determining a maximum value of a maximum frequency of the seismic wave in the signal-to-noise ratio diagram meeting the exploration cost;

[0036] corresponding to the maximum value, as a target number of times of coverage, and a number of the controlled source array corresponding to the controlled source excitation combination, as a target number of combinations.

[0037] In yet another implementation manner of the present disclosure, a device for determining a number of combinations of controlled source excitation and a number of times of coverage is also provided, and the matching device comprises:

[0038] a test data obtaining module, configured to obtain test data by performing multiple seismic exploration tests on a controlled source excitation combination arranged in a work area, wherein the controlled source excitation combination comprises different numbers of controlled sources in any two of the multiple seismic exploration tests;

[0039] a signal-to-noise ratio function determining module, configured to determine a signal-to-noise ratio function of a seismic wave corresponding to different numbers of controlled sources used to excite the seismic wave in the seismic exploration test based on a velocity curve of the seismic wave, the test data, and a viscous acoustic wave equation of seismic wave propagation, wherein the velocity curve is used to express a relationship between a propagation velocity of the seismic wave and a depth of a stratum, and the signal-to-noise ratio function is used to express a relationship among a signal-to-noise ratio, a frequency of the seismic wave, the depth of the stratum, and a number of times of coverage;

[0040] a target number determining module, configured to determine a target number of combinations and a target number of times of coverage based on the signal-to-noise ratio function, wherein the target number of combinations and the target number of times of coverage are used to perform seismic exploration on the work area.

[0041] In yet another implementation manner of the present disclosure, a computer device is also provided, comprising a processor and a memory configured to store instructions executable by the processor; and the processor is configured to execute the above-described method for determining a number of combinations of controlled source excitation and a number of times of coverage.

[0042] In yet another implementation manner of the present disclosure, a computer storage medium is also provided, having computer instructions stored thereon, wherein the computer instructions are executed by a processor to implement the above-described method for determining a number of combinations of controlled source excitation and a number of times of coverage.

[0043] The technical scheme provided by the embodiments of the present disclosure has the following beneficial effects:

[0044] The determination method provided by the embodiment of the present disclosure is to obtain test data according to a seismic exploration test, and determine a signal-to-noise ratio function in combination with a viscous acoustic wave equation of propagation of a seismic wave, the test data and a velocity curve of the seismic wave. Thus, the target combination station number and the target coverage number can be determined scientifically according to the signal-to-noise ratio function, so as to avoid qualitative determination of the target combination station number and the target coverage number by observing a seismic profile by naked eyes, effectively improve the seismic data quality and reduce the seismic acquisition cost. BRIEF DESCRIPTION OF DRAWINGS

[0045] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present disclosure, and other drawings can be obtained by those skilled in the art without creative labor.

[0046] Figure 1 is a flowchart of a determination method of a combination station number and a coverage number of a controllable seismic source provided by the embodiment of the present disclosure;

[0047] Figure 2 is a flowchart of another determination method of a combination station number and a coverage number of a controllable seismic source provided by the embodiment of the present disclosure;

[0048] Figure 3 is a velocity curve diagram of a seismic wave in a certain work area provided by the embodiment of the present disclosure;

[0049] Figure 4 is a seismic data record diagram of a first test provided by the embodiment of the present disclosure;

[0050] Figure 5 is a signal-to-noise ratio diagram of the first test and a preset coverage number of 500 times;

[0051] Figure 6 is a signal-to-noise ratio diagram of the first test and a preset coverage number of 1000 times;

[0052] Figure 7 is a signal-to-noise ratio diagram of a second test and a preset coverage number of 500 times;

[0053] Figure 8 is a signal-to-noise ratio diagram of the second test and a preset coverage number of 1000 times;

[0054] Figure 9 is a matching device schematic diagram of a combination station number and a coverage number of a controllable seismic source provided by the embodiment of the present disclosure;

[0055] Figure 10 is a structural schematic diagram of a computer device provided by the embodiment of the present disclosure. DETAILED DESCRIPTION

[0056] For the purpose, technical solutions and advantages of the present disclosure to be clearer, the present disclosure embodiments will be described in further detail below with reference to the drawings.

[0057] Seismic exploration is a geophysical exploration method that uses the difference in elasticity and density of underground medium, observes and analyzes the response of the earth to artificially excited seismic waves, and infers the properties and morphology of underground rock layers. Seismic exploration needs to set a seismic source, a geophone, and a seismic data acquisition system in a work area (a certain area to be studied). Among them, the seismic source excites seismic waves, the geophone receives the reflection signal of the emission point of the seismic wave after passing through the stratum and converts it into an electrical signal. The seismic data acquisition system amplifies and filters the electrical signal output by the geophone and then records it as a field seismic record (that is, seismic data). Among them, the geophone is multiple and arranged in the work area in a certain way.

[0058] When performing seismic exploration, the positions of the seismic source and the geophone are adjusted multiple times. After adjusting the position each time, each reflection point is observed once. In the process of seismic exploration, the total number of observations is the number of coverages.

[0059] In order to determine the target number of controllable seismic sources and the target number of coverages, a certain area (that is, a test point) in the work area is generally selected in advance to perform multiple seismic exploration tests. Seismic exploration test is to excite the test point in the work area with the corresponding number of controllable seismic sources and the number of coverages, and obtain seismic data through the geophone. Among them, at least one of the number of controllable seismic sources and the number of coverages is different in any two seismic exploration tests. For example, the first exploration test can be set as: after excitation by one controllable seismic source, seismic data is collected once, and a total of 100 collections are performed (the number of coverages is 100 times). The second exploration test is: two controllable seismic sources are excited at the same time, and data is collected once, and a total of 1000 collections are performed (the number of coverages is 1000 times). And so on.

[0060] The present disclosure embodiment provides a method for determining the number of controllable seismic source excitation combinations and the number of coverages, as shown in Figure 1 The determination method comprises:

[0061] S101: Perform multiple seismic exploration tests by a controllable seismic source excitation combination set in a work area to obtain test data. The number of controllable seismic sources included in the controllable seismic source excitation combination in any two seismic exploration tests in the multiple seismic exploration tests is different.

[0062] S102: based on the velocity curve of the seismic wave, the test data, and the viscous acoustic wave equation of the propagation of the seismic wave, a signal-to-noise ratio function corresponding to the seismic wave excited by using different numbers of the controllable seismic source in the seismic exploration test is determined, the velocity curve is used to express the relationship between the propagation velocity of the seismic wave and the depth of the stratum, and the signal-to-noise ratio function is used to express the relationship between the signal-to-noise ratio, the frequency of the seismic wave, the depth of the stratum, and the number of coverages.

[0063] S103: based on the signal-to-noise ratio function, a target combination number and a target number of coverages are determined, and the target combination number and the target number of coverages are used for seismic exploration of the work area.

[0064] Since the determination method provided by the embodiment of the present disclosure is to obtain the test data according to the seismic exploration test, and to determine the signal-to-noise ratio function in combination with the viscous acoustic wave equation of the propagation of the seismic wave, the test data, and the velocity curve of the seismic wave, the target combination number and the target number of coverages can be scientifically determined according to the signal-to-noise ratio function, so as to avoid qualitatively determining the target combination number and the target number of coverages by observing the seismic profile by the naked eye, effectively improve the seismic data quality, and reduce the seismic acquisition cost.

[0065] Figure 2 FIG. 2 is another flowchart of a determination method of a controllable seismic source excitation combination number and a coverage number provided by the embodiment of the present disclosure. As shown in FIG. 2, the determination method comprises the following steps. Figure 2

[0066] S201: a combination of controllable seismic sources is set to perform multiple seismic exploration tests, and test data is obtained. The number of controllable seismic sources in any two seismic exploration tests in the multiple seismic exploration tests is different.

[0067] The test data is seismic data obtained by the multiple seismic exploration tests.

[0068] In this embodiment, two different controllable seismic source excitation combinations are set, that is, two field acquisition tests are performed in the work area. The first test is 1 controllable seismic source for 1 acquisition, and the second test is 2 controllable seismic sources for 1 acquisition. Of course, the number of controllable seismic sources and the number of acquisitions in the seismic exploration test can be designed according to actual needs, and the present disclosure does not limit this.

[0069] Figure 4 FIG. 1 is a seismic record diagram obtained by one of the test acquisitions provided by the embodiment of the present disclosure, Figure 4 in which the horizontal coordinate represents a seismic trace, and the vertical coordinate represents time. The position of the top point in the figure is the position of the excitation point. The black shaded area in the figure is the recorded effective data, and the white area is the noise information.

[0070] ​S202: Obtain a velocity curve of the seismic wave based on logging data in the work area.

[0071] The velocity curve is used to express the relationship between the propagation velocity of the seismic wave and the depth of the stratum.

[0072] In this embodiment, the logging data includes various logging curves, such as a natural gamma logging curve, a caliper logging curve, a spontaneous potential logging, a sonic traveltime logging curve, and the like.

[0073] The velocity curve of the seismic wave can be obtained by performing relevant calculation on the sonic traveltime logging curve in the work area. The manner of determining the velocity curve is not limited in the embodiment of the present disclosure.

[0074] Figure 3 FIG. 1 is a velocity curve diagram of the seismic wave in a certain work area provided by the embodiment of the present disclosure, referring to FIG. 1, Figure 3 Figure 3 the horizontal coordinate is the velocity value v, and the vertical coordinate is the depth z of the stratum. As can be seen from FIG. 1, the velocity of the seismic wave increases in a step-by-step manner with the increase of the depth of the stratum, and the velocity of the seismic wave no longer increases when reaching a certain depth of the stratum. Figure 3

[0075] S203: Establish a viscous acoustic wave equation of the seismic wave propagation.

[0076] In this embodiment, since the underground medium cannot be completely elastic and has viscosity, the seismic wave will produce energy attenuation phenomenon when propagating in the medium, resulting in the decrease of the amplitude value of the seismic wave and the distortion of the phase. Therefore, in order to truly reflect the propagation of the seismic wave in the underground medium, the viscous acoustic wave equation is obtained by the following manner.

[0077] First, the wave equation is established.

[0078] The propagation of the seismic wave in a one-dimensional medium can be described by the following wave equation:

[0079]

[0080] wherein u(x, t) is the displacement wave field, x is the position coordinate of the seismic wave, t is the propagation time of the seismic wave, and v(x) is the propagation velocity of the seismic wave at different positions. Then, Fourier transform (also known as the Fourier transform) is performed on the wave equation.

[0081] At present, most of the wave equation forward modeling is essentially solving equation (1) to obtain the propagation of the underground seismic wave. The Fourier transform is performed on equation (1), so as to transform from the time domain to the frequency domain, and then the absorption attenuation is introduced in the frequency domain.

[0082] ​​Let the Fourier transform of u(x,t) with respect to time t be Then we have:

[0083]

[0084] where, is the Fourier transform of u(x,t) with respect to time t; x is the coordinate of the seismic wave position, and is the depth coordinate of the seismic wave; ω is the frequency of the seismic wave; v(x) is the propagation speed of the seismic wave at different positions.

[0085] Here, the

[0086] Discrete numerical solution is performed on equation (2) to realize numerical simulation of the wave equation. In numerical simulation, a given boundary condition is always performed, and an absorbing boundary condition is always used in seismic exploration simulation. The present disclosure uses a PML (Perfectly Matched Layer) absorbing boundary condition, which can theoretically absorb waves from all directions and frequencies without any reflection. In order to introduce the PML absorbing boundary condition, equation (2) is written in the form of first-order derivative:

[0087]

[0088]

[0089] where, u(x,t) is the displacement wave field; v(x) is the propagation speed of the seismic wave at different positions; A(x,t) is an introduced intermediate variable; x is the coordinate of the seismic wave at different positions.

[0090] Equations (3), (4) and (1) are equivalent. From equations (3), (4), we construct a new equation group:

[0091]

[0092]

[0093] where, u * (x,t) is the conjugate function of u(x,t), and u(x,t) is the displacement wave field; A * (x,t) is the conjugate function of A(x,t), and A(x,t) is an introduced intermediate variable; v(x) is the propagation speed of the seismic wave at different horizontal positions; d(x) is the energy attenuation value of the seismic wave at different horizontal positions, and x is the coordinate of the seismic wave position.

[0094] d(x) does not generate any reflection in the medium when it varies with spatial position. These properties make this medium particularly suitable for use as a boundary absorbing medium for the viscous acoustic wave equation. The above are the governing equations of the time-domain one-dimensional viscous acoustic wave equation complete matching layer. Fourier transform of equations (5)-(6) can be obtained:

[0095]

[0096]

[0097] where i is a complex number (i 2 =-1); ω is the angular frequency of the seismic wave; d(x) is the energy attenuation value of the seismic wave at different horizontal positions; represent the Fourier transform of u * (x, ω) and A * (x, ω), respectively; v(x) is the propagation speed corresponding to different positions in the horizontal direction of the seismic wave. Equations (7) and (8) are the governing equations of the frequency complete matching layer. Combining equations (7) and (8) gives:

[0098]

[0099]

[0100] where i is a complex number (i 2 =-1); ω is the angular frequency of the seismic wave; d(x) is the energy attenuation value of the seismic wave at different horizontal positions; is the Fourier transform of u * (x, ω); v(x) is the propagation speed of the seismic wave at different horizontal positions; x is the position coordinate of the seismic wave; j is a complex number (j 2 =-1, j=-i).

[0101] The present application introduces the viscosity of the seismic wave by using the method of complex velocity:

[0102]

[0103] where v(x) is the propagation speed of the seismic wave at different positions; υ(x, w) is the speed corresponding to different positions and different angular frequencies of the seismic wave; Q(x) is the quality factor of the seismic wave at different positions; j is a complex number (j 2 =-1, j=-i).

[0104]

[0105]

[0106] wherein, υ(w) is the propagation velocity of the seismic wave corresponding to different angular frequencies; ω0is the initial angular frequency of the seismic wave; ω is the angular frequency of the seismic wave; γ is the absorption attenuation coefficient of the medium to the seismic wave; and Q is the quality factor of the seismic wave. Thus, there are

[0107]

[0108] Substituting formula (18) into formula (14) gives:

[0109]

[0110] Adding the source term gives:

[0111]

[0112] wherein, j is a complex number (j 2 = -1, j = -i); ω is the angular frequency of the seismic wave; d(x) is the energy attenuation value of the seismic wave at different positions; is the Fourier transform of u * (x, ω); v(x) is the velocity of the seismic wave at different positions; υ(x, w0) is the propagation velocity of the seismic wave at the horizontal position corresponding to the initial angular frequency; w0is the initial angular frequency of the seismic wave; f(w) is the source term; and Q(x) is the quality factor of the seismic wave at different positions.

[0113] This is the viscous acoustic wave equation. The propagation of the seismic wave in the attenuation medium can be simulated by the calculation of the equation. The equation can be solved by using the finite difference method, in which the difference replaces the differential, and u(x, w) is further obtained, wherein, and u(z, w) are the same variable. That is, z is x, and both are the position coordinates of the seismic wave, that is, the depth of the stratum mentioned above.

[0114] It should be noted that S203 is optional. The viscous acoustic wave equation can be established in advance before the method of the embodiment is executed, and is directly called when the method is executed.

[0115] S204: Based on the velocity curve of the seismic wave, the test data, and the viscous acoustic wave equation of the propagation of the seismic wave, a signal-to-noise ratio function corresponding to the use of different numbers of controlled source arrays to excite the seismic wave in the seismic exploration test is determined, and the signal-to-noise ratio function is used to express the relationship between the signal-to-noise ratio, the frequency of the seismic wave, the depth of the stratum, and the number of coverages.

[0116] S204 includes the following steps:

[0117] 2401: Based on the velocity curve and the viscous acoustic wave equation, a wave field function is obtained, and the wave field function is used to represent the relationship between the wave field value of the propagation of the seismic wave in space, the frequency of the seismic wave, and the depth of the stratum.

[0118] The velocity curve is brought into the viscous acoustic wave equation to obtain a wave field function.

[0119] υ(x, w0) in formula (16) is determined by the velocity curve, and Q(x) is obtained by the following formula.

[0120] Q(x) = 1 / 4υ 2 (x) (17)

[0121] Wherein, Q(x) is the quality factor of the seismic wave at different positions, and v(x) is the velocity of the seismic wave at different positions.

[0122] When υ(x, w0) and Q(x) in formula (16) are determined, f(ω) = 1 is set, so that formula (16) can be solved by finite difference (when solving, the letter z is used instead of x), and the corresponding wave field function is obtained The wave field function is obtained from ω = 2πf

[0123] 2402: Based on the test data, the first signal-to-noise ratio of each excitation point is determined, and the excitation point is the position of the controllable source.

[0124] The signal-to-noise ratio refers to the ratio of the effective signal energy and the noise energy. Among them, the effective signal energy refers to the energy of the seismic wave excited by the excitation point, and the noise energy refers to the energy of various types of noise caused by the propagation of the seismic wave.

[0125] The first signal-to-noise ratio is the ratio of the effective signal energy and the noise energy excited by the controllable source.

[0126] In the process of seismic exploration, the information received by the geophone not only includes the effective signal, but also includes the noise signal. Therefore, the higher the signal-to-noise ratio, the more effective signals, and vice versa.

[0127] Through multiple seismic exploration tests, single-shot seismic records can be obtained, and the strongest energy on the single-shot seismic record is the energy of the excited seismic wave.

[0128] In this embodiment, the first signal-to-noise ratio of each excitation point is determined by the following formula:

[0129]

[0130] Wherein, R1 is the first signal-to-noise ratio of the excitation point, A1 is the amplitude of the effective wave of the excitation point, d i is the amplitude of the i-th noise sample of the record, and the noise sample is the noise signal received by each geophone before the seismic wave reaches the geophone in the process of seismic exploration.

[0131] In formula (18), the denominator is the average amplitude of the noise. That is, in this embodiment, the average amplitude of the noise signal obtained before the arrival of the first wave (the earliest received seismic wave) is used as the amplitude of the noise.

[0132] Combination Figure 4 The effective signal energy is the amplitude in the black shaded area, and the noise energy is the amplitude in the white area.

[0133] Will Figure 4 The black shaded part corresponds to the amplitude of the data and the white part corresponds to the data. Then, using formula (18), the first signal-to-noise ratio of each excitation point in the experiment can be obtained.

[0134] 2403: Determine the first signal-to-noise ratio for each excitation point and the second signal-to-noise ratio after attenuation based on the spherical diffusion effect.

[0135] In this embodiment, the second signal-to-noise ratio is obtained using the following formula:

[0136]

[0137] Where R2 is the second signal-to-noise ratio, z is the formation depth, and R1 is the first signal-to-noise ratio of the excitation point.

[0138] In this embodiment, the spherical diffusion effect is calculated based on the spherical diffusion attenuation curve when calculating the second signal-to-noise ratio.

[0139] 2404: Determine the signal-to-noise ratio function of seismic waves based on the second signal-to-noise ratio and wave field function.

[0140] The signal-to-noise ratio function of seismic waves can be obtained using the following formula:

[0141]

[0142] Where R is the signal-to-noise ratio of the seismic wave; r0 is the closest distance between the geophone and the excitation point during seismic exploration; R2 is the second signal-to-noise ratio; and z is the formation depth. Let n be the wave field function and n be the number of coverages.

[0143] S205: Determine the target number of combined units and the target coverage times based on the signal-to-noise ratio function.

[0144] S205 includes the following steps:

[0145] 2051: Get multiple preset coverage counts.

[0146] In this embodiment, according to multiple seismic exploration tests, multiple signal-to-noise ratio functions corresponding to different combinations of the number of arrays in the multiple seismic exploration tests are obtained, and the number of covers in each signal-to-noise ratio function is preset.

[0147] 2052: Based on the multiple preset numbers of covers and the signal-to-noise ratio functions, multiple signal-to-noise ratio graphs are drawn.

[0148] Different preset numbers of covers are respectively substituted into formula (20), and then the signal-to-noise ratio graphs are drawn according to the function relationship of formula (20).

[0149] In this embodiment, the first exploration test (when the test, the number of arrays is 1, and the number of covers is 500) and the second exploration test (when the test, the number of arrays is 2, and the number of covers is 500) are respectively obtained, and then the signal-to-noise ratio functions (2) corresponding to the first exploration test and the second exploration test are respectively obtained. Then, different preset numbers of covers (n=500, 1000, 1400) are respectively set for the two signal-to-noise ratio functions, and the corresponding signal-to-noise ratio graphs are obtained (see Figures 5-8 ).

[0150] 2053: In each of the multiple signal-to-noise ratio graphs, the maximum frequency of the seismic wave corresponding to the stratum depth of the target layer of the work area when the signal-to-noise ratio is greater than 1 is determined.

[0151] In this embodiment, the obtained signal-to-noise ratio graphs are as shown in Figures 5-8 , wherein Figure 5 is the signal-to-noise ratio graph of the first test and the preset number of covers is 500, Figure 6 is the signal-to-noise ratio graph of the first test and the preset number of covers is 1000. Figure 7 is the signal-to-noise ratio graph of the second test and the preset number of covers is 500, Figure 8 is the signal-to-noise ratio graph of the second test and the preset number of covers is 1000. In each graph, the horizontal coordinate is the frequency of the seismic wave, and the vertical coordinate is the stratum depth. The white part in the graph is the area where the signal-to-noise ratio is greater than 1, the black shaded part is the area where the signal-to-noise ratio is less than 1, and the curve between the white part and the black shaded part is the boundary line where the signal-to-noise ratio is 1.

[0152] In this embodiment, the stratum depth where the target layer is located is 5000m, and in Figure 5 , when the signal-to-noise ratio is greater than 1, the frequency range of the corresponding seismic wave is the left value range (approximately between 0-45Hz) of the horizontal coordinate corresponding to point A in the graph. Figure 5 In the second test, the maximum frequency of the seismic wave is 45Hz. Figure 6 In the second test, when the signal-to-noise ratio is greater than 1, the frequency range of the seismic wave is approximately between 0-53Hz. Figure 5The maximum frequency of the seismic wave is 53Hz. Figure 7 In the middle, when the signal-to-noise ratio is greater than 1, the frequency range of the seismic wave is approximately between 0-56Hz, Figure 7 The maximum frequency of the seismic wave is 56Hz. Figure 8 In the middle, when the signal-to-noise ratio is greater than 1, the frequency range of the seismic wave is 0-60Hz, Figure 8 The maximum frequency of the seismic wave is 60Hz.

[0153] 2054: According to the maximum frequency, determine the target combination number and the target coverage times.

[0154] In the process of seismic exploration, in order to ensure that the obtained seismic data has high resolution, it is necessary to ensure that the frequency of the received seismic wave is within a certain range, that is, in each signal-to-noise ratio diagram, the greater the maximum frequency of the seismic wave, the better. However, as described in the foregoing, in the process of seismic exploration, the more the number of controlled source excitation combinations, the higher the quality of the obtained seismic data, and the higher the cost of seismic exploration. The more the coverage times, the higher the quality of the obtained seismic data, and the higher the cost of seismic exploration. Therefore, after drawing the signal-to-noise ratio diagram, only the comparison analysis is carried out in the multiple signal-to-noise ratio diagrams corresponding to the exploration cost.

[0155] In this embodiment, first, in the signal-to-noise ratio diagram corresponding to the exploration cost, the maximum value of the maximum frequency of the seismic wave is determined. Then, the preset coverage times corresponding to the signal-to-noise ratio diagram corresponding to the maximum value are the target coverage times, and the number of controlled source excitation combinations corresponding to the target coverage times is the target combination.

[0156] For this embodiment, if Figures 5-8 The signal-to-noise ratio diagram in the middle corresponds to the test, which conforms to the exploration cost. Then, according to the above analysis, it can be known that the maximum frequency of the seismic wave is Figure 8 The signal-to-noise ratio diagram in the middle corresponds to the test, which conforms to the exploration cost. Then, according to the above analysis, it can be known that the maximum frequency of the seismic wave is Figure 8 The preset coverage times corresponding to the signal-to-noise ratio diagram in the middle are the target coverage times (that is, 1000), and the number of controlled source excitation combinations is the target combination number (that is, 2).

[0157] In this embodiment, a controlled source excitation combination number and coverage times determination device is also provided, which combines Figure 9 , the device comprises:

[0158] The test data obtaining module 901 is configured to obtain test data by setting the controlled source excitation combination in the work area to perform multiple seismic exploration tests, and the number of controlled sources included in the controlled source excitation combination is different in any two seismic exploration tests in the multiple seismic exploration tests.

[0159] The signal-to-noise ratio function determination module 902 is configured to determine a signal-to-noise ratio function of a seismic wave corresponding to different numbers of controlled sources used to excite the seismic wave in a seismic exploration test based on a velocity curve of the seismic wave, test data, and a viscous acoustic wave equation of propagation of the seismic wave, the velocity curve being used to express a relationship between a propagation velocity of the seismic wave and a stratum depth, and the signal-to-noise ratio function being used to express a relationship between a signal-to-noise ratio, a frequency of the seismic wave, the stratum depth, and a fold number.

[0160] The target number determination module 903 is configured to determine a target combination number and a target fold number based on the signal-to-noise ratio function, the target combination number and the target fold number being used to perform seismic exploration on a work area.

[0161] The above determination device has all the beneficial effects of the method shown in the description, which will not be repeated here. Figure 1 The above determination device has all the beneficial effects of the method shown in the description, which will not be repeated here.

[0162] Optionally, the signal-to-noise ratio function determination module 902 includes:

[0163] The wave field function determination module 9021 is configured to obtain a wave field function based on the velocity curve and the viscous acoustic wave equation, the wave field function being used to express a relationship between a wave field value of propagation of the seismic wave in space, the frequency of the seismic wave, and the stratum depth.

[0164] The first signal-to-noise ratio determination sub-module 9022 is configured to determine a first signal-to-noise ratio of each excitation point based on the test data, the excitation point being a position of the controlled source.

[0165] The second signal-to-noise ratio determination sub-module 9023 is configured to determine a second signal-to-noise ratio of each excitation point after attenuation based on a spherical spreading effect.

[0166] The signal-to-noise ratio function determination sub-module 9024 is configured to determine the signal-to-noise ratio function of the seismic wave based on the second signal-to-noise ratio and the wave field function.

[0167] Optionally, the first signal-to-noise ratio determination sub-module 9022 is further configured to determine the first signal-to-noise ratio of each excitation point by formula (18).

[0168] Optionally, the second signal-to-noise ratio determination sub-module 9023 is further configured to determine the second signal-to-noise ratio by formula (19).

[0169] Optionally, the signal-to-noise ratio function determination sub-module 9024 is further configured to obtain the signal-to-noise ratio function of the seismic wave by the following formula (20).

[0170] Optionally, the target number determination module 903 comprises a preset coverage number determination sub-module 9031 configured to obtain a plurality of preset coverage numbers. A signal-to-noise ratio graph determination sub-module 9032 is configured to draw a plurality of signal-to-noise ratio graphs based on the plurality of preset coverage numbers and a signal-to-noise ratio function. A maximum frequency determination sub-module 9033 is configured to determine, in each of the plurality of signal-to-noise ratio graphs, a maximum frequency of a seismic wave corresponding to a formation depth of a target layer of a work area when a signal-to-noise ratio is greater than 1. A target number determination sub-module 9034 is configured to determine a target combination number and a target coverage number according to the maximum frequency.

[0171] Optionally, the maximum frequency determination sub-module 9043 is further configured to determine a maximum value of the maximum frequency of the seismic wave in the signal-to-noise ratio graph meeting the exploration cost.

[0172] The preset coverage number corresponding to the signal-to-noise ratio graph corresponding to the maximum value is the target coverage number, and the combination number of the vibratory source corresponding to the signal-to-noise ratio graph corresponding to the maximum value is the target combination number.

[0173] Figure 10 is a structural schematic diagram of a computer device provided by an embodiment of the present disclosure, in combination with Figure 10 The computer device 1000 can include one or more of the following components: a processor 1001, a memory 1002, a communication interface 1003, and a bus 1004.

[0174] The processor 1001 includes one or more processing cores. The processor 1001 performs various functional applications and information processing by running software programs and modules. The memory 1002 and the communication interface 1003 are connected to the processor 1001 through the bus 1004. The memory 1002 can be used to store at least one instruction, and the processor 1001 is configured to execute the at least one instruction to implement the steps in the above method.

[0175] In addition, the memory 1002 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, including but not limited to: a magnetic disk or an optical disk, an electrically erasable programmable read-only memory (EEPROM), an erasable programmable read-only memory (EPROM), a static random access memory (SRAM), a read-only memory (ROM), a magnetic memory, a flash memory, and a programmable read-only memory (PROM).

[0176] The present disclosure further provides a computer storage medium, and computer instructions are executed by a processor to implement the above method for determining the combination number of the vibratory source and the coverage number.

[0177] A computer program product containing instructions which, when executed on a computer, cause the computer to perform the above method for determining the number of controlled source excitation groups and the number of coverages provided by the embodiments of the present application.

[0178] The above only describes optional embodiments of the present disclosure and is not intended to limit the present disclosure. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A method for determining the number of controllable source shooting assemblies and the number of coverages, characterized in that, The determination method comprises: a plurality of seismic exploration tests are performed by using a controllable source excitation combination arranged in a work area to obtain test data, and the controllable source excitation combination comprises different numbers of controllable sources in any two of the plurality of seismic exploration tests; based on a velocity curve of a seismic wave, the test data, and a viscous acoustic wave equation of seismic wave propagation, a signal-to-noise ratio function of the seismic wave corresponding to the different numbers of controllable sources used to excite the seismic wave in the seismic exploration tests is determined, the velocity curve is used to express a relationship between a propagation velocity of the seismic wave and a stratum depth, and the signal-to-noise ratio function is used to express a relationship between a signal-to-noise ratio, a frequency of the seismic wave, the stratum depth, and a number of coverages; based on the signal-to-noise ratio function, a target combination number and a target number of coverages are determined, and the target combination number and the target number of coverages are used to perform seismic exploration on the work area; wherein, based on the velocity curve of the seismic wave, the test data, and the viscous acoustic wave equation of seismic wave propagation, the signal-to-noise ratio function of the seismic wave corresponding to the different numbers of controllable sources used to excite the seismic wave in the seismic exploration tests is determined, comprising: based on the velocity curve and the viscous acoustic wave equation, a wave field function is obtained, the wave field function is used to express a relationship between a wave field value of the seismic wave propagating in space, a frequency of the seismic wave, and a stratum depth; based on the test data, a first signal-to-noise ratio of each excitation point is determined, the excitation point is a position where the controllable source is located; a second signal-to-noise ratio of the first signal-to-noise ratio of each excitation point after being attenuated based on a spherical diffusion effect is determined; based on the second signal-to-noise ratio and the wave field function, the signal-to-noise ratio function of the seismic wave is determined; the determination of the first signal-to-noise ratio of each excitation point based on the test data comprises: the first signal-to-noise ratio of each excitation point is determined by the following formula: ； wherein, R1 is the first signal-to-noise ratio of the excitation point, A1 is the amplitude of the effective wave of the excitation point, di is the amplitude of the i-th noise sample recorded, the noise sample is a noise signal received by each receiver before the seismic wave received by the receiver arrives at the receiver during the seismic exploration process; n is the number of noise samples; the determination of the second signal-to-noise ratio of the first signal-to-noise ratio of each excitation point after being attenuated based on the spherical diffusion effect comprises: the second signal-to-noise ratio is obtained by the following formula: ； wherein, R2 is the second signal-to-noise ratio, z is the stratum depth, and R1 is the first signal-to-noise ratio of the excitation point.

2. The determination method according to claim 1, characterized in that, the determination of the signal-to-noise ratio function of the seismic wave based on the second signal-to-noise ratio and the wave field function comprises: the signal-to-noise ratio function of the seismic wave is obtained by the following formula: ； Wherein, R is the signal-to-noise ratio of the seismic wave; r0 is the shortest distance from the detector to the excitation point in seismic exploration; R2 is the second signal-to-noise ratio; z is the stratum depth; is the wave field function, f is the frequency of the seismic wave; m is the number of coverages.

3. The determination method according to claim 1, characterized in that, the determination of the target combination number and the target number of coverages based on the signal-to-noise ratio function comprises: a plurality of preset numbers of coverages are obtained; a plurality of signal-to-noise ratio graphs are drawn based on the plurality of preset numbers of coverages and the signal-to-noise ratio function; in each of the plurality of signal-to-noise ratio graphs, a maximum frequency of the seismic wave corresponding to a stratum depth of a target layer of the work area when the signal-to-noise ratio is greater than 1 is determined. According to the maximum frequency, the target combination number of stations and the target number of coverages are determined.

4. The determination method according to claim 3, characterized in that, The determining the target combination number of stations and the target number of coverages according to the maximum frequency comprises: In the signal-to-noise ratio map conforming to the exploration cost, a maximum value of a maximum frequency of a seismic wave is determined; A preset number of coverages corresponding to the signal-to-noise ratio map corresponding to the maximum value is taken as a target number of coverages, and a number of stations of a controlled source array corresponding to the signal-to-noise ratio map corresponding to the maximum value is taken as a target combination number of stations.

5. A device for determining the number of controllable source firing assemblies and the number of coverages, characterized in that, The determining device comprises: The test data obtaining module is configured to obtain test data by performing multiple seismic exploration tests on a controlled source array arranged in a work area, wherein the controlled source array comprises different numbers of controlled sources in any two of the multiple seismic exploration tests; The signal-to-noise ratio function determining module is configured to determine a signal-to-noise ratio function of a seismic wave based on a velocity curve of the seismic wave, the test data, and a viscous acoustic wave equation of seismic wave propagation, wherein the velocity curve is used to express a relationship between a propagation velocity of the seismic wave and a stratum depth, the signal-to-noise ratio function is used to express a relationship among a signal-to-noise ratio, a frequency of the seismic wave, the stratum depth, and a number of coverages, and the signal-to-noise ratio function is used to obtain a wave field function based on the velocity curve and the viscous acoustic wave equation, wherein the wave field function is used to express a relationship among a wave field value of the seismic wave in space propagation, the frequency of the seismic wave, and the stratum depth; determine a first signal-to-noise ratio of each firing point based on the test data, wherein the firing point is a position of the controlled source; determine a second signal-to-noise ratio of the first signal-to-noise ratio of each firing point after being attenuated based on a spherical diffusion effect; and determine the signal-to-noise ratio function of the seismic wave based on the second signal-to-noise ratio and the wave field function; and configured to determine the first signal-to-noise ratio of each firing point by the following formula: ； wherein R1 is the first signal-to-noise ratio of the firing point, A1 is an amplitude of an effective wave of the firing point, di is an amplitude of an i-th noise sample point recorded, wherein the noise sample point is a noise signal received by each receiver before a seismic wave received by the receiver arrives at the receiver during seismic exploration; and n is a number of noise sample points; and obtain the second signal-to-noise ratio by the following formula: ； wherein R2 is the second signal-to-noise ratio, z is the stratum depth, and R1 is the first signal-to-noise ratio of the firing point; The target number determining module is configured to determine a target combination number of stations and a target number of coverages based on the signal-to-noise ratio function, wherein the target combination number of stations and the target number of coverages are used to perform seismic exploration on the work area.

6. A computer device, comprising: The computer device comprises a processor and a memory configured to store instructions executable by the processor; and the processor is configured to execute the method for determining a combination number of stations and a number of coverages of a controlled source array according to any one of claims 1 to 4.

7. A computer storage medium having stored thereon computer instructions, wherein the computer instructions, when executed by a computer, cause the computer to perform the method of any one of claims 1-6. The computer instructions, when executed by the processor, implement the method for determining a combination number of stations and a number of coverages of a controlled source array according to any one of claims 1 to 4.

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