Seismic observation system design method and device based on two-way wave equation

Abstract

The invention provides a seismological observation system design method and device based on a two-way wave equation. The method comprises the following steps: S10, establishing a typical two-dimensional reservoir model of a work area; s20, based on the two-dimensional reservoir model, shot domain and detection point domain one-way seismic illumination is carried out, and one-way seismic illumination results are obtained; s30, equivalently realizing two-dimensional reservoir two-way illumination by using a two-way wave equation based on the one-way seismic illumination result to obtain a two-way illumination result; and S40, optimizing the parameter design of the seismological observation system according to the bidirectional illumination result. According to the embodiment of the invention, the two-way illumination technology of the observation system is realized through the two-way wave equation forward modeling method, the two-way illumination result of the target layer is obtained, the observation system parameters are optimally designed according to the illumination result, the observation system scheme meeting the exploration requirement is obtained, and the seismic acquisition data quality is improved.

Description

Technical Field

[0001] This invention belongs to the field of seismic exploration technology application, specifically relating to a design method and device for a seismic observation system based on the two-way wave equation. Background Technology

[0002] Seismic illumination technology is a major and effective method for guiding the design and optimization of seismic observation systems. In the past, due to limitations in computing equipment and the simplicity of exploration targets, ray-based forward modeling illumination methods were proposed. However, as exploration targets become increasingly complex, traditional two-point ray-based illumination methods have gradually become insufficient to meet the requirements, resulting in ray blind zones and illumination blind zones.

[0003] In response to this situation, the Gaussian ray beam forward modeling illumination method was proposed. It inherits the advantage of fast computational efficiency of ray-based methods and also considers the energy dynamics characteristics, which have an energy distribution range. However, it is still a ray-based method and is difficult to meet the requirements for particularly complex structures. Summary of the Invention

[0004] In view of this, embodiments of the present invention provide a design method and apparatus for a seismic observation system based on a two-way wave equation to solve the above-mentioned technical problems.

[0005] To achieve the above objectives, firstly, a design method for a seismic observation system based on the two-way wave equation is provided, which includes the following steps:

[0006] S10: Establish a typical two-dimensional reservoir model for the work area;

[0007] S20: Based on the two-dimensional reservoir model, perform unidirectional seismic illumination in the shot area and receiver point area respectively to obtain unidirectional seismic illumination results;

[0008] S30: Based on the unidirectional seismic illumination results, two-dimensional reservoir bidirectional illumination is achieved by using the two-way wave equation to obtain bidirectional illumination results;

[0009] S40: Optimize the parameter design of the seismic observation system based on the bidirectional illumination results.

[0010] In some possible implementations, step S10 includes:

[0011] S11: Acquire typical data of the work area, including depth domain interpretation profile, time domain interpretation profile and vertical seismic profile logging data;

[0012] S12: Based on the size of the work area, establish an initial framework for a two-dimensional reservoir model of the same size range. Then, import the depth domain interpretation profile and the time domain interpretation profile into the initial framework. Draw different stratigraphic lines according to the stratigraphic lines on the depth domain interpretation profile and the time domain interpretation profile to complete the construction of the detailed framework of the two-dimensional reservoir model.

[0013] S13: Extract different formation attributes based on the vertical seismic profile logging data to obtain attribute values ​​including P-wave velocity, S-wave velocity and formation density, and assign the attribute values ​​to the corresponding formations to complete the construction of the two-dimensional reservoir model.

[0014] In some possible implementations, step S20 includes:

[0015] S21: Based on the two-dimensional reservoir model, unidirectional illumination is achieved using the two-way wave equation forward modeling method to obtain forward modeling results;

[0016] S22: Based on the forward modeling results, calculate the unidirectional seismic illumination in the shot area and the unidirectional seismic illumination in the receiver area, respectively, to obtain the unidirectional seismic illumination results in the shot area and the unidirectional seismic illumination results in the receiver area.

[0017] In some possible implementations, step S30 includes:

[0018] The source-direction illumination results and receiver-direction illumination results in the observation system template are obtained. Then, the source-direction illumination results and receiver-direction illumination results in the equivalent observation system template are calculated by multiplying the two illumination results.

[0019] In some possible implementations, step S40 includes:

[0020] S41: A two-way illumination comparison analysis was conducted on different key parameter schemes of the seismic observation system to obtain the target layer illumination intensity distribution of each scheme;

[0021] S42: Based on the target layer illumination intensity distribution and the preset exploration cost threshold, select the optimal key parameters of the observation system; the key parameters include the arrangement length, track spacing and shot distance.

[0022] Secondly, a seismic observation system design device based on the two-way wave equation is provided, which includes:

[0023] The model building module is used to build typical two-dimensional reservoir models for the work area;

[0024] The unidirectional illumination result determination module is used to perform unidirectional seismic illumination in the shot area and receiver point area based on the two-dimensional reservoir model to obtain unidirectional seismic illumination results.

[0025] The two-way illumination result determination module is used to obtain the two-way illumination result by using the two-way wave equation to equivalently realize the two-dimensional reservoir two-way illumination based on the one-way seismic illumination result.

[0026] The parameter optimization module is used to optimize the parameter design of the seismic observation system based on the bidirectional illumination results.

[0027] In some possible implementations, the model building module includes:

[0028] The typical data acquisition submodule for the work area is used to acquire typical data for the work area, including depth domain interpretation profiles, time domain interpretation profiles, and vertical seismic profile logging data.

[0029] The detailed framework construction submodule of the two-dimensional reservoir model is used to establish an initial framework of the two-dimensional reservoir model with the same size range according to the size of the work area, and then import the depth domain interpretation profile and the time domain interpretation profile into the initial framework. According to the stratigraphic lines on the depth domain interpretation profile and the time domain interpretation profile, different stratigraphic lines are drawn to complete the construction of the detailed framework of the two-dimensional reservoir model.

[0030] The formation attribute extraction submodule is used to extract different formation attributes based on the vertical seismic profile logging data, obtain attribute values ​​including P-wave velocity, S-wave velocity and formation density, and assign the attribute values ​​to the corresponding formation to complete the construction of the two-dimensional reservoir model.

[0031] In some possible implementations, the unidirectional lighting module includes,

[0032] The forward modeling submodule is used to achieve unidirectional illumination based on the two-dimensional reservoir model using the two-way wave equation forward modeling method, and obtain forward modeling results.

[0033] The unidirectional seismic illumination result determination submodule is used to calculate the unidirectional seismic illumination in the shot domain and the unidirectional seismic illumination in the receiver domain based on the forward modeling results, so as to obtain the unidirectional seismic illumination results in the shot domain and the unidirectional seismic illumination results in the receiver domain.

[0034] In some possible implementations, the parameter optimization module is further used to,

[0035] A comparative analysis of two-way illumination schemes with different key parameters of the observation system was conducted to obtain the target layer illumination intensity distribution of each scheme.

[0036] Based on the target layer illumination intensity distribution and a preset exploration cost threshold, the optimal key parameters of the observation system are selected, including the arrangement length, track spacing, and shot distance.

[0037] Thirdly, a computer-readable storage medium is provided, on which a computer program is stored, characterized in that, when the program is executed by a processor, it implements any of the wave equation-based seismic observation system design methods described in the first aspect.

[0038] Fourthly, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement any of the wave equation-based seismic observation system design methods described in the first aspect.

[0039] The above technical solution has the following beneficial technical effects:

[0040] This invention implements bidirectional illumination technology for seismic observation systems using a two-way wave equation forward modeling method. It obtains bidirectional illumination results for the target layer, optimizes the design parameters of the seismic observation system based on the illumination results, and obtains a seismic observation system scheme that meets exploration requirements, thereby improving the quality of seismic acquisition data. Attached Figure Description

[0041] Figure 1 This is a flowchart of a seismic observation system design method based on the two-way wave equation according to an embodiment of the present invention;

[0042] Figure 2 This is a flowchart of step S10 in an embodiment of the present invention;

[0043] Figure 3 This is a flowchart of step S20 in an embodiment of the present invention;

[0044] Figure 4 This is a cross-sectional view illustrating the work area according to an embodiment of the present invention;

[0045] Figure 5 This is a complex structural model diagram corresponding to the seismic interpretation profile generated in an embodiment of the present invention;

[0046] Figure 6 These are diagrams showing the bidirectional lighting results with different arrangement lengths according to an embodiment of the present invention;

[0047] Figure 7 This is a comparison diagram of the illumination energy of the target layer under different arrangement lengths according to an embodiment of the present invention;

[0048] Figure 8 This is a functional block diagram of a computer device according to an embodiment of the present invention. Detailed Implementation

[0049] The following description, in conjunction with the accompanying drawings, illustrates exemplary embodiments of the present invention, including various details to aid understanding. These details should be considered merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the invention. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.

[0050] This invention relates to the field of seismic exploration technology applications. It is a technique that uses two-way wave equation numerical simulation technology to achieve equivalent bidirectional illumination of the observation system, and uses the illumination results to guide the optimal design of the observation system in complex areas.

[0051] Although subsequent technologies for achieving two-way seismic illumination based on one-way waves have emerged, two-way wave propagation is the most practical approach because actual seismic waves propagate underground according to a two-way wave propagation pattern. Therefore, this invention's embodiment, based on the two-way wave equation, achieves two-dimensional medium two-way illumination, which can effectively guide the optimized design of complex medium observation systems, maximize the obtained reflection energy of the target layer, and improve the quality of seismic acquisition data.

[0052] This invention implements bidirectional illumination technology for the observation system through a two-way wave equation forward modeling method, obtains bidirectional illumination results for the target layer, optimizes the design of the observation system parameters based on the illumination results, and obtains an observation system scheme that meets exploration requirements, thereby improving the quality of seismic acquisition data.

[0053] Example 1

[0054] like Figure 1 As shown, the method of this embodiment of the invention specifically includes the following steps:

[0055] S10: Establish a typical two-dimensional reservoir model for the work area. For example... Figure 2 As shown, step S10 specifically includes the following steps:

[0056] S11: Acquire typical data for the work area, including depth domain interpretation profiles, time domain interpretation profiles, and vertical seismic profiling (vsp) logging data;

[0057] S12: Based on the size of the work area, establish an initial framework for a two-dimensional reservoir model of the same size range. Then, import the depth domain interpretation profile and the time domain interpretation profile into the initial framework. Draw different stratigraphic lines according to the stratigraphic lines on the depth domain interpretation profile and the time domain interpretation profile to complete the construction of the detailed framework of the two-dimensional reservoir model.

[0058] S13: Extract different formation attributes based on the vertical seismic profile logging data to obtain attribute values ​​including P-wave velocity, S-wave velocity and formation density, and assign the attribute values ​​to the corresponding formations to complete the construction of the two-dimensional reservoir model.

[0059] S20: Perform unidirectional seismic illumination of the shot area and receiver area. For example... Figure 3 As shown, step S20 specifically includes the following steps:

[0060] S21: Unidirectional illumination is achieved using the two-way wave equation forward modeling method, and the forward modeling results are obtained. Specifically, this embodiment of the invention aims to achieve unidirectional illumination using the two-way acoustic wave equation. First, a numerical simulation technique for forming the acoustic wave equation is used, employing a conventional central difference scheme.

[0061] The two-dimensional acoustic wave equation is shown in equation (1):

[0062]

[0063] In the above formula, u is the displacement of the particle vibration, v is the sound wave propagation speed, t is the propagation time, and x and z represent the horizontal and vertical coordinates in two-dimensional space, respectively, describing the changes of the sound wave in these two directions.

[0064] In the above formula, fw(t) is the externally loaded wavelet excitation function. The specific type is determined according to actual needs, and Ricker wavelet, Gaussian wavelet function, and custom wavelet can be used.

[0065] The left side of equation (1) is the second derivative of the sound wave displacement in space, which describes the change of displacement in space. The right side of equation (1) is the second derivative of the sound wave displacement with time, which represents the change of displacement with time. This part is related to the wave propagation speed.

[0066] The difference scheme is used to replace the differential in the above equation to realize the numerical simulation of the wave equation. The first-order partial differential and second-order partial differential difference schemes are established by using Taylor expansion.

[0067] The Taylor forward higher-order polynomial expansion is shown below:

[0068]

[0069] The Taylor backward higher-order polynomial expansion is shown below:

[0070]

[0071] Subtracting equation (3) from equation (2) yields:

[0072]

[0073] Equation (2) + Equation (3) yields:

[0074]

[0075] Further generalization, the first derivative with 2L-order precision central difference approximation can be expressed as follows:

[0076]

[0077] Similarly, by further generalization, the second derivative with 2L-order precision central difference approximation can be expressed as follows:

[0078]

[0079] In the above formula, a m and a′ m The central difference coefficients.

[0080] Therefore, the two-dimensional acoustic wave equation (1) meets the requirements of equation (7). Thus, the equation is expressed by central difference as shown in the following formula. In this embodiment, the time difference is second-order and the spatial difference is eighth-order. The two-way acoustic wave equation can be numerically simulated and calculated using equations (8) to (10).

[0081]

[0082] S22: Unidirectional seismic illumination in the shot area and receiver area, i.e., based on the forward modeling results, unidirectional seismic illumination in the shot area and unidirectional seismic illumination in the receiver area are calculated respectively, and the results of unidirectional seismic illumination in the shot area and receiver area are obtained.

[0083] Source-directed illumination is implemented as follows: Using the forward modeling algorithm described above, this embodiment statistically analyzes the single-source unidirectional illumination results. In the two-dimensional case, let the coordinates of the m-th source be X. m s =(x m ,z m The seismic wave field at the subsurface mass point (x,z) is U(X). m s ;x,z,t), then the two-way wave equation of the subsurface medium can be defined as the intensity of unidirectional illumination from the seismic source:

[0084]

[0085] In the above formula, U(X) m s (x,z,t) represents the wave field amplitude value of the medium at any time during the simulation process at a certain point underground.

[0086] The implementation process of detector domain illumination (hereinafter referred to as detector illumination) is as follows: Similar to source illumination, but the difference lies in the fact that the observation system template is generally an array (detector array or receiver array, referring to the arrangement of multiple detectors placed on the ground according to a certain interval and layout in seismic exploration) containing multiple detectors. Therefore, each detector is considered a seismic source, so it can be seen as multiple sources simultaneously exciting and obtaining array illumination. Assume the number of detectors in the template is Num, and the detectors are rec1, rec2, rec3…rec num Therefore, the illumination of the receiver points is the superposition of all receiver points, and the initial source energy of each receiver point is a coefficient normalized to the energy value and maximum energy value of the direct wave propagating from the shot point forward model to each receiver, i.e., coef1, coef2, coef3…coef num The specific calculation method for each coefficient is shown in the following formula:

[0087]

[0088] In the above formula, DW_U i DW_U represents the maximum amplitude value of the direct wave received at each receiver point in the source excitation observation system template. max The maximum amplitude of the direct wave received at all receiver points is given. This yields the source excitation coefficients for different receiver points. Substituting these coefficients into fw(t) on the right side of equation (1), and multiplying them by the coefficients for each receiver point, we can obtain the source excitation results for the underground medium. Each receiver point can be considered as a source excitation to obtain the illumination results for the underground medium. The specific wavelet function corresponding to each receiver point is fw(t)·coef. i .

[0089] The energy received by each detector is normalized. The normalization coefficient is calculated as the ratio of the energy of the source wavefield directly propagating to each detector to the maximum energy. The purpose is to ensure that the signal strength received by different detectors can be effectively adjusted during superposition, avoiding imaging distortion caused by energy differences.

[0090] In the two-dimensional case, let the coordinates of the m-th receiver out of num receivers be X. m rec =(x m ,z m The seismic wave field at the subsurface mass point (x,z) is U(X). m rec ;x,z,t), then the direction detection illumination intensity corresponding to all detector points in the arrangement can be defined as:

[0091]

[0092] In seismic exploration, multiple geophones (receivers) are used to receive seismic wave signals reflected from the ground. To improve signal acquisition quality and resolution, the geophones are arranged on the surface according to specific rules, forming an array (or arrangement). These geophone arrangements can be linear, two-dimensional grids, or even complex three-dimensional spatial arrangements. In directional illumination, each geophone is considered an independent source excitation point, similar to a seismic source. By observing multiple geophones simultaneously, the overall illumination information of the array can be obtained.

[0093] S30: Bidirectional illumination is achieved using the two-way acoustic wave equation. Step S30 specifically includes the following steps:

[0094] Two-way seismic illumination takes into account the effects of both the source excitation and the detector reception in the seismic observation system, and can reflect the coupled response of the source and detector to the subsurface medium in the seismic observation system.

[0095] Based on the steps in S20, the source illumination and receiver illumination in the seismic observation system template are obtained. The equivalent shot-receiver coupled illumination result in the observation system template can then be calculated by multiplying these two illumination results, as shown in the following formula:

[0096] D shot-rec (X m shot-rec ;x,z,t)=[D s (X m s ;x,z,t)·D rec (X m rec ;x,z,t)] 1 / 2 (14)

[0097] When the total number of shot points is num_shot, the lighting result for the entire model space, i.e., the total illuminance, is as follows:

[0098]

[0099] S40: Based on the bidirectional illumination results of the seismic observation system, guide the optimal design of seismic observation system parameters.

[0100] Step S40 specifically includes the following steps:

[0101] S41: A two-way illumination comparison analysis was conducted on different key parameter schemes of the seismic observation system to obtain the target layer illumination intensity distribution of each scheme;

[0102] S42: Based on the target layer illumination intensity distribution and the preset exploration cost threshold, select the optimal key parameters of the seismic observation system.

[0103] Specifically, by combining the results of two-way illumination, the schemes for different key parameters of the observation system, such as arrangement length, track spacing, and shot distance, can be compared using two-way illumination. Based on the illumination intensity of the target layer and the exploration cost, the optimal key parameters can be selected.

[0104] The above technical solution has the following beneficial technical effects:

[0105] This invention addresses the issue of verifying key parameters in the design of seismic acquisition and observation systems. It proposes the application of wave equation illumination technology to solve the problem of blind spots caused by complex structures where conventional rays do not meet the requirements. This technology adapts to illumination analysis of complex media structures, verifies the illumination results of the target layer for different observation system schemes from the perspective of dynamic characteristics, optimizes key acquisition parameters, and guides seismic acquisition in the field. This will greatly promote the advancement of experimental production in the field.

[0106] Example 2

[0107] The following section uses a work area in ZB as an example to explain in detail the entire technical process and implementation method.

[0108] Step 1: Establishment of a typical complex structural model of the target area.

[0109] Figure 4 Explain the cross-section for the work area, such as Figure 4 As shown, firstly, interpretive cross-sections of the work area are collected. According to design requirements, the corresponding model region requiring verification is selected. The target region is as follows: Figure 4 As shown, the range is from 43km to 75km. The model is 40km long and 9km deep; the main target layers involved are Tjz, TT3x, TT1j, TP21, TP1, and TS, etc. The entire complex model of the work area is as follows: Figure 5 As shown, Figure 5 The complex structural model corresponding to the seismic interpretation profile in the embodiment of the present invention is generated.

[0110] Based on the well data of the work area, the seismic attributes of different strata were obtained, mainly the P-wave velocity. The detailed velocity parameters are shown in Table 1. Table 1 is a table of P-wave parameter values ​​for different strata.

[0111] Table 1. P-wave parameter values ​​for different formations

[0112] strata Longitudinal wave velocity (m / s) 1 4406 2 4427 3 6170 4 4949 5 6215 6 4441 7 4800 8 5000 9 5500 10 6000

[0113] Step 2: Source-detection bidirectional illumination implementation.

[0114] The basic observation system has a track spacing of 10m, a shot spacing of 80m, and a minimum offset of 5m. Based on this, the arrangement length is validated, and three arrangement lengths are designed: 4.8km, 6.0km, and 7.2km. The example only shows the bidirectional illumination results generated by the shot point at the center of the model. Similarly, if there are multiple shot points, the results from different shot points can be superimposed. The bidirectional illumination results corresponding to the three arrangement lengths are as follows: Figure 6 As shown, where Figure 6 (a) corresponds to a length of 4.8 km. Figure 6 (b) Corresponding to a length of 6.0 km, Figure 6 (c) Corresponds to an array length of 7.2 km. Illumination results for the same target layer are extracted as follows: Figure 7 As shown, Figure 7 A comparison of illumination energy for the target layer under different arrangement lengths.

[0115] Step 3: Guide the optimization design of observation system parameters based on the results of two-way illumination.

[0116] according to Figure 4 The results show that a length of 7.2 km is relatively advantageous, therefore, the longer the arrangement length, the better. The same analysis can be conducted for other key parameters, and the optimal design parameters can be selected based on the results.

[0117] This invention belongs to the field of seismic exploration technology application. It is a technology that uses two-way wave equation numerical simulation technology to achieve equivalent bidirectional illumination of the observation system. Based on the illumination results, it guides the optimization design of the observation system in complex areas, solves the problem of ray blind spots caused by the inability of conventional rays to meet the complex structure, adapts to the illumination analysis of complex medium structure, demonstrates the illumination results of the target layer of different observation system schemes from the perspective of dynamic characteristics, selects key acquisition parameters, guides the seismic acquisition in the field, and will play a very good role in promoting the experimental production in the field.

[0118] Example 3

[0119] This embodiment provides a design device for a seismic observation system based on the two-way wave equation, which includes:

[0120] The model building module is used to build typical two-dimensional reservoir models for the work area;

[0121] The unidirectional illumination result determination module is used to perform unidirectional seismic illumination in the shot area and receiver point area based on the two-dimensional reservoir model to obtain unidirectional seismic illumination results.

[0122] The two-way illumination result determination module is used to obtain the two-way illumination result by using the two-way wave equation to equivalently realize the two-dimensional reservoir two-way illumination based on the one-way seismic illumination result.

[0123] The parameter optimization module is used to optimize the parameter design of the seismic observation system based on the bidirectional illumination results.

[0124] In some possible implementations, the model building module specifically includes:

[0125] The typical data acquisition submodule for the work area is used to acquire typical data for the work area, including depth domain interpretation profiles, time domain interpretation profiles, and vertical seismic profile logging data.

[0126] The detailed framework construction submodule of the two-dimensional reservoir model is used to establish an initial framework of the two-dimensional reservoir model with the same size range according to the size of the work area, and then import the depth domain interpretation profile and the time domain interpretation profile into the initial framework. According to the stratigraphic lines on the depth domain interpretation profile and the time domain interpretation profile, different stratigraphic lines are drawn to complete the construction of the detailed framework of the two-dimensional reservoir model.

[0127] The formation attribute extraction submodule is used to extract different formation attributes based on the vertical seismic profile logging data, obtain attribute values ​​including P-wave velocity, S-wave velocity and formation density, and assign the attribute values ​​to the corresponding formation to complete the construction of the two-dimensional reservoir model.

[0128] In some possible implementations, the unidirectional lighting module specifically includes:

[0129] The forward modeling submodule is used to achieve unidirectional illumination based on the two-dimensional reservoir model using the two-way wave equation forward modeling method, and obtain forward modeling results.

[0130] The unidirectional seismic illumination result determination submodule is used to calculate the unidirectional seismic illumination in the shot domain and the unidirectional seismic illumination in the receiver domain based on the forward modeling results, so as to obtain the unidirectional seismic illumination results in the shot domain and the unidirectional seismic illumination results in the receiver domain.

[0131] In some possible implementations, the forward simulation submodule is specifically used to perform the following steps:

[0132] S211: Establish the two-dimensional acoustic wave equation, as shown in equation (1):

[0133]

[0134] In equation (1), u is the particle vibration displacement, v is the sound wave propagation velocity, t is the propagation time, and fw(t) is the externally applied wavelet excitation function.

[0135] S212: The differential scheme is replaced by the difference scheme in equation (1) in order to realize the numerical simulation of the two-way wave equation. The first-order partial differential difference scheme and the second-order partial differential difference scheme are established by Taylor expansion respectively. The Taylor expansion includes Taylor forward higher-order polynomial expansion and Taylor backward higher-order polynomial expansion.

[0136] The Taylor forward higher-order polynomial expansion is shown below:

[0137]

[0138] The Taylor backward higher-order polynomial expansion is shown below:

[0139]

[0140] Equation (2) - Equation (3) yields:

[0141]

[0142] Equation (2) + Equation (3) yields:

[0143]

[0144] S213: The central difference approximation with 2L-order precision and first derivative is derived, as shown in the following equation:

[0145]

[0146] S214: The second derivative central difference approximation with 2L-order precision is derived, as shown in the following equation:

[0147]

[0148] In equations (6) and (7), a m and a′ m The central difference coefficient;

[0149] S214: Formula (1) of the two-dimensional acoustic wave equation meets the requirements of formula (7). Therefore, the two-dimensional acoustic wave equation is expressed by central difference as shown in the following formula, with second-order precision in time and eighth-order difference in space. The numerical simulation calculation of the two-way wave equation is achieved through formulas (8) and (10):

[0150]

[0151] In some possible implementations, the unidirectional seismic illumination result determination submodule is specifically used to perform the following steps:

[0152] S221: Using the aforementioned two-way wave equation forward modeling method, statistical analysis of single-source unidirectional illumination results is performed. In the two-dimensional case, let the coordinates of the m-th source be X. m s =(x m ,z m The seismic wave field at the subsurface mass point (x,z) is U(X). m s (x, z, t), then the two-way wave equation of the subsurface medium is defined as the intensity of unidirectional illumination from the seismic source:

[0153]

[0154] In equation (11), U(X) m s (x, z, t) represents the wave field amplitude value at any time in the underground medium at a certain point during the simulation process;

[0155] S222: Obtain the unidirectional seismic illumination results in the receiver point domain, which specifically includes:

[0156] To obtain the array illumination, assume the template contains Num detectors, labeled rec1, rec2, rec3…rec num The illumination of the receivers is a superposition of all receivers, and the initial source energy of each receiver is a coefficient normalized to the energy value and maximum energy value of the direct wave propagating from the shot point forward model to each receiver, i.e., coef1, coef2, coef3…coef num The specific calculation method for each coefficient is shown in equation (12):

[0157]

[0158] In equation (12), DW_U i DW_U represents the maximum amplitude value of the direct wave received by each receiver point in the source excitation observation system template. max The maximum amplitude of the direct wave received at all receiver points is given, thus obtaining the source excitation coefficients for different receiver points. Substituting this into fw(t) on the right side of equation (1), and multiplying it by the coefficients of each receiver point, each receiver point serves as a source to excite and obtain the illumination results of the subsurface medium. The specific wavelet function corresponding to each receiver point is fw(t)·coef. i ;

[0159] In the two-dimensional case, let the coordinates of the m-th receiver among num receivers be X. m rec =(x m ,z m The seismic wave field at the subsurface mass point (x,z) is U(X). mrec ;x,z,t), then the direction detection illumination intensity corresponding to all detector points in the arrangement is defined as Equation (13):

[0160]

[0161] In some possible implementations, the bidirectional illumination result determination module is specifically used to perform the following steps:

[0162] The source-direction illumination results and receiver-direction illumination results in the observation system template are obtained. Then, the equivalent shot-receiver coupled illumination results in the observation system template are calculated by multiplying the two illumination results, as shown in the following formula:

[0163] D shot-rec (X m shot-rec ;x,z,t)=[D s (X m s ;x,z,t)·D rec (X m rec ;x,z,t)] 1 / 2 (14)

[0164] When the total number of shot points is num_shot, the spatial illumination result of the entire two-dimensional reservoir model is shown in Equation (15):

[0165]

[0166] In some possible implementations, the parameter optimization module is specifically used for: performing a two-way illumination comparison analysis on different key parameter schemes of the observation system to obtain the target layer illumination intensity distribution of each scheme; and, based on the target layer illumination intensity distribution and a preset exploration cost threshold, selecting the optimal key parameters of the observation system; the key parameters include arrangement length, track spacing, and shot distance.

[0167] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0168] Example 4

[0169] This invention also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements any of the above-described seismic observation system design methods based on the two-way wave equation.

[0170] If the integrated module / unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc. Of course, there are other types of readable storage media, such as quantum memories, graphene memories, etc. It should be noted that the content contained in the computer-readable medium may be appropriately added to or subtracted from the content as required by the legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, the computer-readable medium may not include electrical carrier signals and telecommunication signals.

[0171] Example 5

[0172] refer to Figure 8 It shows a schematic diagram of the structure of a computer device 800 suitable for implementing embodiments of the present invention. Figure 8 The computer device shown is merely an example and should not be construed as limiting the functionality or scope of the embodiments of the present invention. The computer device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the wave equation-based seismic observation system design method described above.

[0173] like Figure 8 As shown, the computer device 800 includes a central processing unit (CPU) 801, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 802 or a program loaded from a storage section 808 into a random access memory (RAM) 803. The RAM 803 also stores various programs and data required for the operation of the computer system 800. The CPU 801, ROM 802, and RAM 803 are interconnected via a bus 804. An input / output (I / O) interface 805 is also connected to the bus 804.

[0174] The following components are connected to I / O interface 805: an input section 806 including a keyboard, mouse, etc.; an output section 807 including a cathode ray tube (CRT), liquid crystal display (LCD), etc., and speakers, etc.; a storage section 808 including a hard disk, etc.; and a communication section 809 including a network interface card such as a LAN card, modem, etc. The communication section 809 performs communication processing via a network such as the Internet. A drive 810 is also connected to I / O interface 805 as needed. A removable medium 811, such as a disk, optical disk, magneto-optical disk, semiconductor memory, etc., is installed on drive 810 as needed so that computer programs read from it can be installed into storage section 808 as needed.

[0175] In particular, according to the embodiments disclosed in this invention, the processes described in the above main step diagrams can be implemented as computer software programs. For example, embodiments of this invention include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the main step diagrams. In the above embodiments, the computer program can be downloaded and installed from a network via communication section 809, and / or installed from removable medium 811. When the computer program is executed by central processing unit 801, it performs the functions defined in the system of this invention.

[0176] It should be noted that the computer-readable medium shown in this invention can be a computer-readable signal medium or a computer-readable storage medium, or any combination thereof. A computer-readable storage medium can be, for example,—but not limited to—an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of a computer-readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this invention, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. In this invention, a computer-readable signal medium can include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium, which can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium may be transmitted using any suitable medium, including but not limited to: wireless, wire, optical fiber, RF, etc., or any suitable combination thereof.

[0177] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram or flowchart, and combinations of blocks in a block diagram or flowchart, may be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions. The units described in the embodiments of the present invention may be implemented in software or hardware.

[0178] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can occur depending on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A design method for a seismic observation system based on the two-way wave equation, characterized in that, Includes the following steps: S10: Establish a typical two-dimensional reservoir model for the work area; S20: Based on the two-dimensional reservoir model, perform unidirectional seismic illumination in the shot area and receiver point area respectively to obtain unidirectional seismic illumination results; S30: Based on the unidirectional seismic illumination results, two-dimensional reservoir bidirectional illumination is achieved by using the two-way wave equation to obtain bidirectional illumination results; S40: Optimize the parameter design of the seismic observation system based on the bidirectional illumination results.

2. The method according to claim 1, characterized in that, Step S10 includes: S11: Acquire typical data of the work area, including depth domain interpretation profile, time domain interpretation profile and vertical seismic profile logging data; S12: Based on the size of the work area, establish an initial framework for a two-dimensional reservoir model of the same size range. Then, import the depth domain interpretation profile and the time domain interpretation profile into the initial framework. Draw different stratigraphic lines according to the stratigraphic lines on the depth domain interpretation profile and the time domain interpretation profile to complete the construction of the detailed framework of the two-dimensional reservoir model. S13: Extract different formation attributes based on the vertical seismic profile logging data to obtain attribute values ​​including P-wave velocity, S-wave velocity and formation density, and assign the attribute values ​​to the corresponding formations to complete the construction of the two-dimensional reservoir model.

3. The method according to claim 1, characterized in that, Step S20 includes: S21: Based on the two-dimensional reservoir model, unidirectional illumination is achieved using the two-way wave equation forward modeling method to obtain forward modeling results; S22: Based on the forward modeling results, calculate the unidirectional seismic illumination in the shot area and the unidirectional seismic illumination in the receiver area, respectively, to obtain the unidirectional seismic illumination results in the shot area and the unidirectional seismic illumination results in the receiver area.

4. The method according to claim 1, characterized in that, Step S30 includes: The source-direction illumination results and receiver-direction illumination results in the observation system template are obtained. Then, the source-direction illumination results and receiver-direction illumination results in the equivalent observation system template are calculated by multiplying the two illumination results.

5. The method according to claim 1, characterized in that, Step S40 includes: S41: A two-way illumination comparison analysis was conducted on different key parameter schemes of the seismic observation system to obtain the target layer illumination intensity distribution of each scheme; S42: Based on the target layer illumination intensity distribution and the preset exploration cost threshold, select the optimal key parameters of the observation system; the key parameters include the arrangement length, track spacing and shot distance.

6. A design device for a seismic observation system based on the two-way wave equation, characterized in that, include: The model building module is used to build typical two-dimensional reservoir models for the work area; The unidirectional illumination result determination module is used to perform unidirectional seismic illumination in the shot area and receiver point area based on the two-dimensional reservoir model to obtain unidirectional seismic illumination results. The two-way illumination result determination module is used to obtain the two-way illumination result by using the two-way wave equation to equivalently realize the two-dimensional reservoir two-way illumination based on the one-way seismic illumination result. The parameter optimization module is used to optimize the parameter design of the seismic observation system based on the bidirectional illumination results.

7. The apparatus according to claim 6, characterized in that, The model building module includes: The typical data acquisition submodule for the work area is used to acquire typical data for the work area, including depth domain interpretation profiles, time domain interpretation profiles, and vertical seismic profile logging data. The detailed framework construction submodule of the two-dimensional reservoir model is used to establish an initial framework of the two-dimensional reservoir model with the same size range according to the size of the work area, and then import the depth domain interpretation profile and the time domain interpretation profile into the initial framework. According to the stratigraphic lines on the depth domain interpretation profile and the time domain interpretation profile, different stratigraphic lines are drawn to complete the construction of the detailed framework of the two-dimensional reservoir model. The formation attribute extraction submodule is used to extract different formation attributes based on the vertical seismic profile logging data, obtain attribute values ​​including P-wave velocity, S-wave velocity and formation density, and assign the attribute values ​​to the corresponding formation to complete the construction of the two-dimensional reservoir model.

8. The apparatus according to claim 6, characterized in that, The unidirectional lighting module includes, The forward modeling submodule is used to achieve unidirectional illumination based on the two-dimensional reservoir model using the two-way wave equation forward modeling method, and obtain forward modeling results. The unidirectional seismic illumination result determination submodule is used to calculate the unidirectional seismic illumination in the shot domain and the unidirectional seismic illumination in the receiver domain based on the forward modeling results, so as to obtain the unidirectional seismic illumination results in the shot domain and the unidirectional seismic illumination results in the receiver domain.

9. The apparatus according to claim 6, characterized in that, The parameter optimization module is also used for, A comparative analysis of two-way illumination schemes with different key parameters of the observation system was conducted to obtain the target layer illumination intensity distribution of each scheme. Based on the target layer illumination intensity distribution and a preset exploration cost threshold, the optimal key parameters of the observation system are selected, including the arrangement length, track spacing, and shot distance.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the design method for a seismic observation system based on the wave equation as described in any one of claims 1-5.

11. A computer device, comprising a memory and a processor, characterized in that, The memory stores a computer program, and when the processor executes the computer program, it implements the earthquake observation system design method based on the wave equation as described in any one of claims 1-5.

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