Excitation depth design method based on refraction micro-logging data constraint

Abstract

The invention provides an excitation depth design method based on refraction micro-logging data constraint. The excitation depth design method comprises the steps that 1, common excitation point gather records of different excitation depths are extracted according to refraction micro-logging data; 2, calculating the dominant frequency of the excitation point gathers with different excitation depths; step 3, calculating the frequency band width of the excitation point gathers with different excitation depths, and forming the dominant frequency and frequency band width quantitative results of excitation with different depths; step 4, optimizing the excitation depth according to the quantitative analysis result; 5, establishing a whole-area three-dimensional optimal excitation depth model through a specific algorithm; and step 6, calculating the excitation depth of each known coordinate point through the model. According to the excitation depth design method based on refraction micro-logging data constraint, the well depth is designed for seismic exploration project excitation, the original seismic data frequency can be effectively improved, and then the resolution of seismic data is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of geophysical seismic exploration, and particularly to a method for designing the excitation depth constrained by refraction micro-logging data. Background Art

[0002] In geophysical seismic exploration, to acquire high-quality seismic data, the two most crucial factors are excitation and reception. The most critical aspect of excitation is the selection of the excitation depth. The quality of the seismic records excited at different excitation depths varies significantly, and the excitation depth is particularly important in seismic exploration acquisition.

[0003] The traditional method for designing the excitation depth in seismic exploration is to use data such as micro-logging and lithology detection to obtain the velocity interface near the surface, find the high-velocity layer below the low-velocity layer, and select the clay layer with better excitation effect below the high-velocity layer for excitation. The excitation depth between adjacent surface survey points is designed by means of smooth interpolation.

[0004] The traditional method works well in areas with relatively simple and stable near-surface structures, but may result in poor excitation effects in areas with relatively complex near-surfaces.

[0005] In the Chinese patent application with the application number: CN201410645141.9, a method for determining the excitation depth in seismic exploration is involved, including: obtaining the micro-logging waveform diagram and the micro-logging velocity-depth curve through micro-logging measurement in the seismic work area; determining the first excitation depth at the micro-logging according to the preset excitation depth range and the micro-logging waveform diagram; obtaining the surface structure interpretation profile diagram of the seismic work area by using non-seismic methods; plotting the micro-logging velocity-depth curve, the first excitation depth, the preset minimum excitation depth line, and the maximum excitation depth line on the surface structure interpretation profile diagram; using the first excitation depth as a calibration to determine the excitation depth curve of all profiles in the seismic work area, extracting the elevation corresponding to the excitation depth curve, performing grid interpolation on the elevation, and obtaining the excitation elevation surface of the seismic work area; determining the planar position of the seismic shot points and measuring the ground elevation of each shot point, respectively calculating the height difference between the ground elevation of each shot point and the corresponding position on the excitation elevation surface, and taking the height difference as the excitation depth of the shot point.

[0006] In the Chinese patent application with the application number: CN201910213050.0, a micro-log tomography method for the design of excitation well depth is involved, including: inputting micro-log information, micro-log first arrival travel time data, and micro-log horizon interpretation information; determining the inversion depth and inversion grid; based on the determined inversion grid, gridifying the micro-log horizon interpretation information to obtain an interpretation constraint term consistent with the model scale; constructing an equation set, and adding a velocity smoothing term and a micro-log interpretation constraint term; solving the equation set to obtain an inversion result; resampling the result to obtain a velocity model that meets the requirements. This micro-log tomography method for the design of excitation well depth reduces the human influence, and the obtained velocity distribution contains more near-surface structure details, facilitating the accurate determination of the optimal excitation depth, ensuring the acquisition quality of seismic data, and laying a foundation for subsequent seismic data processing.

[0007] In the Chinese patent application with the application number: CN201410764314.9, a method and system for designing the excitation well depth of a seismic source are involved. Using the embodiments of the present invention, the method includes S1: obtaining the maximum designed excitation well depth of the exploration area; S2: obtaining seismic data of the exploration area by using micro-logs; S3: extracting one seismic data from the seismic data according to a predetermined rule, and arranging the extracted seismic data in the order of the excitation depth of the micro-logs to form an excitation seismic data record; S4: performing a spectral analysis on the excitation seismic data record to obtain the frequency bandwidth of the excitation seismic data;

[0008] S5: selecting the well depth of the micro-log that meets the requirements of the preset amplitude, frequency bandwidth, and adjacent trace waveform consistency in the excitation seismic data record as the optimal excitation section of the seismic source. Using the embodiments of the present application, a reasonable excitation well depth of the seismic source can be designed in a complex surface area, improving the excitation effect of the seismic source and the signal-to-noise ratio of the acquired seismic data.

[0009] The above prior arts are all quite different from the present invention and cannot solve the technical problems we want to solve. Therefore, we have invented a new excitation depth design method based on refraction micro-log data constraints. Summary of the Invention

[0010] The object of the present invention is to provide an excitation depth design method based on refraction micro-log data constraints that is not only suitable for the excitation depth design of seismic exploration with relatively simple near-surface structures but also suitable for the excitation depth design of areas with complex near-surface structures and can design to achieve the optimal excitation depth.

[0011] The object of the present invention can be achieved by the following technical measures: an excitation depth design method based on refraction micro-log data constraints, and this excitation depth design method based on refraction micro-log data constraints includes:

[0012] Step 1: Extract the common-shot gather records at different excitation depths based on the refraction micro-logging data;

[0013] Step 2: Calculate the main frequency of the shot gather at different excitation depths;

[0014] Step 3: Calculate the frequency bandwidth of the shot gather at different excitation depths, and form the quantitative results of the main frequency and frequency bandwidth for different depths of excitation;

[0015] Step 4: Optimize the excitation depth according to the above quantitative analysis results;

[0016] Step 5: Establish a three-dimensional optimal excitation depth model for the whole area through a specific algorithm;

[0017] Step 6: Calculate the excitation depth of each known coordinate point through the model.

[0018] The object of the present invention can also be achieved by the following technical measures:

[0019] In Step 1, during the surface investigation construction, on the basis of the conventional micro-logging ground receiving array, add medium and far offset receiving points, and convert the conventional micro-logging into refraction micro-logging receiving by increasing the layout of receiving points, so that more reflected wave and refracted wave information can be received.

[0020] In Step 1, receive and record the data records of each shot excitation, and output the received records as record files according to the common-shot gather records. The data includes different excitation depth data files through the offset.

[0021] In Step 2, analyze and calculate the frequency components of each excitation record, calculate its main frequency value, sort the refraction micro-logging data according to different offsets, extract the shot gather records of each excitation depth, and sort them according to the excitation depth.

[0022] In Step 3, analyze and calculate the frequency components of each excitation record, and calculate its frequency bandwidth.

[0023] In Step 4, according to the above quantitative analysis and sorting results, optimize and select the best excitation depth of one of the points.

[0024] The excitation depth design method based on refraction micro-logging data constraint further includes, after Step 4, repeating Step 2 to Step 4 to calculate the best excitation depth of all refraction micro-logging survey points within the work area.

[0025] In Step 5, use a specific algorithm to establish a three-dimensional model of the best excitation depth for the whole area. The specific algorithm estimation calculation method: x1……x n are a series of observation points in the region, z(x1),……,z(x n) is the corresponding observed value; the value Z of the regional change at x0 * (x0) can be estimated using a linear combination:

[0026]

[0027] where λ i is the weight coefficient to be determined, satisfying the following relationship:

[0028]

[0029] In step 6, according to each excitation point coordinate, elevation data and the 3D model, the optimal excitation depth of each excitation point is calculated by interpolation.

[0030] In step 6, the interpolation calculation method:

[0031]

[0032] where d m is the designed excitation depth, (x s , y s , z s ) is the coordinate position of the excitation point, (x m , y m , z m ) is the coordinate position of the model. When the excitation point is within the model range, x s -x m = 0, y s -y m = 0 should be selected.

[0033] The object of the present invention can also be achieved by the following technical measures: an excitation depth design system based on refraction micro-logging data constraints. This excitation depth design system based on refraction micro-logging data constraints uses an excitation depth design method based on refraction micro-logging data constraints to select the excitation depth that can excite the best frequency components.

[0034] The excitation depth design method based on refraction micro-logging data constraints in the present invention is suitable for areas with relatively complex near-surface lithology. For the design of the excitation well depth in areas with large near-surface changes, no complete set of excitation lithology, many thin interbeds, and large lateral lithology changes, using this method to design the well depth for seismic exploration project excitation can effectively improve the frequency of the original seismic data, and thus improve the resolution of the seismic data.

[0035] Compared with the traditional conventional excitation depth design method, the present invention adds receiving point information to the traditional micro-logging, enables it to receive refracted wave information, transforms the traditional micro-logging into refraction micro-logging, and conducts analysis and research on the refraction micro-logging data, thereby proposing a high-precision excitation depth design method. The excitation depth design method based on refraction micro-logging data constraint in the present invention establishes a process for excitation depth design based on refraction micro-logging data constraint. This method can improve the excitation depth design accuracy for complex near-surface structures and large lateral lithological variations, increase the frequency bandwidth of seismic data, is relatively simple, convenient for popularization and application, can effectively improve the resolution of seismic data, and improve the quality of seismic data. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a flowchart of a specific embodiment of the excitation depth design method based on refraction micro-logging data constraint of the present invention;

[0037] Figure 2 It is a schematic diagram of the refraction micro-logging observation system of the excitation depth design method based on refraction micro-logging data constraint in a specific embodiment of the present invention;

[0038] Figure 3 It is a schematic diagram of the co-excitation point gather records of the refraction micro-logging excitation data at different excitation depths in a specific embodiment of the excitation depth design method based on refraction micro-logging data constraint of the present invention;

[0039] Figure 4 It is a schematic diagram of the frequency and frequency bandwidth analysis of the co-excitation point gather records of the refraction micro-logging excitation data at different excitation depths in a specific embodiment of the excitation depth design method based on refraction micro-logging data constraint of the present invention;

[0040] Figure 5 It is a schematic diagram of the frequency and frequency bandwidth analysis of the co-excitation point gather records of the refraction micro-logging excitation data at different excitation depths in a specific embodiment of the excitation depth design method based on refraction micro-logging data constraint of the present invention;

[0041] Figure 6 It is a schematic diagram of the main frequency analysis of the co-excitation point gather records of the refraction micro-logging excitation data at different excitation depths sorted by depth in a specific embodiment of the excitation depth design method based on refraction micro-logging data constraint of the present invention;

[0042] Figure 7 It is a schematic diagram of the three-dimensional excitation depth model established by estimating the preferred excitation depth through a specific algorithm after the co-excitation point gather record analysis in a specific embodiment of the excitation depth design method based on refraction micro-logging data constraint of the present invention;

[0043] Figure 8Schematic diagram of well depth designed based on the method of the present invention for actual production data of the excitation depth design method constrained by refraction micro-logging data according to a specific embodiment of the present invention;

[0044] Figure 9 Schematic diagram of well depth designed based on the traditional method for actual production data of the excitation depth design method constrained by refraction micro-logging data according to a specific embodiment of the present invention;

[0045] Figure 10 Schematic diagram of well depth designed based on the traditional method for actual production data of the excitation depth design method constrained by refraction micro-logging data according to a specific embodiment of the present invention;

[0046] Figure 11 Schematic diagram of well depth designed based on the method of the present invention for actual production data of the excitation depth design method constrained by refraction micro-logging data according to a specific embodiment of the present invention. Detailed implementation mode

[0047] It should be noted that the following detailed description is exemplary and is intended to provide further illustration of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0048] It should be noted that the terms used herein are only for describing specific implementation modes and are not intended to limit the exemplary implementation modes according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, and / or combinations thereof.

[0049] The excitation depth design method of the present invention based on refraction micro-logging well constraint is applicable to areas with large and complex changes in the near-surface structure. By calculating the frequency and frequency bandwidth components of different excitation depths and analyzing them, the excitation depth that can excite the best frequency components can be selected more scientifically; thereby improving the quality of the original seismic data. As Figure 1 shown, Figure 1 The flowchart of a specific embodiment of the excitation depth design method of the present invention based on refraction micro-logging data constraint. The excitation depth design method based on refraction micro-logging well data constraint includes:

[0050] Step 1: During the surface survey construction, add medium and far offset receiving points on the basis of the conventional micro-logging ground receiving array, and convert the conventional micro-logging into refraction micro-logging receiving by increasing the layout of receiving points to make it receive the information of refracted waves;

[0051] Step 2: Receive the data records of each shot fired, and output the received records as record files according to the common shot gather records. The data includes the excitation depth data files with different offsets;

[0052] Step 3: Analyze and calculate the frequency components of each excitation record, and calculate its dominant frequency value;

[0053] Step 4: Analyze and calculate the frequency components of each excitation record, and calculate its frequency bandwidth;

[0054] Step 5: Sort according to the dominant frequency and frequency bandwidth respectively according to the results obtained in Step 3 and Step 4;

[0055] Step 6: According to the above quantitative analysis and sorting results, optimize and select the best excitation depth of one of the points;

[0056] Step 7: Repeat Step 3 to Step 6 to calculate the best excitation depth of all refraction micro-logging survey points within the work area;

[0057] Step 8: Establish a three-dimensional model of the best excitation depth for the whole area according to the above calculation results based on a specific algorithm;

[0058] Step 9: According to the coordinates and elevation data of each excitation point, use the model obtained in Step 8 to stagger the best excitation well depth of each excitation point.

[0059] As a preferred technical solution, in Step 1, receive refraction wave information with medium and far offsets on the ground for the conventional micro-logging, so that the conventional micro-logging becomes a refraction micro-logging.

[0060] As a preferred technical solution, in Step 2, sort the refraction micro-logging data according to different offsets, extract the shot gather records of each excitation depth, and sort according to the excitation depth.

[0061] As a preferred technical solution, in Step 3 and Step 4, analyze and calculate the frequency components and frequency bandwidth of each excitation record data.

[0062] As a preferred technical solution, in Step 8, establish a three-dimensional model of the best excitation depth for the whole area using a specific algorithm.

[0063] Specific algorithm estimation calculation method: x1……x n Are a series of observation points in the area, z(x1),……,z(x n ) are the corresponding observed values. The value Z of the regional change amount at x0 * (x0) can be estimated by a linear combination:

[0064]

[0065] where λ i is a weight coefficient to be determined, satisfying the following relational expressions:

[0066] As a preferred technical solution, the optimal excitation depth of each excitation point is calculated by interpolation based on each excitation point coordinate, elevation data, and three-dimensional model.

[0067] Interpolation calculation method:

[0068]

[0069] where d m is the excitation point depth, (x s , y s , z s ) is the coordinate position of the excitation point, (x m , y m , z m ) is the model coordinate position. When the excitation point is within the model range, x s -x m = 0, y s -y m = 0 should be selected.

[0070] Refraction micro-logging excitation can receive direct waves, reflected waves, and refracted waves with rich information. Its excitation effect can directly reflect the excitation effect of the excitation source at this depth. Based on the excitation depth design method constrained by refraction micro-logging data, the frequency band width and main frequency of the co-excitation point micro-logging records excited at different depths are calculated, and the optimal excitation depth is comprehensively analyzed and selected after sorting according to the quantitative analysis results. A three-dimensional model of the optimal excitation depth is established, and the optimal excitation depth of known coordinate points is calculated to improve the excitation effect and obtain high-quality seismic data.

[0071] The following are several specific embodiments of applying the present invention

[0072] Embodiment 1

[0073] In a specific Embodiment 1 of applying the present invention, the excitation depth design method based on refraction micro-logging data constraints includes the following steps:

[0074] Step 1: Add large-offset receiving points on the basis of conventional micro-logging to receive refraction wave information; Step 2: Record common-shot gather data at different depths; Step 3: Calculate the dominant frequency value of each excitation record; Step 4: Calculate the frequency band width of each excitation record; Step 5: Sort the calculated dominant frequency and frequency band values; Step 6: Optimize the best excitation depth according to the dominant frequency and frequency band values; Step 7: Obtain the best excitation depth of all refraction micro-logging survey points; Step 8: Use a specific spatial interpolation algorithm to establish a three-dimensional model of the best excitation depth for the whole area; Step 9: Calculate the best excitation depth of each excitation point according to the coordinates and elevation data of each excitation point by interpolation method according to the model.

[0075] In Step 1, change the receiving array in the conventional micro-logging observation method to a refraction micro-logging. Generally, there are only 5-6 channels in conventional micro-logging, and the offset range is 0-5m, and the received information is relatively small. Add 10-30 receiving points, and the offset can be increased to a maximum of 50-100m. In this way, the excited micro-logging can obtain richer wave field information such as reflection waves and refraction waves, which is closer to the wave field information in production acquisition, and the frequency width and frequency components are more accurate in the subsequent calculation.

[0076] In Step 2, record the refraction micro-logging of the excitation record according to each common-shot gather record, and sort the record files in the order of excitation depth. Generally, there are 20-50 excitation points in one refraction micro-logging, and there are also 50 corresponding common-shot gather data files.

[0077] In Step 3 and Step 4, calculate the dominant frequency value and frequency band width value of each common-shot gather record.

[0078] In Step 5 and Step 6, arrange the calculated dominant frequency and frequency band values in sequence according to the excitation depth to form a frequency curve graph of different excitation depths, mark the position of the water table on the curve graph, and select the depth with the highest dominant frequency and the widest frequency band under the water table as the best excitation depth. According to the principle of seismic exploration, the wider the frequency band and the higher the dominant frequency, the higher the resolution of the seismic record.

[0079] In Step 7, calculate and obtain the best excitation depth of each refraction micro-logging survey point according to the above method.

[0080] In Step 8, establish a three-dimensional model of the best excitation depth for the whole area according to the best excitation depth of each refraction micro-logging survey point calculated. Specific algorithm estimation calculation method: x1……x n Are a series of observation points in the region, z(x1),……,z(x n ) Are the corresponding observed values. The value Z * (x0) of the regional change amount at x0 can be estimated by a linear combination:

[0081]

[0082] where λ i is the weight coefficient to be determined and satisfies the following relational expression:

[0083] In step 9, according to each excitation point coordinate and elevation data, the best excitation depth of each excitation point is obtained by the interpolation method through the three-dimensional model established in step 8.

[0084] Embodiment 2

[0085] In a specific embodiment 2 of applying the present invention, a micro-logging in a certain exploration area of the Jiyang Depression is selected to design the excitation well depth by using the method of the present invention. The specific implementation steps are as follows Figure 2 ; longitudinally is the excitation well, the depth can be set to 30m - 60m according to the depth of the water table. Excitation is carried out at a certain interval in the well. The small triangles above are the ground receiving points. The distance from the wellhead of the excitation well in 4 directions is 1m. Beyond 1m, receiving points can be arranged at intervals of 1m, 2m, 3m, 4m, 5m, 5m, 5m, 10m, 10m along one direction, and the maximum distance from the wellhead of the excitation well is up to 50m; on the basis of the conventional micro-logging observation system, the number of receiving channels is increased. 2 receiving lines are arranged on the ground, each receiving line is 119m long, the channel interval is 1m, and there are 240 receiving channels in total. The depth of the refraction micro-logging well is 30m. Excitation is carried out from the bottom of the well to the wellhead. From 30m - 20m away from the wellhead, excitation is carried out once every 2m, from 20m - 5m, excitation is carried out once every 1m, from 5m - 1m, excitation is carried out once every 0.5m, and above 1m, excitation is carried out once every 0.2m. There are 33 shots in total.

[0086] Figure 3 This is a schematic diagram of the co-excitation point gather records of the refraction micro-logging excitation data with different excitation depths of the excitation depth design method based on refraction micro-logging data constraints in a specific embodiment of the present invention. Longitudinally is the excitation well. Seismic waves are generated by excitation at a certain interval in the high-velocity layer, velocity-decreasing layer, and low-velocity layer in the excitation well, and direct waves, refracted waves, reflected waves, etc. are received on the ground.

[0087] After excitation, co-excitation point gather records are obtained and sorted according to different excitation point depths, such as Figure 4 . Calculate the spectrum of the reflected wave information for all the co-excitation point gather records, as shown in Figure 5 . Read the frequency bandwidth and main frequency from the calculated spectrum, and establish a frequency component curve value, as shown in Figure 6 . It can be seen from the frequency component curve graph that the ideal excitation depth is 9 - 15m. Considering the length of the explosive column, let the bottom of the explosive be located at the bottom of the ideal excitation depth, and the best excitation depth selected at this place is 15m. Obtain the best excitation depth of all refraction micro-logging survey points according to this method, and establish a three-dimensional model of the best excitation depth of the whole area through a specific interpolation method, asFigure 7 As shown, according to requirements, the best excitation depth of the designed point is obtained by interpolation based on the three-dimensional model for the drilling rig excitation point coordinates.

[0088] As Figure 8 For the single-shot record filtered at 30 - 60 Hz with the designed well depth by the method of the present invention, Figure 9 For the single-shot record filtered at 30 - 60 Hz with the designed well depth by the previous method, it can be seen that compared with the single-shot record with the designed well depth by the conventional method, the single-shot record obtained by the designed well depth excitation has stronger energy and higher resolution after 3 s in the middle and deep layers, etc., and can improve the quality of seismic data.

[0089] Example 3

[0090] In a specific Example 3 of applying the present invention, a refraction micro-logging in a certain exploration area of Dongying Sag is selected to design the excitation well depth by the method of the present invention. 13 receiving points are arranged on the ground. One geophone is inserted at the wellhead of the refraction micro-logging, and 4 geophones are placed in a "cross" shape at 1 m away from the wellhead. In addition, 1 geophone is placed at each of 2 m, 4 m, 7 m, 11 m, 15 m, 20 m, 25 m, and 30 m for receiving. The depth of the refraction micro-logging well is 30 m, and the excitation is carried out from the bottom to the wellhead. It is excited once every 2 m from 30 m to 20 m away from the wellhead, once every 1 m from 20 m to 5 m, once every 0.5 m from 5 m to 1 m, and once every 0.2 m above 1 m, with a total of 33 shots.

[0091] After excitation, the common shot gather record is obtained and sorted according to different excitation point depths. The spectrum of the reflected wave information is calculated for all the common shot gather records, the frequency bandwidth and the main frequency are read from the calculated spectrum, the frequency component curve values are established, the best excitation well depth is selected from the frequency component curve graph, the best excitation depths of all the refraction micro-logging survey points are obtained by this method, a three-dimensional model of the best excitation depth for the whole area is established by a specific interpolation method, and the best excitation depth of the designed point is obtained by interpolation based on the three-dimensional model according to the coordinates of the drilling rig excitation point as required.

[0092] As Figure 10 For the single-shot record filtered at 20 - 40 Hz with the designed well depth by the previous method, Figure 11 For the single-shot record filtered at 20 - 40 Hz with the designed well depth by the method of the present invention, it can be seen that compared with the single-shot record with the designed well depth by the conventional method, the single-shot record obtained by the designed well depth excitation by the method of the present invention has higher resolution in the middle and shallow layers and stronger energy in the middle and deep layers, and the quality of seismic data can be improved by this method.

[0093] The excitation well depth design method based on quantitative analysis of refraction micro-logging data proposed by the present invention is suitable for the design of excitation well depth in areas where the near-surface lithology is relatively complex, the refraction micro-logging project is used in the near-surface investigation construction, the near-surface changes greatly, there is no complete set of excitation lithology, there are many thin interbeds, and the lithology changes greatly laterally. Using this method to design the well depth for seismic exploration project excitation can effectively improve the frequency of the original seismic data and then improve the resolution of the seismic data.

[0094] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

[0095] Except for the technical features described in the specification, they are all known technologies to those skilled in the art.

Claims

1. A method for designing the excitation depth constrained by refraction micro-logging data, characterized in that The excitation depth design method based on refraction micro-logging data constraints includes: Step 1: Extract the common shot gather records at different excitation depths according to the refraction micro-logging data. Step 2: Calculate the dominant frequency of the shot gather at different excitation depths. Step 3: Calculate the frequency band width of the shot gather at different excitation depths to form the quantitative results of the dominant frequency and frequency band width for excitation at different depths. Step 4: Optimize the excitation depth according to the above quantitative analysis results. Step 5: Establish a three-dimensional optimal excitation depth model for the whole area through a specific algorithm. Step 6: Calculate the excitation depth of each known coordinate point through the model.

2. The excitation depth design method based on refraction micro-logging data constraint according to claim 1, characterized in that In Step 1, during the surface investigation construction, medium and far offset receivers are added on the basis of the conventional micro-logging surface receiving array. By increasing the layout of receivers, the conventional micro-logging is converted into refraction micro-logging receiving, so that more reflected wave and refracted wave information can be received.

3. The excitation depth design method based on refraction micro-logging data constraint according to claim 2, wherein In Step 1, the data records of each shot excitation are received and recorded. The received records are output as record files according to the common shot gather records. The data includes the excitation depth data files with different offsets.

4. The excitation depth design method based on refraction micro-logging data constraint according to claim 1, wherein In Step 2, analyze and calculate the frequency components of each excitation record, calculate its dominant frequency value, sort the refraction micro-logging data according to different offsets, extract the shot gather records at each excitation depth, and sort them according to the excitation depth.

5. The excitation depth design method based on refraction micro-logging data constraint according to claim 1, characterized in that In Step 3, analyze and calculate the frequency components of each excitation record, and calculate its frequency band width.

6. The excitation depth design method based on refraction micro-logging data constraint according to claim 1, wherein In Step 4, according to the above quantitative analysis and sorting results, optimize the best excitation depth of one of the points.

7. The excitation depth design method based on refraction micro-logging data constraint according to claim 1, wherein The excitation depth design method based on refraction micro-logging data constraints further includes, after Step 4, repeating Steps 2 to 4 to calculate the best excitation depth of all refraction micro-logging survey points in the work area.

8. The excitation depth design method based on refraction micro-logging data constraint according to claim 1, wherein In step 5, a three-dimensional model of the best excitation depth for the whole region is established using a specific algorithm. The estimation calculation method of the specific algorithm is: x1……x n is a series of observation points in the region, z(x1),……,z(x n ) are the corresponding observed values; the value Z of the regional change at x0 * (x0) can be estimated using a linear combination: where λ i is a weight coefficient to be determined and satisfies the following relationship:

9. The excitation depth design method based on refraction micro-logging data constraint according to claim 1, characterized in that In Step 6, according to the coordinates and elevation data of each excitation point and the three-dimensional model, calculate the best excitation depth of each excitation point through interpolation.

10. The excitation depth design method based on refraction micro-logging data constraint according to claim 9, characterized in that, In Step 6, the interpolation calculation method: where d m is the design excitation depth, (x s , y s , z s ) is the coordinate position of the excitation point, (x m , y m , z m ) is the coordinate position of the model. When the excitation point is within the model range, x s -x m = 0, y s -y m = 0.

11. An excitation depth design system constrained by refraction micro-logging data, characterized in that, The excitation depth design system based on refraction micro-logging data constraints selects the excitation depth that can excite the best frequency components by using the excitation depth design method described in any one of claims 1-10.

Images