Excitation method for efficient seismic data acquisition based on time and distance intervals

Abstract

The present invention discloses an excitation method for efficient seismic data acquisition based on time and distance intervals. The method comprises the following steps: constructing a first boundary surface model for zero attenuation of the surface wave aftershocks of the preceding shot based on the records of the shot detection points and the minimum time interval at which the shot point near-track background decays to random noise; calculating the distance between the preceding and succeeding shots using a formula for catching up with the surface wave of the preceding shot based on the length of the detector point arrangement; and constructing a second boundary surface model for catching up with the surface wave of the preceding shot based on the linear relationship between the distance between the preceding and succeeding shots and the time interval between the preceding and succeeding shots; using the overlapping area of the two boundary surface models as the non-interference excitation area of the shot point, the non-interference excitation area encompassing the corresponding non-interference time-distance intervals of all preceding and succeeding shots; and performing shot excitation and acquiring seismic data. The present invention not only overcomes the interference of the preceding shot aftershocks on the succeeding shot, but also eliminates quality risks and can improve blasting efficiency by 20-40%.

Description

Technical Field

[0001] The present invention relates to the field of oil geophysical exploration, and in particular to a high-efficiency seismic data acquisition and excitation method and system based on "double optimization" of time interval and distance interval. Background Art

[0002] With the upgrading of oil seismic exploration equipment, seismic data acquisition technology is also developing. Currently, high-density three-dimensional seismic data acquisition technology has begun to be widely promoted and applied.

[0003] Compared with high-precision three-dimensional seismic data acquisition projects, high-density three-dimensional seismic data acquisition projects have the characteristics of higher design channel density, greater exploration investment, more complex equipment, and a higher degree of informatization. If field seismic data acquisition projects cannot be completed with high quality and efficiency, it will not only cause economic losses to the seismic data acquisition projects, but also affect the subsequent processing and interpretation of seismic data.

[0004] In order to complete the task within the time limit specified in the contract, it is necessary to set the excitation time interval to complete the daily production workload. This means pressing the button for the rear gun excitation when the aftershock of the front gun excitation decays to "0".

[0005] The current test method for testing aftershock attenuation to "0" uses the old technology of previous seismic acquisition excitation tests. A production array is used for the test, and the longest "0" aftershock time in the array is set as the excitation time interval of the front and rear shots. Such test conclusions do not take into account the difference between the rear shot position and the front shot position. At this time, the "0" aftershock position after the front shot is fired (the position of the front shot receiving array) is by no means the "0" aftershock background position before the rear shot is fired (the position of the rear shot receiving array). Whenever the seismic wave vibration at the front shot position returns to "0", it may be exactly when the seismic wave vibration propagates to the rear shot position. The experiment determines a uniform long time interval (for example, 34s). The idea of equating the "0" aftershock background of the front shot arrangement with the "0" background of the rear shot arrangement is flawed. The front shot aftershocks transmitted from a distance (mostly the surface wave aftershocks with the slowest propagation speed) may appear in the ocean of records of the rear shot and cannot be quantitatively discovered. It is unknown how much impact its regular low-frequency seismic phase will have on the data. How to remove it with fidelity in subsequent processing is also a problem. Now the low-frequency effective wave component is extremely precious to seismic data. This idea of ignoring aftershock "contamination" will bring legacy problems to the processing and interpretation of subsequent seismic data. Summary of the Invention

[0006] The main purpose of the present invention is to provide a method for efficiently acquiring seismic data based on the dual dimensions of "time" and "distance".

[0007] The technical solution adopted in the present invention is:

[0008] The present invention provides a method for efficiently acquiring seismic data based on time and distance intervals, which is characterized by comprising the following steps:

[0009] S1, based on the records of the shot detection point and the minimum time interval at which the background of the shot point near the shot decays to random noise, a first boundary surface model is constructed in which the aftershock of the previous shot surface wave decays to zero;

[0010] S2. The calculation formula for the refraction wave of the rear shot to catch up with the surface wave of the front shot based on the length of the detector arrangement is:

[0011]

[0012] Calculate the distance l between the front and rear guns sr :

[0013]

[0014] Where d is the length of the detection point arrangement, Δt is the time interval between the previous and next shots, and v s is the surface wave velocity, v r is the refracted wave velocity; according to the distance between the front and rear guns l sr The linear relationship between the time interval Δt between the front and rear shots is used to construct a second boundary surface model where the refraction wave of the rear shot catches up with the surface wave of the front shot.

[0015] S3, taking the overlapping area of the two boundary surface models as the non-interference excitation area of the shot point, wherein the non-interference excitation area includes the corresponding time-distance intervals of all the front and rear shot points without interference;

[0016] S4. Select the time-distance interval within the safe area to conduct shot point excitation and collect seismic data according to the specific project construction requirements.

[0017] Following the above technical solution, the specific method for constructing the first boundary surface model is as follows:

[0018] Conduct stimulation tests for ultra-long array reception and ultra-long time recording;

[0019] The near-track “0” aftershock boundary adopts a quantitative analysis value with a fixed gain;

[0020] The "0" aftershock boundary line of the distant channel is depicted using AGC display;

[0021] The two "0" aftershock dividing lines are combined to obtain the best attenuation "0" aftershock dividing curve as the first boundary surface model.

[0022] Following the above technical solution, in step S1, the weak aftershock signals are further analyzed through the fixed-gain records of the shot gather, specifically analyzing the surface wave interface of the near arrangement and the medium-near arrangement; the aftershock energy reflected by the fixed-gain near arrangement is analyzed through the gather AGC records and the "0" aftershock boundary position is analyzed.

[0023] Following the above technical solution, the record of the shot detection point is a curve that is optimized based on the qualitative surface wave line recorded by the fixed gain of the shot gather, the control surface wave line recorded by the AGC of the shot gather, the quantitative curve of aftershocks with an energy attenuation value of "0" recorded by the fixed gain of the shot gather, the qualitative surface wave line recorded by the fixed gain of the track gather, the control surface wave line recorded by the AGC of the track gather, and the quantitative curve of aftershocks with an energy attenuation value of "0" recorded by the fixed gain of the track gather.

[0024] Following the above technical solution, step S1 specifically uses the shot gather AGC records to determine the positions of the top arc and the middle line of the surface wave; uses the shot gather fixed gain records to determine the "0" aftershock visual position of the surface wave top arc line; uses the shot gather fixed gain amplitude value to determine the "0" aftershock area of the surface wave triangle; uses the gather AGC records to determine the "0" aftershock position of the middle and far segments of the surface wave; uses the gather AGC records to determine the "0" aftershock visual position of the surface wave top arc line; uses the gather fixed gain records to determine the "0" aftershock visual position of the surface wave top arc line; uses the gather fixed gain records to determine the "0" aftershock visual position of the surface wave top arc line; uses the gather fixed gain records to determine the "0" aftershock visual position of the surface wave top arc line; uses the gather fixed gain curve amplitude value of the gather records to determine the "0" aftershock area of the surface wave triangle.

[0025] Following the above technical solution, the excitation method further includes the steps of: making a standard table of the corresponding time-distance intervals of all the front and rear shot points without interference, so that the blasting personnel can look up the table to determine the time interval and distance interval of the front and rear shot points.

[0026] Following the above technical solution, the corresponding time-distance intervals without interference between the front and rear artillery points include 22s, 50-962m; 23s, 50-1280m; 24s, 50-1598m; 25s, 50-1916m.

[0027] The present invention also provides an excitation system for efficient seismic data acquisition based on time and distance intervals, comprising:

[0028] The module for constructing the zero aftershock curve of the front shot surface wave is used to construct the first boundary surface model of the front shot surface wave aftershock attenuation to zero based on the records of the shot detection point and the minimum time interval at which the shot point near-track background decays to random noise;

[0029] The module for constructing the interface for the rear shot refracted wave to catch up with the front shot surface wave is used to calculate the formula for the rear shot refracted wave to catch up with the front shot surface wave based on the length of the receiver arrangement:

[0030]

[0031] Calculate the distance l between the front and rear gunssr :

[0032]

[0033] Where d is the length of the detection point arrangement, Δt is the time interval between the previous and next shots, and v s is the surface wave velocity, v r is the refracted wave velocity; according to the distance between the front and rear guns l sr The linear relationship between the time interval Δt between the front and rear shots is used to construct a second boundary surface model where the refraction wave of the rear shot catches up with the surface wave of the front shot.

[0034] A non-interference excitation region determination module is used to use the overlapping region of the two boundary surface models as the non-interference excitation region of the shot point, and the non-interference excitation region includes all corresponding time-distance intervals without interference between the preceding and following shot points;

[0035] The seismic data acquisition module is used to select the time-distance interval within the safe area to perform shot point excitation and collect seismic data according to the specific project construction requirements.

[0036] Following the above technical solution, the front-shot surface wave zero aftershock curve construction module specifically uses the shot gather AGC records to determine the positions of the surface wave top arc and the middle line; uses the shot gather fixed gain records to determine the "0" aftershock visual position of the surface wave top arc line; uses the shot gather fixed gain amplitude value to determine the "0" aftershock area of the surface wave triangle; uses the gather AGC records to determine the "0" aftershock position of the middle and far segments of the surface wave; uses the gather AGC records to determine the "0" aftershock visual position of the surface wave top arc line; uses the gather fixed gain records to determine the "0" aftershock visual position of the surface wave top arc line; uses the gather fixed gain records to determine the "0" aftershock visual position of the surface wave top arc line; uses the gather fixed gain curve amplitude value of the gather records to determine the "0" aftershock area of the surface wave triangle.

[0037] The present invention also provides a computer storage medium storing a computer program executable by a processor, wherein the computer program executes the excitation method for efficient seismic data acquisition based on time and distance intervals as described in the above technical solution.

[0038] The beneficial effects of the present invention are as follows: It employs a novel concept to search for a clean "zero" aftershock background within the surface wave triangle of the preceding shot, constructing an iterative "zero" aftershock surface. Furthermore, it constructs a subsequent shot excitation position surface and a new theoretical calculation formula based on interference wave investigation, where the subsequent shot's first-arrival refracted wave catches up with the preceding shot's surface wave. This solves the problem of determining the excitation time interval between preceding and succeeding shot points, thereby realizing a new, efficient, high-quality, and accelerated high-density 3D seismic data acquisition method based on dual optimization of "time interval" and "distance interval." This method not only overcomes the interference of preceding shot aftershocks on subsequent shots, eliminating quality risks, but also utilizes a dynamic efficiency ring excitation method to increase shot efficiency by 20-40%, significantly advancing the implementation of high-density 3D seismic data acquisition projects.

[0039] Furthermore, the present invention also proposes a method for constructing a refined shot point position surface that compares the theoretical shot point position surface with the excitation effects of the front and rear shot positions of an ultra-large arrangement in the field, as well as a time interval test analysis method based on "fixed gain + AGC" and "shot collection record + track collection record" of an ultra-large arrangement, which can further optimize the excitation time and interval. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0041] Figure 1 This is a positional relationship diagram of the influence of the surface wave of the front shot on the propagation position of the seismic wave field of the rear shot according to an embodiment of the present invention;

[0042] Figure 2 Schematic diagram of the positional relationship in which the surface wave of the preceding shot does not affect the propagation of the wave field of the seismic wave of the succeeding shot according to an embodiment of the present invention;

[0043] Figure 3 Schematic diagram of the relative relationship between the wave field of the preceding shot and the wave field of the succeeding shot (adjacent shot) at time t2-t1 in an embodiment of the present invention;

[0044] Figure 4 This is a record relationship diagram of the refraction of the first arrival of the rear shot catching up with the aftershock boundary of the "0" of the front shot in the embodiment of the present invention;

[0045] Figure 5 Schematic diagram of the multi-gun wave field distribution relationship between the front gun and the rear gun in an embodiment of the present invention;

[0046] Figure 6 Schematic diagram of the optimal boundary shot point position for the rear shot in the aftershock area "0" of the front shot according to an embodiment of the present invention;

[0047] Figure 7 This is a theoretical calculation relationship diagram of the refraction of the first arrival of the rear shot catching up with the aftershock boundary of the "0" of the front shot according to an embodiment of the present invention;

[0048] Figure 8This is a test record (fixed gain) of an embodiment of the present invention at a distance of 2000m from the shot point and a 36-second interval, unaffected by the previous shot.

[0049] Figure 9 This is a test record (AGC) of an embodiment of the present invention at a distance of 2000m from the firing point and a 36-second interval, unaffected by the preceding firing;

[0050] Figure 10 This is an embodiment of the present invention, where the front and rear shot points are 3000m apart and the rear shot record view at 28s interval is superimposed on the non-interference record of the front shot in the test (fixed gain);

[0051] Figure 11 This is an example of the present invention where the post-shot recording view at a distance of 1000m and 26s intervals are superimposed on the mutual interference recording (AGC) of the pre-shot in the test;

[0052] Figure 12 Schematic diagram of iterative optimization curve for shot point distance interval calculation and testing based on the “0” aftershock curve according to an embodiment of the present invention;

[0053] Figure 13 AGC records of interference wave surveys according to an embodiment of the present invention;

[0054] Figure 14 Schematic diagram of the excitation efficiency loop based on dual optimization of the "time interval + distance interval" dual dimensions according to an embodiment of the present invention;

[0055] Figure 15 Fixed gain display record for a single shot of 36 seconds;

[0056] Figure 16 AGC display record of a single shot of 36 seconds;

[0057] Figure 17 Schematic diagram of the linear relationship between offset and shot distance of a two-dimensional observation system;

[0058] Figure 18 Schematic diagram of the stepped relationship between the offset and the three-dimensional observation system;

[0059] Figure 19 The weak aftershock test record displayed for the shot gather (left: fixed gain; right: AGC record);

[0060] Figure 20 The "0" aftershock test record displayed for the gather (left: fixed gain; right: AGC record);

[0061] Figure 21 Schematic diagram of iterative construction of the “0” aftershock interface;

[0062] Figure 22-1This is a "0" aftershock investigation test observation system using a fixed arrangement and shot tracking method;

[0063] Figure 22-2 A comparison chart of the number of channels placed at wired detection points and the number of channels placed at wireless node instruments;

[0064] Figure 23 The difference between the survey of previous production record curves and the survey of super-large arrangement curves;

[0065] Figure 24 Compare the information volume and location of wired array positions and wireless node instrument data;

[0066] Figure 25 A schematic diagram is shown for a high-density three-dimensional observation system;

[0067] Figure 26 A schematic diagram of an excitation method for efficient seismic data acquisition based on dual dimensions of time and distance intervals according to an embodiment of the present invention;

[0068] Figure 27 This is a flow chart of an excitation method for efficient seismic data acquisition based on dual dimensions of time and distance intervals according to an embodiment of the present invention. DETAILED DESCRIPTION

[0069] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0070] In the existing technology, the time interval is determined as if it is a cover-up. Regardless of the type of seismic wave or the propagation characteristics of the seismic wave, the only concern is the time decay. When the energy is extremely weak, there will be no interference. As we all know, the surface wave still propagates over a large area in the work area without disappearing. Figure 1 、 2 It can be seen that there are two modes of positional relationship between the seismic wave propagation of the front and rear shots. These two modes are apparently directly related to the positions of the two front and rear shots, but in fact they are related to the propagation relationship of the surface waves of the front and rear shots, including three factors:

[0071] (1) The time interval between the firing of the preceding and following shots;

[0072] (2) The relative position distance between the front and rear gun points;

[0073] (3) Length of data record collected from earthquakes.

[0074] The first mode: The surface wave from the leading shot is still traveling in the receiving array of the trailing shot. Due to its slow speed, it is overtaken or encountered by the refracted or reflected waves from the trailing shot within the length of the recording array. In this case, even within 34 seconds (in one example, this is determined mainly based on the duration of the visible "zero" aftershock recorded by a single shot with fixed gain, taking into account the farthest receiver in the near array, the farthest receiver in the far array, the maximum offset, the longest decay time, and customer requirements), the surface wave from the leading shot still has interference energy equivalent to the background energy and with a seismic phase.

[0075] The second mode: The surface wave of the front shot travels in the receiving array. Although the speed is slow, it has almost reached the boundary of the receiving array. Within the recording array length, the refracted wave of the rear shot has not caught up with the surface wave of the front shot. This mode is exactly what we need.

[0076] The two patterns appear to have nothing to do with the "time interval," but rather the position of the surface wave from the leading shot within the array of the trailing shot. The closer the trailing shot is to the firing point of the leading shot, the less likely the aftershocks from the leading shot will affect the trailing shot within the 34-second interval, beyond the 7-second recording time. This means that the closer the leading and trailing shots are, the more advantageous it is. However, consideration must be given to whether the energy of the near-shot aftershocks from the leading shot is attenuated to random interference energy due to their proximity (the stronger the energy of the near-shot shot, the stronger the energy interference generated by the shot point in damaging the surrounding rock). This requires careful characterization of the temporal boundary for "zero" aftershocks near the shot point.

[0077] Figure 3 A schematic diagram showing the relative relationship between the wave field of the preceding shot and the wave field of the succeeding shot (adjacent shot) at time t2-t1.

[0078] Figure 4 It shows that the rear shot was excited at t1 seconds, and at t2 the first arrival refracted wave of the rear shot just caught up with the slow surface wave of the front shot, and the time period t2-t1 was just equal to the record length of 7 seconds (Note: the catching up time is related to the width of the arrangement and the distance between the front and rear shots. Generally, it catches up in 2-3 seconds, but it has nothing to do with the record length. The record length is longitudinal and is determined manually, and can be 6-100 seconds).

[0079] Figure 5 This shows that the front shot has no effect on the back shot. The propagation time t1 of the front shot is much longer than the recording length of 7 seconds. The required seismic data has already been recorded, and the back shot will not have any effect on the front shot. Figure 5 It shows that as long as the "0" aftershock curve of the surface wave triangle area of the previous shot is recorded in the subsequent shot as the boundary of the arrival of the first-arrival refracted wave, that is, the position to which the first-arrival refracted wave of the subsequent shot propagates, there will be no mutual influence between the previous shot and the subsequent shot, and between the subsequent shot and the subsequent shot, and they are all clean "0" aftershock shots.

[0080] Figure 6The position of the boundary gun chasing the rightmost "0" aftershock is shown. This position is related to the excitation time interval and the distance between the front and rear gun points. This is conducive to improving production efficiency. The gun point position that saves blasting time is within the cylindrical platform in the red area, and is not outside the excitation time interval determined by Party A. In this "time-distance" space, each gun point has the ability to save time.

[0081] Figure 7 The middle DAOBC curve segment (black double-dashed line) represents the background energy boundary for the "0" aftershock. The AOB segment is quantitatively determined by the amplitude values of numerous geophones in single-shot records close to the shot point, or by AGC visual determination from the gather records. Revisions based on both methods yield optimal accuracy. The AD and BC segments are quantitatively determined by AGC visual determination or by the amplitude values of numerous geophones arranged mid- to long-range in single-shot records. Revisions based on AGC visual determination from gather records would further improve accuracy. At the top of the AOB segment, because the first-arrival refracted wave from the subsequent shot cannot catch up with the surface wave from the preceding shot within the 7-second recording time, the top of the AOB segment can be determined as the optimal minimum time interval, which is 22 seconds in the figure. 34 seconds is the time interval determined by Party A, and 30 seconds was selected in the figure as the maximum time interval for improved efficiency.

[0082] The theoretical formula for the refraction wave of the rear shot to catch up with the surface wave of the front shot based on the arrangement length of the shot detection points is:

[0083]

[0084] Where:

[0085] d: length of shot detection point arrangement;

[0086] Δt: time interval;

[0087] v s : surface wave velocity;

[0088] v r : refracted wave velocity;

[0089] l sr : Distance between front and rear guns.

[0090] get:

[0091]

[0092] Visible: l sr It is linearly related to Δt, where Δt is the variable and the others are fixed values. Therefore, the EGF exhibits a triangular linear relationship identical to the surface wave pattern, namely, the shot point boundary triangle. Shot points cannot be designed during the OG time period, as aftershock interference is strong in this period.

[0093] Therefore, the judgment criteria for the environmental excitation of the post-shot "0" aftershock in the present invention are mainly: the prerequisite for post-shot excitation is that after the seismic wave energy generated by the front shot excitation decays with the propagation distance and propagation time, the environmental noise energy left for the post-shot receiving arrangement before the post-shot excitation must be restored to the random background noise energy of the natural environment before the front shot excitation.

[0094] After the above analysis, the embodiment of the present invention is based on the method of efficient seismic data acquisition of time and distance intervals, such as Figure 26 、 27 As shown, the following steps are included:

[0095] S1, based on the records of the shot detection point and the minimum time interval when the background of the shot point near the decay is random noise, a first boundary surface model is constructed in which the aftershock of the previous shot surface wave decays to zero;

[0096] S2. Calculate the distance l between the front and rear guns based on the calculation formula for the rear gun refraction wave catching up with the front gun surface wave based on the length of the detection point arrangement. sr ; According to the distance between the front and rear guns l sr The linear relationship between the time interval Δt between the front and rear shots is used to construct a second boundary surface model where the refraction wave of the rear shot catches up with the surface wave of the front shot.

[0097] S3, taking the overlapping area of the two boundary surface models as the non-interference excitation area of the shot point, wherein the non-interference excitation area includes the corresponding time-distance intervals of all the front and rear shot points without interference;

[0098] S4. Select the time-distance interval within the safe area to conduct shot point excitation and collect seismic data according to the specific project construction requirements.

[0099] Furthermore, the experiment is based on the "distance interval + time interval" dual-dimensional design as in the above embodiment, such as Figure 8 、 9 Display: The excitation effect test of adjacent shots was carried out, and the effects of the excitation distance interval and the excitation time interval were verified through actual data. The two-dimensional interval curve was corrected through calibration of this method to obtain the practical "0" aftershock interference shot point area in the entire work area, which was recorded in the natural environment background noise.

[0100] Figure 10 、 Figure 11 Display: Different time intervals and distance intervals can achieve clean recording without mutual interference.

[0101] Figure 12 Schematic diagram of iterative optimization curve for shot point distance interval calculation and testing based on the “0” aftershock curve in an embodiment of the present invention.

[0102] By combining testing, analysis, calculation, and curve verification, we obtain a fundamentally accurate two-dimensional interval surface: "time interval + distance interval." During production, the curve can be adjusted at any time based on regional geology, structural units, and surface lithology changes, further improving real-time dynamic accuracy.

[0103] Specific methods:

[0104] (1) Adjust the time interval;

[0105] (2) Adjust the interval between the gun points.

[0106] The excitation design of optimizing “time interval + distance interval” can be carried out by using interference wave survey records.

[0107] Depend on Figure 13 The interference wave survey records show that the initial refracted wave velocity is 2346m / s; the surface wave velocity is 318m / s; the array length is 6980m / s; the shot point spacing is 50m; the time intervals are 18s, 19s, 20s, 21s, 22s, 23s, 24s, 25s, 26s, 27s, 28s, 29s, 30s, 31s, 32s, 33s, and 34s, and the calculations are shown in Table 1:

[0108] 22s is the optimal minimum time interval for this work area. According to the conditions of the work area, the plan is to achieve a daily production of 2,000 shots. If an excitation time interval of 25s is adopted, the shot point excitation efficiency can be increased by 40%. In order to ensure the realization of this efficiency, the maximum interval between the front and rear shot points cannot exceed 1,916m.

[0109] During actual blasting, a standard table can be created for the corresponding time-distance intervals of all preceding and succeeding shots without interference, making it easier for blasters to determine the time and distance intervals between the preceding and succeeding shots. Optional on-site selection of firing intervals based on shot distance allows for flexible on-site selection: 22s, 50-962m; 23s, 50-1280m; 24s, 50-1598m; 25s, 50-1916m, and more, improving efficiency by over 40%.

[0110] Table 1: Efficiency improvement and speed increase blasting efficiency calculated based on the test parameters of a project in Xinjiang

[0111]

[0112]

[0113] Figure 14The upper portion shows a three-dimensional diagram of the effectiveness calculated theoretically, while the lower portion corresponds to the distribution of the effectiveness rings at the blasting points. As can be seen, the greater the effectiveness, the smaller the time interval and the distance interval. When firing, the distribution of the gunners must be considered. Gunners must be present in front, behind, and on both sides of the gunner to ensure efficient blasting production. Since 22 seconds is the minimum firing interval, the minimum time interval in this area is set at 22 seconds, and the distance between blasting points is 900 meters. Previously, 1,440 shots were fired daily, but now each line can fire at least 2,290 shots, increasing daily production efficiency by at least 40%.

[0114] The above is a theoretical calculation based on actual data. We will consider increasing the condition parameters to see the adaptability of this method and the adaptability and variation characteristics of "time interval + distance interval" and excitation efficiency:

[0115] Assumptions: first arrival refracted wave velocity is 3200m / s (increase first arrival refracted wave velocity); surface wave velocity is 280m / s (reduce surface wave velocity); array length is 7600m / s; shot point spacing is 50m; take: time intervals of 18s, 19s, 20s, 21s, 22s, 23s, 24s, 25s, 26s, 27s, 28s, 29s, 30s, 31s, 32s, 33s, 34s, and calculate Table 2.

[0116] Table 2 Relationship between “time interval + distance interval” and blasting efficiency based on increased parameters

[0117]

[0118]

[0119] Negative values in Tables 1 and 2 indicate that this condition does not exist. Since 22 seconds is the minimum firing interval, and 24 seconds is a negative value, the minimum interval for this area is set at 25 seconds, with a 50-meter spacing between the front and rear shots. The original daily firing rate of 1,440 shots will now be increased to at least 1,938 shots per line, increasing daily production efficiency by at least 35%. However, in field operations, it is unrealistic to achieve a firing interval of just one shot between operators. We can choose 30 seconds as the minimum firing interval, which allows a maximum of 30 shots between the front and rear shots of 1,460 meters, increasing firing efficiency by 17%.

[0120] From the calculation results in Table 1 and Table 2 above, we can see that there are four key factors that restrict the improvement of efficiency:

[0121] 1. Surface wave velocity;

[0122] 2. Refracted wave velocity;

[0123] 3. Arrangement length;

[0124] 4. The “0” aftershock time near the blast point.

[0125] In summary, 1, 2, and 3 relate to the spacing between shot points, while 4 relates to daily firing efficiency. The spacing between the front and rear shot points is less critical and can be addressed by increasing the number of gunners and firing crews, but this must be done economically. "Zero" aftershocks near the shot points can be addressed through experiments such as reducing the charge and depth of the firing well.

[0126] In order to optimize and iterate the "0" aftershock interface of the front shot excitation, the present invention can further analyze the precise time interval of weak energy aftershock decay based on the AGC records of the shot gather with an ultra-long and ultra-wide receiving array to determine:

[0127] (1) The fixed gain display method is a method in which both strong and weak signals are amplified or reduced under one parameter, so the changes in the relative strength of the energy of different types of wave fields can be intuitively seen. Figure 15 The fixed-gain amplitude value quantitatively shows that there is no aftershock at 22 seconds, which is considered to be background natural noise. The fixed-gain visual display shows that some of the nearby geophone points have "0" aftershocks at around 12 seconds, indicating a large difference between the two.

[0128] (2) AGC is an instantaneous dynamic floating-point gain method that compresses strong energy and amplifies weak energy. It can compress the energy of strong surface waves in the near and medium ranges, and amplify the energy of dispersed weak surface waves in the far ranges and other weak aftershocks. Figure 16 The AGC in the middle amplifies the background noise and aftershock energy. It can be seen that there are still aftershocks for more than 34 seconds, and they are aftershocks with seismic phases, indicating that Party A's 34-second time interval is still not safe. The remaining surface wave aftershocks are received by the rear gun. Surface wave 2 appears at 6 seconds, indicating that the AGC clearly depicts the top interface position of surface wave 2. Note that this is not the "0" aftershock interface, but the surface wave interface; at the same time, fixed gain records can be seen Figure 15 The far-flung surface wave boundary that cannot be seen on the Figure 16 AGC records cannot reflect the actual amplitude differences and cannot be used for quantitative analysis, but they can identify the difference boundaries of weak signals, which is exactly what we need to construct the "0" aftershock boundary.

[0129] (3) The “0” aftershock boundary of the front shot can be constructed by combining the quantitative “0” aftershock top boundary of the fixed gain with the qualitative mid- and far-surface wave boundaries of the AGC.

[0130] The iterative implementation steps are as follows:

[0131] Conduct stimulation tests with long array reception and long recording time;

[0132] The near-track “0” aftershock boundary adopts a quantitative analysis value with a fixed gain;

[0133] The "0" aftershock boundary line of the distant channel is depicted using AGC display;

[0134] The curve that combines the two is the best attenuation "0" aftershock dividing line curve.

[0135] The present invention utilizes a long array for receiving surface waves and long-term recording, enabling the characterization of surface wave boundaries within long time intervals. For example, a 40-second surface wave propagation distance can be recorded. This requires a long array for receiving, and the corresponding recording time is extended to 40 seconds. This also allows for testing the tracking effect of front and rear shots during excitation tests. Previously, recording was performed for 7 seconds, and the array was not long enough to characterize surface wave boundaries.

[0136] The offset is a multiple of the track distance, and the offset is the distance from the shot point to the receiver point. Figure 17 When displaying a two-dimensional test, the shot points are arranged so that the offset and the offset are integer multiples of the trace distance, showing a linear relationship. Therefore, the right figure shows a linear relationship. Figure 18 When displaying a 3D test, the shot points are not aligned, and the offset and offset distances are not integer multiples of the trace distance, so the relationship is not linear. Therefore, the right image shows a stepped and irregular pattern.

[0137] Figure 18 The gather record is a composite record of many shot points at a certain receiver point in the three-dimensional work area. Figure 17 The records synthesized from many detection points for a certain gun are different.

[0138] Figure 19 The relationship between the offset and the offset is Figure 17 same, Figure 20 The relationship between the offset and the offset is Figure 18 same.

[0139] Figure 19 and Figure 16 Similarly, the linear surface wave boundary at a distance is vaguely visible, but the precise location is not clear;

[0140] Figure 20 and Figure 18 Similarly, the surface waves at long distances present a clear layered shape, which is easy to accurately identify the position and obtain a clear relationship between the surface wave transmission distance and time. Combined with the AGC display, it can be considered that this is the true position of the "0" aftershock.

[0141] Get the precise analysis method of aftershock attenuation:

[0142] (1) Characterizing weak aftershock signals:

[0143] Shot gather records: The surface wave interfaces in the close and medium-close arrays are relatively clear. The close array with fixed gain can reflect the energy of stronger aftershocks.

[0144] Gather records: The surface wave interface is unclear in the near and medium near arrays. The near array with fixed gain can reflect the energy of stronger aftershocks.

[0145] (2) Aspects of characterizing “0” aftershocks

[0146] Shot collection records: AGC's recognition capability is clear at long ranges, but due to the single shot excitation, it cannot clearly reflect the changes in the "0" aftershock;

[0147] Gather records: The background signals of non-zero aftershocks can be clearly seen in the near and near-medium AGC arrays. This is related to the energy balance of multiple shots, as more shots provide better statistical effects. The background signals of distantly arrayed zero aftershocks can be clearly seen in a stepped pattern. This is related to the distribution of the shot offsets of the acquisition observation system, making it easy to identify the boundary position of the zero aftershock.

[0148] The AGC record of the gather is a synthetic record of different shot points passing through one detection point, which can better reflect the attenuation change characteristics of the excitation energy. Figure 20 The left fixed gain shows that the energy of surface wave 1 is much stronger than that of surface wave 2. Figure 19 This cannot be seen from the records of the left artillery collection; Figure 20 The AGC display of the right channel set at around 24 seconds is basically the natural environment background ("0" aftershock). This is related to the fact that multiple shots are involved in the synthetic recording, and the energy difference between shots is large, which increases the dynamic range and improves the accuracy of AGC in depicting detailed changes. Figure 20 The attenuation change point of face wave 2 in the right AGC trace is more clear and prominent. The gather display of face wave 2 is basically horizontal. Figure 19 It is easier to identify the "time-distance" mutation point of attenuation on the right.

[0149] Conditions: The gather records are based on existing 3D old data, or can only be obtained after a certain number of shots and strip work is completed in the new 3D work area.

[0150] The accuracy of the “time interval + distance interval” surface of “0” aftershocks can be further improved through iteration. Figure 21It reflects the relationship between the iterative construction process of the "0" aftershock interface and its accuracy (this is related to the richness of the data and is not indispensable), specifically: using the shot gather AGC records to determine the positions of the top arc and the middle line of the surface wave; using the shot gather fixed gain records to determine the visual position of the "0" aftershock of the top arc line of the surface wave; (for reference only); using the shot gather fixed gain amplitude value to determine the "0" aftershock area in the surface wave triangle; using the gather AGC records to determine the "0" aftershock position in the middle and far segments of the surface wave; using the gather AGC records to determine the "0" aftershock visual position of the top arc of the surface wave (high credibility); using the gather fixed gain records to determine the "0" aftershock visual position of the top arc of the surface wave (for reference only); using the fixed gain curve amplitude value of the gather records to determine the "0" aftershock area in the surface wave triangle.

[0151] Furthermore, field "zero" aftershock "time-distance" interface investigation and testing techniques based on ultra-large arrays can be optimized. For example, a decay curve investigation method using multi-shot tracking excitation with fixed multi-channel reception using conventional geophones can be employed. Conventional geophones utilize a wired array for reception, and data is recorded by seismic acquisition instruments. The acquisition time and data volume are both limited by the channels. Therefore, even with a 60-second recording length, the limited array of slices resulted in wave leakage. Figure 22-1 This paper demonstrates an experimental observation system that uses a fixed array and shot tracking to extend the receiving distance. This method can compensate for equipment limitations and capture a complete surface wave attenuation curve that cannot be captured using a finite-length array. It also allows for the acquisition of first-arrival refracted waves using additional shots, but the shots are then very far away.

[0152] A node receiver is a wireless seismic data acquisition instrument that can independently receive 10-15 days of continuous seismic data (depending on the battery charge) without interfering with each other. This allows backup node receivers far from the shot point to receive data. This is significantly different from wired reception. A wired receiver uses a separate seismic instrument for reception, while a node receiver can receive seismic information as long as it is placed and powered on. This allows node receivers far from the shot point to receive seismic wave data generated by the distant shot point at any time.

[0153] Figure 22-2 Display: High-density 3D seismic data acquisition projects require a high density of shot channels, and the number of receiving channels required at one time is much greater than that of high-density 3D acquisition projects (a seismic acquisition project can usually be equipped with more than 100,000 node instruments, while wired equipment usually only has 30,000 receivers).

[0154] Figure 23 The red block shows the length and range of the high-precision three-dimensional data arrangement; the blue block area is very large, and as long as enough node instruments are placed, the leakage wave can be received.

[0155] Figure 23 Display: When investigating the attenuation of aftershock curves, the original test was affected by the array length and could not fully depict the wave field and the aftershock red line surface wave 2 and yellow line surface wave 1, so a super-large array test was needed to form Figure 11 Background attenuation energy curve within the complete surface wave triangle area above the middle time interval line.

[0156] Figure 24 Display: In the past, due to limited arrangement, the fixed gain test records missed the decay background time of the left and right yellow arcs. Moreover, the length of the white line required for AGC to characterize weak signals was even insufficient.

[0157] Figure 15 It is a high-density 3D seismic acquisition observation system. Based on this blasting observation system, the following can be extracted: Figure 16 A single shot excitation and multiple array receiving single shot recording observation system, the test record obtained is as follows Figure 19 As shown; can be extracted Figure 27 The test record is as follows: Figure 20 shown.

[0158] The present invention also provides a computer-readable storage medium, such as a flash memory, a hard disk, a multimedia card, a card-type memory (e.g., SD or DX memory), a random access memory (RAM), a static random access memory (SRAM), a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), a programmable read-only memory (PROM), a magnetic storage device, a disk, an optical disk, a server, an App store, etc., storing a computer program that implements corresponding functions when executed by a processor. The computer-readable storage medium of this embodiment is used to implement the method for efficient seismic data acquisition based on time and distance intervals according to the method embodiment when executed by the processor.

[0159] The dual-dimensional "time interval + distance interval" efficiency loop excitation method of the present invention not only overcomes the interference of aftershocks of the previous shot on the subsequent shot and eliminates quality risks, but also the dynamic efficiency loop excitation mode can improve the shooting efficiency by 20-40%, which will greatly promote the implementation of high-density 3D seismic data acquisition projects.

[0160] The present invention is suitable for seismic data acquisition projects with surface acquisition conditions such as deserts, Gobi, saline-alkali land, and farmland in Xinjiang, and has broad prospects for promotion and application. Currently, due to the restriction of "time interval", the daily workload cannot be increased, and the advantages of advanced acquisition equipment cannot be brought into play, resulting in that high-density three-dimensional geophysical methods that improve the quality of seismic acquisition data cannot be well utilized. Only when the daily workload is increased can the value of high-density three-dimensional acquisition be fully reflected. This invention breaks the bottleneck of fixed time intervals, greatly improves the daily production workload, and greatly promotes the growth rate and improvement of acquisition. The technology proposed by the invention to stimulate in the "0" aftershock zone avoids the pain point of interference from non-"0" aftershocks in the past, ensures the excellent quality of the acquired data, and is another great progress and breakthrough in achieving geological goals through seismic acquisition.

[0161] This invention begins by studying the area of "0" aftershocks following the preceding shot. It finds that the surface wave triangle is the primary distribution area for "0" aftershocks. Using a fixed-gain quantitative analysis method, this method determines the minimum and optimal excitation time interval. It then introduces wavefield tracking analysis techniques for preceding and succeeding shot excitations. It proposes a distance interval efficiency time loop technique that controls the time interval between the first arrival of the subsequent shot's refracted wave and the preceding shot's surface wave, based on the length of the receiving array. Furthermore, it proposes an observation method validated with actual experimental data and a method for selecting time efficiency distance loops based on the percentage of speed improvement. This method achieves significant efficiency gains. The novel excitation acquisition concept established by this invention will promote improvements in corresponding acquisition technologies.

[0162] The present invention creatively proposes a new design idea for improving the efficiency of blasting construction. The summarized seismic data acquisition blasting technology plays a role in greatly improving the efficiency of current seismic acquisition construction, and the production efficiency can be increased by 20-40%, which can greatly save construction production time and money. At the same time, it solves the hidden problem of weak low-frequency information interference in the previous seismic data acquisition "rush time", further improving and ensuring the recording quality.

[0163] This invention breaks the shackles of the previous concept of a single time interval and creates a new "time interval + distance interval" dual-dimensional blasting technology theory and concept. On this basis, it can lay a theoretical foundation for the high-quality and efficient construction of high-density three-dimensional seismic data acquisition.

[0164] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all such improvements and changes should fall within the scope of protection of the appended claims of the present invention.

Claims

1. A method for efficient seismic data acquisition based on time and distance intervals, characterized in that: The following steps are involved: S1, based on the records of the shot detection point and the minimum time interval when the background of the shot point near the decay is random noise, a first boundary surface model is constructed in which the aftershock of the previous shot surface wave decays to zero; S2. The calculation formula for the refraction wave of the rear shot to catch up with the surface wave of the front shot based on the length of the detector arrangement is: Calculate the distance between the front and rear guns : in is the detection point arrangement length, is the time interval between the front and rear shots, is the surface wave velocity, is the refracted wave velocity; according to the distance between the front and rear guns Time interval between the front and rear guns The linear relationship between them is used to construct the second boundary surface model where the refraction wave of the rear gun catches up with the surface wave of the front gun; S3, taking the overlapping area of the two boundary surface models as the non-interference excitation area of the shot point, wherein the non-interference excitation area includes the corresponding time-distance intervals of all the front and rear shot points without interference; S4. Select the time-distance interval within the overlap area to perform shot point excitation and collect seismic data according to the specific project construction requirements.

2. The method for efficient seismic data acquisition based on time and distance intervals according to claim 1, characterized in that: The specific construction method of the first boundary surface model is as follows: Conduct stimulation tests for ultra-long array reception and ultra-long time recording; The near-track "0" aftershock boundary adopts a quantitative analysis value with a fixed gain; The "0" aftershock boundary line of the distant channel is depicted using AGC display; The two "0" aftershock dividing lines are combined to obtain the best attenuation "0" aftershock dividing curve as the first boundary surface model.

3. The method for efficient seismic data acquisition based on time and distance intervals according to claim 1, characterized in that: In step S1, the weak aftershock signals are further analyzed by fixed-gain shot gather records, specifically the surface wave interfaces of near and medium-near arrangements; the aftershock energy reflected by the fixed-gain near arrangement is analyzed by gather AGC records, and the position of the "0" aftershock boundary is analyzed.

4. The method for efficient seismic data acquisition based on time and distance intervals according to claim 1, characterized in that: The records of the shot inspection points are optimized curves based on the qualitative surface wave lines recorded by the shot gather with fixed gain, the control surface wave lines recorded by the shot gather with AGC, the quantitative curve of aftershocks with energy attenuation value "0" recorded by the shot gather with fixed gain, and the qualitative surface wave lines recorded by the track gather with fixed gain, the control surface wave lines recorded by the track gather with AGC, and the quantitative curve of aftershocks with energy attenuation value "0" recorded by the track gather with fixed gain.

5. The method for efficient seismic data acquisition based on time and distance intervals according to claim 1, characterized in that: Step S1 specifically uses the shot gather AGC record to determine the positions of the top arc and the middle line of the surface wave; uses the shot gather fixed gain record to determine the "0" aftershock visual position of the surface wave top arc line; uses the shot gather fixed gain amplitude value to determine the "0" aftershock area of the surface wave triangle; uses the gather AGC record to determine the "0" aftershock position of the middle and far segments of the surface wave; uses the gather AGC record to determine the "0" aftershock visual position of the surface wave top arc line; uses the gather fixed gain record to determine the "0" aftershock visual position of the surface wave top arc line; uses the gather fixed gain record to determine the "0" aftershock visual position of the surface wave top arc line; and uses the fixed gain curve amplitude value of the gather record to determine the "0" aftershock area of the surface wave triangle.

6. The method for efficient seismic data acquisition based on time and distance intervals according to claim 1, characterized in that: The excitation method further includes the steps of: making a standard table of the corresponding time-distance intervals of all the front and rear shot points without interference, so that the blasting personnel can look up the table to determine the time interval and distance interval of the front and rear shot points.

7. The method for efficient seismic data acquisition based on time and distance intervals according to claim 1, characterized in that: The corresponding time-distance intervals without interference between the front and rear artillery points include 22s, 50-962m; 23s, 50-1280m; 24s, 50-1598m; 25s, 50-1916m.

8. An excitation system for efficient seismic data acquisition based on time and distance intervals, characterized in that: include: The module for constructing the zero aftershock curve of the front shot surface wave is used to construct the first boundary surface model of the front shot surface wave aftershock attenuation to zero based on the records of the shot detection point and the minimum time interval at which the shot point near-track background decays to random noise; The module for constructing the interface of the rear shot refracted wave catching up with the front shot surface wave is used to calculate the formula for the rear shot refracted wave catching up with the front shot surface wave based on the length of the detection point arrangement: Calculate the distance between the front and rear guns : in is the detection point arrangement length, is the time interval between the front and rear shots, is the surface wave velocity, is the refracted wave velocity; according to the distance between the front and rear guns Time interval between the front and rear guns The linear relationship between them is used to construct the second boundary surface model where the refraction wave of the rear gun catches up with the surface wave of the front gun; A non-interference excitation region determination module is used to use the overlapping region of the two boundary surface models as the non-interference excitation region of the shot point, and the non-interference excitation region includes all corresponding time-distance intervals without interference between the preceding and following shot points; The seismic data acquisition module is used to select the time-distance interval within the overlap area to perform shot point excitation and collect seismic data according to the specific project construction requirements.

9. The excitation system for efficient seismic data acquisition based on time and distance intervals according to claim 8, characterized in that: The front-shot surface wave zero aftershock curve construction module specifically uses the shot gather AGC records to determine the positions of the surface wave top arc and middle line; uses the shot gather fixed-gain records to determine the "0" aftershock visual position of the surface wave top arc line; uses the shot gather fixed-gain amplitude value to determine the "0" aftershock area of the surface wave triangle; uses the gather AGC records to determine the "0" aftershock positions of the middle and far segments of the surface wave; uses the gather AGC records to determine the "0" aftershock visual position of the surface wave top arc line; uses the gather fixed-gain records to determine the "0" aftershock visual position of the surface wave top arc line; uses the gather fixed-gain records to determine the "0" aftershock visual position of the surface wave top arc line; and uses the gather fixed-gain curve amplitude value to determine the "0" aftershock area of the surface wave triangle.

10. A computer storage medium, characterized in that A computer program executable by a processor is stored therein, and the computer program executes the excitation method for efficient seismic data acquisition based on time and distance intervals according to any one of claims 1 to 7.

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