CN112180431A - Air gun seismic source setting method and device and machine readable storage medium - Google Patents
Air gun seismic source setting method and device and machine readable storage medium Download PDFInfo
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- 238000004088 simulation Methods 0.000 claims description 33
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Abstract
The invention relates to the technical field of air gun seismic sources, and discloses an air gun seismic source setting method and device and a machine readable storage medium. The method comprises the following steps: acquiring the target frequency of a target layer; determining the sinking depth of an air gun seismic source according to the target frequency; determining the total capacity of an air gun seismic source according to the sinking depth; and determining the arrangement combination of the air gun seismic sources according to the target frequency and the total capacity. The air gun seismic source is arranged according to the combination of the sinking depth and the capacity, the application effect is good, and the air gun seismic source has the advantages of high signal-to-noise ratio of seismic data, smooth frequency spectrum, good seismic source directivity and the like.
Description
Technical Field
The invention relates to the technical field of air gun seismic sources, in particular to an air gun seismic source method, an air gun seismic source device and a machine readable storage medium.
Background
The air gun seismic source is an artificial seismic source which has the advantages of environmental protection, good repeatability, economy, practicability and the like, and is widely applied to marine seismic exploration. The requirements for air gun seismic sources are different due to different seismic geophysical conditions of exploration blocks and different exploration target layers. In order to obtain good marine seismic exploration data, a high-performance seismic source meeting seismic exploration requirements is designed firstly.
The prior art provides a combined method for constructing an air gun seismic source from the perspective of total capacity, the method is too single, the method is limited by the total capacity and the combination mode of the air gun, and the application effect of the air gun seismic source is poor.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides a method and a device for setting an air gun seismic source and a machine readable storage medium, which can solve the technical problems that the combination method for constructing the air gun seismic source in the prior art is too single and the application effect is poor.
In a first aspect, the invention provides a method for setting an air gun seismic source, the method comprising:
acquiring the target frequency of a target layer;
determining the sinking depth of an air gun seismic source according to the target frequency;
determining a total capacity of the air gun seismic source according to the sinking depth;
and determining the arrangement combination of the air gun seismic sources according to the target frequency and the total capacity.
Optionally, the manner of obtaining the destination frequency of the destination layer includes:
and carrying out spectrum analysis on the original data of the exploration area to obtain the target frequency.
Optionally, the step of determining the sinking depth of the air gun seismic source according to the target frequency includes:
and searching the sinking depth from a depth frequency corresponding table according to the principle that the target frequency is less than the notch point frequency.
Optionally, the method further includes:
and determining the number of the submatrices of the air gun seismic sources according to the total capacity.
Optionally, the step of determining the number of subarrays of the air gun seismic sources according to the total capacity and the geophysical prospecting ship hardware condition includes:
after the number of the air gun seismic sources is determined, calculating the number of sub-arrays forming the air gun seismic sources according to the total capacity and the number of the air gun seismic sources, wherein the sum of the capacities of all the sub-arrays is equal to the total capacity;
the step of calculating the number of the submatrices forming the air gun sources according to the total capacity and the number of the air gun sources comprises the following steps:
judging whether the ratio of the total capacity divided by the number of the air gun seismic sources is larger than a preset capacity or not, if so, determining the number of the sub-arrays to be the number of the first sub-arrays; and if not, the number of the sub-arrays is the number of the second sub-arrays, and the number of the first sub-arrays is larger than or equal to the number of the second sub-arrays.
Optionally, the method further includes:
and determining the subarray spacing of the air gun seismic source according to the target frequency.
Optionally, the step of determining the subarray spacing of the air gun seismic source according to the target frequency includes:
performing source simulation on at least two adjacent sub-arrays with an initial spacing;
sequentially increasing preset increments on the initial interval at the same time, and performing seismic source simulation on all sub-arrays with the gradually increased intervals one by one;
and analyzing a simulation result obtained from the seismic source simulation according to the target frequency to obtain the optimal spacing between the adjacent sub-arrays.
Optionally, the air-gun seismic source includes a single gun and a coherent gun, and the spread combination includes:
the number of the single guns and the coherent guns with different capacities, the combination of the coherent guns and the arrangement positions of the single guns and the coherent guns in a plane; wherein the sum of the capacities of all single guns and coherent guns in all said spread combinations is equal to said total capacity.
Optionally, the air gun seismic source further comprises a spare gun, the spare gun is arranged on the single gun and the coherent gun, and has the same capacity as that of the single gun and the coherent gun which are arranged adjacently, and is used for being turned on when the single gun or the coherent gun fails.
In a second aspect, the present invention provides an air gun source setting apparatus, comprising:
the acquisition module is used for acquiring the target frequency of the target layer;
the depth determination module is used for determining the sinking depth of the air gun seismic source according to the target frequency;
a total capacity determination module for determining a total capacity of the air gun seismic source according to the sinking depth;
and the arrangement combination module is used for determining the arrangement combination of the air gun seismic sources according to the target frequency and the total capacity.
Optionally, the obtaining module includes a spectrum analysis module, configured to perform spectrum analysis on the raw material of the exploration area to obtain the target frequency.
Optionally, the depth determining module includes a searching module, configured to search the sinking depth from a depth frequency correspondence table according to a principle that the target frequency is smaller than the notch point frequency.
Optionally, the apparatus further comprises:
and the submatrix number determining module is used for determining the submatrix number of the air gun seismic sources according to the total capacity.
Optionally, the sub-array number determining module includes:
the submatrix number calculation module is used for calculating the number of the submatrix forming the air gun seismic sources according to the total capacity and the number of the air gun seismic sources after the number of the air gun seismic sources is determined, wherein the sum of the capacities of all the submatrixes is equal to the total capacity;
the subarray number calculation module comprises:
the judging module is used for judging whether the ratio of the total capacity divided by the number of the air gun seismic sources is larger than a preset capacity or not, and if yes, the number of the sub-arrays is the first sub-array number; and if not, the number of the sub-arrays is the number of the second sub-arrays, and the number of the first sub-arrays is larger than or equal to the number of the second sub-arrays.
Optionally, the apparatus further comprises:
and the subarray spacing determination module is used for determining the subarray spacing of the air gun seismic source according to the target frequency.
Optionally, the subarray pitch determining module includes:
a seismic source simulation module for performing seismic source simulation on at least two adjacent sub-arrays with an initial spacing;
the distance increasing module is used for sequentially increasing preset increments on the initial distance at the same time, and the seismic source simulation module is also used for performing seismic source simulation on all the sub-arrays with the increased distances one by one;
and the optimal spacing determining module is used for analyzing the simulation result obtained by the seismic source simulation according to the target frequency to obtain the optimal spacing between the adjacent sub-arrays.
Optionally, the air-gun seismic source includes a single gun and a coherent gun, and the spread combination includes:
the number of the single guns and the coherent guns with different capacities, the combination of the coherent guns and the arrangement positions of the single guns and the coherent guns in a plane; wherein the sum of the capacities of all single guns and coherent guns in all said spread combinations is equal to said total capacity.
Optionally, the air gun seismic source further comprises a spare gun, the spare gun is arranged on the single gun and the coherent gun, and has the same capacity as that of the single gun and the coherent gun which are arranged adjacently, and is used for being turned on when the single gun or the coherent gun fails.
A third aspect of the invention provides a machine-readable storage medium having instructions stored thereon for enabling the machine-readable storage medium to perform the air gun source setting method described above.
The invention discloses an air gun seismic source setting method, an air gun seismic source setting device and a machine readable storage medium.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.
Fig. 1 is a schematic flow chart of a method for setting an air gun seismic source according to an embodiment of the present invention;
fig. 2 is a schematic flow chart of an air gun seismic source setting method according to a second embodiment of the present invention;
fig. 3 is an air gun seismic source arrangement diagram of an air gun seismic source setting method according to a third embodiment of the present invention;
FIG. 4 is a diagram of a simulated far field wavelet waveform for the air gun source of FIG. 3 in accordance with the present invention;
FIG. 5 is a graph of simulated far-field wavelet spectra for the air gun source of FIG. 3 in accordance with the present invention;
FIG. 6 is a top view of the air gun seismic source of FIG. 3 simulating far field wavelet energy directivity in accordance with the present invention;
FIG. 7 is a 0 degree directivity pattern of a simulated far-field wavelet for the air-gun seismic source of FIG. 3 in accordance with the present invention;
FIG. 8 is a 90 degree directivity pattern of a simulated far field wavelet for the air gun seismic source of FIG. 3 in accordance with the present invention;
fig. 9 is a schematic structural diagram of an air gun seismic source setting device according to a fourth embodiment of the present invention.
Detailed Description
In order to make the objects, features and advantages of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without making creative efforts based on the embodiments of the present invention, belong to the protection scope of the present invention.
The prior art is a combined approach to constructing air gun seismic sources from a total capacity perspective. The application effect of the air gun seismic source is not only limited by the total capacity and the combination mode of the air gun, but also related to the excitation frequency, so that the low-frequency information is more beneficial to deep-layer imaging, and the high-frequency information is more beneficial to improving the resolution of the shallow stratum. However, the prior art does not provide a frequency-based air gun source setting.
The single gun is the most basic unit of the air gun, the coherent gun is established for further suppressing bubbles and improving the quality of a seismic source, the standby gun is used for preventing some single guns or coherence from being broken down when in field production, and the standby gun is opened when one single gun is broken down, so that field construction can be continued, and the production efficiency is improved.
Referring to fig. 1, fig. 1 is a schematic flow chart of an air gun seismic source setting method according to an embodiment of the present invention.
As shown in fig. 1, a first aspect of the present invention provides an air-gun seismic source installation method by which an air-gun seismic source can be installed offshore, thereby acquiring marine seismic data of a target zone in an exploration area. The method comprises the following steps:
and S100, acquiring the target frequency of the target layer. The target frequencies include a main frequency, a low frequency and a high frequency. The target frequency of the target layer in the exploration area can be obtained from the raw data of the exploration area. The target frequency is obtained as the effective frequency band of the target layer, and generally refers to the frequency band range of the effective wave, i.e. low frequency to high frequency, and is generally limited to-6 dB (decibel).
And S200, determining the sinking depth of the air gun seismic source according to the target frequency. I.e. the air gun source needs to be lowered to a certain depth for subsequent work.
The air gun seismic source is a device like a gun, and high-pressure gas (air) is pressed into a gun bore and released at a gun mouth at a short moment to generate strong impulsive force. The air gun seismic source is a typical pulse seismic source, and an excitation signal has the characteristics of high frequency and wide frequency band. The frequency of such vibrations is related to the volume of air in the bubbles, the pressure, and the depth of the water, and a certain seismic effect can be obtained by appropriately selecting these parameters.
And S300, determining the total capacity of the air gun seismic source according to the sinking depth. Generally, the deeper the sinking depth, the greater the total capacity of the air-gun source. Because the deeper the target zone, the more energy is absorbed and attenuated, and it is desired to maintain a specific energy of the target zone, the more energy is required for the activation of the air-gun source, i.e., the greater the total capacity of the air-gun source. The total volume of the air gun source is typically given based on experience with the last time the seismic data was acquired, or a reference range that is known in advance. For example, in a sunken area of east-sea West lake, the exploration target layer is about 4000 meters, and the total capacity of an air gun seismic source is more than 4000 cubic inches.
And S400, determining the arrangement combination of the air gun seismic sources according to the target frequency and the total capacity. The arrangement combination comprises the number of single guns and coherent guns with different capacities, the combination of the coherent guns, the plane arrangement positions of the single guns and the related guns and the like.
Air gun combinations are arranged according to air gun tuning and coherence principles. And the combination of air guns with different capacities, the arrangement position and the combination distance of the air guns with large capacities can influence the performance of the single-element array.
The air guns with different capacities are combined to form a tuning array, so that the bubble effect can be well suppressed and the dominant frequency band can be widened under the condition of not influencing wavelet energy. The combined use of air guns of different capacities is preferably performed when designing the air gun array.
According to the theory of tuning guns, in the process of designing a tuning array, the bubble period of each air gun is sequentially different by half of the first bubble pulse bubble wavelet period. And (3) assuming that the capacity of the first air gun is determined, calculating the capacity of the air gun adjacent to the first air gun, calculating the capacity of the adjacent air gun when the air guns with different capacities are combined into a tuning array after appropriate parameters are obtained, and selecting the air gun with the appropriate capacity for combined use when the tuning array is designed.
Taking seawater with the density of 1020Kg/m3(kilogram/cubic meter), according to the critical distance criterion that air guns are not influenced mutually, the combined distance of the air guns with different capacities can be calculated, and the combined distance can be determined by referring to the Safar criterion, the Nooteboom criterion and the Johnston criterion when the tuning array is designed.
After the sinking depth and the arrangement combination of the air gun seismic sources are determined according to the target frequency, the air gun seismic sources with the corresponding total capacity can be arranged at the sinking depth of the exploration area according to the arrangement combination to generate seismic waves, and seismic data of a target layer are collected.
According to the air gun seismic source setting method disclosed by the invention, the sinking depth and capacity combination of the air gun seismic source are determined through the acquired target frequency of the target layer, and the air gun seismic source is set according to the sinking depth and capacity combination, so that the application effect is good, and the method has the advantages of high signal-to-noise ratio of seismic data, smooth frequency spectrum, good seismic source directivity and the like.
Referring to fig. 2, fig. 2 is a schematic flow chart of an air gun seismic source setting method according to a second embodiment of the present invention.
Further, as shown in fig. 1 to 2, the manner of acquiring the destination frequency of the destination layer in S100 includes:
s101, carrying out spectrum analysis on the original data of the exploration area to obtain the target frequency. The original data refers to the existing seismic data of the exploration area and is also acquired through seismic acquisition. Because the existing seismic data can not meet the requirements of further oil and gas exploration and development, the seismic data needs to be acquired again, and an air gun seismic source meeting the requirements needs to be redesigned.
Further, the step of determining the sinking depth of the air gun seismic source according to the target frequency in S200 includes:
s201, finding the sinking depth from the depth frequency corresponding table according to the principle that the target frequency is smaller than the notch point frequency.
Significant notching of the streamer seismic data may occur due to the presence of sea surface ghost. Under the condition of only considering the seismic source end ghost, the filter characteristic formula of the water layer ghost is as follows
Where f is the frequency value (Hz) and h is the depth of subsidence (m) of the seismic source. Several special points are known from the above formula:
wave trapping points: when in use
When the amplitude is minimum (equal to zero), f is the notch point;
low and high cut-off frequency: when in use
And
water layer filtering characteristic of seismic source
The amplitude is equal to-6 dB, and the corresponding two frequencies are low cut-off frequency and high cut-off frequency;
main frequency points: when in use
Water layer filtering characteristic of seismic source
Reaching a maximum value, the frequency is the dominant frequency.
And calculating a main frequency value, a low frequency value, a high frequency value, a frequency width value and a trapped wave point frequency value corresponding to 3m-20m of seismic source sinking through the formulas, and listing a depth frequency corresponding table which is a reference table and has basically unchanged numerical values. As shown in the table below.
| Depth of seismic source sinking | Dominant frequency | Low frequency | High Frequency | Bandwidth of | |
| 3 | 125 | 42 | 208 | 167 | 250 |
| 4 | 94 | 31 | 156 | 125 | 188 |
| 5 | 75 | 25 | 125 | 100 | 150 |
| 6 | 63 | 21 | 104 | 83 | 125 |
| 7 | 54 | 18 | 89 | 71 | 107 |
| 8 | 47 | 16 | 78 | 63 | 94 |
| 9 | 42 | 14 | 69 | 56 | 83 |
| 10 | 38 | 13 | 63 | 50 | 75 |
| 11 | 34 | 11 | 57 | 45 | 68 |
| 12 | 31 | 10 | 52 | 42 | 63 |
| 13 | 29 | 10 | 48 | 38 | 58 |
| 14 | 27 | 9 | 45 | 36 | 54 |
| 15 | 25 | 8 | 42 | 33 | 50 |
| 16 | 23 | 8 | 39 | 31 | 47 |
| 17 | 22 | 7 | 37 | 29 | 44 |
| 18 | 21 | 7 | 35 | 28 | 42 |
| 19 | 20 | 7 | 33 | 26 | 39 |
| 20 | 19 | 6 | 31 | 25 | 38 |
Further, the method further comprises:
and S500, determining the number of the submatrices of the air gun seismic sources according to the total capacity.
Further, the step of determining the number of subarrays of the air gun seismic sources according to the total capacity in S500 includes:
s501, after the number of air gun seismic sources is determined during two-dimensional operation or three-dimensional operation, the number of sub-arrays forming the air gun seismic sources is calculated according to the total capacity and the number of the air gun seismic sources, wherein the sum of the capacities of all the sub-arrays is equal to the total capacity. Preferably, the total number of sub-arrays multiplied by the capacity of the sub-arrays equals the total capacity.
The type of geophysical vessel is selected by the user determining whether the two-dimensional operation or the three-dimensional operation is to be performed. The geophysical prospecting ship comprises a two-dimensional ship and a three-dimensional ship, wherein the two-dimensional ship generally acquires single-source single cables, the ship is not provided with more seismic source submatrixes, 4-5 submatrixes are generally adopted, and if one is reserved for standby, 3-4 submatrixes are adopted during conventional operation. The three-dimensional ship generally adopts double-source multi-cable acquisition, at least two seismic sources are needed, the two air gun seismic sources are completely identical and symmetrically arranged, 6-7 sub-arrays are also equipped for the seismic source expansion capacity of the rear deck of the general three-dimensional ship, a spare one is reserved, and 3 sub-arrays are provided for each seismic source in the case of double sources.
The step of calculating the number of the submatrices forming the air gun sources according to the total capacity and the number of the air gun sources in the S501 comprises the following steps:
s511, judging whether the ratio of the total capacity divided by the number of the air gun seismic sources is larger than a preset capacity or not, if so, taking the number of the sub-arrays as the number of the first sub-arrays; if not, the number of the sub-arrays is the number of the second sub-arrays, and the number of the first sub-arrays is larger than or equal to the number of the second sub-arrays.
For example, the total capacity 1160CI (capacity unit) can use only 2 sub-arrays because the capacity is small, and the total capacity 4350CI can use 3 sub-arrays because the capacity is large. Because the number of single guns and coherent guns on each subarray is fixed, the subarrays are rarely used if the capacity is small. Theoretically, the larger the number of the sub-arrays is, the better the effect is, but when the number of the sub-arrays is 3-4, the improvement of the effect of adding the sub-arrays is not obvious.
The single gun capacity has a specific capacity, only more than ten capacities, the maximum 380CI, and the minimum 45CI, for example, the single gun without the capacity of 135 CI. Accordingly, the coherent gun comprised of a single gun also has a specific capacity, i.e., both the single gun and the coherent gun have a maximum capacity, as do the individual sub-arrays.
Preferably, the capacity of the single sub-array can be distributed according to the total capacity and the number of the sub-arrays, or can be distributed according to the maximum capacity of the single sub-array. For example, when the total capacity is 4350CI, 3 sub-arrays are provided, and the maximum capacity of a single sub-array is 1500CI, the capacity of 2 sub-arrays is 1500CI, and the capacity of the remaining 1 sub-array is 1350 CI. Or the capacity of 3 subarrays is 4350 CI/3.
For example, the total capacity is 4400CI, when the two-dimensional operation is performed, the number of the seismic sources is determined to be 1, the total capacity 4400CI is larger than the preset capacity 4000CI, 4 sub-arrays are taken, the maximum capacity of a single sub-array is 1200CI, and the capacity of each sub-array is uniformly distributed as 4400CI/4 ═ 1100 CI. When three-dimensional operation is carried out, the number of the seismic sources is determined to be 2, 4400CI/2 is 2200CI, 2200CI is less than 3000CI (if the total capacity is more than 3000CI and less than 4000CI, the sub-arrays can be 3), then 2 sub-arrays are taken, the maximum capacity of a single sub-array is 1200CI, and the capacity of each sub-array is uniformly distributed to 2200CI/2 is 1100 CI.
Further, the method further comprises:
s600, determining the subarray spacing of the air gun seismic source according to the target frequency.
Further, the step of determining the subarray spacing of the air gun seismic source according to the target frequency and the field construction conditions in the step S600 comprises:
s601, performing seismic source simulation on at least two adjacent sub-arrays with the initial spacing.
And S602, sequentially increasing preset increments on the initial interval at the same time, and performing seismic source simulation on all the sub-arrays with the increased intervals one by one.
The subarray combination pitch is horizontally increasing, such as 8m, 9m, 10m, 11m, 12m, and so on. The planar seismic sources studied by the invention, namely each subarray, have the same depth level with each single gun. Generally, the sub-array combination distance is not too small during field collection, otherwise, winding is easy to occur, and the construction risk is large.
And S603, analyzing the simulation result obtained by the seismic source simulation according to the target frequency to obtain the optimal spacing between the adjacent subarrays. The simulation result is that the air gun seismic source simulates a far-field wavelet spectrogram.
Referring to fig. 3, fig. 3 is an air gun seismic source arrangement diagram of an air gun seismic source setting method according to a third embodiment of the present invention.
Further, as shown in FIG. 3, Inactive gun is a spare gun, cluster gun is a coherent gun, and single gun is a single gun. The air gun seismic source comprises a single gun and a coherent gun, and the arrangement combination comprises:
the number of single guns and coherent guns with different capacities, the combination of coherent guns and the arrangement positions of the single guns and the coherent guns in a plane. Wherein the sum of the capacities of all single guns and coherent guns in all spread combinations equals the total capacity.
Further, the air gun seismic source further comprises a spare gun, wherein the spare gun is arranged on the single gun and the coherent gun, the capacity of the spare gun is the same as that of the single gun and the coherent gun which are arranged adjacently, and the spare gun is used for starting when the single gun or the coherent gun fails.
In order to improve the gun closing performance of the air gun seismic source and the consistency of the seismic source energy, a method of arranging standby guns beside the single gun and the coherent gun is adopted, offline shutdown caused by the fault of a certain single gun can be prevented, the field acquisition construction efficiency is improved, and the cost is saved.
Illustratively, the marine air gun seismic source setting method based on frequency of the invention comprises the following steps:
1) and carrying out spectrum analysis on the original data of the exploration area to obtain the target frequency of a target layer, wherein the target frequency comprises a main frequency, a low frequency and a high frequency.
2) And determining the range of the sinking depth of the air gun seismic source according to the target frequency and depth frequency corresponding table and the principle that the target frequency is less than the frequency of the notch point.
3) And determining the total capacity of the air gun seismic source according to the sinking depth and construction requirements, wherein the deeper the target layer, the higher the total capacity requirement of the air gun seismic source, and the actual condition of a geophysical prospecting ship compressor is also considered.
4) And determining the number of subarrays of air gun seismic sources according to the range of the total capacity and the hardware condition of the geophysical prospecting ship, wherein the two-dimensional seismic ship is configured with 4-5 subarrays more, and the three-dimensional seismic ship is configured with 6-7 subarrays under the current mainstream geophysical prospecting ship hardware configuration condition. In order to ensure the field construction efficiency, the geophysical prospecting ship reserves 1 subarray as a spare. For two-dimensional operation, 3 or 4 seismic sources are usually used. Three-dimensional seismic operations employ 2 seismic sources, each of which is configured with 3 sub-arrays. The hardware condition of the geophysical prospecting ship refers to the number of air compressors providing energy for the air guns on the ship, and 3 air compressors are arranged on the general ship, 1 is standby, and 2 is in normal operation.
5) According to field construction conditions, the characteristics of the main peak value, the initial bubble ratio, the frequency spectrum and the like of the seismic source wavelets with different distances are contrastively analyzed by changing the sub-array combination distance. The variation range of the combination interval is 3-15m, the increment is 1m, and the simulation is carried out one by one. And determining the optimal spacing of the subarrays according to the target frequency by the simulation result.
6) As shown in fig. 3, after the sinking depth, the total volume range, the number of sub-arrays and the sub-array combination distance of the air gun seismic source are determined, the air gun combination is further arranged according to the air gun tuning and coherence principle, each sub-array is composed of a single gun and a coherent gun with different volumes, the air gun volumes are various, and the air gun compression is facilitated. And each single gun and the coherent gun are provided with the spare gun with the same capacity, when a certain gun in the air gun seismic source breaks down, the spare gun with the same capacity beside the gun can be opened immediately while the gun with the fault is closed, offline shutdown caused by the fact that the certain single gun breaks down is prevented, and production efficiency is improved.
The single gun and the standby gun with the same capacity are arranged beside the coherent gun, when one of the coherent guns breaks down, the adjacent standby gun with the same capacity can be opened, the standby gun and the single gun form a new coherent gun, and the original coherent gun becomes the single gun. The standby gun is a gun which is not excited during normal blasting, the overall performance of a gun array cannot be influenced, and the standby gun is opened only when one single gun or one branch of a coherent gun breaks down, so that the production efficiency can be improved. Gun position information is located according to an acoustic network, with acoustic receivers on the gun array, using the WGS84 coordinate system.
The characteristics of the air gun seismic source constructed by applying the arrangement provided by the invention are described in the following with reference to fig. 4-8. Referring to fig. 4 to 8, fig. 4 is a graph of a simulated far-field wavelet waveform of the air gun source of fig. 3 according to the present invention, fig. 5 is a graph of a simulated far-field wavelet spectrum of the air gun source of fig. 3 according to the present invention, fig. 6 is a top view of an energy directivity of the simulated far-field wavelet of the air gun source of fig. 3 according to the present invention, fig. 7 is a 0-degree directivity diagram of the simulated far-field wavelet of the air gun source of fig. 3 according to the present invention, and fig. 8 is a 90-degree directivity diagram of the simulated far-field wavelet of the air gun source of fig..
Fig. 4-8 are graphs illustrating the relatively good performance of the seismic source of the present invention.
FIG. 4 is a waveform diagram of wavelets, the main performance parameters of the diagram are: the larger the indexes such as Peak-Peak value (Peak-Peak), primary Peak value (primary), primary bubble Ratio (P/B Ratio) and the like are, the better the indexes are, the stronger the energy of the seismic source is, and the higher the signal-to-noise Ratio is.
FIG. 5 is a graph of the spectra of wavelets, the smoother the spectrum the better, and the-6 dB line corresponds to the bandwidth, i.e., low to high frequencies, which are all the effective bands, the wider the band is, the better relatively. For deep surveys, the more low frequencies the better. For thin layer identification, the wider the bandwidth, the better the resolution.
6-8 are diagrams of seismic source directivity, which are that the more circular the graphs corresponding to all directions and frequencies are, the better the directivity consistency is, the energy is more uniform, and the oil and gas exploration is facilitated.
As can be seen from fig. 4 to 8, the air gun seismic source constructed using the arrangement provided by the present invention has the following advantages: the major peak value, peak-peak value and initial bubble of the seismic source wavelet are large, which is beneficial to improving the signal-to-noise ratio of seismic data. The frequency spectrum is smooth and both low and high frequency energy is abundant. The direction of the seismic source is good, and the energy in all directions is uniform. Each single gun and each coherent gun are provided with spare guns with the same capacity, so that consistency of seismic source energy is kept, and production efficiency is improved.
Referring to fig. 9, fig. 9 is a schematic structural diagram of an air gun seismic source setting apparatus according to a fourth embodiment of the present invention.
As shown in fig. 9, a second aspect of the present invention provides an air gun source setting apparatus, including:
the acquisition module 1 is configured to acquire a destination frequency of a destination layer.
And the depth determination module 2 is used for determining the sinking depth of the air gun seismic source according to the target frequency.
And the total capacity determination module 3 is used for determining the total capacity of the air gun seismic source according to the sinking depth.
And the arrangement combination module 4 is used for determining the arrangement combination of the air gun seismic sources according to the target frequency and the total capacity.
Preferably, the air gun seismic source is arranged at the sinking depth of the target layer according to the arrangement combination.
Further, the obtaining module 1 includes a spectrum analyzing module 11, configured to perform spectrum analysis on the raw data of the exploration area to obtain the target frequency.
Further, the depth determining module 2 includes a searching module 21 for searching the sinking depth from the depth frequency corresponding table according to the principle that the target frequency is less than the notch point frequency.
Further, the apparatus further comprises:
and the subarray number determination module 5 is used for determining the number of subarrays of the air gun seismic sources according to the total capacity and the hardware condition of the geophysical prospecting ship.
Further, the sub-array number determining module 5 includes:
the subarray number calculation module 51 is configured to calculate the number of subarrays forming the air gun seismic sources according to the total capacity and the number of the air gun seismic sources after determining the number of the air gun seismic sources, where the capacity of all the subarrays is equal to the total capacity;
the subarray number calculation module 51 includes:
the judging module 511 is configured to judge whether a ratio of the total capacity divided by the number of air gun seismic sources is greater than a preset capacity, and if so, the number of the sub-arrays is the first number of the sub-arrays; if not, the number of the sub-arrays is the number of the second sub-arrays, and the number of the first sub-arrays is larger than or equal to the number of the second sub-arrays.
Further, the apparatus further comprises:
and the subarray spacing determination module 6 is used for determining the subarray spacing of the air gun seismic source according to the target frequency.
Further, the subarray spacing determination module 6 includes:
and a source simulation module 61 for performing source simulation on at least two adjacent sub-arrays with an initial spacing.
And the distance increasing module 62 is used for sequentially increasing preset increments on the initial distance at the same time, and the seismic source simulation module is also used for performing seismic source simulation on all the sub-arrays with the increased distance one by one.
And the optimal spacing determining module 63 is used for analyzing the simulation result obtained by the seismic source simulation according to the target frequency to obtain the optimal spacing of the adjacent sub-arrays.
Further, the air gun seismic source comprises a single gun and a coherent gun, and the arrangement combination comprises:
the number of single guns and coherent guns with different capacities, the combination of coherent guns and the arrangement positions of the single guns and the coherent guns in a plane. Wherein the sum of the capacities of all single guns and coherent guns in all spread combinations equals the total capacity.
Further, the air gun seismic source further comprises a spare gun, wherein the spare gun is arranged on the single gun and the coherent gun, the capacity of the spare gun is the same as that of the single gun and the coherent gun which are arranged adjacently, and the spare gun is used for starting when the single gun or the coherent gun fails.
The working principle and technical effect of the air gun seismic source setting device provided by the second aspect of the invention are the same as those of the air gun seismic source setting method, and are not repeated here.
A third aspect of the invention provides a machine-readable storage medium having instructions stored thereon for enabling the machine-readable storage medium to perform the air gun source setting method described above.
The invention discloses a method and a device for setting an air gun seismic source and a machine readable storage medium.
In the above embodiments, the description of each embodiment has its own emphasis, and for parts not described in detail in a certain embodiment, reference may be made to the description of other embodiments. In view of the above description of the method, apparatus and machine-readable storage medium for setting air gun seismic source provided by the present invention, those skilled in the art will recognize that changes may be made in the embodiments and applications of the method and apparatus according to the teachings of the present invention.
Claims (19)
1. An air gun source setting method, characterized in that the method comprises:
acquiring the target frequency of a target layer;
determining the sinking depth of an air gun seismic source according to the target frequency;
determining a total capacity of the air gun seismic source according to the sinking depth;
and determining the arrangement combination of the air gun seismic sources according to the target frequency and the total capacity.
2. The method of claim 1, wherein obtaining the destination frequency of the destination layer comprises:
and carrying out spectrum analysis on the original data of the exploration area to obtain the target frequency.
3. The method of claim 1, wherein the step of determining a depth of repose for the air-gun seismic source based on the frequency of interest comprises:
and searching the sinking depth from a depth frequency corresponding table according to the principle that the target frequency is less than the notch point frequency.
4. The method of claim 1, further comprising:
and determining the number of the submatrices of the air gun seismic sources according to the total capacity.
5. The method of claim 4, wherein determining the number of subarrays of the air-gun seismic sources based on the total volume comprises:
after the number of the air gun seismic sources is determined, calculating the number of sub-arrays forming the air gun seismic sources according to the total capacity and the number of the air gun seismic sources, wherein the sum of the capacities of all the sub-arrays is equal to the total capacity;
the step of calculating the number of the submatrices forming the air gun sources according to the total capacity and the number of the air gun sources comprises the following steps:
judging whether the ratio of the total capacity divided by the number of the air gun seismic sources is larger than a preset capacity or not, if so, determining the number of the sub-arrays to be the number of the first sub-arrays; and if not, the number of the sub-arrays is the number of the second sub-arrays, and the number of the first sub-arrays is larger than or equal to the number of the second sub-arrays.
6. The method of claim 1, further comprising:
and determining the subarray spacing of the air gun seismic source according to the target frequency.
7. The method of claim 6, wherein the step of determining a subarray spacing of the air-gun seismic source according to the frequency of interest comprises:
performing source simulation on at least two adjacent sub-arrays with an initial spacing;
sequentially increasing preset increments on the initial interval at the same time, and performing seismic source simulation on all sub-arrays with the gradually increased intervals one by one;
and analyzing a simulation result obtained from the seismic source simulation according to the target frequency to obtain the optimal spacing between the adjacent sub-arrays.
8. The method of claim 1, wherein the air-gun seismic source comprises a single gun and a coherent gun, and the spread combining comprises:
the number of the single guns and the coherent guns with different capacities, the combination of the coherent guns and the arrangement positions of the single guns and the coherent guns in a plane; wherein the sum of the capacities of all single guns and coherent guns in all said spread combinations is equal to said total capacity.
9. The method of claim 8, wherein the air gun source further comprises a reserve gun disposed on the single gun and the coherence gun having the same capacity as the adjacently disposed single gun and coherence gun, respectively, for firing upon failure of the single gun or the coherence gun.
10. An air gun source setting device, comprising:
the acquisition module is used for acquiring the target frequency of the target layer;
the depth determination module is used for determining the sinking depth of the air gun seismic source according to the target frequency;
a total capacity determination module for determining a total capacity of the air gun seismic source according to the sinking depth;
and the arrangement combination module is used for determining the arrangement combination of the air gun seismic sources according to the target frequency and the total capacity.
11. The apparatus of claim 10, wherein the obtaining module comprises a spectrum analysis module for performing spectrum analysis on the raw material of the survey area to obtain the target frequency.
12. The apparatus of claim 10, wherein the depth determination module comprises a lookup module for looking up the sinking depth from a depth-frequency correspondence table according to a rule that the destination frequency is less than the notch point frequency.
13. The apparatus of claim 10, further comprising:
and the submatrix number determining module is used for determining the submatrix number of the air gun seismic sources according to the total capacity.
14. The apparatus of claim 13, wherein the sub-array number determining module comprises:
the submatrix number calculation module is used for calculating the number of the submatrix forming the air gun seismic sources according to the total capacity and the number of the air gun seismic sources after the number of the air gun seismic sources is determined, wherein the sum of the capacities of all the submatrixes is equal to the total capacity;
the subarray number calculation module comprises:
the judging module is used for judging whether the ratio of the total capacity divided by the number of the air gun seismic sources is larger than a preset capacity or not, and if yes, the number of the sub-arrays is the first sub-array number; and if not, the number of the sub-arrays is the number of the second sub-arrays, and the number of the first sub-arrays is larger than or equal to the number of the second sub-arrays.
15. The apparatus of claim 10, further comprising:
and the subarray spacing determination module is used for determining the subarray spacing of the air gun seismic source according to the target frequency.
16. The apparatus of claim 15, wherein the subarray spacing determination module comprises:
a seismic source simulation module for performing seismic source simulation on at least two adjacent sub-arrays with an initial spacing;
the distance increasing module is used for sequentially increasing preset increments on the initial distance at the same time, and the seismic source simulation module is also used for performing seismic source simulation on all the sub-arrays with the increased distances one by one;
and the optimal spacing determining module is used for analyzing the simulation result obtained by the seismic source simulation according to the target frequency to obtain the optimal spacing between the adjacent sub-arrays.
17. The apparatus of claim 10, wherein the air-gun seismic source comprises a single gun and a coherent gun, and the spread combination comprises:
the number of the single guns and the coherent guns with different capacities, the combination of the coherent guns and the arrangement positions of the single guns and the coherent guns in a plane; wherein the sum of the capacities of all single guns and coherent guns in all said spread combinations is equal to said total capacity.
18. The apparatus of claim 17, wherein the air gun source further comprises a backup gun disposed on the single gun and the coherence gun and having a capacity equal to a capacity of the adjacently disposed single gun and coherence gun, respectively, for firing upon failure of the single gun or the coherence gun.
19. A machine-readable storage medium having instructions stored thereon for enabling the machine-readable storage medium to perform the air gun source setting method according to any one of claims 1-9.
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