CN111781645B - Method for jointly calculating marine seismic wavelets by using seabed stratum and first arrival waves - Google Patents
Method for jointly calculating marine seismic wavelets by using seabed stratum and first arrival waves Download PDFInfo
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Abstract
The invention relates to a method for jointly calculating marine seismic wavelets by using a seabed stratum and a first-motion wave, which comprises the following steps: step 1: selecting two work areas as current work areas; step 2: carrying out pretreatment; and step 3: obtaining a primary wave spectrum envelope curve from the preprocessed seismic data; and 4, step 4: superposing the first-arrival wave spectral envelope curves to obtain frequency correction factors; and 5: acquiring a superposition reflection section of the current work area, and performing cross correlation to obtain a phase correction factor; step 6: combining the frequency correction factor and the phase correction factor to obtain a difference shaping factor, and performing matching shaping correction to obtain marine seismic wavelets; and 7: and (4) continuously selecting a new work area from the rest work areas, and repeating the steps 2 to 6 to obtain n unified marine seismic wavelets of the work areas. The seismic wavelet obtained by the method has more effective frequency bandwidth and retains more effective information.
Description
Technical Field
The invention relates to the technical field of seismic wavelet solving, in particular to a method for jointly solving marine seismic wavelets by using seabed stratums and first arrival waves.
Background
As shown in fig. 1, the marine seismic data acquisition work mainly includes designing a seismic source, seismic source excitation, seismic signal reception, and the like, and usually, marine seismic data acquisition is completed by an acquisition vessel, seismic source excitation is performed by the seismic source, seismic signals after seismic source excitation are transmitted to the sea bottom and then reflected, seismic signals are received by each demodulator probe on a streamer, and finally, the received seismic signals are transmitted to the acquisition vessel. In the process, because the obtained seismic data are interfered by various factors, effective reflection information in the seismic signals received by the wave detection point cannot be completely revealed, and the effective reflection information can be provided for subsequent geologists to carry out explanation and comprehensive research after data processing. The distance from the wave detection point to the seismic source is offset, and the section formed by seismic data of each seismic source received by the first wave detection point is a first-channel section.
The seismic wavelet is the minimum composition unit of seismic data, is an excitation wavelet formed by fixed amplitude, frequency and phase emitted by a seismic source with well designed acquisition parameters, is reflected back to the sea surface when encountering a stratum interface when being transmitted to a seabed stratum, and is a wavelet received by an instrument, wherein the received wavelet is the seismic wavelet. The reflected wavelets undergo energy attenuation as they travel through the formation, changing in amplitude, frequency, and phase compared to the original excitation wavelets. The more it passes through the formation, the higher the degree to which the seismic wavelet is modified, i.e., the greater the change in seismic wavelet compared to the excitation wavelet. Meanwhile, the seismic wavelet characteristics obtained by different acquisition parameters and acquisition systems are usually different.
When a plurality of work area seismic data acquired by different acquisition parameters and acquisition systems need to be processed in a continuous mode, the consistency processing of the seismic wavelets is the key of seismic data splicing processing, all the seismic wavelets have basically consistent characteristics, and subsequent processing can be carried out only, so that the final processing result can have more consistent imaging characteristics, and data interpretation and comprehensive research can be carried out later.
In order to make the seismic wavelets of a plurality of work area seismic data obtained by different acquisition parameters and acquisition systems have basically consistent characteristics, the prior art mainly has three types:
(1) carrying out simulation by related software by adopting a mathematical method;
(2) obtaining the superposition result data processed from a plurality of work areas by using a cross-correlation method;
(3) if there is well drilling in the work area, the seismic wavelet can be calculated by using the logging data.
(1) The difference between the wavelets simulated by the mathematical method and the actual wavelets is large. The reason is that the comprehensive response of the seismic source and the receiving instrument cannot be simulated; secondly, the convolution of the stratum and the excitation wavelets cannot be simulated because the stratum composition characteristics are unknown. The finally obtained seismic wavelets are over ideal, and the deviation from the actual situation is large.
(2) The seismic wavelets obtained by using the superposition result are fuzzy or cannot be used in the situation with higher requirements on resolution. The method has the advantages that the signal-to-noise ratio of original single shot data is low, wavelets are unstable, the method can only select data with high signal-to-noise ratio and relatively smooth stratum through multi-channel superposition, the wavelets are analyzed and extracted through processing software, and the wavelets are fuzzy due to superposition; secondly, the seismic wavelets in the superposition result contain a large amount of stratum information, so that the frequency is low, and therefore, the method cannot be used under the condition of high requirement on seismic data resolution.
(3) The wavelet is calculated by utilizing the logging data, which is often just 'one-hole observation', and the method is not suitable for the work area with large work area range and complex geological condition change or the work area without well drilling. The method mainly utilizes well-to-seismic combination to calculate the reflection coefficient by using well side channel information to obtain seismic wavelets. However, the coverage area of the well drilling is very small, so that the well drilling device cannot be used in a work area with a large range or complex geological conditions. Meanwhile, the method is not suitable for solving the seismic wavelets in the well-free areas.
In summary, the method for obtaining seismic wavelets has been a difficult problem for processing personnel when processing seismic data of multiple work areas in a well-free sea area or by different acquisition parameters and acquisition systems in a continuous manner. Therefore, a method for obtaining seismic wavelets is urgently needed, so that the obtained seismic wavelets can be used for shaping and consistency processing of the seismic wavelets in the multiple work areas, and can be used as standard wavelets for suppressing multiple waves and carrying out other processing flows, and the seismic wavelets are not excessively transformed and have the reflection information of the stratum.
Disclosure of Invention
Aiming at the defects of the prior art, the invention aims to provide a method for jointly calculating marine seismic wavelets by using seabed strata and first arrival waves, which can solve the splicing processing problem of seismic exploration.
The technical scheme for realizing the purpose of the invention is as follows: a method for jointly obtaining marine seismic wavelets by utilizing a seabed stratum and a first arrival wave selects n work areas needing to be processed in a connected mode, wherein n is larger than or equal to 2, any two work areas in the n work areas have direct or indirect closing points, the direct closing points refer to the fact that the two work areas have direct data overlapping areas, the indirect closing points refer to the fact that the two work areas do not have direct data overlapping areas, but the two work areas and at least one work area in other work areas have a common data overlapping area, and the method comprises the following steps:
step 1: randomly selecting two work areas with direct closing points from the n work areas, and taking the selected two work areas as the current work area;
step 2: obtaining marine seismic data of each current work area, and preprocessing the marine seismic data, wherein the preprocessing at least comprises stacking processing to obtain preprocessed seismic data, and the preprocessed seismic data comprise stacking sections;
and step 3: presetting a data time window near the bottom reflection on the first-channel common offset section in the preprocessed seismic data, selecting at least two first-arrival waves of complete waveforms containing wave crests and wave troughs in the data time window, and respectively performing wavelet analysis and extraction on each first-arrival wave to obtain a first-arrival wave spectrum envelope curve of the current work area;
and 4, step 4: superposing the two first arrival wave spectrum envelope curves of the current work area to obtain a current superposed spectrum envelope curve, using the superposed spectrum envelope curve as an expected sample, and respectively dividing the expected sample by the first arrival wave spectrum envelope curves of the work areas of the current work area to obtain frequency correction factors corresponding to the work areas of the current work area;
and 5: acquiring superposed reflection sections of a current work area, and performing cross correlation on the two superposed reflection sections to obtain phase correction factors corresponding to each work area in the current work area, wherein in the cross correlation, the phase of one work area in the two work areas is selected as a standard to obtain the phase correction factors of each work area in the current work area;
step 6: combining frequency correction factors and phase correction factors corresponding to current work areas to obtain difference shaping factors corresponding to the current work areas, and performing matching shaping correction on the current work areas according to the difference shaping factors, wherein the matching shaping correction refers to performing convolution operation on the difference shaping factors and seismic data of the corresponding work areas to obtain unified marine seismic wavelets and spliced work areas representing the current work areas;
and 7: continuously selecting one work area which has a direct closing point with at least one of the two work areas from the rest work areas, using the newly selected work area and the splicing work area as a new current work area,
and then repeating the steps 2-6 until all the work areas are processed, thereby obtaining the uniform ocean seismic wavelets of the n work areas and forming a complete spliced work area.
Further, in the step 2, before the stacking processing of the preprocessing, noise removal is further included, and then multiple removal, velocity analysis and data sorting are sequentially performed.
Further, in the step 1, two work areas are selected from the n work areas as the current work area,
two work areas which are provided with direct closing points and have the first-arrival wave spectrum envelope curves with the frequency ranges as wide as possible are selected as the current work area, so that the frequency range of the superimposed spectrum envelope curves obtained by superimposing the selected two work areas can cover the frequency ranges of the first-arrival wave spectrum envelope curves of all the work areas.
Further, in the step 1, the signal-to-noise ratio is greater than or equal to 3.
Further, in step 3, when wavelet analysis and extraction are performed on each first-motion wave, a spectrum on the first-pass common offset profile which is not overlapped is selected, and a first-motion wave spectrum envelope curve of the current work area is obtained.
Further, in step 5, the stacked reflection segment obtained from the current work area is a stacked reflection segment selected from a stacked profile in the preprocessed seismic data.
The invention has the beneficial effects that: the ocean seismic wavelet is obtained by combining the seabed stratum and the first arrival wave, the first arrival wave frequency spectrum of each work area is corrected to the widest superposition frequency spectrum, the phase of each work area is subjected to consistency processing, and then the ocean seismic wavelet is obtained, so that the obtained seismic wavelet has more effective frequency bandwidth, more effective information is reserved in the later wavelet shaping, the resolution of seismic data is improved, particularly high-frequency and low-frequency information is enriched, the artificial influence is reduced, and the production and application effects are better.
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FIG. 1 is a schematic diagram of collecting seismic data in a sea area;
FIG. 2 is a flow chart of the preferred embodiment of the present invention;
FIG. 3 is a schematic flow diagram of the pretreatment of the present invention;
FIG. 4 is a schematic diagram of a process of obtaining a superimposed spectrum envelope curve by superimposing first arrival spectrum envelope curves of two work areas;
FIG. 5 is a schematic diagram of a process for obtaining respective frequency correction factors for two work areas;
FIG. 6 is a schematic diagram of a process for obtaining a phase correction factor according to a superimposed profile of two work areas;
FIG. 7 is a schematic diagram of differential shaping factors for two work areas;
FIG. 8 is a schematic diagram comparing the overlay profiles before and after optimization;
FIG. 9 shows five work areas (N)1,N2,N3,N4,N5) Schematic diagram of the relationship between them.
Detailed description of the preferred embodiments
The invention will be further described with reference to the accompanying drawings and specific embodiments:
as shown in fig. 2-9, a method for jointly determining marine seismic wavelets by using a seabed stratum and a first-arrival wave includes the following steps:
step 1: selecting N work areas needing to be processed in a continuous mode, wherein N is more than or equal to 2 and is respectively marked as N1、N2、…、NnAnd (5) a work area. Any two of the n work areas have a direct or indirect closing point, the direct closing point means that the two work areas have a direct data overlapping area, and the indirect closing point means that the two work areas have no direct data overlapping area, but the two work areas have a common data overlapping area with at least one of the other work areas. For example, work area N1And region N3Without direct data overlap, but with work area N1And region N3Homogeneous working area N2With direct data overlap, i.e. work area N1And region N3Homogeneous working area N2Have a common data overlap region, so that work area N1And region N3There is no direct closing point, but there is an indirect closing point. In the present embodiment, five work areas are taken as an example, as shown in fig. 9, five work areas are (N)1,N2,N3,N4,N5) Wherein, the work area N1And region N2Work area N2And region N3Work area N3And region N4Work area N4And region N5All have direct closing points between them, work area N3Through a work area N2And work area N1With indirect closing point, thereby making five work areas (N)1,N2,N3,N4,N5) Any two of the work areas have a direct or indirect closing point. And carrying out seismic wavelet splicing treatment, namely carrying out connection treatment on the five work areas.
The seismic wavelet splicing process for two work areas without direct or indirect closing points in the n work areas is out of the protection scope of the application and is not discussed. However, in this case, the two work areas without direct or indirect closing points will find out the close data area to approximate as the closing point of the two work areas, so as to convert to the scheme of the present application, but what data area to approximate to replace the closing point of the two work areas is selected, and the details are not described herein since the two work areas are not used as the protection scheme of the present application.
In five work areas (N)1,N2,N3,N4,N5) Selecting any two work areas with direct closing points, wherein the two selected work areas are used as the current work area, and the two selected work areas are assumed to be work areas N1And region N2. The seismic data with high signal-to-noise ratio and small sea bottom fluctuation are screened from the data overlapping area of the initial work area group, the signal-to-noise ratio is generally higher than or equal to 3, and the seismic data with the signal-to-noise ratio less than 3 can be regarded as the seismic data with the high signal-to-noise ratio, but the seismic data with the signal-to-noise ratio more than or equal to 3 is preferred. The selected seismic data are used as seismic data required by extracting seismic wavelets of each work area, namely, the selected seismic data are respectively used as five work areas (N)1,N2,N3,N4,N5) Seismic data required for the seismic wavelets are respectively extracted.
Two selected work areas (N)1,N2) As the current work area.
Preferably, two work areas are selected from the n work areas as the current work area,
two work areas which are provided with direct closing points and have the first-arrival wave spectrum envelope curves with the frequency ranges as wide as possible are selected as the current work area, so that the frequency range of the superimposed spectrum envelope curves obtained by superimposing the selected two work areas can cover the frequency ranges of the first-arrival wave spectrum envelope curves of all the work areas.
Step 2: as shown in FIG. 3, for a work area N1And region N2The seismic data are preprocessed, wherein the preprocessing mainly comprises defining an observation system, manually editing bad-path and bad-cannon and processing by Omega seismic processing software (or other seismic processing software) so as to suppress the influence of seismic noise such as sea waves, surge waves, direct waves, ghost waves and the like. The preprocessing flow is as shown in fig. 3, and the seismic data is subjected to low-cut filtering, then abnormal noise removal processing, multiple wave removal, velocity analysis, data sorting and stacking are sequentially performed, and finally preprocessed seismic data are obtained, wherein the preprocessed seismic data comprise trace gather data and a stacking section, and the trace gather data comprise a first-channel common offset section. It is composed ofThe superposition treatment is one treatment step necessary for the pretreatment, and the remaining treatments are the preferred treatment steps.
And step 3: as shown in fig. 4, a data time window is preset near the bottom reflection on the first-pass common-offset section in the preprocessed seismic data, and the data time window is used as a first-arrival frequency analysis time window. M (m is larger than or equal to 2) first-motion waves with complete waveforms are selected in the data time window, as shown in the two uppermost graphs in fig. 4, at least 2 first-motion waves with complete waveforms are selected in the longitudinal direction, and complete waveforms refer to the fact that the wave crests and the wave troughs are included. Performing wavelet analysis and extraction on the selected first-motion waves, and preferably selecting the frequency spectrums on the common offset distance of the first channels without superposition to obtain respective representative work areas N1And region N2The envelope curve of the first arrival spectrum of (1). Will represent two work areas (N)1，N2) The two first-arrival wave spectrum envelope curves are superposed to obtain a product containing two work areas (N)1，N2) The frequency range of the superimposed spectral envelope curve, i.e. the frequency range of the superimposed spectral envelope curve (corresponding to the abscissa range of the last diagram in fig. 4) covers two work areas (N)1，N2) The frequency range of the first arrival wave spectral envelope curve of (a), the superimposed spectral envelope curve being used as the desired spectral sample for both work zones. FIG. 4 shows two work areas (N)1，N2) The first arrival wave spectrum envelope curves are superposed to obtain a process schematic diagram of the superposed spectrum envelope curves.
And 4, step 4: as shown in FIG. 5, the desired sample is divided by two work areas (N) respectively1，N2) The respective first arrival wave spectrum envelopes to obtain two work areas (N)1，N2) A corresponding frequency correction factor. I.e. dividing the desired sample by the work area N1The first arrival wave spectrum envelope to obtain a work area N1A corresponding frequency correction factor; divide the desired sample by work area N2The first arrival wave spectrum envelope to obtain a work area N2A corresponding frequency correction factor. FIG. 5 shows two work areas (N)1，N2) The respective frequency correction factors are illustrated schematically in the process, wherein the abscissa of the lower three graphs in the graph represents frequency and the ordinate represents amplitude.
And 5: as shown in fig. 6, from the current work area (N)1,N2) And respectively selecting superposed reflection sections with higher signal-to-noise ratio (generally, the signal-to-noise ratio is more than or equal to 3, and the other superposed reflection sections can be selected) in the superposed positions of the respective superposed data through preprocessing, thereby obtaining two superposed reflection sections which are used as seismic data for obtaining the phase correction factor. I.e. from two work areas (N)1，N2) And respectively selecting superposed reflection sections with high signal-to-noise ratio in the preprocessed superposed sections, wherein the two selected superposed reflection sections are used as seismic data for obtaining a phase correction factor. The step of obtaining the phase correction factor comprises the following steps:
with one of the work stations (e.g. station N)1) Is the standard, i.e. one of the work areas is used as the target phase work area, here work area N is used1As target phase working area, i.e. working area N2In other words, work area N1The phase correction factor of (2) can be regarded as 0, and another work area (work area N)2) Is ahead of the phase of the previous work area (i.e. work area N)1) And (4) aligning. The alignment means that two selected superposed reflection sections are mutually correlated to obtain the current work area (i.e. work area N)2) The phase correction factor of (1). FIG. 6 shows two work areas (N)1，N2) The superimposed profile of (A) is used to obtain a process schematic diagram of a phase correction factor, a work area N in the diagram1Is 0.
Step 6: as shown in fig. 7, the frequency correction factor obtained in step 4 and the phase correction factor obtained in step 5 are combined according to the respective work area correspondence, so as to obtain the differential shaping factor corresponding to each work area in the current work area. I.e. the work area N1The frequency correction factor and the phase correction factor are combined to obtain a work area N1The differential shaping factor of (3); will work area N2The frequency correction factor and the phase correction factor are combined to obtain a work area N2The differential shaping factor of (1). FIG. 7 shows two work areas (N)1，N2) Schematic representation of respective differential shaping factors. In FIG. 7
The expression is subjected to convolution operations.
The seismic wavelet is decomposed to obtain frequency and phase by Fourier transformation, and the frequency and phase are combined to obtain the seismic wavelet by inverse Fourier transformation, so that the combination is inverse Fourier transformation.
As shown in fig. 8, two work areas (N) are respectively processed according to their respective differential shaping factors1，N2) Performing matching, shaping and correcting to obtain two work areas (N)1，N2) The seismic wavelets after respective optimization are obtained by solving two work areas (N)1，N2) When the frequency correction factors are respectively calculated, the two work areas are respectively aligned to the superposed spectrum envelope curve to obtain two work areas (N)1，N2) The respective phase correction factor is the work area N1As a standard, work area N2To a working area N1The difference shaping factors of the two work areas are obtained only by aligning, so that the two work areas (N) are subjected to the difference shaping factors1，N2) Two work areas (N) obtained by matching, shaping and correcting1，N2) The seismic wavelets are consistent and identical, namely, the uniform seismic wavelets in the current work area are obtained after matching, shaping and correcting. Wherein, the matching shaping correction refers to the convolution operation of the seismic data of the different shaping factors and the corresponding work areas, thereby obtaining each work area (N)1，N2) And respectively optimizing the seismic wavelets. Fig. 8 is a schematic diagram comparing the superposed sections before and after optimization.
In addition, two work areas (N)1，N2) After the above treatment, two work areas (N)1，N2) The frequency spectrum and the phase are processed in a consistent way, so that two work areas (N) can be processed1，N2) The current work area (N) is obtained after the steps are processed1，N2) A splicing work area corresponding to an area containing (N)1，N2) The large work area.
And 7: from the remaining work area (N)3,N4,N5) And selecting one work area which has a direct closing point with at least one of the two work areas, and taking the newly selected work area and the splicing work area as a new current work area. The two work areas selected initially are (N)1，N2) Only work area N3And work area N2With closing point, will work area N3As the newly selected work area, work area (N)1，N2) Splicing the work area and the work area N after the step processing3As a new current work area.
Then repeating the steps 2 to 6 until the work area N is obtained5The spectrum envelope curve is used as a corresponding superimposed spectrum envelope curve in one of the current work areas, namely all the work areas are processed. And taking the envelope curve at the moment as a final expected sample, and dividing the final expected sample by five work areas (N)1,N2,N3,N4,N5) The first arrival wave spectrum envelope curve of each work area obtains the frequency correction factor of each work area, thereby obtaining the respective frequency correction factor of all work areas (namely n work areas).
Of course, the frequency correction factor of the current work area can also be calculated by obtaining the superimposed spectrum envelope curve each time, so as to obtain the respective frequency correction factors of all the work areas, and the results obtained by the two work areas are the same. Similarly, repeating the steps 2 to 6 to obtain the phase correction factors corresponding to all the work areas, thereby obtaining the marine seismic wavelets of the n work areas and forming a complete spliced work area, namely splicing the n work areas into a complete work area.
The embodiments disclosed in this description are only an exemplification of the single-sided characteristics of the invention, and the scope of protection of the invention is not limited to these embodiments, and any other functionally equivalent embodiments fall within the scope of protection of the invention. Various other changes and modifications to the above-described embodiments and concepts will become apparent to those skilled in the art from the above description, and all such changes and modifications are intended to be included within the scope of the present invention as defined in the appended claims.
Claims (5)
1. A method for jointly obtaining ocean seismic wavelets by utilizing a seabed stratum and a first arrival wave is characterized in that n work areas needing to be processed in a connected mode are selected, wherein n is larger than or equal to 2, any two work areas in the n work areas have direct or indirect closing points, the direct closing points mean that the two work areas have a direct data overlapping area, the indirect closing points mean that the two work areas have no direct data overlapping area, and the two work areas at least have a common data overlapping area with one of the other work areas, and the method comprises the following steps:
step 1: randomly selecting two work areas with direct closing points from the n work areas, and taking the selected two work areas as the current work area;
step 2: obtaining marine seismic data of each current work area, and preprocessing the marine seismic data, wherein the preprocessing at least comprises stacking processing to obtain preprocessed seismic data, and the preprocessed seismic data comprise stacking sections;
and step 3: presetting a data time window near the bottom reflection on the first-channel common offset section in the preprocessed seismic data, selecting at least two first-arrival waves of complete waveforms containing wave crests and wave troughs in the data time window, and respectively performing wavelet analysis and extraction on each first-arrival wave to obtain a first-arrival wave spectrum envelope curve of the current work area;
and 4, step 4: superposing the two first arrival wave spectrum envelope curves of the current work area to obtain a current superposed spectrum envelope curve, using the superposed spectrum envelope curve as an expected sample, and respectively dividing the expected sample by the first arrival wave spectrum envelope curves of the work areas of the current work area to obtain frequency correction factors corresponding to the current work area;
and 5: acquiring superposed reflection sections of a current work area, and performing cross correlation on the two superposed reflection sections to obtain phase correction factors corresponding to each work area in the current work area, wherein in the cross correlation, the phase of one work area in the two work areas is selected as a standard to obtain respective phase correction factors of the current work area;
step 6: combining frequency correction factors and phase correction factors corresponding to current work areas to obtain difference shaping factors corresponding to the current work areas, and performing matching shaping correction on the current work areas according to the difference shaping factors, wherein the matching shaping correction refers to performing convolution operation on the difference shaping factors and seismic data of the corresponding work areas to obtain unified marine seismic wavelets and spliced work areas representing the current work areas;
and 7: continuously selecting one work area which has a direct closing point with at least one of the two work areas from the rest work areas, using the newly selected work area and the splicing work area as a new current work area,
and then repeating the steps 2-6 until all the work areas are processed, thereby obtaining the uniform ocean seismic wavelets of the n work areas and forming a complete spliced work area.
2. The method of claim 1, wherein the step 2 further comprises denoising, and then performing multiple elimination, velocity analysis and data sorting sequentially, before the stacking process of the pre-processing.
3. The method for obtaining marine seismic wavelets using a combination of seafloor strata and first arrival waves as claimed in claim 1, wherein in step 1, two work areas are selected from the n work areas as the current work area,
two work areas which are provided with direct closing points and have the first-arrival wave spectrum envelope curves with the frequency ranges as wide as possible are selected as the current work area, so that the frequency range of the superimposed spectrum envelope curves obtained by superimposing the selected two work areas can cover the frequency ranges of the first-arrival wave spectrum envelope curves of all the work areas.
4. The method as claimed in claim 1, wherein in step 3, when wavelet analysis and extraction are performed on each first-arrival wave, spectrum on the first-arrival-path common-offset-distance section that is not overlapped is selected to obtain the first-arrival-wave spectrum envelope curve of the current work area.
5. The method of claim 1, wherein in step 5, the stacked reflection segments for the current work area are selected from stacked sections in the preprocessed seismic data.
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Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20100008184A1 (en) * | 2008-06-02 | 2010-01-14 | Stian Hegna | Method for aquiring and processing marine seismic data to extract and constructively use the up-going and down-going wave-fields emitted by the source(s) |
| CN102176054A (en) * | 2011-02-18 | 2011-09-07 | 中国石油化工股份有限公司 | Near-surface comprehensive information processing explanation method |
| CN105301658A (en) * | 2014-06-26 | 2016-02-03 | 中石化石油工程地球物理有限公司胜利分公司 | Method for extracting near-surface deconvolution operator by utilizing record of microlog |
| CN105353407A (en) * | 2015-10-28 | 2016-02-24 | 中国石油化工股份有限公司 | Post-stack earthquake wave impedance inversion method |
| CN105388521A (en) * | 2015-10-28 | 2016-03-09 | 中国石油天然气集团公司 | Splicing method and device of post-stack seismic data |
| CN106291707A (en) * | 2015-06-01 | 2017-01-04 | 中国石油化工股份有限公司 | Three dimensional seismic data polylith splicing TEC time error correction method and apparatus |
| CN108594302A (en) * | 2018-07-26 | 2018-09-28 | 广州海洋地质调查局 | A kind of extracting method and processing terminal of seismic wavelet |
| CN109100789A (en) * | 2018-07-30 | 2018-12-28 | 中国石油化工股份有限公司 | The full waveform inversion wavelet extraction method propagated based on the wave field inverse time |
-
2020
- 2020-06-18 CN CN202010570846.4A patent/CN111781645B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20100008184A1 (en) * | 2008-06-02 | 2010-01-14 | Stian Hegna | Method for aquiring and processing marine seismic data to extract and constructively use the up-going and down-going wave-fields emitted by the source(s) |
| CN102176054A (en) * | 2011-02-18 | 2011-09-07 | 中国石油化工股份有限公司 | Near-surface comprehensive information processing explanation method |
| CN105301658A (en) * | 2014-06-26 | 2016-02-03 | 中石化石油工程地球物理有限公司胜利分公司 | Method for extracting near-surface deconvolution operator by utilizing record of microlog |
| CN106291707A (en) * | 2015-06-01 | 2017-01-04 | 中国石油化工股份有限公司 | Three dimensional seismic data polylith splicing TEC time error correction method and apparatus |
| CN105353407A (en) * | 2015-10-28 | 2016-02-24 | 中国石油化工股份有限公司 | Post-stack earthquake wave impedance inversion method |
| CN105388521A (en) * | 2015-10-28 | 2016-03-09 | 中国石油天然气集团公司 | Splicing method and device of post-stack seismic data |
| CN108594302A (en) * | 2018-07-26 | 2018-09-28 | 广州海洋地质调查局 | A kind of extracting method and processing terminal of seismic wavelet |
| CN109100789A (en) * | 2018-07-30 | 2018-12-28 | 中国石油化工股份有限公司 | The full waveform inversion wavelet extraction method propagated based on the wave field inverse time |
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