CN115774285A - Method and system for improving seismic section resolution based on attenuation synthesis recording - Google Patents
Method and system for improving seismic section resolution based on attenuation synthesis recording Download PDFInfo
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- CN115774285A CN115774285A CN202211525345.XA CN202211525345A CN115774285A CN 115774285 A CN115774285 A CN 115774285A CN 202211525345 A CN202211525345 A CN 202211525345A CN 115774285 A CN115774285 A CN 115774285A
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Abstract
The invention belongs to the technical field of seismic exploration post-stack reflected wave seismic data processing, and relates to a method, a system and a readable medium for improving seismic section resolution based on attenuation synthesis recording, wherein the method comprises the following steps: calculating an initial absorption parameter value through VSP logging data; generating an attenuation synthesis seismic record according to the initial absorption parameter value, the reflection coefficient sequence and the Rake wavelets, and selecting the best matching absorption parameter value through the attenuation synthesis seismic record; calculating an absorption parameter value based on the seismic data according to the actual seismic data, and calibrating the absorption parameter value based on the seismic data through the adjusted absorption parameter to obtain an optimal absorption parameter; and processing the post-stack seismic data volume through the optimal absorption parameters to obtain a high-resolution seismic profile. The method can solve the problem that the seismic data absorption parameter alpha is difficult to solve in the prior art.
Description
Technical Field
The invention relates to a method, a system and a readable medium for improving seismic section resolution ratio based on attenuation synthesis recording, and belongs to the technical field of seismic exploration post-stack reflected wave seismic data processing.
Background
Due to the fact that the underground medium has viscoelasticity, when seismic waves propagate in the underground medium, energy absorption attenuation and phase stretching distortion can be caused, and the integral resolution of data is reduced. The absorption parameter alpha is an important parameter for describing the absorption attenuation degree of the underground medium, and the accurate calculation of the absorption parameter alpha has important significance for seismic data absorption attenuation compensation. However, the underground structure is complex, and the factors influencing the attenuation of the seismic waves are very many, so the absorption parameter alpha is often difficult to be calibrated. The method for estimating the absorption parameter alpha can be mainly divided into a centroid frequency shift method, a spectral ratio method and the like according to different principles, and the methods have simple principles and easy realization, but are easily influenced by the quality of data and have unstable calculation results; the data can be divided into two categories according to different data sources: the seismic data estimation alpha value and the well data estimation absorption parameter alpha value have wide sources, but are influenced by thin layer tuning, the calculation stability, efficiency and precision fluctuation are large, the well data estimation absorption parameter alpha value is high in precision but limited by the small number of wells, and the absorption parameter alpha value of a well-free position in a work area cannot be obtained. In addition, in the aspect of jointly solving the well-seismic absorption parameter alpha, due to the lack of a unified absorption parameter alpha evaluation standard, the practicability of the method is limited.
Disclosure of Invention
In view of the above problems, it is an object of the present invention to provide a method, system and readable medium for improving seismic section resolution based on attenuation synthesis recording, which can solve the problem of difficulty in obtaining seismic data absorption parameter α in the prior art.
In order to realize the purpose, the invention provides the following technical scheme: a method for improving seismic section resolution based on attenuation synthesis recording comprises the following steps: calculating an initial absorption parameter value through VSP logging data; generating an attenuation synthesis seismic record according to the initial absorption parameter value, the reflection coefficient sequence and the Rake wavelets, and selecting an optimally matched absorption parameter value through the attenuation synthesis seismic record; calculating an absorption parameter value based on the seismic data according to the actual seismic data, and calibrating the absorption parameter value based on the seismic data through the adjusted absorption parameter to obtain an optimal absorption parameter; and processing the post-stack seismic data volume through the optimal absorption parameters to obtain a high-resolution seismic profile.
Further, the initial absorption parameter value is obtained by a logarithmic spectrum ratio method, and the calculation formula is as follows:
where α is the absorption parameter value, f is the frequency value of the log data, τ is the time depth of the log data, A 1 (f) Is the amplitude value of the overburden, A 2 (f) Is the amplitude value of the current formation.
Further, the dominant frequency of shallow seismic data is used as the dominant frequency of the Rake wavelets.
Further, the method for selecting the best matching absorption parameter value comprises the following steps: generating a oscillogram corresponding to each different absorption parameter value; marking peak locations in the attenuated synthetic seismic record; comparing the peak positions in the oscillograms corresponding to different absorption parameter values with the peak positions in the attenuation synthetic seismic record, and selecting the oscillogram with the peak position same as that in the attenuation synthetic seismic record; and taking the absorption parameter value corresponding to the selected oscillogram as the best matching absorption parameter value.
Further, the different absorption parameter values are obtained by multiplying the initial absorption parameter value by a set of preset coefficients.
Further, the formula for calculating the seismic data-based absorption parameter value from the actual seismic data is:
α＝14v 2.2
wherein, alpha is the absorption parameter value, and v is the root mean square velocity of the seismic data.
Further, the best matched absorption parameter value is denoted as α w Recording the absorption parameter value based on the seismic data as alpha s Will be alpha w Alpha corresponding to its time depth s And dividing one by one to obtain a correction coefficient, wherein the formula is as follows:
wherein eta is a correction coefficient, the correction coefficient eta is subjected to spatial interpolation smoothing, and the correction coefficient eta subjected to the spatial interpolation smoothing is multiplied by alpha s And obtaining the optimal absorption parameters.
Further, the post-stack seismic data volume is processed by the following formula:
wherein w(t) is the seismic data amplitude,
is the inverse fourier transform, w (ω) is the fourier transform result of the seismic data, ω is the angular frequency, t is the time depth, α is the absorption parameter.
The invention also discloses a system for improving the seismic section resolution based on the attenuation synthesis record, which comprises the following steps: the initial absorption parameter value acquisition module is used for calculating an initial absorption parameter value through VSP logging data; the optimal matching absorption parameter value acquisition module is used for generating an attenuation synthesis seismic record according to the initial absorption parameter value, the reflection coefficient sequence and the Rake wavelets, and selecting the optimal matching absorption parameter value through the attenuation synthesis seismic record; the optimal absorption parameter acquisition module is used for calculating an absorption parameter value based on the seismic data according to the actual seismic data, calibrating the absorption parameter value based on the seismic data through the adjusted absorption parameter, and obtaining an optimal absorption parameter; and the seismic profile acquisition module is used for processing the post-stack seismic data volume through the optimal absorption parameters to acquire a high-resolution seismic profile.
The invention also discloses a computer readable storage medium, wherein a computer program is stored on the computer readable storage medium, and the computer program is executed by a processor to realize any method for improving the seismic section resolution based on the attenuation synthesis recording.
Due to the adoption of the technical scheme, the invention has the following advantages:
1. the method models the absorption parameter alpha based on the attenuation synthesis record, and realizes the optimal calculation of the absorption parameter alpha by performing waveform matching on the attenuation synthesis seismic record and the well side seismic data, and has the characteristics of simple method, easy realization and high precision.
2. The invention can compensate the attenuation of high-frequency signals of the seismic data after the stack by using the acquired absorption parameter alpha field, broaden the frequency band of the seismic data and effectively improve the resolution of the seismic data.
Drawings
FIG. 1 is a flow chart of a method for improving seismic profile resolution based on attenuated synthetic recording in an embodiment of the present invention;
FIG. 2 is a schematic diagram of a method for selecting a best match absorption parameter value according to an embodiment of the present invention;
FIG. 3 is a post-stack seismic section prior to high resolution processing by the method of the present invention;
FIG. 4 is a high resolution processed post-stack seismic section prior to processing by the method of the present invention.
Detailed Description
The present invention is described in detail with reference to specific embodiments for better understanding of the technical solutions of the present invention. It should be understood, however, that the detailed description is provided for a better understanding of the invention only and that they should not be taken as limiting the invention. In describing the present invention, it is to be understood that the terminology used is for the purpose of description only and is not intended to be interpreted as indicating or implying any relative importance.
The method aims to solve the problems that in the prior art, absorption parameters are easily influenced by data quality during calculation, and the calculation result is unstable; the invention provides a method and a system for improving Seismic section resolution based on attenuation synthesis recording, which are used for solving the problems that the calculation stability, the efficiency and the precision fluctuation are large, or the number of wells is limited to be small, the absorption parameter alpha value of a well-free position in a work area cannot be solved, a unified absorption parameter alpha evaluation standard is lacked, and the like; then generating an attenuation synthesis seismic record through the initial absorption parameter alpha value, and adjusting the absorption parameter alpha value according to the waveform similarity of the attenuation synthesis seismic record and the well-side seismic data channel; calculating an absorption parameter alpha value derived from the seismic data; obtaining the optimal absorption parameter through adjustment; and finally, performing high-resolution processing on the stacked seismic data body through the optimal absorption parameters, compensating high-frequency signal attenuation caused by energy dissipation in the seismic wave propagation process, and obtaining an underground structure image with improved resolution. The invention will be explained in detail below by means of examples with reference to the accompanying drawings.
The first embodiment is as follows:
the implementation discloses a method for improving seismic section resolution based on attenuation synthesis recording, as shown in fig. 1, comprising the following steps:
in this embodiment, three-dimensional post-stack seismic data of a certain block of the eastern oilfield is taken as an example, the data sampling interval is 1ms, the recording time of a seismic signal is 3s, and the track spacing is 20m.
S1, calculating an initial absorption parameter value through VSP logging data.
The initial absorption parameter value is obtained by a logarithmic spectrum ratio method, and the calculation formula is as follows:
where α is the absorption parameter value, f is the frequency value of the log data, τ is the time depth of the log data, A 1 (f) Is the amplitude value of the overburden, A 2 (f) Is the amplitude value of the current formation.
When the amplitude value of the overlying stratum and the amplitude value of the current stratum are input, the initial absorption parameter value alpha can be obtained layer by layer through the formula 0 . Repeating the operation of the step on all the VSP wells in the work area to obtain the initial absorption parameter values alpha of all the VSP wells 0 。
And S2, generating an attenuation synthesis seismic record according to the initial absorption parameter value, the reflection coefficient sequence and the Rake wavelets, and selecting the best matched absorption parameter value through the attenuation synthesis seismic record.
S2.1, generating a non-attenuated synthetic seismic record, wherein the dominant frequency of shallow seismic data can be used as the dominant frequency of the Rake wavelet, and the dominant frequency is selected to be 25Hz.
S2.2 the different absorption parameter values are obtained by multiplying the initial absorption parameter value by a set of predetermined coefficients, in this example a set of predetermined coefficients 0.5,0.6,0.7,0.8,0.9,1.0,1.1,1.2,1.3,1.4,1.5, yielding 11 different absorption parameter values.
S2.3, generating oscillograms corresponding to different absorption parameter values, wherein as shown in figure 2, a channel 0 is an attenuation synthesis seismic record, a channel 1 is an oscillogram obtained by multiplying an initial absorption parameter value by 0.5, a channel 2 is an oscillogram obtained by multiplying an initial absorption parameter value by 0.6, and the like, and a channel 11 is an oscillogram obtained by multiplying an initial absorption parameter value by 1.5. Taking 6 peak positions of the attenuation synthesis seismic record in the trace 0 as reference waveforms, marking the start positions and the end positions of the peaks by using dotted lines respectively, wherein the amplitude of intersection points of the two dotted lines and the waveform diagram of the trace 0 is 0, and 6 peaks represent 6 stratums;
and comparing the peak positions in the oscillogram corresponding to different absorption parameter values with the peak positions in the attenuation synthetic seismic record, namely extending two dotted lines corresponding to each peak from the trace 0 to the trace 11.
Selecting a oscillogram with the same peak position as the peak position in the attenuation synthesis seismic record; and taking the absorption parameter value corresponding to the selected oscillogram as the best matched absorption parameter value. That is, whether the absorption parameter value is optimal is determined according to whether the two dotted lines intersect with the oscillogram corresponding to each different absorption parameter value at the amplitude of 0. The 6 black boxes in fig. 2 are the locations where the best matching absorption parameter values are marked.
And S3, calculating an absorption parameter value based on the seismic data according to the actual seismic data, and calibrating the absorption parameter value based on the seismic data through the adjusted absorption parameter to obtain an optimal absorption parameter.
The formula for calculating the seismic data-based absorption parameter values from actual seismic data is:
α＝14v 2.2
where α is the absorption parameter value and v is the root mean square velocity of the seismic data.
The best-matched absorption parameter value is designated as alpha w The absorption parameter value based on seismic data is recorded as alpha s Will be alpha w Alpha corresponding to its time depth s And the correction coefficients are obtained by dividing one by one, and the formula is as follows:
wherein eta is correction coefficient, spatial interpolation smoothing is carried out on the correction coefficient eta, and the correction coefficient eta after the spatial interpolation smoothing is multiplied by alpha s And obtaining the optimal absorption parameters.
And S4, processing the post-stack seismic data volume through the optimal absorption parameters to obtain a high-resolution seismic profile.
Processing the post-stack seismic data volume by:
where w (t) is the seismic data amplitude,
is the inverse fourier transform, w (ω) is the fourier transform result of the seismic data, ω is the angular frequency, t is the time depth, α is the absorption parameter.
Fig. 3 is a post-stack seismic cross-sectional view before high resolution processing, fig. 4 is a post-stack seismic cross-sectional view after high resolution processing, and comparing the post-stack seismic cross-sectional views in fig. 3 and fig. 4, it can be seen that after the absorption parameters obtained in this embodiment are used, the resolution of the seismic cross-sectional view in fig. 4 is obviously improved, the originally overlapped event is better separated, and the event transverse continuity becomes better.
Example two:
based on the same inventive concept, the embodiment discloses a system for improving seismic section resolution based on attenuation synthesis recording, which comprises:
the initial absorption parameter value acquisition module is used for calculating an initial absorption parameter value through VSP logging data;
the optimal matching absorption parameter value acquisition module is used for generating an attenuation synthesis seismic record according to the initial absorption parameter value, the reflection coefficient sequence and the Rake wavelets, and selecting the optimal matching absorption parameter value through the attenuation synthesis seismic record;
the optimal absorption parameter acquisition module is used for calculating an absorption parameter value based on the seismic data according to the actual seismic data and calibrating the absorption parameter value based on the seismic data through the adjusted absorption parameter to obtain an optimal absorption parameter;
and the seismic profile acquisition module is used for processing the post-stack seismic data volume through the optimal absorption parameters to obtain a high-resolution seismic profile.
Processing the post-stack seismic data volume by:
where w (t) is the seismic data amplitude,
is the inverse fourier transform, w (ω) is the fourier transform result of the seismic data, ω is the angular frequency, t is the time depth, α is the absorption parameter.
Example three:
based on the same inventive concept, the present embodiment discloses a computer readable storage medium, on which a computer program is stored, the computer program being executed by a processor to implement any of the above methods for improving seismic section resolution based on an attenuation synthesis recording.
As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting the same, and although the present invention is described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications and equivalents may be made to the embodiments of the invention without departing from the spirit and scope of the invention, which is to be covered by the claims. The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.
Claims (10)
1. A method for improving seismic section resolution based on attenuation synthesis recording, comprising:
calculating an initial absorption parameter value through VSP logging data;
generating an attenuation synthesis seismic record according to the initial absorption parameter value, the reflection coefficient sequence and the Rake wavelets, and selecting the best matching absorption parameter value through the attenuation synthesis seismic record;
calculating an absorption parameter value based on the seismic data according to the actual seismic data, and calibrating the absorption parameter value based on the seismic data through the adjusted absorption parameter to obtain an optimal absorption parameter;
and processing the post-stack seismic data volume through the optimal absorption parameters to obtain a high-resolution seismic profile.
2. The method for improving seismic section resolution based on attenuated synthetic logs of claim 1 wherein said initial absorption parameter values are obtained by log-spectral ratio method using the formula:
where α is the absorption parameter value, f is the frequency value of the log data, τ is the time depth of the log data, A 1 (f) Is the amplitude value of the overburden, A 2 (f) Is the amplitude value of the current formation.
3. The method for improving seismic section resolution based on attenuated synthetic recording of claim 1 wherein the dominant frequency of shallow seismic data is used as the dominant frequency of the Ricker wavelets.
4. A method for improving seismic profile resolution based on damped synthetic recordings as claimed in claim 3 wherein said method of selecting best matching absorption parameter values is:
generating a waveform diagram corresponding to each different absorption parameter value;
marking peak locations in the attenuated synthetic seismic record;
comparing the peak positions in the oscillograms corresponding to different absorption parameter values with the peak positions in the attenuation synthetic seismic records, and selecting the oscillograms with the peak positions identical to the peak positions in the attenuation synthetic seismic records;
and taking the absorption parameter value corresponding to the selected oscillogram as the best matching absorption parameter value.
5. The method for improving seismic profile resolution based on damped synthetic recordings of claim 4 wherein the different absorption parameter values are obtained by multiplying the initial absorption parameter value by a set of predetermined coefficients.
6. The method for improving seismic section resolution based on attenuation synthesis recording according to any of claims 1 to 5, wherein the formula for calculating seismic data-based absorption parameter values from actual seismic data is:
α＝14v 2.2
where α is the absorption parameter value and v is the root mean square velocity of the seismic data.
7. The method for improving seismic section resolution based on the recording of an attenuated synthesis according to any of claims 1 to 5, wherein the best matching absorption parameter value is designated as α w Recording the absorption parameter value based on the seismic data as alpha s α is prepared by w Alpha corresponding to its time depth s And the correction coefficients are obtained by dividing one by one, and the formula is as follows:
wherein eta is a correction coefficient, the correction coefficient eta is subjected to spatial interpolation smoothing, and the correction coefficient eta subjected to the spatial interpolation smoothing is multiplied by alpha s And obtaining the optimal absorption parameters.
8. The method for enhanced seismic section resolution based on attenuation synthesis recording according to any of claims 1 to 5, wherein the post-stack seismic data volume is processed by the following formula:
where w (t) is the seismic data amplitude,
is the inverse fourier transform, w (ω) is the fourier transform result of the seismic data, ω is the angular frequency, t is the time depth, α is the absorption parameter.
9. A system for enhancing seismic profile resolution based on attenuation synthesis recording, comprising:
the initial absorption parameter value acquisition module is used for calculating an initial absorption parameter value through VSP logging data;
the optimal matching absorption parameter value acquisition module is used for generating an attenuation synthesis seismic record according to the initial absorption parameter value, the reflection coefficient sequence and the Rake wavelets, and selecting the optimal matching absorption parameter value through the attenuation synthesis seismic record;
the optimal absorption parameter acquisition module is used for calculating an absorption parameter value based on the seismic data according to the actual seismic data, calibrating the absorption parameter value based on the seismic data through the adjusted absorption parameter, and obtaining an optimal absorption parameter;
and the seismic profile acquisition module is used for processing the post-stack seismic data volume through the optimal absorption parameters to acquire a high-resolution seismic profile.
10. A computer-readable storage medium having stored thereon a computer program for execution by a processor to perform the method for enhanced seismic profile resolution based on attenuation synthesis recording according to any of claims 1-8.
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