CN102129083B - Coherent energy spectrum acquisition method - Google Patents

Abstract

The invention provides a coherent energy spectrum acquisition method. The method comprises the following steps of: calculating coherent energy spectrum values by selecting the seismic data of part of sampling points at certain intervals among a plurality of sampling points in each seismic channel from the seismic data from multiple seismic channels in the seismic data of a plurality of seismic channels by using a plurality of sampling points from each seismic channel according to certain intervals to calculate coherent energy spectrum values; in the calculation process, calculating coherent energy spectrum values by adopting a neighboring channel, a neighboring point, an inter-point interpolation, a time window and an N exponential mode; and in each seismic channel, performing interpolation by using the obtained coherent energy spectrum values of the selected sampling points to obtain the coherent energy spectrum values of the unselected sampling points. Therefore, the calculation quantity of the coherent energy spectrums can be reduced, and the coherent energy spectrums with high resolution can be acquired.

Description

Coherent energy spectrum acquisition method

Technical field

The present invention relates to geophysical exploration technology, more particularly, relate to a kind of method that can reduce the calculated amount of coherent energy spectrum and obtain the coherent energy spectrum with high resolvability.

Background technology

The method of geophysical survey by routine will further be processed geological data after obtaining recording geometry, generally need to superpose and the migration processing flow process.Superpose in anisotropic medium when being offset, need accurate stack velocity and migration velocity, and the anisotropic parameters value.The main method of obtaining these speed and anisotropic parameters value is to carry out speed and anisotropic parameters scanning.From the speed and anisotropic parameters value of minimum, finish to maximum speed and anisotropic parameters value, carry out successively result of calculation scanning.The result of scanning embodies by coherent energy spectrum.Therefore, how making coherent energy spectrum distinguish more significantly and show the difference of scan values, is the standard of distinguishing energy spectrum acquisition methods quality.

Existing coherent energy spectrum acquisition method generally includes following steps:

Step 1: the formula that comprises speed and anisotropic parameters is derived, draw the calculating formula of coherent energy spectrum;

Step 2: the coherent energy spectrum calculating formula that adopts step 1 to obtain calculates coherent energy spectrum, and its computation process generally includes following steps:

1, each sampled point of a certain seismic trace of geological data scanned calculating;

2, when calculating the coherent energy spectrum value of some sampling points, only the data of current seismic trace are calculated, and do not considered the impact of the seismic trace adjacent with current seismic trace;

3, when determining the geological data amplitude of certain point, if the numbering of this point is not integer, get the geological data amplitude of the point adjacent with this point as the geological data amplitude participation calculating of this point by the mode that rounds up;

4, after coherent energy spectrum calculates end, directly export the result of calculating;

5, adopt true color to show the coherent energy spectrum of output, pick up for the user.

In existing coherent energy spectrum acquisition method, each sampled point is all calculated its coherent energy spectrum value, thereby calculated amount is huge, and can makes energy spectrum seem discontinuous, rough.Because do not consider the impact of adjacent seismic trace, exceptional value appears in resulting coherent energy spectrum sometimes, for example the coherent energy spectrum value of certain point is very large, be 5 powers of 10, and the coherent energy spectrum value that its adjacent road, front and back and adjacent front and back point calculate is less, be 2 powers of 10, with respect to closing on and point of proximity, this value is exceptional value.To put the amplitude of adjacent point as the amplitude of this point with this by the mode that rounds up, and make the coherent energy spectrum value of this point that obtains become unreliable; The purpose of obtaining coherent energy spectrum is to embody the relativeness of the value of point wherein, and directly the baseline results of output calculating can not well embody such relativeness; Because adopted true color when showing coherent energy spectrum, so can not well embody such relativeness.

Summary of the invention

The purpose of embodiment is to overcome above and other shortcoming in the prior art.For this reason, embodiment provides a kind of method with high-resolution coherent energy spectrum of obtaining.

According to embodiment, a kind of coherent energy spectrum acquisition method can comprise the steps:

(1) in comprising the geological data of a plurality of seismic traces, utilize the geological data of at least a portion sampled point of selecting from a plurality of sampled points of each seismic trace to calculate the coherent energy spectrum value;

(2) in each seismic trace, the coherent energy spectrum value of the sampled point of the selection that use step (1) obtains is carried out interpolation, to obtain the coherent energy spectrum value of unselected sampled point.

Can select sampled point by the predetermined time interval.

Can adopt following formula 1 to calculate the coherent energy spectrum value

$s(\mathrm{\τ},\mathrm{spectrum})=\frac{{\left[\underset{x}{\mathrm{\Σ}}u(\widehat{\mathrm{\τ}}(\mathrm{\τ},x,\mathrm{spectrum}),x)\right]}^2}{\underset{x}{\mathrm{\Σ}}{\left[u(\widehat{\mathrm{\τ}}(\mathrm{\τ},x,\mathrm{spectrum}),x)\right]}^2}......$ Formula 1

Wherein, τ is the time, and x is offset distance,

Be the time offset calculating formula,

Be the geological data amplitude at time offset and x offset distance.

In the situation that give timing window scope T, can adopt following formula 2 to calculate the coherent energy spectrum value.

$s(\mathrm{\τ},\mathrm{spectrum})=\frac{\underset{\mathrm{\τ}-T}{\overset{\mathrm{\τ}+T}{\mathrm{\Σ}}}{\left[\underset{x}{\mathrm{\Σ}}u(\widehat{\mathrm{\τ}}(\mathrm{\τ},x,\mathrm{spectrum}),x)\right]}^2}{\underset{\mathrm{\τ}-T}{\overset{\mathrm{\τ}+T}{\mathrm{\Σ}}}\underset{x}{\mathrm{\Σ}}{\left[u(\widehat{\mathrm{\τ}}(\mathrm{\τ},x,\mathrm{spectrum}),x)\right]}^2}......$ Formula 2

In step (1), can be with the mean value of the geological data of the geological data of the sampled point of each selection and the sampled point adjacent with the sampled point of this selection geological data as the sampled point of this selection.the described sampled point adjacent with sampled point this selection can comprise the last sampled point before the sampled point of this selection in the seismic trace of selecting under the sampled point of this selection, the rear sampled point after the sampled point of this selection in seismic trace under the sampled point of this selection, sampled point corresponding to the sampled point with this selection in last seismic trace before seismic trace under the sampled point of this selection, at least one sampled point in sampled point corresponding to the sampled point with this selection in the rear seismic trace after the seismic trace under the sampled point of this selection.

In step (1), can by interpolation obtain with adjacent sampled point in each seismic trace between geological data corresponding to the moment, so that this geological data is used for calculating corresponding coherent energy spectrum value.

The coherent energy spectrum value that obtains can be carried out power operation.

Result and the predetermined reference value of the power operation of coherent energy spectrum value can be compared, and adopt the color of different colour systems to come the result of the power operation of mark coherent energy spectrum value according to result relatively.Can adopt different color mark in the first colour system more than or equal to the result of the power operation of the coherent energy spectrum value of reference value, and adopting the different color in the colour system different from the first colour system to come mark less than the result of the power operation of the coherent energy spectrum value of predetermined reference value, the colour system sum that adopts is greater than 2.

Therefore, according to can the improve coherent energy spectrum of resolvability of the coherent energy spectrum acquisition method of embodiment, make the user can distinguish better the power of the coherent energy spectrum value of the each point in coherent energy spectrum, and pick up convenient being used for.And adopted sparse point methods according to the coherent energy spectrum acquisition method of embodiment, thereby can greatly reduce the calculated amount of coherent energy spectrum value, improved computing velocity, and can obtain coherent energy spectrum relatively smooth, that concentrate, the accuracy, longitudinal frame and the statistical law that have improved the coherent energy spectrum that obtains are regular.

Embodiment

Hereinafter, with the coherent energy spectrum acquisition method of describing in detail according to embodiment.

At first, carry out the ground observation collection with method well known in the art, to obtain the data of acquired original, then, process through seismic data, obtain to carry out the geological data that coherent energy spectrum calculates.For example, geological data can be the data after the front data of stack or stack.Level stack is in the seismic prospecting process, and a plurality of shot points and a plurality of acceptance point have reflection in certain underground position, and the signal from the different shot points of underground same reflection point with different acceptance points are received stacks up after normal moveout correction.

Then, in the coherent energy spectrum acquisition method according to embodiment, " sparse point " method of employing is carried out the calculating of coherent energy spectrum value.In this sparse point methods, at least a portion sampled point of selecting in can a plurality of sampled points from geological data, and the coherent energy spectrum value of the sampled point of calculating selection, then, can use the coherent energy spectrum value that obtains to carry out interpolation, thereby obtain the coherent energy spectrum value of unselected sampled point.

The below will describe the sparse point methods according to example embodiment particularly.

Geological data can comprise a plurality of seismic traces.Each seismic trace can comprise a plurality of sampled points.Each sampled point can the corresponding different time.Here, a plurality of sampled points of supposing each seismic trace comprise sampled point 1t, sampled point 2t, sampled point 3t ..., sampled point nt, wherein, n is natural number.For example, be 5s when T.T., and when sampling take t=2ms as the interval, each seismic trace can comprise 2500 sampled points, that is, and n=2500.Under these circumstances, can select sampled point by the predetermined time interval.For example, can by selecting sampled point every the mode of a sampled point (that is, the time interval equals 4ms), therefore can obtain the sampled point of 1250 selections.Yet embodiment is not limited to this, can select sampled point by various time intervals such as 6ms, 8ms, 10ms.Therefore, compare with traditional method of the coherent energy spectrum value of calculating all sampled points, according to the sparse point methods of embodiment the calculated amount of coherent energy spectrum value can be reduced to traditional coherent energy spectrum value calculating method 1/2 or still less.Therefore, can improve the computing velocity of coherent energy spectrum value according to the sparse point methods of embodiment.

Can utilize the geological data of at least a portion sampled point of selecting from a plurality of sampled points of each seismic trace formula 1 below adopting to calculate the coherent energy spectrum value.

$s(\mathrm{\τ},\mathrm{spectrum})=\frac{{\left[\underset{x}{\mathrm{\Σ}}u(\widehat{\mathrm{\τ}}(\mathrm{\τ},x,\mathrm{spectrum}),x)\right]}^2}{\underset{x}{\mathrm{\Σ}}{\left[u(\widehat{\mathrm{\τ}}(\mathrm{\τ},x,\mathrm{spectrum}),x)\right]}^2}......$ Formula 1

In formula 1, τ is the time, and x is offset distance. Be the time offset calculating formula,

Be the geological data amplitude at time offset and x offset distance, can obtain by known the whole bag of tricks

The form that embodies, the V of the residue time difference of isotropic medium normal moveout equation for example _nmoThe analysis of spectrum formula:

In order to increase the number of samples of statistics, the mode of window when embodiment has adopted.Specifically, in the situation that give timing window scope T, can adopt following formula 2 to calculate the coherent energy spectrum value.

$s(\mathrm{\τ},\mathrm{spectrum})=\frac{\underset{\mathrm{\τ}-T}{\overset{\mathrm{\τ}+T}{\mathrm{\Σ}}}{\left[\underset{x}{\mathrm{\Σ}}u(\widehat{\mathrm{\τ}}(\mathrm{\τ},x,\mathrm{spectrum}),x)\right]}^2}{\underset{\mathrm{\τ}-T}{\overset{\mathrm{\τ}+T}{\mathrm{\Σ}}}\underset{x}{\mathrm{\Σ}}{\left[u(\widehat{\mathrm{\τ}}(\mathrm{\τ},x,\mathrm{spectrum}),x)\right]}^2}......$ Formula 2

That is, window scope T when given (for example, 50ms), calculate and cumulative τ-T and τ+T time range in the geological data amplitude, thereby obtain the τ coherent energy spectrum value in the moment.Thereby can improve significantly the resolution of vertical (along the time shaft) of coherent energy spectrum.Generally, the T specified value is time-sampling point number in seismic event half wavelength time range.The coherent energy spectrum that through type 2 obtains is higher with respect to the coherent energy spectral resolution that formula 1 obtains, and coherent energy spectrum is more smooth continuously.Formula 2 is the optimization on formula 1 basis.

In the computation process of above-mentioned coherent energy spectrum value, for the result of calculation that makes coherent energy spectrum has more statistical law, can be with the mean value of the geological data of the geological data of the sampled point of each selection and the sampled point adjacent with the sampled point of this selection geological data as the sampled point of this selection according to the coherent energy spectrum acquisition method of embodiment.specifically, if select sampled point (M, N) (wherein, M is the seismic trace number, N is the time), with the sampled point (M that selects, N) adjacent sampled point can comprise (M, N-1), (M, N+1), (M-1, N), (M+1, N), wherein, sampled point (M, N-1) be sampled point (M, N) in the seismic trace M under at sampled point (M, N) before last sampled point, sampled point (M, N+1) be sampled point (M, N) in the seismic trace M under at sampled point (M, N) afterwards a rear sampled point, sampled point (M-1, N) be at sampled point (M, N) in the last seismic trace M-1 before the seismic trace M under with sampled point (M, N) corresponding sampled point, sampled point (M+1, N) be at sampled point (M, N) in the rear seismic trace M+1 after the seismic trace M under with sampled point (M, N) corresponding sampled point.Can be with sampled point (M, N) geological data and the sampled point (M that is adjacent, N-1), (M, N+1), (M-1, N), (M+1, N) in the mean value of the geological data of at least one sampled point is as the geological data of sampled point (M, N) and participate in the calculating of above-mentioned coherent energy spectrum value, thereby can make the result of calculation of coherent energy spectrum have more statistical law.

In addition, in the computation process of above-mentioned coherent energy spectrum value, may need to use at the N sampled point (time point) of a certain seismic trace and the geological data sometime between N+1 sampled point (time point).Under these circumstances, according to the coherent energy spectrum acquisition method of embodiment can by interpolation obtain with adjacent sampled point in this seismic trace between geological data corresponding to the moment, and participate in the calculating of above-mentioned coherent energy spectrum value, to obtain corresponding coherent energy spectrum value.Therefore, can be so that the coherent energy spectrum value that calculates be more accurate.

Afterwards, the coherent energy spectrum value of the sampled point of the selection that will obtain according to the coherent energy spectrum acquisition method of embodiment is carried out interpolation, to obtain the coherent energy spectrum value of unselected sampled point.Therefore, can make the coherent energy spectrum after interpolation relatively smooth, coherent energy spectrum is concentrated.

As mentioned above, adopted sparse point methods according to the coherent energy spectrum acquisition method of embodiment, thereby can greatly reduce the calculated amount of coherent energy spectrum value, improved computing velocity, and can obtain coherent energy spectrum relatively smooth, that concentrate, the accuracy, longitudinal frame and the statistical law that have improved the coherent energy spectrum that obtains are regular.

After the calculating of completing the coherent energy spectrum value, the coherent energy spectrum value that obtains can also be carried out power operation according to the coherent energy spectrum acquisition method of embodiment, so that the relative trend of the value of the each point in coherent energy spectrum is more obvious.For example, the coherent energy spectrum value of supposing certain two point in coherent energy spectrum is respectively A ₁And A ₂If, A ₁Equal A ₂, carrying out the value A after power operation n time ₁ ⁿEqual A ₂ ⁿIf A ₁Be not equal to A ₂, carrying out the value A after power operation n time ₁ ⁿAnd A ₂ ⁿThe difference of family will become more apparent.Here, n is positive integer, and n can not be zero or negative integer.Preferably, n can be 6.Being in order to embody relativeness because obtain the purpose of coherent energy spectrum, therefore, is the resolvability that can improve coherent energy spectrum by above-mentioned power operation.

After having carried out power operation, result and the predetermined reference value of the power operation of coherent energy spectrum value can also be compared according to the coherent energy spectrum acquisition method of embodiment, and adopt the color of different colour systems to come the result of the power operation of mark coherent energy spectrum value according to result relatively.For example, can adopt different color mark in the first colour system more than or equal to the result of the power operation of the coherent energy spectrum value of reference value, and can adopt the different color in the second colour system different from the first colour system to come mark less than the result of the power operation of the coherent energy spectrum value of predetermined reference value.In one embodiment, the result of the power operation of coherent energy spectrum value can be divided into m group A1～Am, wherein, m is the natural number more than or equal to 2.For example, m can be 299.M group can satisfy such relation: the result that is included in the power operation of all coherent energy spectrum values in Ai group can be all less than the result that is included in the power operation of organizing all coherent energy spectrum values in Ai+1, wherein, and 1≤i＜m.At this moment, the result of power operation that is included in the coherent energy spectrum value of the minimum of group in Am can be described reference value.M group can also satisfy such relation: be included in the power operation in Ai group result can from i * [(result of the power operation of the result of maximum power operation-minimum) ÷ m] to (i+1) * scope of [(result of the power operation of the result of the power operation of maximum-minimum) ÷ m] in, wherein, 1≤i＜m, the result of the result of maximum power operation and minimum power operation refers to respectively maximal value and the minimum value in the result of power operation of coherent energy spectrum value.At this moment, (m-1) * [(result of the power operation of the result of maximum power operation-minimum) ÷ m] can be chosen as described reference value.Can adopt one or more colors in red colour system to come the result of the power operation of the coherent energy spectrum value in mark group Am, can use one or more colors in one or more colour systems different from red colour system (for example, green system and blue series) to come mark group A1～Am-1 respectively.Therefore, can distinguish better the power of coherent energy spectrum value in the coherent energy spectrum that obtains, and facilitate the user to pick up.In one embodiment, the colour system sum that adopts can be greater than 2.

Therefore, according to can the improve coherent energy spectrum of resolvability of the coherent energy spectrum acquisition method of embodiment, make the user can distinguish better the power of the coherent energy spectrum value of the each point in coherent energy spectrum, and pick up convenient being used for.And adopted sparse point methods according to the coherent energy spectrum acquisition method of embodiment, thereby can greatly reduce the calculated amount of coherent energy spectrum value, improved computing velocity, and can obtain coherent energy spectrum relatively smooth, that concentrate, the accuracy, longitudinal frame and the statistical law that have improved the coherent energy spectrum that obtains are regular.

Although illustrated and described the example of embodiment, it will be understood by those skilled in the art that embodiment is not limited to this, in the situation that do not break away from the spirit and scope as claim, can make various changes and modifications.

Claims (8)

1. a coherent energy spectrum acquisition method, is characterized in that described method comprises the steps:

(1) in comprising the geological data of a plurality of seismic traces, utilize the geological data of at least a portion sampled point of selecting from a plurality of sampled points of each seismic trace to calculate the coherent energy spectrum value;

(2) in each seismic trace, use the coherent energy spectrum value of the sampled point of the selection that step (1) obtains to carry out interpolation, obtaining the coherent energy spectrum value of unselected sampled point,

Wherein, in step (1), the formula 1 below adopting is calculated the coherent energy spectrum value

$s(\mathrm{\τ},\mathrm{spectrum})=\frac{{\left[\underset{x}{\mathrm{\Σ}}u(\widehat{\mathrm{\τ}}(\mathrm{\τ},x,\mathrm{spectrum}),x)\right]}^2}{\underset{x}{\mathrm{\Σ}}{\left[u(\widehat{\mathrm{\τ}}(\mathrm{\τ},x,\mathrm{spectrum}),x)\right]}^2}$ ... formula 1

In formula 1, τ is the time, and x is offset distance,

Be the time offset calculating formula,

Be the geological data amplitude at time offset and x offset distance, perhaps

Wherein, in step (1), in the situation that give timing window scope T, the formula 2 below adopting is calculated the coherent energy spectrum value

$s(\mathrm{\τ},\mathrm{spectrum})=\frac{\underset{\mathrm{\τ}-T}{\overset{\mathrm{\τ}+T}{\mathrm{\Σ}}}{\left[\underset{x}{\mathrm{\Σ}}u(\widehat{\mathrm{\τ}}(\mathrm{\τ},x,\mathrm{spectrum}),x)\right]}^2}{\underset{\mathrm{\τ}-T}{\overset{\mathrm{\τ}+T}{\mathrm{\Σ}}}\underset{x}{\mathrm{\Σ}}{\left[u(\widehat{\mathrm{\τ}}(\mathrm{\τ},x,\mathrm{spectrum}),x)\right]}^2}$ ... formula 2

In formula 2, τ is the time, and x is offset distance,

Be the time offset calculating formula,

Be the geological data amplitude at time offset and x offset distance.

2. the method for claim 1, is characterized in that in step (1), by predetermined time the interval select sampled point.

3. as claim 1 or method claimed in claim 2, it is characterized in that in step (1), with the mean value of the geological data of the geological data of the sampled point of each selection and the sampled point adjacent with the sampled point of this selection geological data as the sampled point of this selection.

4. method as claimed in claim 3, it is characterized in that the described sampled point adjacent with sampled point this selection comprises the last sampled point before the sampled point of this selection in the seismic trace of selecting under the sampled point of this selection, the rear sampled point after the sampled point of this selection in seismic trace under the sampled point of this selection, sampled point corresponding to the sampled point with this selection in last seismic trace before seismic trace under the sampled point of this selection, at least one sampled point in sampled point corresponding to the sampled point with this selection in the rear seismic trace after the seismic trace under the sampled point of this selection.

5. as claim 1 or method claimed in claim 2, it is characterized in that in step (1), by interpolation obtain with adjacent sampled point in each seismic trace between geological data corresponding to the moment, so that this geological data is used for calculating corresponding coherent energy spectrum value.

6. the method for claim 1, is characterized in that the coherent energy spectrum value that obtains is carried out power operation.

7. method as claimed in claim 6 is characterized in that result and the predetermined reference value of the power operation of coherent energy spectrum value are compared, and adopts the color of different colour systems to come the result of the power operation of mark coherent energy spectrum value according to result relatively.

8. method as claimed in claim 7, it is characterized in that adopting different color mark in the first colour system more than or equal to the result of the power operation of the coherent energy spectrum value of predetermined reference value, and adopting the different color in the colour system different from the first colour system to come mark less than the result of the power operation of the coherent energy spectrum value of predetermined reference value, the colour system sum that adopts is greater than 2.