CN105242304A - Seismic data gap compensation method based on frequency-space domain wave field continuation - Google Patents

Abstract

The invention provides a seismic data gap compensation method based on frequency-space domain wave field continuation, which comprises the steps of carrying out three-dimensional Fourier transform on three-dimensional seismic data, and converting seismic data of a (x, y, z) domain into to kx-ky-f domain; carrying out continuation on the wave field of non-deletion trace seismic data according to a wave field continuation relation in a time-space domain by using spatial coherence of seismic signals, acquiring wave field information of a deletion trace, and then carrying out three-dimensional Fourier transform so as to acquire compensation data of the (x, y, z) domain. According to the invention, three-dimensional Fourier transform belongs to orthogonal transform and has good amplitude preservation performance in the kx-ky-f domain and the (x, y, z) domain, so that signals before and after changes are enabled to be consistent in energy. The method provided by the invention carries out deletion seismic data compensation through wave filed continuation, and has specific geophysical significances. Meanwhile, the seismic data gap compensation method adopts fast Fourier transform, and has high computing efficiency.

Description

Based on the seismic data gap penalties method of territory, frequency space wave field extrapolation

Technical field

The present invention relates to exploration geophysics seismic data processing technology field, is a kind of method of the wave field extrapolation relational implementation seismic data gap penalties utilized in temporal-spatial field.

Background technology

In seismic data process, seismic trace disappearance and spatial sampling deficiency are very common, and it shows as dead trace or due to the trace record disallowable in preprocessing process containing strong noise.Like this, processing procedure based on multiple tracks Processing Algorithm will be subject to the impact lacking road, wherein most affectedly comprise wave equation migration, based on the method for the suppression surface-related multiple of wave equation, the processing procedures such as the elimination of the multiple reflection relevant with earth's surface and Power estimation.

Seismic data compensation method when not re-starting seismic data acquisition, can compensate the geological data of disappearance, ensures carrying out smoothly of subsequent treatment.Seismic data compensation method conventional at present mainly contains Sinc interpolation method, f-x territory interpolation method, t-x territory predicated error filter coefficients method and the Trace Interpolation method based on Radon converter technique.Although wherein Sinc interpolation method is carrying out Trace Interpolation hourly velocity soon, be easy to realize, correctly interpolation cannot having the seismic trace of spatial aliasing.Although the t-x territory predicated error filter coefficients method of the f-x territory Trace Interpolation method of Spitz and Claerbout correctly interpolation can have the seismic trace of spatial aliasing, but these method calculated amount are large especially, its practicality in real data is reduced greatly.Trace Interpolation method based on Radon converter technique may be used for the compensation of seismic data, but the method itself is not protect width, and geological data is after Radon direct transform and Radon inverse transformation, and data have small change.

In addition multiple reflection is the multiple reflections of subsurface reflector, also stratal configuration information has been contained, under extremely complicated geologic condition, even contain the subsurface information that primary reflection does not have, be used by suitable method and can obtain more abundant geological structure information, but this method is only applicable to marine data usually, the multiple reflection of most of land seismic data agensis.

Summary of the invention

The object of the invention is the defect for prior art, propose a kind of for improving seismic imaging quality, solving in 3-d seismic exploration causes seismic trace to lack because instrument failure or surface conditions affect, and causes the seismic data gap penalties method based on the wave field extrapolation of territory, frequency space of subsequent treatment difficulty.

Object of the present invention realizes by following technical measures:

(1) three-dimensional Fourier transform is carried out to 3D seismic data, (x, y, t) territory geological data is transformed into k _x-k _y-f territory;

(2) utilize the spatial coherence of seismic signal, according to the wave field extrapolation relation in temporal-spatial field, continuation is carried out to the wave field of non-disappearance road geological data, obtain the wave field information lacking road;

(3) carry out three-dimensional Fourier inversion, obtain the offset data in (x, y, t) territory.

Technical scheme of the present invention is optimized for further:

(1) three-dimensional Fourier transform is carried out to the 3D seismic data of input, (x, y, t) territory geological data is transformed into k _x-k _y-f territory, transformation for mula is;

$A(k_x,k_y,f)=\underset{-\∞}{\overset{\∞}{\∫}}\mathrm{dx}\underset{-\∞}{\overset{\∞}{\∫}}\mathrm{dy}\underset{-\∞}{\overset{\∞}{\∫}}u(x,y,t)e^{-i2\mathrm{\π}[\mathrm{ft}-(k_{x}x+k_{y}y)]}\mathrm{dt}.$

Wherein u (x, y, t) is the 3D seismic data of input, and prestack compensates can use various roads collection data, but usually selects common offset effect data better; Poststack compensates and is superposition of data; A (k _x, k _y, f) be the frequency space numeric field data after conversion.

(2) utilize the spatial coherence of seismic signal, according to the wave field extrapolation relation in temporal-spatial field, carry out continuation to the wave field of non-disappearance road geological data, continuation formula is:

$A({k^{\′}}_x,{k^{\′}}_y,\mathrm{\ω})=A(k_x,k_y,\mathrm{\ω})e^{i2\mathrm{\π}(k_x{x}_0+k_y{y}_0)]}$

Wherein A (k' _x, k' _y, ω) for continuation obtain at (x+x ₀, y+y ₀) the frequency space numeric field data at place.

(3) carry out three-dimensional Fourier inversion, obtain the offset data in (x, y, t) territory, transformation for mula is.

$u(x+x_0,y+y_0,t)=\underset{-\∞}{\overset{\∞}{\∫}}{{\mathrm{dk}}^{\′}}_x\underset{-\∞}{\overset{\∞}{\∫}}{{\mathrm{dk}}^{\′}}_y\underset{-\∞}{\overset{\∞}{\∫}}A({k^{\′}}_x,{k^{\′}}_y,\mathrm{\ω})e^{i2\mathrm{\π}[\mathrm{\ωt}-({k^{\′}}_{x}x+{k^{\′}}_{y}y)]}\mathrm{df}$

Wherein u (x+x ₀, y+y ₀, t) for continuation obtain at (x+x ₀, y+y ₀) place disappearance data.

Consider the scrambling that in three dimensions, seismic trace lacks in different directions, after considering three-dismensional effect, the actual seismic trace compensated should be:

$\tilde{u}(x+x_0,y+y_0,t)=\∫B\left(x_{0,}{y}_0\right)u(x+x_0,y+y_0,t)d{x}_{0}d{y}_0$

Wherein B (x ₀, y ₀) be direction factor, its orientation with each road and the number of channels at every turn compensated relevant, the energy match factor between Ye Shi road. actual in (x+x for considering after three-dismensional effect ₀, y+y ₀) place compensate data.

The present invention is by seismic data gap penalties, and encryption space sampling frequency, effectively can prevent from alias appears in migrated section, improve signal to noise ratio (S/N ratio) simultaneously, for the process of latter earthquake data and explanation provide strong technical support; The present invention simultaneously well solves in 3-d seismic exploration, because instrument failure or surface conditions impact cause seismic trace to lack, cause the problem (as alias appears in imaging section, lateral resolution variation etc.) of subsequent treatment difficulty, and then improve seismic imaging quality.

Accompanying drawing explanation

Fig. 1 is the process flow diagram of a kind of exemplary embodiments of the present invention;

Fig. 2 is the raw data that track pitch is too large;

Fig. 3 is the frequency wavenumber spectrum of corresponding diagram 2;

Fig. 4 is through the frequency wavenumber spectrum after wave field extrapolation;

Data after Tu5Shi Ge road compensates;

Fig. 6 is vertical survey line number is section before the compensation of 3933;

Fig. 7 is vertical survey line number is section after the compensation of 3933;

The horizontal survey line of Fig. 8 number is section before the compensation of 1290;

The horizontal survey line of Fig. 9 number is section after the compensation of 1290;

Figure 10 compensates front 600ms time slice;

Figure 11 compensates rear 600ms time slice.

Embodiment

For making above and other object of the present invention, feature and advantage can become apparent, cited below particularly go out preferred embodiment, and coordinate institute's accompanying drawings, be described in detail below.

As shown in Figure 1, Fig. 1 is the process flow diagram of the seismic data gap penalties method based on the wave field extrapolation of territory, frequency space of the present invention.

In step 101, input three-dimensional data to be compensated, prestack compensates can use various roads collection data, but usually selects common offset effect data better; Poststack compensates and is superposition of data.Owing to have employed Fourier transform, therefore must according to uniform geophone offset grid arrangement.If geophone offset is uneven in input data, first regularization process should be carried out by trace interpolation technology.Then flow process enters into step 102.

In step 102, three-dimensional data is transformed into territory, frequency space, flow process enters into step 103.

In step 103, utilize the spatial coherence of seismic signal, according to the wave field extrapolation relation in temporal-spatial field, carry out continuation to the wave field of non-disappearance road geological data, obtain the wave field information lacking road, flow process enters into step 104.

In step 104, carry out three-dimensional Fourier inversion, frequency space numeric field data is transformed into time domain, and flow process enters into step 105.

In step 105, the output of data, only can export offset data as required, also raw data can be exported together with offset data.

By above flow process, can effective compensation disappearance geological data.Fig. 2 utilizes the big gun record of just drilling means and obtaining, and its track pitch is too large, needs to carry out compensating every road; Fig. 3 is the frequency wavenumber spectrum of corresponding diagram 2.By wave field extrapolation, obtain the frequency wavenumber spectrum after continuation (shown in Fig. 4), then convert back time domain, the data after being compensated.Data after compensation, compensation effect is better.

Fig. 6-Figure 11 is the embodiment of real data, Fig. 6 and Fig. 7 is vertical survey line number is section section rear with compensation before the compensation of 3933; Fig. 8 and Fig. 9 is horizontal survey line number is section section rear with compensation before the compensation of 1290; Can find out that from section gap portions is compensated, lineups continuously and maintain relative energy relationships.Figure 10 and Figure 11 is the 600ms time slice before compensating and after compensating, and also can find out to have good compensation effect.Just drilling data and real data all to demonstrate the present invention there is good compensation effect.

Claims (3)

1., based on the seismic data gap penalties method of territory, frequency space wave field extrapolation, it is characterized in that comprising:

(1) three-dimensional Fourier transform is carried out to 3D seismic data, (x, y, t) territory geological data is transformed into k _x-k _y-f territory;

(2) utilize the spatial coherence of seismic signal, according to the wave field extrapolation relation in temporal-spatial field, continuation is carried out to the wave field of non-disappearance road geological data, obtain the wave field information lacking road;

(3) carry out three-dimensional Fourier inversion, obtain the offset data in (x, y, t) territory.

2. the seismic data gap penalties method based on the wave field extrapolation of territory, frequency space according to claim 1, is characterized in that:

(1) to the transformation for mula that the 3D seismic data of input carries out three-dimensional Fourier transform be

$A(k_x,k_y,f)=\underset{-\∞}{\overset{\∞}{\∫}}\mathrm{dx}\underset{-\∞}{\overset{\∞}{\∫}}\mathrm{dy}\underset{-\∞}{\overset{\∞}{\∫}}u(x,y,t)e^{-i2\mathrm{\π}[\mathrm{ft}-(k_{x}x+k_{y}y)]}\mathrm{dt}$

Wherein u (x, y, t) is the 3D seismic data of input, A (k _x, k _y, f) be the frequency space numeric field data after conversion;

(2) carry out continuation to the wave field of non-disappearance road geological data, continuation formula is

$A({k^{\′}}_x,{k^{\′}}_y,\mathrm{\ω})=A(k_x,k_y,\mathrm{\ω})e^{i2\mathrm{\π}(k_x{x}_0+k_y{y}_0)]}$

Wherein A (k' _x, k' _y, ω) for continuation obtain at (x+x ₀, y+y ₀) the frequency space numeric field data at place.

(3) transformation for mula carrying out three-dimensional Fourier inversion is

$u(x+x_0,y+y_0,t)=\underset{-\∞}{\overset{\∞}{\∫}}{{\mathrm{dk}}^{\′}}_x\underset{-\∞}{\overset{\∞}{\∫}}{{\mathrm{dk}}^{\′}}_y\underset{-\∞}{\overset{\∞}{\∫}}A({k^{\′}}_x,{k^{\′}}_y,\mathrm{\ω})e^{i2\mathrm{\π}[\mathrm{\ωt}-({k^{\′}}_{x}x+{k^{\′}}_{y}y)]}\mathrm{df}$

Wherein u (x+x ₀, y+y ₀, t) for continuation obtain at (x+x ₀, y+y ₀) place disappearance data.

3. the seismic data gap penalties method based on the wave field extrapolation of territory, frequency space according to claim 1 and 2, is characterized in that also comprising in above-mentioned steps:

After three-dismensional effect, the actual seismic trace compensated should be

$\tilde{u}(x+x_0,y+y_0,t)=\∫B\left(x_{0,}{y}_0\right)u(x+x_0,y+y_0,t)d{x}_{0}d{y}_0$

Wherein B (x ₀, y ₀) be direction factor, for actual in (x+x after three-dismensional effect ₀, y+y ₀) place compensate data.