CN106842297A - Borehole restraint unstable state method for correcting phase - Google Patents

Abstract

It is the important content of geological data uniformity in waveform correction the invention discloses borehole restraint unstable state method for correcting phase.Its object is under local earthquake's attribute and part plan wave pattern, propose a kind of unstable state method for correcting phase of borehole restraint, the method not only allows for the unstable state of sub-wave phase, and takes full advantage of well logging synthetic seismogram and carry out the advantage of phasing high precision.The present invention combines log data and borehole-side seismic data envelope forms model trace, the local phase symbolic animal of the birth year of well side geological data is estimated using local similarity criterion, recycle local obliquity information that the phase information of seismic trace near well is interpolated into whole seismic profile, so as to obtain the phase information with time and spatial variations, phasing can be carried out to whole piece section using the information.Compare other method more reasonable.

Description

Borehole restraint unstable state method for correcting phase

Technical field

It is the unstable state phasing based on borehole restraint the invention belongs to oil-gas exploration seism processing field Method, is the important content of geological data uniformity in waveform correction.

Prior art

Dephasing on wavelet, foreign study starting is relatively early, Levy and Oldenburg, Longbottom Deng, White on the basis of the blind deconvolution that Wiggins is proposed, propose to cause output geological data non-Gaussian system Most strong constant phase correction method.With respect to Wiggins methods, the method free parameter that they propose tails off, Algorithm is more stablized.In order to consider the situation that seismic wavelet phase is changed over time, Baan uses sliding window Method estimated sub-wave phase, but the method is effective on condition that phase place change piecewise stationary, in order to This restrictive condition, Baan and Fomel is avoided further to regard phase estimation as an optimal inversion problem, Unstable state phase estimation is carried out using local variance mould maximal criterion, so as to improve the precision of phase estimation, is changed The stability of kind phasing.Fomel pointed out in the case where well-log information is lacked, can using seismic channel with The maximum criterion of its envelope local similarity, estimates the sub-wave phase of unstable state data, and the method is relative to office Portion's variance mould method has bigger dynamic range, therefore the phase information of pickup is more accurate.

Domestic scholars have also been made the research of many novelties in terms of phasing.Zhou Xingyuan proves, Chang Xiangwei Correction simply changes the waveform of wavelet on the premise of unchanged shake road envelope.It is false that Bai Zhixin is based on Chang Xiangwei It is located at frequency domain and realizes optimum phase correction.Old must far grade is influenceed for sub-wave phase by complicated factor, Propose a kind of method for correcting phase changed with time, space and frequency.Guo Xiangyu etc. is existing each in analysis On the basis of kind wavelet processing advantage and disadvantage, it is proposed that a kind of calculation of new estimation mixed phase wavelet phase Method.Li Hequn etc. has carried out local directed complete set to phase and the time difference simultaneously.Song's ancestor's equality is in prestack road pooled applications Constant phase correction technology, improves stacked section quality.The English of state nine and Zhou Xingyuan are based on maximum stack energy method, A kind of earth's surface-consistent method for correcting phase is proposed, the phase school of shot point, geophone station is asked for using iterative algorithm Positive operator, is corrected to earthquake record.Gao Shaowu etc. is approached earth's surface change using pure-phase filter and drawn The phase place change for rising, earth's surface has been carried out to the geological data after earth's surface-consistent the amplitude processing and static corrections processing The treatment of uniformity phasing.Simply connected fine jade etc. proposes a kind of new phasing criterion, first with most generous Differential mode method is corrected to the excess phase of model, then with the phasing angle in each road of analytic calculation, So as to realize accurate phasing.

In seismic prospecting data treatment, the dephasing of wavelet be favorably improved the resolution ratio of seismic data, Improve the quality of stacked section.Conventional method for correcting phase is to well side earthquake note using composite traces of logging well Record carries out phase estimation, then carries out constant phase correction to whole piece section, and the method does not account for seismic wavelet The unstable state (phase is with time and spatial variations) of phase.Although by local similarity method using maximum Variance mould criterion or envelope maximum similarity criterion are estimated that the phase attributes with time and spatial variations, But because zero phase criterion has certain limitation, therefore limited precision in itself.

Because near surface is low, the change of transverse gage of the reduction of speed with weathered layer and speed, and in seismic spread The heterogencity and ground of the near surface factors such as shot point coupling, the difference of geophone station coupling condition and underground medium Complexity of lower construction etc. causes seismic wavelet phase with time and spatial variations (Li Zhenchun etc., 2008). Seismic wavelet is corrected to zero phase, can not only improve the quality of stacked section, and can effectively improve The resolution ratio of data.Therefore, in common seismic Data processing, it is necessary to carry out method for correcting phase aspect Research.

The content of the invention

The purpose of the present invention is directed to above mentioned problem, under local earthquake's attribute and part plan wave pattern, proposes A kind of unstable state method for correcting phase of borehole restraint, the method not only allows for the unstable state of sub-wave phase, Its change with time and space is taken into full account in phasing, and takes full advantage of well logging synthesis earthquake Record carries out the advantage of phasing high precision.

The technical scheme is that：

A kind of borehole restraint unstable state method for correcting phase, mould is formed with reference to log data and borehole-side seismic data envelope Type road, the local phase symbolic animal of the birth year of well side geological data is estimated using local similarity criterion, is recycled local The phase information of seismic trace near well is interpolated into whole seismic profile by obliquity information, so as to obtain with time and sky Between the phase information that changes, can carry out phasing to whole piece section using the information.

Such scheme further includes to include：

(1) model trace is built using log data and seismic trace near well envelope, the time is recorded using log data The seismic data recording time is shorter than, by the envelope of the data seismic trace near well outside the log data record time To replace, synthesize and former seismic data recording time identical model trace；

(2) according to model trace, unstable state phase estimation is carried out to seismic trace near well with similarity criteria；

(3) plane wave predictive operator is utilized by the local phase continuation of seismic trace near well to other positions；

(4) to carrying out unstable state phase estimation at all log data positions, then all local phases are belonged to Property section is averaged, and obtains the local phase attribute with time and spatial variations；

(5) unstable state phasing is carried out to seismic profile according to the local phase attribute for estimating, and it is defeated The seismic profile gone out after phasing.

Such scheme also includes：

(2) local phase of seismic trace near well is estimated, according to model trace, with similarity criteria to well side earthquake Road carries out unstable state phase estimation, two time series a_iAnd b_iSimilarity factor be defined as：

Formula (1) regards two products of Least squares inversion solution as,

c²=c₁c₂ (2)

c₁=(a^Ta)^-1(a^Tb) (3)

c₂=(b^Tb)^-1(b^Ta) (4)

Wherein a, b are respectively the vector representation of signal a (t), b (t), x^TY represents vector x and y dot products, by The element of vectorial a, b constructs diagonal matrix A, B respectively, is added just equivalent to inverting after being localized to equation Then change condition, scalar c₁And c₂It is changed into vectorial c₁And c₂, using integer regularization, equation (3), (4) are changed into：

c₁=[λ²I+S(A^TA-λ²I)]^-1SA^Tb (5)

c₂=[λ²I+S(B^TB-λ²I)]^-1SB^Tb (6)

Wherein S is smoothing operator, vectorial c₁And c₂The Local Phase that each element correspondence is changed over time after being multiplied Like degree c, its result is iterated the approximate solution for obtaining above formula using shaping regularization inverting.

(3) using plane wave predictive operator by the local phase continuation of seismic trace near well to other positions, use Be interpolated into the phase information of Jing Shuojuweizhichu at other positions by plane wave predictive filter operator, plane wave Predictive filter is described with the following differential equation：

Wherein P (t, x) is seismic wave field, and σ is the local inclination angle with time and spatial variations；

It is assumed that seismic profile s is made up of a series of seismic channels, s=[s₁ s₂ ... s_N]^T, plane wave destructing filtering Device (PWD) operator predicts the track data according to neighboring track, and original road is subtracted each other with prediction road, mathematical expression Formula is：

R=Ds (8)

Wherein r is surplus, and D is PWD operators, is defined as：

Wherein I is unit operator, and P is predictive operator, and original road is moved come pre- by along lineups inclination direction Survey next road geological data, P_i,jRepresent by the operator in the i-th road prediction jth road；

Formula (8) minimizes predicated error r and estimates main local obliquity information by regularization conjugate gradient method, PWC operators are the inverse of PWD operators, and PWC operators can be quickly realized by recursive algorithm：

c₁=s₁,c_k=s_k+P_k-1,kc_k-1, k=2,3 ..., N (10).

(5) unstable state phasing is carried out to seismic profile according to the local phase attribute for estimating, and it is defeated The seismic profile gone out after phasing, seismic channel x (t) after phase place by being changed into：

x_rot(t)=x (t) cos φ (t)+H [x (t)] sin φ (t) (11)

In formula, to change over time phase rotation angle, H [x (t)] becomes φ (t) for the Hilbert of seismic channel x (t) Change, using different zero phase criterions, obtain different method for correcting phase.

Invention effect

Borehole restraint unstable state method for correcting phase considers the unstable state of sub-wave phase, and takes full advantage of Well logging synthetic seismogram carries out the advantage of phasing high precision.Its specific advantage and feature show following Several aspects：

First, the reliability of method effect.The method comprehensively not only allows for the phase with time and spatial variations Information, and the local structure information of seismic profile is considered, therefore it is more reasonable.

2nd, easy realization simple to operate.The method flow and parameter setting are simple, fast operation, not based on It is any it is assumed that not limited by conventional phase bearing calibration application.

3rd, phasing high precision.The method is not limited by zero phase criterion limitation, and is filled Divide the advantage that make use of well logging synthetic seismogram to carry out phasing high precision

Brief description of the drawings

Fig. 1 is borehole restraint unstable state phase correction techniques flow chart of the invention；

Fig. 2 is the effect contrast figure that out of phase bearing calibration is used to one-dimensional generated data；Wherein, Fig. 2 A () is wave impedance log, Fig. 2 (b) is reflection coefficient curve, and Fig. 2 (c) is and zero phase Ricker Earthquake record after wavelet convolution, Fig. 2 (d) is that -90 ° to 0 degree linear changes are carried out to synthetic seismogram Change the earthquake record after phase place, Fig. 2 (e), Fig. 2 (f), Fig. 2 (g) correct result respectively；Figure 2 (h) is the phase angle comparison diagram of these three methods estimation.

Fig. 3 is two-dimentional real data single track phasing；Wherein, the original stacked sections of Fig. 3 (a), Fig. 3 B () is the local inclination angle estimated using PWD.Fig. 3 (c) is well side geological data, and Fig. 3 (d) is Well side geological data envelope and the model trace of well logging generated data synthesis, Fig. 3 (e) is the phase angle estimated, Fig. 3 (f) is the seismic channel after correction.

Fig. 4 is two-dimentional real data phasing；The wherein phase information of Fig. 4 (a) whole pieces seismic profile, Fig. 4 (b) corrects result, and Fig. 4 (c), Fig. 4 (d) are respectively Fig. 4 (a), the part of Fig. 4 (b) is put Big figure.

Specific embodiment

The present embodiment is target target area with certain exploratory area 2-d seismic data, and the data is processed using this method, To verify the effect of this method, flow chart is shown in Fig. 1.

1) model trace is built using log data and seismic trace near well envelope；

2) local phase of seismic trace near well is estimated；

3) plane wave predictive operator is utilized by the local phase continuation of seismic trace near well to other positions；

4) to carrying out unstable state phase estimation at all log data positions, then to all local phase attributes Section is averaged, and obtains the local phase attribute with time and spatial variations；

5) unstable state phasing is carried out to seismic profile according to the local phase attribute for estimating, and is exported Seismic profile after phasing.

The detailed operation sketch of invention is as shown in Figure 1.Major technique key point is following four：1. mould, is built Type road；2. the local phase of seismic trace near well, is estimated；3., local phase continuation；4., section is carried out Unstable state phasing.

The unstable state method for correcting phase implementation process of borehole restraint is as follows：

(1) model trace is built using log data and seismic trace near well envelope

When there is well-log information, first using well-log information synthetic seismogram, because log data records the time The seismic data recording time is often shorter than, therefore, the data well side earthquake outside the log data record time The envelope in road replaces, thus synthesized together with former seismic data recording time identical model trace.

(2) local phase of seismic trace near well is estimated

According to model trace, unstable state phase estimation can be carried out to seismic trace near well.Phase estimation depends on similar Degree criterion.Two time series a_iAnd b_iSimilarity factor be defined as：

Formula (1) is considered as two products of Least squares inversion solution,

c²=c₁c₂ (2)

c₁=(a^Ta)^-1(a^Tb) (3)

c₂=(b^Tb)^-1(b^Ta) (4)

Wherein a, b are respectively the vector representation of signal a (t), b (t), x^TY represents vector x and y dot products.By The element of vectorial a, b constructs diagonal matrix A, B respectively, is added just equivalent to inverting after being localized to equation Then change condition, scalar c₁And c₂It is changed into vectorial c₁And c₂, using integer regularization, equation (3), (4) are changed into：

c₁=[λ²I+S(A^TA-λ²I)]^-1SA^Tb (5)

c₂=[λ²I+S(B^TB-λ²I)]^-1SB^Tb (6)

Wherein S is smoothing operator, vectorial c₁And c₂The Local Phase that each element correspondence is changed over time after being multiplied Like degree c, its result can using shaping regularization inverting be iterated it is approximate obtain above formula solution (Claerbout, 1992)。

(3) plane wave predictive operator is utilized by the local phase continuation of seismic trace near well to other positions.

In order to the phase information of Jing Shuojuweizhichu is interpolated at other positions, this patent is predicted using plane wave Filter operator solves this problem.

Plane wave predictive filter, can be with following micro- from the part plan wave pattern of description geological data Equation is divided to describe：

Wherein P (t, x) is seismic wave field, and σ is the local inclination angle with time and spatial variations.

It is assumed that seismic profile s is made up of a series of seismic channels, s=[s₁ s₂ ... s_N]^T.Plane wave destructing filtering Device (PWD) operator (Fomel, 2002) predicts the track data according to neighboring track, and by original road and predicts Road subtracts each other, and mathematic(al) representation is：

R=Ds (8)

Wherein r is surplus, and D is PWD operators, is defined as：

Wherein I is unit operator, and P is predictive operator, and original road is moved come pre- by along lineups inclination direction Survey next road geological data, P_i,jRepresent by the operator in the i-th road prediction jth road.Formula (8) can be by canonical Change conjugate gradient method minimum predicated error r and estimate main local obliquity information.The constraint of the inversion problem Condition is usually such that data space inclination angle smooth change (Fomel, 2007).

PWC operators are the inverse of PWD operators, and PWC operators can be quickly realized by recursive algorithm：

c₁=s₁,c_k=s_k+P_k-1,kc_k-1, k=2,3 ..., N (10)

The specific derivation process of the formula refer to document (Fomel et al., 2006).

(4) to carrying out unstable state phase estimation at all log data positions, then all local phases are belonged to Property section is averaged, and obtains the local phase attribute with time and spatial variations.

(5) unstable state phasing is carried out to seismic profile according to the local phase attribute for estimating, and it is defeated The seismic profile gone out after phasing.

Seismic channel x (t) after phase place by being changed into：

x_rot(t)=x (t) cos φ (t)+H [x (t)] sin φ (t) (11)

In formula, to change over time phase rotation angle, H [x (t)] becomes φ (t) for the Hilbert of seismic channel x (t) Change, using different zero phase criterions, different method for correcting phase can be obtained.

Relative to local variance mould and envelope local similarity criterion, the unstable state phasing based on well data Method has highest precision, and in order to prove this point, we are tested using the log data in certain exploratory area. Fig. 2 (a) is wave impedance log, and Fig. 2 (b) is reflection coefficient curve, and Fig. 2 (c) is and zero phase Earthquake record after Ricker wavelet convolutions, Fig. 2 (d) is to carry out -90 ° to 0 to synthetic seismogram Earthquake record after degree linear change phase place, to the record respectively in maximum variance norm criterion, envelope Unstable state phasing is carried out under maximum similarity criterion, Log-constrained maximum similarity criterion, result is corrected Respectively as shown in Fig. 2 (e), Fig. 2 (f), Fig. 2 (g), contrast is as can be seen that because maximum variance module has The premise of effect is that reflection coefficient sequence meets random super-Gaussian distribution, therefore the method is corresponding by each crest Position is corrected to zero phase as a reflecting layer, but when there is thin layer, it is impossible to it is corrected to Correct phase.Envelope maximum similarity criterion is calculated by envelope to be influenceed, and cannot equally correct thin layer earthquake The phase of response, and the precision highest of borehole restraint method for correcting phase.Fig. 2 (h) is estimated for these three methods Phase angle comparison diagram, it can be seen that the phase angle that the three kinds of methods in 0.02s positions or so are estimated is compared It is close, and be unable to estimate out correctly using maximum variance module and envelope maximum similarity criterion at other positions Phase angle.

In order to further verify the validity of this patent method, certain exploratory area real data is carried out at phasing Reason, the original stacked sections of Fig. 3 (a), the position where five-pointed star represents well in figure, bold portion is well logging Time range.Fig. 3 (b) is the local inclination angle estimated using PWD.Fig. 3 (c) is well side earthquake number According to Fig. 3 (d) is the model trace of well side geological data envelope and well logging generated data synthesis.Office is used below Portion's similarity carries out phase estimation to seismic trace near well, shown in phase angle such as Fig. 3 (e) of estimation, using this Phase angle carries out phasing to seismic trace near well, shown in such as Fig. 3 (f) of the seismic channel after correction, from figure As can be seen that the seismic channel wavelet basic correction corrects effect to zero phase, especially sub-wave phase shown in arrow Fruit becomes apparent.

After phase estimation being carried out using generated data of logging well to well side data, will using plane wave predictive operator The phase information is interpolated into other positions, so as to obtain the phase information of whole piece seismic profile, such as Fig. 4 (a) It is shown, phasing, correction result such as Fig. 4 are carried out to original stacked section using the phase information after interpolation B shown in (), Fig. 4 (c), Fig. 4 (d) are respectively the partial enlarged drawing of Fig. 4 (a), Fig. 4 (b).From As can be seen that the method for correcting phase proposed using this patent can effectively by the wavelet of seismic profile in figure Zero phase is corrected to, so as to improve the quality of stacked section, the resolution ratio of stacked section is improved.

Relative to the mathematical interpolation method such as linear interpolation, plane wave Forecasting Methodology considers the part of seismic profile Tectonic information, thus it is more reasonable.

Claims (3)

1. a kind of borehole restraint unstable state method for correcting phase, it is characterised in that with reference to log data and well side ground Shake record envelope forms model trace, and the local phase of well side geological data is estimated using local similarity criterion Symbolic animal of the birth year, recycles local obliquity information that the phase information of seismic trace near well is interpolated into whole seismic profile, from And the phase information with time and spatial variations is obtained, can enter line phase school to whole piece section using the information Just.

2. borehole restraint unstable state method for correcting phase according to claim 1, it is characterised in that including：

(1) model trace is built using log data and seismic trace near well envelope, the time is recorded using log data The seismic data recording time is shorter than, by the envelope of the data seismic trace near well outside the log data record time To replace, synthesize and former seismic data recording time identical model trace；

(2) according to model trace, unstable state phase estimation is carried out to seismic trace near well with similarity criteria；

(3) plane wave predictive operator is utilized by the local phase continuation of seismic trace near well to other positions；

(4) to carrying out unstable state phase estimation at all log data positions, then all local phases are belonged to Property section is averaged, and obtains the local phase attribute with time and spatial variations；

(5) unstable state phasing is carried out to seismic profile according to the local phase attribute for estimating, and it is defeated The seismic profile gone out after phasing.

3. borehole restraint unstable state method for correcting phase according to claim 2, it is characterised in that：

(2) local phase of seismic trace near well is estimated, according to model trace, with similarity criteria to well side earthquake Road carries out unstable state phase estimation, two time series a_iAnd b_iSimilarity factor be defined as：

$c\[a,b\]=\frac{\underset{i=1}{\overset{N}{\Σ}}{a}_i{b}_i}{\sqrt{\underset{i=1}{\overset{N}{\Σ}}{a}_i^2\underset{i=1}{\overset{N}{\Σ}}{b}_i^2}}---\left(1\right)$

Formula (1) regards two products of Least squares inversion solution as,

c²=c₁c₂ (2)

c₁=(a^Ta)^-1(a^Tb) (3)

c₂=(b^Tb)^-1(b^Ta) (4)

Wherein a, b are respectively the vector representation of signal a (t), b (t), x^TY represents vector x and y dot products, by The element of vectorial a, b constructs diagonal matrix A, B respectively, is added just equivalent to inverting after being localized to equation Then change condition, scalar c₁And c₂It is changed into vectorial c₁And c₂, using integer regularization, equation (3), (4) are changed into：

c₁=[λ²I+S(A^TA-λ²I)]^-1SA^Tb (5)

c₂=[λ²I+S(B^TB-λ²I)]^-1SB^Tb (6)

Wherein S is smoothing operator, vectorial c₁And c₂The Local Phase that each element correspondence is changed over time after being multiplied Like degree c, its result is iterated the approximate solution for obtaining above formula using shaping regularization inverting；

(3) using plane wave predictive operator by the local phase continuation of seismic trace near well to other positions, use Be interpolated into the phase information of Jing Shuojuweizhichu at other positions by plane wave predictive filter operator, plane wave Predictive filter is described with the following differential equation：

$\frac{\∂P}{\∂x}+\mathrm{\σ}\frac{\∂P}{\∂t}=0---\left(7\right)$

Wherein P (t, x) is seismic wave field, and σ is the local inclination angle with time and spatial variations；

It is assumed that seismic profile s is made up of a series of seismic channels, s=[s₁ s₂ ... s_N]^T, plane wave destructing filtering Device (PWD) operator predicts the track data according to neighboring track, and original road is subtracted each other with prediction road, mathematical expression Formula is：

R=Ds (8)

Wherein r is surplus, and D is PWD operators, is defined as：

$D=I_N-P=\left[\begin{array}{ccccc}I& 0& 0& ...& 0\\ -P_{1,2}& I& 0& ...& 0\\ 0& -P_{2,3}& I& ...& 0\\ ...& ...& ...& ...& ...\\ 0& 0& ...& -P_{N-1,N}& I\end{array}\right]---\left(9\right)$

Wherein I is unit operator, and P is predictive operator, and original road is moved come pre- by along lineups inclination direction Survey next road geological data, P_i,jRepresent by the operator in the i-th road prediction jth road；

Formula (8) minimizes predicated error r and estimates main local obliquity information by regularization conjugate gradient method, PWC operators are the inverse of PWD operators, and PWC operators can be quickly realized by recursive algorithm：

c₁=s₁,c_k=s_k+P_k-1,kc_k-1, k=2,3 ..., N (10)

(5) unstable state phasing is carried out to seismic profile according to the local phase attribute for estimating, and it is defeated The seismic profile gone out after phasing, seismic channel x (t) after phase place by being changed into：

x_rot(t)=x (t) cos φ (t)+H [x (t)] sin φ (t) (11)

In formula, to change over time phase rotation angle, H [x (t)] becomes φ (t) for the Hilbert of seismic channel x (t) Change, using different zero phase criterions, obtain different method for correcting phase.