Seismic migration with inverse q filtering wang 2004. Filtering of seismic data the interpretation of seismic data is made purely on the basis of what is observed in the final processed section. Seismic inverse q filtering ebok wang yanghua wang. Seismic inverseq filtering can be regarded as a reversal procedure of wave propagation. Spatial variations in the absorption properties of the overburden cause frequencydependent dissipation effects. Cmp processing greatly enhances the signal to noise ratio. A stable and efficient approach of inverse q filtering.
Robinson pointed out that the algorithm of inverse q filtering is similar to seismic deconvolution. It employs a wave propagation reversal procedure that compensates for energy absorption. Application of inverse q filtering methods in the near. Application of inverse q filtering to land seismic data to. Introduction seismic absorption compensation is commonly implemented by means of inverse q filtering or spectrum whitening yilmaz, 2000. The degree of attenuation can be approximated from q measured in seismic data, and the q can be used to design an attenuation compensation scheme to correct the effects of energy absorption and phase dispersion caused referred to as q inverse filtering wang, 2002. Robinson pointed out that the algorithm of inverseq filtering is similar to seismic deconvolution.
The key point raised in this paper is that a dispersive 1d backward propagation can form the basis of a number of different algorithms for inverse q filtering, each of which is akin to a particular migration algorithm. Seismic inverse qfiltering employs a wave propagation reversal procedure that compensates for energy absorption and corrects wavelet distortion due to velocity dispersion. The proposed method is used to compensate the synthetic seismic trace produced by boundary element method. Estimation of q and inverse q filtering for prestack. Seismic inverse q filtering by yanghua wang overdrive. Introduction seismic absorption compensation is commonly implemented by means of inverse q. Thus, q can be used as a direct indicator of hydrocarbons toksoz et al. A stable and efficient approach of inverse q filtering geophysics. The distortion can be compensated by using prestack inverse q filtering, or by a more sophisticated q migration. Pdf seismic migration with inverse q filtering yanghua.
Inverse q filtering by pseudodifferential operators. This results in seismic amplitude attenuation and wavelet phase. Inverse q filtering is an important dataprocessing procedure broadly used for enhancing seismic data. Jan 31, 2019 seismic inverse q filtering can be regarded as a reversal procedure of wave propagation. Pdf inverse q filter for seismic resolution enhancement wang 2006 proposed a stabilized inverse q filtering approach in an attempt to broaden the seismic spectrum for resolution enhancement.
Inverse q filtering and deconvolution are two common methods for seismic resolution enhancement. Inverse qfilter for seismic resolution enhancementstabilized. An inverse q filtered migration algorithm performs seismic migration and inverse q filtering simultaneously, in which the latter compensates for the amplitudes and corrects the phase distortions. This results in seismic amplitude attenuation and wavelet phase distortion which masks underlying events and decreases resolution. Projection methods and applications for seismic nonlinear inverse problems with multiple constraints. Seismic inverse q filtering is a data processing technology for enhancing the resolution of reflection seismology images. The distortion can be compensated by using prestack inverse q. In this paper we present a stable approach to inverse qfiltering, based on the theory of wavefield downward continuation. Seismic amplitude interpretation deep seismic reflection data interpretation using balanced filtering method jin zhang, yanguo wang, david c. It is implemented in a layered manner, assuming a layeredearth q model. And then constant q inverse filtering was applied in each layer. Through the use of conventional inverse q filtering algorithm can be applied to derive a stable and efficient inverse q filtering algorithm continuous medium, and through a stable and efficient data. Pdf application of inverse q filtering for improvement. But it also amplifies the noise and reduces the snr of the seismic data after compensation.
Noisefree synthetic traces and the result of two inverse q filtering algorithms. The result shows that it can correct amplitude attenuation and phase distortion effectively and stably. Unfortunately, there is no reliable way to estimate the attenuation factor q directly from seismic data. An inverse q filtering procedure attempts to remove the q effect to produce highresolution seismic data, but some existing methods either reduce the sn ratio, which limits spatial resolution, or generate an illusory highresolution wavelet that contains no more subsurface information than the original lowresolution data. This can make reservoir evaluation based on the deeper seismic image difficult. Application of inverse q filtering for improvement of seismic. By compensating for amplitude attenuation, seismic data can provide true relativeamplitude information for amplitude inversion and. In seismic wave propagation, both the amplitude attenuation and the phase distortion are the exponential functions of the frequency and the travelling time. Seismic inverse q filtering is a data processing technology for enhancing the resolution of seismic images. Seismic migration with inverse inverse q filtering algorithm to improve the vertical resolution in migrated seismic section, in order to recover a weak reflection of the target gaslayer underneath the strong coalseam reflections. At best, inverse q filtering can be applied to post or prestack data appendix b.
Yan and liu 2009 implemented the inverse q filtering on prestack common shot pp and pswaves along the ray path. An inverseq filtered migration algorithm performs seismic migration and inverseq filtering simultaneously, in which the latter compensates for the amplitudes and corrects the phase distortions. It employs a wave propagation reversal procedure that compensates for energy absorption and corrects wavelet distortion due to velocity dispersion. Compensating for attenuation by inverse q filtering crewes. Stabilized inverse q filtering is a data processing technology for enhancing the resolution of reflection seismology images where the stability of the method used is considered.
Application of generalized stable inverse q filtering to real seismic data. The effectiveness of stable inverse q filtering to land seismic. It employs a wave propagation reversal procedure that compensates for energy. Enhanced imaging using bandwidth extending operators and. When seismic waves propagate through the earth subsurface, the anelasticity and inhomogeneity of the subsurface media will have two effects on the seismic waves. Stabilised inverseq filtering for seismic characterisation of. Compensating for attenuation by inverse q filtering. Multicomponent seismic exploration technology, combining reflected pp and converted pswaves, is an effective tool for solving complicated oil and gas exploration problems.
Different methods to apply forward and inverse q filtering can be applied. The conventional stable inverse q filtering method overcomes the instability of the inverse q filtering and can effectively perform amplitude compensation and phase correction. Cmp processing greatly enhances the signal to noise ratio and allows coherent reflections to be visible. Seismic inverseq filtering is a datadriven process. Researchers have successfully improved the time resolution of seismic data using proper inverse q filtering wang, 2002. A principal limitation on seismic resolution is the earth attenuation, or qeffect, including the energy dissipation of highfrequency wave. In the forward q filter, each method is characterized by a particular accuracy and computational.
Pdf a stable and efficient approach of inverse q filtering. Estimation of q factors from reflection seismic data for a. Inverse qfilter for seismic resolution enhancement spiral. When seismic waves propagate through the earth subsurface, the anelasticity and. Seismic anelastic attenuation estimation using prestack. For each individual constant q layer, the seismic wavefield recorded at the surface is first extrapolated down to the top of the current layer and a. Seismic inverseq filtering can be regarded as a reversal procedure of. However, the data that goes into the cmp processing is often contaminated with noise. Inverse q filtering is inherently unstable since the inverse operator will boost high frequency noise.
Cggs proprietary q tomography and q psdm help address these issues. In this study area, reflection seismic surveys are often complicated by. Although some attention has been paid to the idea that seismic migration is equivalent to a type of deconvolution of the spatial. This paper presents a stable, efficient approach to inverse q filtering. Pdf inverse qfilter for seismic resolution enhancement. Comparing three methods for inverseq filtering crewes. Here we estimate the q values from borehole vsp data, and use these values to perform inverse q filtering to the surface seismic data across the borehole to improve the resolution of the surface. Seismic inverse q filtering by yanghua wang seismic inverse q filtering by yanghua wang pdf, epub ebook d0wnl0ad seismic inverse q filtering is a data processing technology for enhancing the. Q is the anelastic attenuation factor or the seismic quality factor, a measure of the energy loss as the seismic wave moves. Use qrtm to image beneath gas hydrates in alaminos. Wang 2006 studied the influences of inverse q filtering, which corrects the wavelet distortion in terms of shape and timing, compensates for.
Different methods to apply inverseq filtering have been developed. The method is good when knowledge of the q values is. Seismic attenuation compensation by bayesian inversion. Seismic inverse q filtering using malvar window based time. Seismic inverse q filtering by yanghua wang pdf, epub ebook d0wnl0ad seismic inverse q filtering is a data processing technology for enhancing the resolution of seismic images. Stabilised inverseq filtering for seismic characterisation. Although practical methods for inverse qfiltering have existed for many years e. Seismic inverse q filtering can be regarded as a reversal procedure of wave propagation.
In real data processing, we often need to redo the. Highresolution seismic processing by gabor deconvolution. Reflections on the deconvolution of land seismic data. An inverse qfilter neither suppresses nor amplifies the data components with high frequencies at late times.
Application of inverse q filtering to land seismic data to improve signal where there is no vsp data control r. Seismic inverse q filtering is a dataprocessing technology for enhancing the resolution of seismic images. Use qrtm to image beneath gas hydrates in alaminos canyon. The stable approach of inverse q filtering based on wavefield continuation theory can simultaneously perform amplitude compensation and phase correction. Corrections for attenuation effects broaden the spectra. Inverse q filtering by fourier transform geophysics. Figure 4c depicts the results of inverse q filtering based on a varying stabilization factor, we can see that the amplitude and phase of the wavelet have been compensated, meanwhile there is almost no noise energy amplification. For each individual constant q layer, the seismic wavefield recorded at the surface is first extrapolated down to the top of the current layer and a constant q inverse. Roy ongc, geophysical services, chennai summary the effect of dispersion and attenuation on land seismic data can be removed by applying inverse q filtering thus. By compensating for amplitude attenuation with a model of the viscoelastic attenuation model type, seismic data can provide true relativeamplitude information for amplitude inversion and subsequent reservoir.