MULTICHANNEL DECONVOLUTION FILTERING OF FIELD RECORDED SEISMIC DATA

Geophysics ◽  
1968 ◽  
Vol 33 (5) ◽  
pp. 711-722 ◽  
Author(s):  
E. B. Davies ◽  
E. J. Mercado

Several writers have proposed the use of multichannel filters for the elimination of coherent noise on seismic records. One filter of this type which can be constructed is a multichannel Wiener filter which has a multichannel input and a single channel output. In this form, it is applicable to data collected for vertical or horizontal common‐depth‐point stack processing. The choice of desired output characteristics for this Wiener filter is flexible and, for example, can be tuned to correspond to multichannel deconvolution. The results of the application of filters of this type to field and synthetic data, in general, show little if any advantage over single‐channel deconvolution. This failure appears to be connected with the low cross coherence of both noise and reflection signal on field‐recorded, common‐depth‐point traces.

Geophysics ◽  
2006 ◽  
Vol 71 (3) ◽  
pp. V79-V86 ◽  
Author(s):  
Hakan Karsli ◽  
Derman Dondurur ◽  
Günay Çifçi

Time-dependent amplitude and phase information of stacked seismic data are processed independently using complex trace analysis in order to facilitate interpretation by improving resolution and decreasing random noise. We represent seismic traces using their envelopes and instantaneous phases obtained by the Hilbert transform. The proposed method reduces the amplitudes of the low-frequency components of the envelope, while preserving the phase information. Several tests are performed in order to investigate the behavior of the present method for resolution improvement and noise suppression. Applications on both 1D and 2D synthetic data show that the method is capable of reducing the amplitudes and temporal widths of the side lobes of the input wavelets, and hence, the spectral bandwidth of the input seismic data is enhanced, resulting in an improvement in the signal-to-noise ratio. The bright-spot anomalies observed on the stacked sections become clearer because the output seismic traces have a simplified appearance allowing an easier data interpretation. We recommend applying this simple signal processing for signal enhancement prior to interpretation, especially for single channel and low-fold seismic data.


Geophysics ◽  
1995 ◽  
Vol 60 (1) ◽  
pp. 191-203 ◽  
Author(s):  
A. Frank Linville ◽  
Robert A. Meek

Primary reflections in seismic records are often obscured by coherent noise making processing and interpretation difficult. Trapped water modes, surface waves, scattered waves, air waves, and tube waves to name a few, must be removed early in the processing sequence to optimize subsequent processing and imaging. We have developed a noise canceling algorithm that effectively removes many of the commonly encountered noise trains in seismic data. All currently available techniques for coherent noise attenuation suffer from limitations that introduce unacceptable signal distortions and artifacts. Also, most of those techniques impose the dual stringent requirements of equal and fine spatial sampling in the field acquisition of seismic data. Our technique takes advantage of characteristics usually found in coherent noise such as being localized in time, highly aliased, nondispersive (or only mildly so), and exhibit a variety of moveout patterns across the seismic records. When coherent noise is localized in time, a window much like a surgical mute is drawn around the noise. The algorithm derives an estimate of the noise in the window, automatically correcting for amplitude and phase differences, and adaptively subtracts this noise from the window of data. This signal estimate is then placed back in the record. In a model and a land data example, the algorithm removes noise more effectively with less signal distortion than does f-k filtering or velocity notch filtering. Downgoing energy in a vertical seismic profile (VSP) with irregular receiver spacing is also removed.


Geophysics ◽  
1968 ◽  
Vol 33 (5) ◽  
pp. 723-733 ◽  
Author(s):  
John C. Robinson

A simple seismic record synthesis for common‐depth‐point data was examined for analytic representation in terms of its harmonic spectrum. This frequency‐domain investigation revealed that the primary‐reflection signal can be completely recovered in the absence of random noise, or it can be better recovered in the presence of random noise than normal stacking affords, especially, if the coherent‐noise‐to‐random‐noise ratio is high. The success of this technique is founded upon the principle that difference equations in the time domain become algebraic equations in the frequency domain. The technique is partially “probabilistic” because analytic solutions for the primary‐reflection signal are stacked for further attenuation of noise. The constituents of the seismic records, after static and normal‐moveout corrections, are: identical, coincident, primary‐reflection signal; identical, time‐shifted coherent noise; and random noise. The coherent‐noise time shifts must be determined for application of the semideterministic technique; methods are discussed in the Data Processing section.


Geophysics ◽  
1970 ◽  
Vol 35 (3) ◽  
pp. 436-446 ◽  
Author(s):  
John C. Robinson

A theory for weighting seismic records in the stacking process has been developed from a statistical seismic model. The model applies to common‐depth‐point seismic records which have been statically and dynamically corrected; the same model applies to an ordinary stacking procedure. The model stipulates for the signal and noise components, respectively, of a seismic record that (1) the signal is coincident with and similarly shaped to the signal on other records, and (2) the noise is statistically independent of that on any other record and of the signal and has zero mean value. In accord with the model, a seismic record is completely described for the purpose of weighting by its signal scale and its signal‐to‐noise energy ratio. Several statistical procedures for evaluating these parameters for seismic field data are presented. The most favorable procedure is demonstrated with both synthetic and field seismic records.


2016 ◽  
Vol 13 (2) ◽  
pp. 109
Author(s):  
Udaya Kamiludin ◽  
I Nyoman Astawa ◽  
Moch. Akrom Mustafa

Penelitian geofisika di Perairan Todak, Singkep, Kepulauan Riau menggunakan seperangkat peralatan seismik pantul dangkal saluran tunggal. Tujuan penelitian ini adalah untuk menunjang penelitian keterdapatan endapan plaser pembawa timah dan unsur tanah jarang (REE). Hasil interpretasi rekaman seismik diperoleh terdapatnya lembah/mangkuk yang terbentuk secara alami akibat adanya terobosan batuan granit, di mana lembah/mangkuk-mangkuk ini merupakan tempat terjadinya sedimentasi dari hasil pelapukan batuan di sekitarnya. Hasil interpretasi rekaman seismik pantul saluran tunggal analog di perairan Todak, Singkep, dapat diklasifikasikan menjadi 3 runtunan yaitu runtunan A, B, dan runtunan C.Kata kunci Data seismik, endapan plaser, lembah/mangkuk, Perairan Todak. Geophysical research at Todak, Singkep, Riau Archipelago Province, by using single channel sahllow seismic refletion. The purpose of research is to support placer deposit bearing tin and rare earth element research at this area. From seismic interpretation can be recognized the distribution of valley/bowls which is naturally formed, caused by granite rock intrusion. Those valleys are sedimentation places of wheathered rock from the surrounding area. Beside that, the seismic research also for determining the placer deposit thickness. Interpratation of analog single channel seismic records in the Todak waters, Singkep, result 3 seismic sequences and intrusive feature, A sequences, B, and C. Keywords: Seismic data, placer deposit, valley/basin, Todak Watres.


Geophysics ◽  
1984 ◽  
Vol 49 (8) ◽  
pp. 1140-1152 ◽  
Author(s):  
Thomas K. Fulton ◽  
K. Michele Darr

The offset panel is a display of basic seismic data which combines single‐channel profiles from successive offsets (source‐to‐receiver distances) into one format. The profiles are displayed one below another and arranged vertically by offset and horizontally by common‐depth‐point. This arrangement allows for comparison of variations observed at one offset to those at another offset. Alteration of the data due to near‐surface geologic variations generates geometric patterns on the display which are different from patterns due to changes in seismic source or receiver. This display has utility in data processing to verify field recording geometry, monitor the seismic source (primarily a marine application), and determine processing parameters. It aids data interpretation by allowing for the detection of an anomalous velocity zone in the near‐surface which may affect deeper structural interpretation. Utilization of the offset panel in identification of shallow events of high amplitude also allows identification of shallow drilling hazards in the marine environment with conventional seismic data.


Geophysics ◽  
1986 ◽  
Vol 51 (1) ◽  
pp. 34-44 ◽  
Author(s):  
Barry J. Newman

The presence of random additive noise is the most important degrading factor in the deconvolution of seismic data. Noise‐induced distortion of signal phase and amplitude produces severe stack attenuation, makes poststack recovery difficult with spectral enhancement techniques, and leaves the stratigraphic imprint unclear. The random noise component in the data is estimated from trace segments before the first arrivals and at the bottom of the record beyond seismic basement. An autocorrelation of this noise is used to adjust the signal autocorrelation prior to Wiener‐Levinson deconvolution filter design. To improve the robustness of the technique, an iterative surface‐consistent wavelet solution (common source, receiver, and offset) is used in preference to a single‐channel operation. Use of this deconvolution technique is shown by synthetic and case examples to result in correct phase alignment, enhanced stacking fidelity, and extended signal bandwidth even on very noisy data. The improvement, coupled with sensible handling of coherent noise energy, is crucial for the interpretation of subtle statigraphic plays in many areas.


Geophysics ◽  
2021 ◽  
Vol 86 (1) ◽  
pp. V23-V30
Author(s):  
Zhaolun Liu ◽  
Kai Lu

We have developed convolutional sparse coding (CSC) to attenuate noise in seismic data. CSC gives a data-driven set of basis functions whose coefficients form a sparse distribution. The noise attenuation method by CSC can be divided into the training and denoising phases. Seismic data with a relatively high signal-to-noise ratio are chosen for training to get the learned basis functions. Then, we use all (or a subset) of the basis functions to attenuate the random or coherent noise in the seismic data. Numerical experiments on synthetic data show that CSC can learn a set of shifted invariant filters, which can reduce the redundancy of learned filters in the traditional sparse-coding denoising method. CSC achieves good denoising performance when training with the noisy data and better performance when training on a similar but noiseless data set. The numerical results from the field data test indicate that CSC can effectively suppress seismic noise in complex field data. By excluding filters with coherent noise features, our method can further attenuate coherent noise and separate ground roll.


Geophysics ◽  
2012 ◽  
Vol 77 (5) ◽  
pp. R217-R225 ◽  
Author(s):  
Luiz Alberto Santos ◽  
Webe Joao Mansur ◽  
George A. McMechan

Diffractions carry the same kinematic information provided by common focus point operators (CFPOs). Thus CFPO and diffraction time trajectories may be used separately, or combined into a single unified tomography for velocity analysis. Velocity estimation by tomography of CFPOs reduces the depth-velocity ambiguity compared to two-way time tomography. CFPO estimation is complicated where there are event discontinuities and diffractions. This problem is overcome by using the kinematic information in diffractions in near-offset common-offset gathers. The procedure is illustrated using synthetic data, and a single-channel field seismic profile from the Blake Ridge (off the east coast of the United States). The results show the effectiveness of the proposed method for estimation of velocity from single channel seismic data, and for refinement of the velocity field from multichannel data. Both applications are cost-competitive.


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