A method of ground‐roll elimination

Amplitude‐ and frequency‐modulated wave motion constitute the ground‐roll noise in seismic reflection prospecting. Hence, it is possible to eliminate ground roll by applying one‐dimensional, linear frequency‐modulated matched filters. These filters effectively attenuate the ground‐roll energy without damaging the signal wavelet inside or outside the ground roll’s frequency interval. When the frequency bands of seismic reflections and ground roll overlap, the new filters eliminate the ground roll more effectively than conventional frequency and multichannel filters without affecting the vertical resolution of the seismic data.

Download Full-text

Ground-roll attenuation using curvelet downscaling

Geophysics ◽

10.1190/geo2017-0562.1 ◽

2018 ◽

Vol 83 (3) ◽

pp. V185-V195 ◽

Cited By ~ 14

Author(s):

Mostafa Naghizadeh ◽

Mauricio Sacchi

Keyword(s):

Seismic Data ◽

Curvelet Transform ◽

Low Frequencies ◽

High Frequencies ◽

Seismic Records ◽

Mask Function ◽

Ground Roll ◽

Least Squares Optimization ◽

Seismic Reflections ◽

Content Information

We have developed a ground-roll attenuation strategy for seismic records that adopts the curvelet transform. The curvelet transform decomposes the seismic events based on their dip and frequency content information. The curvelet panels that contain only either reflection or ground-roll energy can be used to alter the curvelet panels with mixed reflection and ground-roll energies. We build a curvelet-domain mask function from the ground-roll-free curvelet coefficients (high frequencies) and downscale it to the ground-roll-contaminated curvelet coefficients (low frequencies). The mask function is used inside a least-squares optimization scheme to preserve the seismic reflections and attenuate the ground roll. Synthetic and real seismic data examples show the application of the proposed ground-roll attenuation method.

Download Full-text

Case history: Seismic exploration in Egypt’s Eastern Desert

Geophysics ◽

10.1190/1.1443243 ◽

1992 ◽

Vol 57 (2) ◽

pp. 296-305 ◽

Cited By ~ 1

Author(s):

Norman Mark

Keyword(s):

Seismic Data ◽

Low Frequency ◽

Eastern Desert ◽

High Energy ◽

Seismic Exploration ◽

Depth Of Penetration ◽

Ground Roll ◽

New Processing ◽

Seismic Reflections

Although oil exploration has been performed in the Eastern Desert of Egypt for over a century, seismic reflection techniques have only been in use for less than a fourth of that time. In an effort to improve seismic imaging of geologic targets, many styles of acquisition and processing have been tested, accepted, or discarded. Over the last twenty‐four years, seismic data acquisition has evolved from low‐channel analog to high‐channel digital recordings. The most difficult exploration problems encountered in these efforts have been the low‐frequency and high‐energy ground roll and depth of penetration when imaging the oil producing Pre‐Miocene sandy reservoirs below the highly reflective salt and evaporites. Efforts have been focused on developing seismic processing procedures to enhance the seismic data quality of recently acquired seismic data and developing new acquisition methods to improve seismic data through acquisition and processing. In older acquisition, the new processing has improved the seismic quality (vertical and lateral resolution), but it still retains a low‐frequency character. In the newly acquired seismic data, however, there is improved reflection continuity, depth of penetration, and resolution. We attribute this result to the change from low‐fold (6–24 fold), long receiver and source patterns (50 to 222 m) to high fold (96 fold) short receiver and source group (25 m), and spectral balancing in the processing. The most recent acquisition and processing have greatly improved the quality of the shallow seismic reflections and the deeper reflections that have helped unravel the structural and stratigraphic style of the deeper portions of the basin.

Download Full-text

Simultaneous reconstruction of seismic reflections and diffractions using a global hyperbolic Radon dictionary

Geophysics ◽

10.1190/geo2017-0655.1 ◽

2018 ◽

Vol 83 (6) ◽

pp. V315-V323 ◽

Cited By ~ 1

Author(s):

Amr Ibrahim ◽

Paolo Terenghi ◽

Mauricio D. Sacchi

Keyword(s):

Seismic Data ◽

Seismic Reflection ◽

Small Data ◽

Inversion Algorithm ◽

Efficient Tool ◽

Reconstruction Methods ◽

Simultaneous Reconstruction ◽

Sparse Inversion ◽

Data Windows ◽

Seismic Reflections

We have developed a new transform with basis functions that closely resemble seismic reflections and diffractions. The new transform is an extension of the classic hyperbolic Radon transform and accounts for the apex shifts of the seismic reflection hyperbolas and the asymptote shifts of the seismic diffraction hyperbolas. The adjoint and forward operators of the proposed transform are computed using Stolt operators in the frequency domain to increase the computational efficiency of the transform. This new transform is used, in conjunction with a sparse inversion algorithm, to reconstruct common-shot gathers. Our tests indicate that this new transform is an efficient tool for interpolating coarsely sampled seismic data in cases in which one cannot use small data windows to validate the linear event assumption that is often made by Fourier-based reconstruction methods.

Download Full-text

Transform-domain noise synthesis and normal moveout-stack deconvolution approach to ground roll attenuation

Geophysics ◽

10.1190/geo2019-0638.1 ◽

2020 ◽

Vol 86 (1) ◽

pp. V15-V22

Author(s):

Felix Oghenekohwo ◽

Mauricio D. Sacchi

Keyword(s):

Least Squares ◽

Seismic Data ◽

Field Data ◽

Transform Domain ◽

Coherent Noise ◽

Least Squares Problem ◽

Fourier Filtering ◽

Ground Roll ◽

Seismic Reflections ◽

Strong Ground

Ground roll is coherent noise in land seismic data that contaminates seismic reflections. Therefore, it is essential to find efficient ways that remove this noise and still preserve reflections. To this end, we have developed a signal and noise separation framework that uses a hyperbolic moveout assumption on reflections, coupled with the synthesis of coherent ground roll. This framework yields a least-squares problem, which we solve using a sparsity-promoting program that gives coefficients capable of modeling the signal and noise. Subtraction of the predicted noise from the observed data produces data with amplitude-preserved reflections. We develop this technique on synthetic and field data contaminated by weak and strong ground roll noise. Compared to conventional Fourier filtering techniques, our method accurately removes the ground roll while preserving the amplitude of the signal.

Download Full-text

APPLICATION OF THE EMPIRICAL MODE DECOMPOSITION METHOD TO GROUND-ROLL NOISE ATTENUATION IN SEISMIC DATA

Brazilian Journal of Geophysics ◽

10.22564/rbgf.v31i4.342 ◽

2013 ◽

Vol 31 (4) ◽

pp. 619 ◽

Cited By ~ 1

Author(s):

Luiz Eduardo Soares Ferreira ◽

Milton José Porsani ◽

Michelângelo G. Da Silva ◽

Giovani Lopes Vasconcelos

Keyword(s):

Empirical Mode Decomposition ◽

Seismic Data ◽

Low Frequency ◽

High Amplitude ◽

Seismic Line ◽

Seismic Processing ◽

Mode Decomposition ◽

Ground Roll ◽

Fortran 90 ◽

Emd Method

ABSTRACT. Seismic processing aims to provide an adequate image of the subsurface geology. During seismic processing, the filtering of signals considered noise is of utmost importance. Among these signals is the surface rolling noise, better known as ground-roll. Ground-roll occurs mainly in land seismic data, masking reflections, and this roll has the following main features: high amplitude, low frequency and low speed. The attenuation of this noise is generally performed through so-called conventional methods using 1-D or 2-D frequency filters in the fk domain. This study uses the empirical mode decomposition (EMD) method for ground-roll attenuation. The EMD method was implemented in the programming language FORTRAN 90 and applied in the time and frequency domains. The application of this method to the processing of land seismic line 204-RL-247 in Tacutu Basin resulted in stacked seismic sections that were of similar or sometimes better quality compared with those obtained using the fk and high-pass filtering methods.Keywords: seismic processing, empirical mode decomposition, seismic data filtering, ground-roll. RESUMO. O processamento sísmico tem como principal objetivo fornecer uma imagem adequada da geologia da subsuperfície. Nas etapas do processamento sísmico a filtragem de sinais considerados como ruídos é de fundamental importância. Dentre esses ruídos encontramos o ruído de rolamento superficial, mais conhecido como ground-roll . O ground-roll ocorre principalmente em dados sísmicos terrestres, mascarando as reflexões e possui como principais características: alta amplitude, baixa frequência e baixa velocidade. A atenuação desse ruído é geralmente realizada através de métodos de filtragem ditos convencionais, que utilizam filtros de frequência 1D ou filtro 2D no domínio fk. Este trabalho utiliza o método de Decomposição em Modos Empíricos (DME) para a atenuação do ground-roll. O método DME foi implementado em linguagem de programação FORTRAN 90, e foi aplicado no domínio do tempo e da frequência. Sua aplicação no processamento da linha sísmica terrestre 204-RL-247 da Bacia do Tacutu gerou como resultados, seções sísmicas empilhadas de qualidade semelhante e por vezes melhor, quando comparadas as obtidas com os métodos de filtragem fk e passa-alta.Palavras-chave: processamento sísmico, decomposição em modos empíricos, filtragem dados sísmicos, atenuação do ground-roll.

Download Full-text

Seismic reflection test on the granite of the Skye Tertiary igneous centre

Geological Magazine ◽

10.1017/s0016756800021804 ◽

1992 ◽

Vol 129 (5) ◽

pp. 633-636 ◽

Cited By ~ 7

Author(s):

N. R. Goulty ◽

M. Leggett ◽

T. Douglas ◽

C. H. Emeleus

Keyword(s):

Seismic Data ◽

Seismic Reflection ◽

Intrusive Complex ◽

Gravity Modelling ◽

Test Location ◽

Basic Rocks

AbstractWe have conducted a seismic reflection test over a short profile on the granite of the Skye Tertiary central intrusive complex. From previous gravity modelling work it had been inferred that the granite is approximately 1.5 km thick and overlies basic rocks. The seismic data indicate that the granite is at least 2 km thick at the test location. Reflection events of alternating polarity between depths of 2.1 and 2.4 km suggest that basic and acidic sheets are interlayered at the base of the granitic mass.

Download Full-text

Recording seismic reflections using rigidly interconnected geophones

Geophysics ◽

10.1190/1.1487126 ◽

2001 ◽

Vol 66 (6) ◽

pp. 1838-1842 ◽

Cited By ~ 6

Author(s):

C. M. Schmeissner ◽

K. T. Spikes ◽

D. W. Steeples

Keyword(s):

Wave Propagation ◽

Data Acquisition ◽

Seismic Reflection ◽

Spatial Sampling ◽

P Wave ◽

Signal Distortion ◽

Reflection And Refraction ◽

First Arrival ◽

The Cost ◽

Seismic Reflections

Ultrashallow seismic reflection surveys require dense spatial sampling during data acquisition, which increases their cost. In previous efforts to find ways to reduce these costs, we connected geophones rigidly to pieces of channel iron attached to a farm implement. This method allowed us to plant the geophones in the ground quickly and automatically. The rigidly interconnected geophones used in these earlier studies detected first‐arrival energy along with minor interfering seismic modes, but they did not detect seismic reflections. To examine further the feasibility of developing rigid geophone emplacement systems to detect seismic reflections, we experimented with four pieces of channel iron, each 2.7 m long and 10 cm wide. Each segment was equipped with 18 geophones rigidly attached to the channel iron at 15‐cm intervals, and the spikes attached to all 18 geophones were pushed into the ground simultaneously. The geophones detected both refracted and reflected energy; however, no significant signal distortion or interference attributable to the rigid coupling of the geophones to the channel iron was observed in the data. The interfering seismic modes mentioned from the previous experiments were not detected, nor was any P‐wave propagation noted within the channel iron. These results show promise for automating and reducing the cost of ultrashallow seismic reflection and refraction surveys.

Download Full-text

LONG-PERIOD SURFACE-RELATED MULTIPLE SUPPRESSION IN 2D MARINE SEISMIC DATA USING PREDICTIVE DECONVOLUTION AND COMBINATION OF SURFACE-RELATED MULTIPLE ELIMINATION AND PARABOLIC RADON FILTERING

10.32008/geolinks2021/b1/v3/30 ◽

2021 ◽

Author(s):

Pimpawee Sittipan ◽

Pisanu Wongpornchai

Keyword(s):

Seismic Data ◽

Seismic Reflection ◽

Petroleum Reservoirs ◽

The United States ◽

Multiple Reflections ◽

Long Period ◽

Predictive Deconvolution ◽

Short Period ◽

Marine Seismic ◽

Multiple Elimination

Some of the important petroleum reservoirs accumulate beneath the seas and oceans. Marine seismic reflection method is the most efficient method and is widely used in the petroleum industry to map and interpret the potential of petroleum reservoirs. Multiple reflections are a particular problem in marine seismic reflection investigation, as they often obscure the target reflectors in seismic profiles. Multiple reflections can be categorized by considering the shallowest interface on which the bounces take place into two types: internal multiples and surface-related multiples. Besides, the multiples can be categorized on the interfaces where the bounces take place, a difference between long-period and short-period multiples can be considered. The long-period surface-related multiples on 2D marine seismic data of the East Coast of the United States-Southern Atlantic Margin were focused on this research. The seismic profile demonstrates the effectiveness of the results from predictive deconvolution and the combination of surface-related multiple eliminations (SRME) and parabolic Radon filtering. First, predictive deconvolution applied on conventional processing is the method of multiple suppression. The other, SRME is a model-based and data-driven surface-related multiple elimination method which does not need any assumptions. And the last, parabolic Radon filtering is a moveout-based method for residual multiple reflections based on velocity discrimination between primary and multiple reflections, thus velocity model and normal-moveout correction are required for this method. The predictive deconvolution is ineffective for long-period surface-related multiple removals. However, the combination of SRME and parabolic Radon filtering can attenuate almost long-period surface-related multiple reflections and provide a high-quality seismic images of marine seismic data.

Download Full-text