Case history: Seismic array length comparison in Eastern Desert, Egypt, or how to get high‐resolution seismic data and not worry about ground roll

1987 ◽  
Author(s):  
Norman I. Mark ◽  
Darko Tufekcic
Keyword(s):  
High Resolution ◽  
Case History ◽  
Seismic Data ◽  
Eastern Desert ◽  
Seismic Array ◽  
Ground Roll

scholarly journals Imaging Complex Subsurface Structures for Geothermal Exploration at Pirouette Mountain and Eleven-Mile Canyon in Nevada

2021 ◽  
Vol 9 ◽  
Author(s):  
Yunsong Huang ◽  
Miao Zhang ◽  
Kai Gao ◽  
Andrew Sabin ◽  
Lianjie Huang
Keyword(s):  
High Resolution ◽  
Least Squares ◽  
Seismic Data ◽  
Seismic Wave Propagation ◽  
Reverse Time ◽  
Reverse Time Migration ◽  
Geothermal Exploration ◽  
Subsurface Structures ◽  
Time Migration ◽  
Ground Roll

Accurate imaging of subsurface complex structures with faults is crucial for geothermal exploration because faults are generally the primary conduit of hydrothermal flow. It is very challenging to image geothermal exploration areas because of complex geologic structures with various faults and noisy surface seismic data with strong and coherent ground-roll noise. In addition, fracture zones and most geologic formations behave as anisotropic media for seismic-wave propagation. Properly suppressing ground-roll noise and accounting for subsurface anisotropic properties are essential for high-resolution imaging of subsurface structures and faults for geothermal exploration. We develop a novel wavenumber-adaptive bandpass filter to suppress the ground-roll noise without affecting useful seismic signals. This filter adaptively exploits both characteristics of the lower frequency and the smaller velocity of the ground-roll noise than those of the signals. Consequently, this filter can effectively differentiate the ground-roll noise from the signal. We use our novel filter to attenuate the ground-roll noise in seismic data along five survey lines acquired by the U.S. Navy Geothermal Program Office at Pirouette Mountain and Eleven-Mile Canyon in Nevada, United States. We then apply our novel anisotropic least-squares reverse-time migration algorithm to the resulting data for imaging subsurface structures at the Pirouette Mountain and Eleven-Mile Canyon geothermal exploration areas. The migration method employs an efficient implicit wavefield-separation scheme to reduce image artifacts and improve the image quality. Our results demonstrate that our wavenumber-adaptive bandpass filtering method successfully suppresses the strong and coherent ground-roll noise in the land seismic data, and our anisotropic least-squares reverse-time migration produces high-resolution subsurface images of Pirouette Mountain and Eleven-Mile Canyon, facilitating accurate fault interpretation for geothermal exploration.

Case history: Seismic exploration in Egypt’s Eastern Desert

Geophysics ◽  
1992 ◽  
Vol 57 (2) ◽  
pp. 296-305 ◽  
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.

A high-density, high-resolution joint 3D VSP–3D surface seismic case study in the Canadian oil sands

2019 ◽  
Vol 38 (1) ◽  
pp. 35-44
Author(s):  
Sylvestre Charles ◽  
Jiwu Lin ◽  
Rick Kuzmiski ◽  
Philip Leung ◽  
Ahmed Mouaki ◽  
...  
Keyword(s):  
High Resolution ◽  
Case History ◽  
Seismic Data ◽  
Oil Sands ◽  
Velocity Model ◽  
High Density ◽  
Initial Time ◽  
Time Processing ◽  
3D Surface ◽  
Vsp Data

This Canadian oil sands case history illustrates how a high-density, high-resolution joint 3D vertical seismic profile (VSP)–3D surface seismic survey was designed, acquired, and processed to successfully meet the objective of obtaining a detailed image of the subsurface, including the cap rock, the internal architecture of the oil sands reservoir, the underlying carbonates, and the fault and fracture network that runs from surface to basement. The VSP-driven processing was essential in determining the effects of attenuation, multiples, and converted waves, and in quantifying the anisotropy for imaging and time-to-depth conversion. The joint 3D tomography inversion of the VSP and surface seismic data provided an accurate velocity model to migrate the 3D surface seismic data and the 3D VSP data in depth. Each of the 28 wells located within the survey area tied in to the final seismic volume very well. Depth imaging resolved the shallow velocity variations that the initial time processing could not. The apparent (but erroneous) azimuthal velocity effects in the time processing were minimized in the depth processing, resulting in an anisotropy velocity model that was in accordance with the 3D VSP data. A 3D full-waveform inversion test complemented this case history.

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

2013 ◽  
Vol 31 (4) ◽  
pp. 619 ◽  
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.

Pre-stack sea bottom detection and swell correction within an expected hyperbolic range for noisy high-resolution 8-channel airgun seismic data

2021 ◽  
Vol 42 (1) ◽  
Author(s):  
Ho-Young Lee ◽  
Nam-Hyung Koo ◽  
Byoung-Yeop Kim ◽  
Young-Jun Kim ◽  
Woohyun Son ◽  
...  
Keyword(s):  
High Resolution ◽  
Seismic Data ◽  
Sea Bottom

2D-3C high-resolution seismic data from the Abitibi Greenstone Belt, Canada

2009 ◽  
Vol 472 (1-4) ◽  
pp. 226-237 ◽  
Author(s):  
David B. Snyder ◽  
Peter Cary ◽  
Matt Salisbury
Keyword(s):  
High Resolution ◽  
Seismic Data ◽  
Greenstone Belt ◽  
Abitibi Greenstone Belt
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