Fine-scale velocity distribution revealed by datuming of very-high-resolution deep-towed seismic data: Example of a shallow-gas system from the western Black Sea

Very-high-resolution (VHR) marine seismic reflection helps to identify and characterize potential geohazards occurring in the upper part (300 m) of the subseafloor. Although the lateral and vertical resolutions achieved in shallow water depths ([Formula: see text]) using conventional surface-towed technology are adequate, these resolutions quickly deteriorate at greater water depths. The SYstème SIsmique de Fond (SYSIF), a multichannel deep-towed seismic system, has been designed to acquire VHR data (frequency bandwidth [220–1050 Hz] and vertical resolution of 0.6 m) at great water depths. However, the processing of deep-towed multichannel data is challenging because the source and the receivers are constantly moving with respect to each other according to the towing configuration. We have introduced a new workflow that allows the application of conventional processing algorithms to extended deep-towed seismic data sets. First, a relocation of the source and receivers is necessary to obtain a sufficiently accurate acquisition geometry. Variations along the profile in the depth of the deep-towed system result in a complex geometry in which the source and receiver depth vary separately and do not share the same acquisition datum. We have designed a dedicated datuming algorithm to shift the source and receivers to the same datum. Thus, the procedure allows the application of conventional processing algorithms to perform velocity analysis and depth imaging and therefore allows access to the full potential of the seismic system. We have successfully applied this methodology to deep-towed multichannel data from the western Black Sea. In particular, the derived velocity model highlights shallow gas charged anticline structures with unrivaled resolution.

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Very high-resolution seismic mapping of shallow gas in the Belgian coastal zone

Continental Shelf Research ◽

10.1016/s0278-4343(02)00056-0 ◽

2002 ◽

Vol 22 (16) ◽

pp. 2291-2301 ◽

Cited By ~ 58

Author(s):

T Missiaen ◽

S Murphy ◽

L Loncke ◽

J.-P Henriet

Keyword(s):

High Resolution ◽

Coastal Zone ◽

Shallow Gas ◽

Very High

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Basins Analysis and Petroleum Systems Modeling of Western Black Sea, Ukrainian Sector

10.2118/208527-ms ◽

2021 ◽

Author(s):

Ivan Karpenko ◽

Ihor Ischenko ◽

Olha Nikolenko ◽

Felipe Rodrigues ◽

Serhii Levonyuk ◽

...

Keyword(s):

Black Sea ◽

Seismic Data ◽

Basin Analysis ◽

Systems Modeling ◽

Analysis Program ◽

Biogenic Gas ◽

Petroleum Systems ◽

Ranking Procedures ◽

New Generation ◽

Water Depths

Abstract The Ukrainian sector of the Western Black Sea (WBS) is one of the last remaining exploration frontiers in Europe. This area, which includes shelf to deepwater environments, is underexplored with no drilling of targets in water depths exceeding 100 meters. That is why, the Ukrainian sector of the WBS is attractive for exploration, especially in the context of new play types and targets such as biogenic gas. These hydrocarbon formations have been proven by neighboring Romania and Turkey in the areas adjacent to Ukrainian waters. Therefore, a rigorous Basin Analysis program has been initiated to assess the petroleum systems and play risks in the entire Ukrainian sector of the WBS. The goals of this program are: 1) to establish a regional geoscience foundation following best industrial practices in exploration; 2) to enable establishing more accurate risking and ranking procedures for an exploration portfolio and 3) to provide critical support for the analysis of a new generation of seismic data that is currently being acquired. In this paper the initial scope of work is presented.

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Use of fast simple migration processing for very high resolution seismic data

56th EAEG Meeting ◽

10.3997/2214-4609.201409992 ◽

1994 ◽

Cited By ~ 3

Author(s):

G. Lericolais ◽

M. Olagnon ◽

S. Berne

Keyword(s):

High Resolution ◽

Seismic Data ◽

Very High

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Processing Workflow for the Dynamic Interpretation of Very-high-resolution P-wave Seismic Data

Near Surface Geoscience 2016 - Second Applied Shallow Marine Geophysics Conference ◽

10.3997/2214-4609.201602154 ◽

2016 ◽

Cited By ~ 2

Author(s):

R. Isaenkov ◽

A.I. Ponimaskin ◽

M.J. Tokarev

Keyword(s):

High Resolution ◽

Seismic Data ◽

P Wave ◽

Dynamic Interpretation ◽

Very High

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Analysis of Holocene sedimentary features on the Adriatic shelf from 3D very high resolution seismic data (Triad survey)

Marine Geology ◽

10.1016/j.margeo.2004.10.002 ◽

2004 ◽

Vol 213 (1-4) ◽

pp. 73-89 ◽

Cited By ~ 18

Author(s):

T. Marsset ◽

B. Marsset ◽

Y. Thomas ◽

A. Cattaneo ◽

E. Thereau ◽

...

Keyword(s):

High Resolution ◽

Seismic Data ◽

Very High

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The Celtic Sea banks: an example of sand body analysis from very high-resolution seismic data

Marine Geology ◽

10.1016/s0025-3227(98)00188-1 ◽

1999 ◽

Vol 158 (1-4) ◽

pp. 89-109 ◽

Cited By ~ 20

Author(s):

T Marsset ◽

B Tessier ◽

J.-Y Reynaud ◽

M De Batist ◽

C Plagnol

Keyword(s):

High Resolution ◽

Seismic Data ◽

Sand Body ◽

Celtic Sea ◽

Very High

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New Insights in Shallow Gas Generation from Very High Resolution Seismic and Bathymetric Surveys in the Marennes-Oléron Bay, France

Marine Geophysical Research ◽

10.1007/s11001-005-3720-y ◽

2005 ◽

Vol 26 (2-4) ◽

pp. 225-233 ◽

Cited By ~ 14

Author(s):

Xavier Bertin ◽

Eric Chaumillon

Keyword(s):

High Resolution ◽

Gas Generation ◽

Shallow Gas ◽

Very High

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Coastal flooding of urban areas by overtopping: dynamic modelling application to the Johanna storm (2008) in Gâvres (France)

Natural Hazards and Earth System Science ◽

10.5194/nhess-15-2497-2015 ◽

2015 ◽

Vol 15 (11) ◽

pp. 2497-2510 ◽

Cited By ~ 31

Author(s):

S. Le Roy ◽

R. Pedreros ◽

C. André ◽

F. Paris ◽

S. Lecacheux ◽

...

Keyword(s):

High Resolution ◽

Urban Area ◽

Urban Areas ◽

Digital Terrain Model ◽

Time Dependent ◽

Shock Capturing ◽

Terrain Model ◽

Digital Terrain ◽

Very High ◽

Water Depths

Abstract. Recent dramatic events have allowed significant progress to be achieved in coastal flood modelling over recent years. Classical approaches generally estimate wave overtopping by means of empirical formulas or 1-D simulations, and the flood is simulated on a DTM (digital terrain model), using soil roughness to characterize land use. The limits of these methods are typically linked to the accuracy of overtopping estimation (spatial and temporal distribution) and to the reliability of the results in urban areas, which are places where the assets are the most crucial. This paper intends to propose and apply a methodology to simulate simultaneously wave overtopping and the resulting flood in an urban area at a very high resolution. This type of 2-D simulation presents the advantage of allowing both the chronology of the storm and the particular effect of urban areas on the flows to be integrated. This methodology is based on a downscaling approach, from regional to local scales, using hydrodynamic simulations to characterize the sea level and the wave spectra. A time series is then generated including the evolutions of these two parameters, and imposed upon a time-dependent phase-resolving model to simulate the overtopping over the dike. The flood is dynamically simulated directly by this model: if the model uses adapted schemes (well balanced, shock capturing), the calculation can be led on a DEM (digital elevation model) that includes buildings and walls, thereby achieving a realistic representation of the urban areas. This methodology has been applied to an actual event, the Johanna storm (10 March 2008) in Gâvres (South Brittany, in western France). The use of the SURF-WB model, a very stable time-dependent phase-resolving model using non-linear shallow water equations and well-balanced shock-capturing schemes, allowed simulating both the dynamics of the overtopping and the flooding in the urban area, taking into account buildings and streets thanks to a very high resolution (1 m). The results obtained proved to be very coherent with the available reports in terms of overtopping sectors, flooded area, water depths and chronology. This method makes it possible to estimate very precisely not only the overtopping flows, but also the main characteristics of flooding in a complex topography like an urban area, and indeed the hazard at a very high resolution (water depths and vertically integrated current speeds). The comparison with a similar flooding simulation using a more classical approach (a digital terrain model with no buildings, and a representation of the urban area by an increased soil roughness) has allowed the advantages of an explicit representation of the buildings and the streets to be identified: if, in the studied case, the impact of the urbanization representation on water levels does indeed remain negligible, the flood dynamics and the current speeds can be considerably underestimated when no explicit representation of the buildings is provided, especially along the main streets. Moreover, on the seaside, recourse to a time-dependent phase-resolving model using non-stationary conditions allows a better representation of the flows caused by overtopping. Finally, this type of simulation is shown to be of value for hazard studies, thanks to the high level of accuracy of the results in urban areas where assets are concentrated. This methodology, although it is currently still quite difficult to implement and costly in terms of calculation time, can expect to be increasingly resorted to in years to come, thanks to the recent developments in wave models and to the increasing availability of LiDAR data.

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