scholarly journals Pre-stack full waveform inversion of ultra-high-frequency marine seismic reflection data

2017 ◽  
Vol 209 (3) ◽  
pp. 1593-1611 ◽  
Author(s):  
Giuseppe Provenzano ◽  
Mark E. Vardy ◽  
Timothy J. Henstock
Keyword(s):  
High Frequency ◽  
Seismic Reflection ◽  
Waveform Inversion ◽  
Full Waveform Inversion ◽  
Seismic Reflection Data ◽  
Ultra High Frequency ◽  
Reflection Data ◽  
Full Waveform ◽  
Marine Seismic

scholarly journals Time-lapse imaging using 3D ultra-high-frequency marine seismic reflection data

Geophysics ◽  
2020 ◽  
Vol 85 (2) ◽  
pp. P13-P25
Author(s):  
Michael J. Faggetter ◽  
Mark E. Vardy ◽  
Justin K. Dix ◽  
Jonathan M. Bull ◽  
Timothy J. Henstock
Keyword(s):  
High Frequency ◽  
Seismic Reflection ◽  
High Tide ◽  
Time Lapse ◽  
Data Set ◽  
Seismic Reflection Data ◽  
Near Surface ◽  
Ultra High Frequency ◽  
Reflection Data ◽  
Marine Seismic

Time-lapse (4D) seismic imaging is now widely used as a tool to map and interpret changes in deep reservoirs as well as investigate dynamic, shallow hydrological processes in the near surface. However, there are very few examples of time-lapse analysis using ultra-high-frequency (UHF; kHz range) marine seismic reflection data. Exacting requirements for navigation can be prohibitive for acquiring coherent, true-3D volumes. Variable environmental noise can also lead to poor amplitude repeatability and make it difficult to identify differences that are related to real physical changes. Overcoming these challenges opens up a range of potential applications for monitoring the subsurface at decimetric resolution, including geohazards, geologic structures, as well as the bed-level and subsurface response to anthropogenic activities. Navigation postprocessing was incorporated to improve the acquisition and processing workflow for the 3D Chirp subbottom profiler and provide stable, centimeter-level absolute positioning, resulting in well-matched 3D data and mitigating 4D noise for data stacked into [Formula: see text] common-midpoint bins. Within an example 4D data set acquired on the south coast of the UK, interpretable differences are recorded within a shallow gas blanket. Reflections from the top and bottom of a gas pocket are imaged at low tide, whereas at high tide only the upper reflection is imaged. This case study demonstrates the viability of time-lapse UHF 3D seismic reflection for quantitative mapping of decimeter-scale changes within the shallow marine subsurface.

scholarly journals Characterization of shallow overpressure in consolidating submarine slopes via seismic full waveform inversion

2020 ◽  
Vol 53 (3) ◽  
pp. 366-377 ◽  
Author(s):  
Giuseppe Provenzano ◽  
Antonis Zervos ◽  
Mark E. Vardy ◽  
Timothy J. Henstock
Keyword(s):  
Pore Pressure ◽  
Seismic Reflection ◽  
Mass Movement ◽  
Waveform Inversion ◽  
P Wave ◽  
Excess Pore Pressure ◽  
Full Waveform Inversion ◽  
Seismic Reflection Data ◽  
Reflection Data ◽  
Full Waveform

Pore pressures higher than hydrostatic correspond to localized reductions of the level of shear stress required to induce lateral mass movement in a slope, and therefore play a key role in preconditioning submarine landsliding. In this paper, we investigate whether multi-channel seismic reflection data can be used to infer potentially destabilizing pore-pressure levels at a resolution and sensitivity useful for in-situ slope stability characterization. We simulate the continuous deposition of sediment on consolidating slopes in two scenarios, with combinations of sedimentation rate and permeability distribution leading to disequilibrium compaction. Ultra-high-frequency (UHF; 0.2–2.5 kHz) seismic reflection data are computed for each model and a stochastic full waveform inversion (FWI) method is used to retrieve the sub-seabed properties from the computed seismograms. These are then interpreted as time–depth variations in the effective stress (σʹ) regime, and therefore local overpressure ratio and factor of safety, using a combination of p-wave velocity to σʹ transforms. The results demonstrate that multi-channel UHF seismic data can provide valuable constraints on the distribution of physical properties in the top 50 m below seabed at a sub-metric scale, and with a sensitivity useful to infer destabilizing excess pore pressure levels.Thematic collection: This article is part of the Measurement and monitoring collection available at: https://www.lyellcollection.org/cc/measurement-and-monitoring

Stereotomography

Geophysics ◽  
2008 ◽  
Vol 73 (5) ◽  
pp. VE25-VE34 ◽  
Author(s):  
Gilles Lambaré
Keyword(s):  
Seismic Reflection ◽  
Waveform Inversion ◽  
Data Cube ◽  
Three Dimensions ◽  
Seismic Reflection Data ◽  
Depth Imaging ◽  
Traveltime Tomography ◽  
Reflection Data ◽  
Full Waveform ◽  
Efficiency And Reliability

Stereotomography was proposed [Formula: see text] ago for estimating velocity macromodels from seismic reflection data. Initially, the goal was to retain the advantages of standard traveltime tomography while providing an alternative to difficult interpretive traveltime picking. Stereotomography relies on the concept of locally coherent events characterized by their local slopes in the prestack data cube. Currently, stereotomography has been developed in two and three dimensions, and precious experience has been gained. The expected advantages have been demonstrated fully (in particular, the efficiency and reliability of the semiautomatic stereotomographic picking strategies), and further studies have increased the method’s potential and flexibility. For example, stereotomographic picking can now be done in either the prestack or poststack domain, in either the time (migrated or unmigrated) or depth domain. It appears that the theoretical frame of stereotomography can reconcile, very satisfactorily and efficiently, most methods proposed for velocity-macromodel estimation for depth imaging. Moreover, an extension of the method to full-waveform inversion already exists and opens the way for very interesting developments.

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