A5023369313- Seismic Imaging and Inversion Techniques
- Seismic Waves and Analysis
- Geophysical Methods and Applications
- Drilling and Well Engineering
- Advanced Topics in Algebra
- Underwater Acoustics Research
- Algebraic structures and combinatorial models
- Medical Imaging Techniques and Applications
- Reservoir Engineering and Simulation Methods
- Nonlinear Waves and Solitons
- Geological and Geophysical Studies
- Geophysics and Sensor Technology
- Underwater Vehicles and Communication Systems
- Advanced Algebra and Geometry
- Hydraulic Fracturing and Reservoir Analysis
- Microwave Imaging and Scattering Analysis
- Acoustic Wave Resonator Technologies
- Seismology and Earthquake Studies
- NMR spectroscopy and applications
- Geophysical and Geoelectrical Methods
- Advanced X-ray and CT Imaging
Shell (Netherlands)
2000-2022
University of Illinois Urbana-Champaign
1993
Utrecht University
1992
Centrum Wiskunde & Informatica
1991
University of Amsterdam
1991
We considered the importance of low frequencies in seismic reflection data for enhanced resolution, better penetration, and waveform impedance inversion. reviewed various theoretical arguments underlining why adding may be beneficial provided experimental evidence improvements by several case studies with recently acquired broadband data. discussed where research development efforts industry respect to should focusing.
ABSTRACT Velocity model building and impedance inversion generally suffer from a lack of intermediate wavenumber content in seismic data. Intermediate wavenumbers may be retrieved directly data sets if enough low frequencies are recorded. Over the past years, improvements acquisition have allowed us to obtain with broader frequency spectrum. To illustrate benefits broadband acquisition, notably recording frequencies, we discuss land acquired Inner Mongolia, China. This set contains 1.5–80...
ABSTRACT Dense, wide‐aperture and broad frequency band acquisition improves seismic imaging potentially allows the use of full waveform inversion for velocity model building. The cost dense acquisitions however limits its applicability. Blended or simultaneous shooting could lead to a good compromise between acquisition, although cross‐talk sweeps may reduce capabilities. Onshore, is achieved with distance separated sweeping because shots are easily when processing focuses on pre‐critical...
In this paper, I will study a Kirchhoff-type integral, which can be seen as linear operator mapping angle–azimuth-dependent reflection coefficients along reflector into data for the acoustic wave equation. show that minor adaptation of construction images proposed by Sava and Fomel leads to left inverse operator, maps primary coefficients. The new naturally reformulation Kirchhoff acting on space-shift-extended images, implemented completely in terms fundamental solutions composition...
Summary Seismic acquisition is never perfect, and sparsity irregularity issues lead to suboptimal images when using standard seismic imaging schemes. The remedy of Least-Squares Migration has been topic research since the early eighties, but take-up in industry limited so far. This paper describes experiences obtained for a number real data cases, which show that method does deliver worth extra cost effort.
We present a reflection angle- and azimuth-dependent least-squares reverse-time migration (LSRTM) method aimed at obtaining physically meaningful subsurface seismic image amplitudes suitable for quantitative interpretation under complex overburdens. The is formulated as linear inverse problem solved iteratively with the Conjugate Gradient method. It requires an adjoint pair of operators angle/azimuth-dependent demigration based on full wave-equation propagation. implement these in efficient...
We have determined the potential of elastic full-waveform inversion (FWI) to overcome some difficult challenges in onshore seismic imaging. The approach allows for simultaneous surface and body waves and, theoretically, is free from limitations traditional dispersion curve analysis traveltime inversion. Indeed, identification separation different wavefield types are not required, all wave can be treated within a unified scheme. However, FWI requires reasonably good initial model, sensitivity...
Abstract This paper introduces an operator, which extends the Born operator for linearized variable density acoustic wave equation. Inspired by angle dependent scattering, I will define it as acting on distributions depending space and coordinates. show that can be written a weighted integral of space-shift extended operators associated to arbitrary directions after suitable coordinate transform. also formulate conditions under its normal is pseudo-differential operator. These seen less...
We give an explicit description of the Kac-Peterson-Lepowsky constr tion basic representation for affine Lie algebra sˆo2n(C). Using conjugacy classes Weyl group sˆo2n(C), we describe all equivalent maximal Heisenberg subalgebras (HSA's) correspond: algebra. associate to these HSA's multicomponent charged and neutral free fermionic fields. The boson-fermion correspondence fields provides us with vertex operators, whose 'norr, ordered products' (twisted) operators Kac-Peters( Lepowsky construction.
Summary We describe the physical principles underlying a new type of marine seismic source, so-called Tuned Pulse Source and show that it generates more low frequency less spurious high content than conventional airgun arrays. The enhanced is attractive for exploration. reduced leads to lower environmental impact. measurements on prototype such source model its relevance Full Waveform Inversion.
A new pneumatic seismic source with a resonance frequency of 2.8 Hz has been built and tested during an OBN sea trial in the Gulf Mexico. Data from demonstrates that low refracted signal can be recorded for offsets up to at least 45 km. The is very much improved compared data array conventional airguns.
Attenuation of non-compressional energy, such as shear body waves and scattered surface waves, is a critical step in the processing ocean bottom node seismic data, because this unwanted energy interferes with desired compressional signals. In paper, we first review conventional methods for attenuating vertical geophone recordings, including cooperative denoising procedures adaptive subtraction techniques. We then introduce use rotational measurements from new type attenuation energy. Our...
In this paper, we report a new implementation of joint leastsquares migration (LSM) in time-lapse (4D) imaging. As previous work, invert baseline and monitor reflectivities simultaneously. Instead promoting the sparsity signal, use structure compliant constraint term LSM objective function, assuming that majority signal is due to rock fluid pressure or saturation changes such conform spatially with geological structures. Using synthetic real data examples demonstrate produces superior...
Summary In this paper, results from a field trial using novel 20,600 cui TPS source are described. During trial, data was acquired different firing pressures and depths. An analysis is provided showing the dependence of low frequency radiation on volume, pressure depth.
PreviousNext No AccessSEG Technical Program Expanded Abstracts 2000Automatic crosswell tomography by differential semblance optimizationAuthors: René‐Edouard PlessixFons ten KroodeWim MulderRené‐Edouard PlessixShell Int'l E&P, Fons KroodeShell and Wim MulderShell E&Phttps://doi.org/10.1190/1.1815908 SectionsAboutPDF/ePub ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinked InRedditEmail Permalink:...
Summary Onshore, the application of full waveform inversion (FWI) for imaging is challenged by surface waves. Commonly, after their removal, it possible to approximate background velocities inverting diving/transmitted waves with low-frequency, wide-angle seismic data. However, provide information on near that difficult obtain from body A straight forward an elastic FWI land data solely focuses interpreting more pronounced energy footprints. In this study, we tested approach based...
Summary In this abstract, we discuss an elastic full waveform inversion approach to estimate high resolution shallow subsurface parameters from both surface and body waves in onshore seismic data. We have used a spacetime domain weighting function balance the amplitudes of dominant with respect other waves. This allows us simultaneous extract information refracted reflected/converted The different wave types are complimentary terms depth wavenumber information. concept results illustrated...
Summary We have tested a new marine source whose initial volume of up to 100 times the conventional airgun produces low-frequency bubble oscillations with resonance in order 3 Hz. The resulting improvement low frequency output is 40 dB when compared single airgun, without any increase peak pressure and significant reduction slope pressure. A correction procedure for effect rising was developed, yielding improved correlation between observed well-known Rayleigh-Willis scaling. data from...
Following a series of field tests, low frequency acquisition and processing Full Waveform Inversion techniques have been applied successfully in 3D, long offset, Wide Azimuth surveys from the Middle East. The testing evolved downhole vibrator sweeps to an extensive high channel count 2D line test. development has accompanied by maturation techniques, eventually leading quality velocity model estimates for state art onshore data.