69th EAGE Conference and Exhibition - Workshop Package

Workshop 8 The seislet transform and seislet frames Sergey Fomel (University of Texas at Austin) SUMMARY____________________________________________________________ I introduce the seislet transform: a digital wavelet-like transform tailored specifically for representing seismic data. The transform provides a multiscale orthogonal basis with basis functions aligned along seismic event slopes in the input data. In the case of multiple conflicting slopes the basis decomposition can be replaced with a frame composed of different bases. I define seislets with the help of the wavelet lifting scheme combined with local plane-wave destruction. The main objective is an optimal seismic data compression for designing efficient algorithms. Many

Seismic Data Analysis With Dual-Tree M-Band Wavelet Transforms Laurent Duval (Institut Français du Pétrole (IFP)) Caroline Chaux (ARIANA research group) and Stéphan Ker (IFREMER Marine Geosciences Department) SUMMARY____________________________________________________________ The complexity of seismic data still challenges signal processing algorithms in several applications. The rediscovery of wavelet transforms by J.Morlet et al. has allowed improvements in addressing several data representation (local analysis compression) and restoration problems. However despites their achievements traditional approaches based on discrete and separable (both for computational purposes) wavelets fail at efficiently representing directional or higher dimensional data features such as line or plane singularities especially in severe noise

Curvelet reconstruction with sparsity-promoting inversion:successes and challenges Gilles Hennenfent (Seismic Laboratory for Imaging and Modeling Department of Earth and Ocean Sciences The University of British Columbia) and Felix J. Herrmann (Seismic Laboratory for Imaging and Modeling Department of Earth and Ocean Sciences The University of British Columbia) SUMMARY____________________________________________________________ In this overview of the recent Curvelet Reconstruction with Sparsity-promoting Inversion (CRSI) method we present our latest 2-D and 3-D interpolation results on both synthetic and real datasets. We compare these results to interpolated data using other existing methods. Finally we discuss the challenges related to sparsity-promoting solvers for the large-scale problems

Just diagonalize: a curvelet-based approach to seismic amplitude recovery Felix J. Herrmann (Seismic Laboratory for Imaging and Modeling Department of Earth and Ocean Sciences The University of British Columbia) and Peyman Moghaddam (Seismic Laboratory for Imaging and Modeling Department of Earth and Ocean Sciences The University of British Columbia) SUMMARY____________________________________________________________ In this presentation we present a nonlinear curvelet-based sparsity-promoting formulation for the recovery of seismic amplitudes. We show that the curvelet’s wavefront detection capability and invariance under wave propagation lead to a formulation of this recovery problem that is stable under noise and missing data. EAGE 69 th Conference &

Seismic migration using the complex shiftable Pyramid Truong Nguyen (Ecole des Mines de Paris) and Hervé Chauris (Ecole des Mines de Paris) SUMMARY____________________________________________________________ We consider how the 2-D seismic Kirchhoff migration scheme can benefit from a recently introduced shiftable directional pyramid. First the pyramidal dual-tree directional filter bank is presented with some modifications to make it more suitable to the seismic migration problem. Since the decomposition by this filter bank is multiresolution and multidirectional it can be regarded as a digital curvelet transform. We implement the first-order approximation of the Kirchhoff migration scheme. It essentially consists of a rotation a

Interactive seismic imaging by fast beam migration Fuchun Gao (CGGVeritas) Po Zhang (CGGVeritas) Bin Wang (CGGVeritas) Guillaume Thomas-Collignon (CGGVeritas) and Volker Dirks (CGGVeritas) SUMMARY____________________________________________________________ This paper presents a Fast Beam migration algorithm which has been specifically designed to facilitate very rapid migration turnarounds to allow for interactive velocity model building and validation. The very fast imaging turnaround is achieved by only migrating pre-picked events in a wavelet by wavelet fashion. Coherent noise and migration artifacts are reduced compared to classical Kirchhoff migration techniques by using a sophisticated event selection scheme during the event picking phase and by subsequent multi-path migration

Beamlet and Directional Wavelet: Phase-Space Localization and Wave Propagation Ru-Shan Wu (University of California) SUMMARY____________________________________________________________ First I review the development of beamlet decomposition and propagation in the framework of phase-space localization especially the space-wavenumber localization. Then the relation between the beamlet and the directional wavelet is discussed in the context of wave propagation. Beamlet and directional wavelet have the same capacity of representing phasespace localized wavefield due to the angle-wavenumber correspondence. Some examples of propagator decomposition and seismic imaging using local cosine beamlet propagator are given. EAGE 69 th Conference & Exhibition — London UK 11 - 14 June 2007

Trends in waterborne electrical and EM induction methods for high resolution sub-bottom imaging Karl E. Butler (University of New Brunswick) SUMMARY____________________________________________________________ Electrical and electromagnetic (EM) methods are used extensively for near-surface applications on land but their use on water remains relatively novel. Shallow water applications are becoming more common however as there has been growing recognition over the past five years of the useful information these methods can provide in groundwater hydrology sedimentology engineering and other fields. In many applications spatial variations in resistivity variations are useful as a proxy for variations in another bulk material property such as pore

EC Imaging of aquifers beneath watercourses of the Murray Darling Basin Australia David Allen (Groundwater Imaging Pty. Ltd.) and Torleif Dahlin (Teknisk Geologi Lunds Tekniska Högskola Lunds Universitet) SUMMARY____________________________________________________________ Electrical conductivity imaging of numerous rivers segments and canals of the Murray Darling Basin Australia has been conducted using both geo-electric arrays and transient electromagnetic devices towed along the watercourses. Permeable pathways beneath the watercourses are clearly evident due to fresh water moving downwards or saline water moving upwards through them. EC imaging is proving to be a very cost effective tool for managing saline inflow to rivers and seepage loss

Using Controlled Source EM Methods to Constrain Physical Properties of the Uppermost Seafloor: An Example of Instrumentation and a Case Study from a Gas Pock-Mark Offshore Ireland. Xavier Garcia (Dublin Institute for Advanced Studies (DIAS)) Rob. L. Evans (Dept of Geology and Geophysics Woods Hole Oceanographic Institution) and Xavier Monteys (Geological Survey of Ireland) SUMMARY____________________________________________________________ We discuss a towed frequency-domain magnetic-dipole electromagnetic (EM) system that is used to map the uppermost 20 m of seafloor in a variety of settings. To date the system has been used in water depths of ranging from 10-20m nearshore out to 1300 m on