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69th EAGE Conference and Exhibition - Workshop Package
- Conference date: 11 Jun 2007 - 14 Jun 2007
- Location: London, UK
- ISBN: 978-94-6282-105-7
- Published: 10 June 2007
21 - 40 of 76 results
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Water bottom electrical tomography in the river Tiber
Authors L. Orlando and L. TramontiWATER BOTTOM ELECTRICAL TOMOGRAPHY IN THE RIVER TIBER Luciana Orlando (Dept. Idraulica Trasporti e Strade “La Sapienza University”) and Luigi Tramonti (Freelance researcher) SUMMARY____________________________________________________________ The paper deals with electrical tomography performed on the Tiber river bottom with the goal of reconstructing the setting of sediments and characterising their lithologies. The data were acquired by a cable lying along the river bottom equipped with 24 electrodes set 1m apart and with Wenner dipole-dipole and Schlumberger spreads. The efficiency of electrical tomography was validated with 1D theoretical modelling performed with finite differences algorithm. We have obtained to constrain the uncertainties in the
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Integration of high-resolution seismics and multi-offset GPR for shallow freshwater basins studies: a case history from the Cheko Lake area (Russia)
Authors M. Pipan, G. Dal Moro, E. Forte and L. GasperiniIntegration of high-resolution seismics and multioffset GPR for shallow freshwater basins studies: a case history from the Cheko Lake area (Russia) M.Pipan (University of Trieste) G. Dal Moro (University of Trieste) E.Forte (University of Trieste) L.Gasperini (ISMAR-Bologna) SUMMARY____________________________________________________________ This study focuses on the integration of linear multi-fold GPR techniques and High- Resolution Seismics to study the Cheko Lake area (101 o E 62 o N). Primary objectives of the study are acoustic and electromagnetic subsurface imaging in the offshore area and in the southern coastal sector and characterization of subsurface properties of the materials. Imaging and material characterization aim at
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Stream-Axis EM from a helicopter: identifying salinity sources in a large river basin
Authors J. G. Paine, E. W. Collins and H. S. NanceStream-Axis EM from a Helicopter: Identifying Salinity Sources in a Large River Basin Jeffrey G. Paine (Bureau of Economic Geology Jackson School of Geosciences The University of Texas at Austin) Edward W. Collins (Bureau of Economic Geology Jackson School of Geosciences The University of Texas at Austin) and H.S. Nance (Bureau of Economic Geology Jackson School of Geosciences The University of Texas at Austin) SUMMARY____________________________________________________________ We combined multifrequency airborne EM measurements of apparent ground conductivity with chemical analyses of surface water to delineate natural and oil-field salinity sources that degrade water quality in the upper Colorado River (western Texas U.S.A).
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GeoChirp 3D: high resolution 3D sub-bottom profiling
Authors M. Gutowski, J. M. Bull, J. K. Dix, T. J. Henstock, P. I. Hogarth and T. M. HillerGeoChirp 3D: High Resolution 3D Sub-Bottom Profiling Martin Gutowski (GeoAcoustics Ltd) Jon M. Bull (National Oceanography Centre) Justin K. Dix (National Oceanography Centre) Timothy J. Henstock (National Oceanography Centre) Peter I. Hogarth (GeoAcoustics Ltd) and Thomas M. Hiller (GeoAcoustics Ltd) SUMMARY____________________________________________________________ This article describes the concept of high resolution 3D sub-bottom profiling outlines the design and application of the GeoChirp 3D system and demonstrates its capabilities using a dataset imaging a buried cofferdam in the Port of Southampton (UK). EAGE 69 th Conference & Exhibition — London UK 11 - 14 June 2007 Introduction The hydrocarbon exploration industry has routinely
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High-resolution 2D deep-towed seismic system for shallow water surveying
Authors M. Tokarev, N. Kuzub and R. PevznerHigh-resolution 2D deep-towed seismic system for shallow water surveying Mikhail Tokarev (Lomonosov Moscow State University) Nikolay Kuzub (Lomonosov Moscow State University) and Roman Pevzner (Lomonosov Moscow State University) SUMMARY____________________________________________________________ Under certain conditions when it is needed to ensure high resolution (tens of cm) with relatively low penetration (10-15 m) at relatively deep water (tens of m) deep towed seismic systems have significant advantages comparing to the conventional seismic systems. These conditions are typical for inspection of sites for drilling platform construction as well as for lithological biological and environmental investigations etc. Deep-towed systems demonstrate robustness to rough weather conditions lower
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AVO analysis for the study of lacustrine sediments, in Lake Geneva, Switzerland
Authors D. Hammami and F. MarillierAVO analysis for the study of lacustrine sediments in Lake Geneva Switzerland D. Hammami and F. Marillier SUMMARY____________________________________________________________ A new system was developed to acquire 2D and 3D high-resolution seismic data in lakes. More than 400 km of 2D data and three 3D data volumes made it possible to study different features in Lake Geneva. To better understand the physical characteristics of sedimentary deposits in this lake we carried out a quantitative seismic analysis of our data. Accurate amplitude measurements were obtained after correction for the frequency response of the hydrophones that were individually calibrated. After amplitude preserving processing followed
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Shallow time slices from deep 3-D time slices: a new world discovered?
Authors B. F. Paap, J. H. Brouwer and S. van HeterenShallow time slices from deep 3-D time slices: a new world discovered? Bob F. Paap (TNO Built Environment and Geosciences – Geological Survey of the Netherlands) Jan H. Brouwer (TNO Built Environment and Geosciences – Geological Survey of the Netherlands) and Sytze van Heteren (TNO Built Environment and Geosciences – Geological Survey of the Netherlands) SUMMARY____________________________________________________________ In recent years shallow time slices of marine 3D-seismics acquired for petroleum-exploration purposes have been used to reconstruct paleolandscapes that are presently buried and submerged. These shallow time slices provide information on the distribution of various lithological units that are present in the upper
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UHR marine 3D seismic investigation of the Limantepe/Carantina Island archaeological sites (Urla/Turkey)
More LessUHR Marine 3D Seismic Investigation of the Limantepe/Carantina Island Archaeological Sites (Urla/Turkey) Christof Müller (Christian-Albrechts-University Kiel Germany) Susanne Woelz (Christian-Albrechts-University Kiel Germany) Tobias Jokisch (Christian-Albrechts-University Kiel Germany) Yasar Ersoy (Bilkent University Ankara Turkey) Gert Wendt (Rostock University Rostock Germany) and Wolfgang Rabbel (Christian-Albrechts-University Kiel Germany) SUMMARY____________________________________________________________ As part of the SEAMAP-3D project 2D and 3D high resolution seismic investigations of the Iskele (Limantepe and Necropolis) and Carantina Island shore areas were carried out in October 2006. Archaeological findings indicate that sea level change led to the submersion of man-made structures. Based on a 2D reconnaissance survey two areas were selected
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High-resolution seismic from LakeTana, Ethiopia
Authors C. R. Bates and D. HuwsHigh-resolution Seismic from LakeTana Ethiopia C. Richard Bates (University of St Andrews) and D. Huws (University of Wales) SUMMARY____________________________________________________________ Two high-resolution seismic surveys have recently been conducted at Lake Tana as part of a regional palaeo-climate study. Lake Tana the source of the Blue Nile is located in the Ethiopian Highlands and as the largest northern latitude sub-tropical lake in Africa it contains an important record of regional climate events. The lake is approximately 70km by 50km but has an average depth of only 8m. Seismic data acquired using both a Geoacoustics Chirp system and a Seistec Boomer showed an
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Seismic data acquisition in shallow water: A case history In The Venice Lagoon
Authors L. Baradello and F. DondaSeismic Data Acquisition In Shallow Water: A Case History in The Venice Lagoon Luca Baradello (Istituto Nazionale di Geofisica Sperimentale – OGS) and Federica Donda (Istituto Nazionale di Geofisica Sperimentale – OGS) SUMMARY____________________________________________________________ This work shows how is possible to collect High Resolution Seismic data in very shallow water with a boomer and a mono-channel streamer. Using mono-channel is necessary for improving Signal/Noise but in shallow water the aliasing ruins the signal. We tested a special acquisition geometry in which the streamer and the plate are towed on opposite sides (only lateral offset) behind the stern. In this case the
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Irregular sampling from aliasing to noise
More LessIrregular sampling from aliasing to noise G. Hennenfest (University of British Columbia) SUMMARY____________________________________________________________ EAGE 69 th Conference & Exhibition — London UK 11 - 14 June 2007 Adequate sampling of seismic data is traditionally understood as evenly-distributed time and space measurements of the reflected wavefield. Moreover the sampling rate along each axis must be equal to or above twice the highest frequency/wavenumber of the continuous signal being discretized (Shannon/Nyquist sampling theorem). In practice however seismic data is often irregularly and/or sparsely sampled along spatial coordinates which is generally considered as a nuisance since it breaks one or both previouslystated conditions
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Near Surface Noise Characterization With Multicomponent Measurements
Authors E. Kragh and E. MuyzertNear Surface Noise Characterization With Multicomponent Measurements Ed Kragh (Schlumberger Cambridge Research (SCR)) and Everhard Muyzert (Schlumberger Cambridge Research (SCR)) SUMMARY____________________________________________________________ On land the effect of the near-surface is the major cause of poor seismic data quality. Surface noise heterogeneity causing scattering statics coupling variations wavefield attenuation and anisotropy all degrade the quality of the wavefield recorded at the surface. To further improve the quality of land seismic data one approach is to gain a fundamental understanding of the wave propagation in the near-surface. As an example a consistent observation which requires explaining is the amount of cross-line energy recorded
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Noise Reduction in Land Seismic Acquisition by the use of High-fold, Multi-Component Single Point Sensors
By B. DonnellyNoise Reduction in Land Seismic Acquisition by the use of High-fold Multi-Component Single Point Sensors. Brian Donnelly (Input/Output UK Ltd) SUMMARY____________________________________________________________ We discuss how recent developments in seismic recording techniques can be used to dramatically improve noise attenuation in land seismic acquisition. The use of wireless technology allows for unrestricted fully-configurable survey geometries making super-high fold recording practical. The optimised orthogonal survey spread lends itself to the use of Offset Vector Tiling methods for geometry regularisation and enhanced seismic data processing. Married to the use of multi-component sensors this yields a full-wavefield image with data quality which has not been
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Attenuating the ice flexural wave on arctic seismic data
By D. C. HenleyAttenuating the ice flexural wave on arctic seismic data David C. Henley (CREWES) SUMMARY____________________________________________________________ Although providing good surface coupling for seismic surveying in the arctic floating ice also generates of one of the most powerful known coherent noises—the ice flexural wave. This set of modes is unique in its massive dispersion with the highest frequency energy propagating at near the ice compressional velocity and the lowest frequencies often moving at speeds well below air velocity. While its large dispersion makes the ice flexural wave difficult to attenuate using conventional techniques such as f-k filtering it suggests the use of the
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Improvements to Radon-based noise removal
By M. D. SacchiImprovements to Radon-based noise removal Mauricio D. Sacchi (Department of Physics University of Alberta) SUMMARY____________________________________________________________ I will discuss different strategies to improve the performance of Radon-based filtering with application to coherent noise removal. In particular I propose to combine multi-parameter Radon transforms (operators with more than one type of integration path) with filter banks. The latter significantly increases our ability to separate signal from coherent noise. I also examine new ways to gaining efficiency in the computation of time-variant Radon transforms. In particular time-variant multi-parameter Radon transforms can be quite demanding from the computational point of view when used for
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Examples of 3D Noise Attenuation Processes Applied to Land and OBC data
More LessExamples of 3D Noise Attenuation Processes Applied to Land and OBC data Simon Shaw (ConocoPhillips) Chuck Mosher (ConocoPhillips) Stephen Chiu (ConocoPhillips) Yunqin Shen (ConocoPhillips) Jack Howell (ConocoPhillips) and Mark Wuenscher (ConocoPhillips) SUMMARY____________________________________________________________ Land and ocean bottom seismic data can be readily acquired with wide azimuth acquisition geometries. The orthogonal cross spread has advantages for noise attenuation including that ground roll can be well sampled and these 3D gathers allow for the application of more powerful 3D processing algorithms. In this workshop we will present a variety of synthetic and field data results that compare and contrast some of these 3D
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A review of some powerful noise elimination techniques for Land Processing
Authors J. A. Stein and T. Langston“A review of some powerful noise elimination techniques for Land Processing” Jaime A. Stein (Geotrace Technologies Inc.) and Tom Langston (Geotrace Technologies Inc.) SUMMARY____________________________________________________________ As part of a successful processing project especially on land a proper suite of noise elimination techniques is paramount. The failure to eliminate or at least to reduce the effect of any of these noises can dramatically affect the outcome of the interpretation. Noises left in the data are virtually impossible to eliminate in the latter stages of processing and have devastating consequences for interpretation. We herby review three of the most used and successful technaiques
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Local Directional And Uncoherent Seismic Noise Filtering With Oversampled Filter Banks
Authors J. Gauthier, M-C. Cacas and L. DuvalLocal Directional And Uncoherent Seismic Noise Filtering With Oversampled Filter Banks Jérôme Gauthier (Institut Français du Pétrole (IFP)) Marie-Christine Cacas (Institut Français du Pétrole (IFP)) and Laurent Duval (Institut Français du Pétrole (IFP)) SUMMARY____________________________________________________________ Seismic data are subject to different kinds of unwanted perturbations. These random or organised noises which can be acquisition or processing related for instance may disturb geophysical interpretations and thwart attempts at automated processing methods. Since the relative features (e.g. amplitude spectrum) of the signals of interest and the noises may vary locally signal and noise separation is obtained by a local data-driven filtering with two
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Effective data denoising using new data driven and model driven algorithms
Authors M. Buia, E. Loinger and P. MarchettiEffective data denoising using new data driven and model driven algorithms Michele Buia (Eni) Eugenio Loinger (Eni) and Paolo Marchetti (Eni) SUMMARY____________________________________________________________ The noise problem in land seismic is sometimes a real show stopper for a correct geological interpretation; in particular there are environments like thrust belts where it is impossible to get “at least an image” of the subsurface despite a careful processing work. Unfortunately new frontier of exploration sometimes have to deal with such bad areas and with not properly acquired seismic data. In this paper will be described two processing algorithms that demonstrated themselves practically effective in
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Using Least-Squares to Reduce Migration Noise
Authors R. Leggott, R. Wombell, T. Noss, G. Conroy and G. WilliamsUsing Least-Squares to Reduce Migration Noise Richard Leggott (CGGVeritas) Richard Wombell (CGGVeritas) Tony Noss (CGGVeritas) Graham Conroy (CGG Veritas) and Gareth Williams (CGGVeritas) SUMMARY____________________________________________________________ Seismic data should be migrated before analysis and interpretation. However the process of migration is often a source of noise; this is especially true of onshore seismic data where an “acquisition footprint” is a common problem. The origin of this migration noise lies in the difficulty of computing an accurate migration operator. If simplifying assumptions are used such as regular acquisition geometry then the computation of the migration operator becomes practical. Such assumptions are almost universal
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