- Home
- Conferences
- Conference Proceedings
- Conferences
60th EAGE Conference and Exhibition
- Conference date: 08 Jun 1998 - 12 Jun 1998
- Location: Leipzig, Germany
- ISBN: 978-90-73781-09-2
- Published: 08 June 1998
21 - 40 of 489 results
-
-
t-p Domain Combination of Dual-Sensor Ocean Bottom Cable Data
By R. WombellOBC data is usually processed assuming normal incidence and ignoring angular variations in the geophone response, water bottom reflectivity and reverberation period. A z-p domain decomposition allows the angular variations within the data to be separated and handled. An approach to handling the ghost attenuation is described
-
-
-
An Essential Processing Correction for Seabed Recording
By C. MacBethThe processing of recordings made at, or near, the seabed is rendered inaccurate by naturally occuring amplitude and phase changes
-
-
-
Azimuthal Moveout Analysis for Fracture Detection in Marine Streamer Data
By X-Y. LiIn dual-sensor ocean-bottom-cable surveys both pressure and velocity data are recorded. Both data sets contain the up-going energy convolved with their corresponding receiver-ghost operators. The ultimate goal of dual-sensor processing is to eliminate the ghost response and the water bottom reverberation
-
-
-
Hydrophone-Geophone Deghosting of OBC Data in the t-p Domain
By R. BaleThe receiver ghost for ocean bottom recording, unlike a towed streamer ghost, generates notches in the seismic passband. Fortunately, the positioning of dual or multi-component sensors on the sea bottom presents an opportunity for removing the receiver ghost and reverberation sequence whilst producing a single combined output from the hydrophone and geophone
-
-
-
3D Target-Oriented AVO Inversion of Data from the Statfjord Field
Authors S. Østmo, E. Tjåland, A. Buland and R. SollieStratigraphic full waveform AVO-inversion is a powerful technique for determining P- and S-wave velocities and densities from seismic pre-stack data
-
-
-
AVO Behaviour at the Top of a Class-4 Sand - a Case Study of the Maitland-1 Well
More LessThe Maitland gas field is located in the Barrow Sub-basin, offshore Western Australia. The well Maitland-1 was drilled in September 1992 on a strong amplitude anomaly. It intersected a 23m thick land with gas saturation. The well was plugged and abandoned as a gas discovery (Sit).
-
-
-
Improved Seismic Resolution of the Ty Reservoir by AVO-Processing, Sleipner Øst Field
Authors K. Duffaut, T. Erling and K. HorpestadThe field has its main production from a Paleocene deepwater sandstone reservoir . The main geophysical challenges in the field have been to identify the top reservoir, the reservoir pinch-out zone and internal reservoir geometry. To understand the seismic response at reservoir level a geophysical modeling study (including AVO-modeling) was performed. Well data and pre-stack data from 10 lines were used in the modeling. The modeling showed that the mis-tie between synthetic seismograms and surface seismic data in the hydrocarbon bearing part of the reservoir was caused by an AVO effect. Both the modeled and the real CMP-gathers showed a rapid decrease of the amplitude with offset including a polarity reversal. To avoid the effect of this polarity reversal on the stacked data the concept of Intercept-stack was introduced. The Intercept-stack is an extrapolation of the near offset reflectivity to zero offset.
-
-
-
Postcritical-Angle AVO for Carbonate Reservoirs
Authors O. K. Youn, H-W. Zhou, S. A. Hall and R. E. SheriffMost carbonate reefs under shale have small critical angle and small amplitude variation with offset (AVO) in the precritical offset range.
-
-
-
AVA and Residual Moveout
By I. MooreIt is well known that residual moveout can cause large errors in the estimate of amplitude versus angle (AVA) attributes, and in particular in the estimate of gradients. This paper illustrates the problem and proposes two complementary approaches to reducing the effect. Synthetic data are used to assess the effectiveness of these methods, which have also been applied to real data.
-
-
-
Are Near-Offset Shear Wave Conversions Useful?
By C. MacBethIt is standard to record near-or zero-offset VSP with three-component receiver tools. However, the principal use of these data is to determine model velocities and a high resolution section as an aid to interpretation of surface seismic data. These objectives are fulfilled using only the vertical component recordings.
-
-
-
Amplitude Versus Offset for Refracted Waves
Authors P. Borejko, E. Brückl and W. ChwatalThe analysis of amplitude versus offset (AVO) is widely used in reflection seismic processing and interpretation. By this technique lithological information (S-wave velocity and density) can be extracted from P-wave reflection coefficients.
-
-
-
Viscoacoustic Asymptotic Waveform Inversion of Ultrasonic Laboratory Data
Authors A. Ribodetti, H. -P. Valero, S. Operto, J. Virieux and D. GilbertIn this study, we test asymptotic diffraction tomography for viscoacoustic medium imaging by scaled model ultrasonic experiment. Diffraction tomography (namely, the inverse scattering problem) is a useful technique to save various classes of problems involving non destructive evaluation such as seismic exploration and ultrasonic medical imaging . Diffraction tomography is used to image the discontinuities of parameters describing the medium both in terms of localization and true amplitude of the discontinuities.
-
-
-
Joint 3D Inversion of Direct and Reflected Arrivals from Surface and SWD Seismic Data
Authors G. Rossi, P. Corubolo, G. Böhm, P. Dell‘Aversana and E. CeragioliVertical Seismic Profiles (VSP) provide an effective tie between well information (as logs and core analysis) and surface seismics, by linking the local geology to the Earth reflectivity. Seismic tomography gets similar benefits from the joint inversion of direct and reflected arrivals, recorded both at the surface and in a well.
-
-
-
Stochastic Inversion of Seismic Data by Evaluation of Pseudo-Wells
Authors B. Bril and P. De GrootA seismic inversion method is described based upon the ranking of realistic local subsurface models. Real wells and/or stochastically simulated pseudo-wells are scored at real seismic locations for seismic response and geostatistical probability. The resulting scores are analysed to yield both detailed local and generalised spadal information on geological and petrophysical subsurface properties.
-
-
-
Statistical Reservoir Thickness Estimation
By A. G. SenaWith the increasing availability of 3D seismic data, good quality amplitude maps can be generated for prospective horizons. In interpreting these maps the quantification of how much pay is involved is essential and difficult to obtain. By analyzing reflection amplitudes from nearby well log data, a systematic analysis of the amplitude variation with respect to lithology, porosity, hydrocarbon pore fluid saturation, bedding geometries, and reservoir thickness con be carried out.
-
-
-
Spatially Varying Wavelet in Seismic Inversion
Authors K. B. Rasmussen, H. Wagner and J. M. PedersenWith the introduction of relatively fast globally aptimized post-stack seismic inversion it is now possible to apply post stack seismic inversion of large seismic data volumes. Large seismic data volumes challenge the normal assurnption that a constant wavelet can be used to describe the relationship between acoustic impedance reflectivity and the seismic data for the whole tube. For this reason the determination and use of a spatially varying wavelet has been developed. It is presented below.
-
-
-
A High-Order Pertubative Approach - Examples of Inversion
Authors A. Druzhinin and A. HanygaA common procedure in nonlinear seismic inversion involves least squares optimization (LSO) [6,8] implemented by various Newton type iteratie algorithms [4]. Recent papers [2,3] indicate that the highorder perturbations can overcome the problems of the LSO concerning initial guess, a priori information, CPU/acquisition costs, etc. The purpose of this paper is to show how such additional constraints can be incorporated into the available LSO algorithms without their special modification.
-
-
-
Can we Image Complex Structures with Ray-Born Inversion?
Authors S. Xu, S. Operto and G. LambaréSummary not available
-