- Home
- Conferences
- Conference Proceedings
- Conferences
69th EAGE Conference and Exhibition incorporating SPE EUROPEC 2007
- Conference date: 11 Jun 2007 - 14 Jun 2007
- Location: London, UK
- ISBN: 978-90-73781-54-2
- Published: 11 June 2007
61 - 80 of 574 results
-
-
Analysis of Shear-Wave Splitting in Multicomponent Seismic Data for Oil-Water Discrimination during Water Flooding
Authors X. Y. Li, M. Chapman, Y. Zhang, Y. Wang and J. XiaB023 Analysis of Shear-Wave Splitting in Multicomponent Seismic Data for Oil-Water Discrimination during Water Flooding X.Y. Li* (British Geological Survey) M. Chapman (British Geological Survey) Y. Zhang (SinoPec) Y. Wang (SinoPec Shengli Oilfield Ltd.) & J. Xia (SinoPec Shengli Oilfield Ltd.) SUMMARY Understanding pore-pressure and saturation changes is important in mature reservoirs. Here we analyze shear-wave splitting in a 3D3C onshore survey from Shengli Oilfield China where the thin sand-reservoir has been undergone production through water-flooding which altered the fluid composition and the porefluid pressure. Dividing the data into orthogonal azimuthal sectors and processing each sector separately reveals significant shear-wave
-
-
-
Identifying Gas Channel Sweet Spots through Multi-Component Seismic Interpretation
By M. W. RothB024 Identifying Gas Channel Sweet Spots through Multi-Component Seismic Interpretation M.W. Roth* (Transform Software & Services Inc.) SUMMARY Lower Cretaceous fluvial sands offer tantalizing yet challenging gas plays in the Rocky Mountain basins of Canada and the United States. Reservoirs range from single sand channels often with high porosity and permeability to stacked sequences of channels hundreds or even thousands of feet thick generally of low porosity and permeability. Across this spectrum of reservoir types the similar objective is to identify drilling “sweet spots” using available seismic and other E&P data. In this case study the effectiveness of multi-component seismic
-
-
-
Irregular Sampling – From Aliasing to Noise
Authors G. Hennenfent and F. J. HerrmannB025 Irregular Sampling – From Aliasing to Noise G. Hennenfent* (University of British Columbia) & F.J. Herrmann (University of British Columbia) SUMMARY Seismic data is often irregularly and/or sparsely sampled along spatial coordinates. We show that these acquisition geometries are not necessarily a source of adversity in order to accurately reconstruct adequately-sampled data. We use two examples to illustrate that it may actually be better than equivalent regularly subsampled data. This comment was already made in earlier works by other authors. We explain this behavior by two key observations. Firstly a noise-free underdetermined problem can be seen as a noisy
-
-
-
Seismic Interference Noise Removal, Interpolation, and Regularization
Authors R. L. Abma, P. Jilek, S. S. Rothe and J. E. MikaB026 Seismic Interference Noise Removal Interpolation and Regularization R.L. Abma* (BP) P. Jilek (BP) S.S. Rothe (BP) & J.E. Mika (BP) SUMMARY Seismic interference noise also referred to as crew noise is the result of acquiring a survey while the sources used to acquire another nearby survey are being fired. Because large 3D surveys may last several months and may be close to each other it is likely that a survey suffering from any seismic interference will have a significant number of shot records with interference noise. Due to the size of 3D surveys an automatic method of removing the
-
-
-
Application of Frequency Split Structurally Oriented Filtering to Seismic Whitening and Seismic Inversion Workflows
Authors S. Helmore, A. P. Merry and I. HumberstoneB027 Application of Frequency Split Structurally Oriented Filtering to Seismic Whitening and Seismic Inversion Workflows S. Helmore* (Helix RDS) A.P. Merry (Helix RDS) & I. Humberstone (Helix RDS) SUMMARY This paper describes a new method that uses dip-steered filtering to improve the performance of subsequent seismic whitening and relative impedance inversion. Given favourable acquisition and processing parameters the availability of high frequency signals is ultimately limited by poor Signal/Noise ratio (S/N) at high frequencies. Dealing with this noise is key to accessing the high frequency information. We show that though spatial filters applied to broadband seismic data affect mainly the
-
-
-
Predictive Deconvolution for Correction of Nonstationary Seismic Records
Authors M. A. Poluboyarinov and D. B. FinikovB028 Predictive Deconvolution for Correction of Nonstationary Seismic Records D.B. Finikov (GeoTechSystem) & M.A. Poluboyarinov* (Deco Geophysical) SUMMARY Generalization of the autoregressive model for the case of nonstationarity is used. Proposed way of parameterization of nonstationarity allows effective correction of the waveform at even significantly nonstationary seismic data. Nostationary predictive deconvolution described can be used both for elimination of reverberations and for wavelet correction and provides better results than the traditional approach. EAGE 69 th Conference & Exhibition — London UK 11 - 14 June 2007 When seismic record does not satisfy stationary convolutional model the problem of waveform correction
-
-
-
Robust Wavelet Estimation and Blind Deconvolution of Noisy Surface Seismics
Authors M. A. van der Baan and D. T. PhamB029 Robust Wavelet Estimation and Blind Deconvolution of Noisy Surface Seismics M.A. van der Baan* (University of Leeds) & D.T. Pham (LMC-IMAG) SUMMARY Robust blind deconvolution is a challenging problem - in particular if the bandwidth of the wavelet is quite narrow (say around 2 octaves). The principal problem is to estimate the phase of the wavelet with sufficient accuracy. The mutual information rate is a general-purpose criterion to measure whiteness using statistics of all orders. We derive a modification of this criterion that measures the phase of the wavelet within its passband yet remains stable in the presence of
-
-
-
Unified Green's Function Representation for Interferometry
Authors K. Wapenaar, E. Slob, R. Snieder, D. Draganov, J. Thorbecke, J. van der Neut and S. de RidderB031 Unified Green's Function Representation for Interferometry K. Wapenaar* (Delft University of Technology) E. Slob (Delft University of Technology) R. Snieder (Colorado School of Mines) D. Draganov (Delft University of Technology) J. Thorbecke (Delft University of Technology) J. van der Neut (Delft University of Technology) & S. de Ridder (Delft University of Technology) SUMMARY It has been shown by many authors that the cross-correlation of two acoustic wave field recordings yields the Green's function between these receivers (in geophysics this is also known as ‘seismic interferometry’). Recently the theory has been extended for situations where time-reversal invariance does not hold
-
-
-
Data-Driven Regularization/Extrapolation Using Interferometry with the Direct Wave
Authors A. C. Ramírez Pérez, K. Hokstad and E. OtnesB032 Data-Driven Regularization/Extrapolation Using Interferometry with the Direct Wave A.C. Ramírez Pérez* (M-OSRP University of Houston) K. Hokstad (Statoil R&D Trondheim Norway) & E. Otnes (Statoil R&D Trondheim Norway) SUMMARY We present a method to extrapolate and regularize data. The procedure is based on crosscorrelation of the measured field with the direct wave and it is independent of earth properties. The method is derived from Green’s theorem and in principle requires the total field and its normal derivative at the receiver locations. Hence it is well-suited for OBS data. In order to apply the method to towed streamer data certain
-
-
-
Applications of Time-Domain High-Resolution Radon Demultiple
Authors M. A. Schonewille and P. A. AaronB033 Applications of Time-Domain High-Resolution Radon Demultiple M.A. Schonewille* (PGS) & P.A. Aaron (PGS) SUMMARY The frequency domain high-resolution (HR) Radon transform can provide improved resolution in the curvature direction compared with the frequency domain least squares transform. The time domain HR transform also provides improved resolution in the time direction and paradoxically in many cases also a further improvement of the resolution in the curvature direction. In this paper the effect of the improved resolution is studied on synthetic and field data and it is shown that particularly for more complex data the time domain HR Radon transform can
-
-
-
A Model-Based Two-Way Wave-Equation Approach for Multiple Prediction
More LessB034 A Model-Based Two-Way Wave-Equation Approach for Multiple Prediction Z. Jiang* (BP) & B. Hornby (BP) SUMMARY Multiples from the sea bed or salt boundary are usually strong and will interfere and generate artifacts on migration images. In order to attenuate these multiples one approach is to first predict and then subtract them. We use a model-based prediction method that requires a velocity model which contains the strong multiple generating interfaces such as the sea bed or salt boundary. This method is also a two-way waveequation approach in the sense that it solves the full wave equation by finite-difference approximation
-
-
-
Surface Related Multiple Prediction from Incomplete Data
More LessB035 Surface Related Multiple Prediction from Incomplete Data F.J. Herrmann* (University of British Columbia) SUMMARY Incomplete data unknown source-receiver signatures and free-surface reflectivity represent challenges for a successful prediction and subsequent removal of multiples. In this paper a new method will be represented that tackles these challenges by combining what we know about wavefield (de-)focussing by weighted convolutions/correlations and recently developed curvelet-based recovery by sparsity-promoting inversion (CRSI). With this combination we are able to leverage recent insights from wave physics towards a nonlinear formulation for the multiple-prediction problem that works for incomplete data and without detailed knowledge on the surface
-
-
-
Seismic Processing in the Inverse Data Space, Removal of Surface–Related and Internal Multiples
Authors A. J. Berkhout and D. J. VerschuurB036 Seismic Processing in the Inverse Data Space Removal of Surface–Related and Internal Multiples A.J. Berkhout* (Delft University of Technology) & D.J. Verschuur (Delft University of Technology) SUMMARY Considering the dominant role of multiple scattering in seismic data it is proposed to replace data matrix P by its inverse P-1 before starting seismic processing. Making use of the feedback model for seismic data it is shown that surface-related multiple scattered energy is mapped onto the zero time axis of the inverse data space. The practical consequence of this property may be significant: multiple elimination in the inverse data space simplifies
-
-
-
Advantages and Challenges of Wide Azimuth Data for 3D SRME
Authors D. Lin, W. Lin and B. VerWestB037 Advantages and Challenges of Wide Azimuth Data for 3D SRME D. Lin* (CGGVeritas) W. Lin (CGGVeritas) & B. VerWest (CGGVeritas) SUMMARY We use a synthetic dataset to demonstrate that 3D SRME is still effective and important for wide azimuth data. The wide distribution of azimuths actually helps 3D SRME processing with trace reconstruction by replacing extrapolations with interpolations. Therefore better predictions can be obtained from wide azimuth data compared to those obtained from narrow azimuth data. Migration results show that the stacking power of wide azimuth data suppresses multiples but leaves significant amount of multiple noise in the images.
-
-
-
3D Surface Related Multiple Elimination for Wide Azimuth Towed Streamer Seismic Data
By K. H. MatsonB038 3D Surface Related Multiple Elimination for Wide Azimuth Towed Streamer Seismic Data K.H. Matson* (BP America) SUMMARY The application of 3D SRME to Wide Azimuth Towed Streamer Seismic data represents a step forward in terms of predicting complex 3D multiples compared to methods that use Narrow Azimuth Streamer data alone. We present synthetic and field data tests and discuss some of the data processing challenges. EAGE 69 th Conference & Exhibition — London UK 11 - 14 June 2007 Introduction The application of Surface Related Multiple Elimination (SRME) has provided significant added value to practical processing projects over the
-
-
-
Adaptive Subtraction of Multiples – Application to Complex Seismic Data Onshore Libya
Authors C. Hanitzsch, L. J. van Veen, J. Ali and R. van BorselenB039 Adaptive Subtraction of Multiples – Application to Complex Seismic Data Onshore Libya C. Hanitzsch* (Wintershall) L.J. van Veen (Wintershall) J. Ali (PGS Geophysical) & R. van Borselen (PGS Geophysical) SUMMARY The main difficulties for processing seismic data in Wintershall’s onshore concessions in the Libyan Sirte Basin are the presence of severe noise high-amplitude surface related multiples and internal reverberations that are interfering and partially masking the primary signal and some localized complexities in the overburden. This paper discusses the application of a cascaded de-multiple approach that resulted in a significant enhancement of the structural image of the 3D seismic
-
-
-
Adaptive Multiple Subtraction in the 2D Wavelet Transform Domain
Authors I. Ahmed, K. H. Matson and Z. YuB040 Adaptive Multiple Subtraction in the 2D Wavelet Transform Domain I. Ahmed* (BP) K.H. Matson (BP) & Z. Yu (BP) SUMMARY In SRME the multiples are predicted by convolving the data by itself. It is a common practice in the industry to use Least-Squares adaptive subtraction in the space-time domain to match the predicted multiples to the multiples in the data. The existing Least-Squares adaptive subtraction in the space-time domain though quite robust does have some limitations. This paper will try to address some of those limitations by doing the Least-Squares adaptive subtraction in the 2D Wavelet-Transform domain. EAGE 69
-
-
-
Generalized Non-Hyperbolic Moveout Approximation
Authors S. B. Fomel and A. M. StovasB041 Generalized Non-Hyperbolic Moveout Approximation S.B. Fomel* (University of Texas at Austin) & A.M. Stovas (NTNU) SUMMARY We propose a general functional form for nonhyperbolic moveout approximations that can be applied to any kind of seismic media. The proposed form includes five coefficients as opposed to two coefficients in the classic hyperbolic approximation. In certain cases the number of coefficients can be reduced. In the general case determining the optimal coefficients requires tracing of only one non-zero-offset ray. Using analytical ray tracing solutions and numerical experiments we compare the accuracy of our approximation with the accuracy of other known approximations
-
-
-
NMO Inversion for Multilayer Subsurface with Horizontal Transverse Isotropic Layers
By E. BliasB042 NMO Inversion for Multilayer Subsurface with Horizontal Transverse Isotropic Layers E. Blias* (VSFusion) SUMMARY The NMO inversion problem for HTI medium was solved by Contrera et al (1999) using a technique originally developed by Grechka and Tsvankin (1999). They derived a formula for azimuth-dependent NMO velocity using 2x2 matrices responsible for the ‘interval’ NMO ellipses in each layer. Here I suggest an alternative approach to NMO velocity derivation for the multilayered transverse isotropic model with depth-varying orientation of the symmetry axis. This approach leads to a simplier explicit formula for NMO velocity. Explicit analytical formula for azimuth-dependent NMO velocity
-
-
-
Using CRS Processing to Design a Sparse 3D Acquisition Geometry
Authors G. Gierse, H. Bezouska-Strozyk, J. Thiessen and U. WeberB043 Using CRS Processing to Design a Sparse 3D Acquisition Geometry G. Gierse* (TEEC) H. Bezouska-Strozyk (TEEC) J. Thiessen (RWE Dea AG) & U. Weber (RWE Dea AG) SUMMARY 3D seismic acquisition proved to solve many complex subsurface problems which could not be addressed by 2D seismics. However 3D acquisition is expensive. This is the reason why sparse 3D acquisition has become popular which results in a lower image quality at lower cost. CRS processing is a tool which increases image quality again without the need for high subsurface fold in acquisition. It therefore proves to be the ideal combination
-