Technical Library

Seismic Data Processing Technical Library

Frequency-domain rank-reduction applications in seismic processing
Presenter: Stewart Trickett
Presented at SEG 2015 as a post-convention workshop
Friday, October 23, 8:30 AM – Noon
Ernest L. Morial Convention Center, Room 215/216
New Orleans, LA, USA
Summary: Over the last 15 years, matrix rank reduction methods have been developed for noise removal and interpolation of seismic data. These methods have primarily been applied on constant-frequency slices, as a key theorem states that the signal should have low rank in this domain. Over the years these filters have been extended to multiple dimensions, robust filtering for erratic noise, source deblending, de-aliasing, tensor rank reduction, coherent noise removal, automatic rank determination, and computational speedups. I will briefly describe these developments and show many examples. I will also list some open questions and avenues for future research.

Preserving Signal: Automatic Rank Determination for Noise Suppression
Author: Stewart Trickett
October, 2015
Presented at SEG 2015
New Orleans, LA, USA
Summary: Matrix rank reduction filters such as Cadzow / SSA applied to constant-frequency slices have become popular for suppressing random noise on seismic data sets. A critical parameter for such methods is the matrix rank. A small rank gives strong noise suppression that may damage signal, and is best suited for noisy data and simple geological structures. A large rank gives weak noise suppression that preserves signal well, and is best suited for cleaner data and complex geological structures. Even within a single seismic survey, however, conditions change with time, space, and frequency, making a fixed rank inappropriate. Here I describe how the rank can be automatically determined for each matrix, allowing the filter to adapt to changing conditions. Examples are given on synthetic and real data. The result is an easy-to-use noise suppressor that finds a reasonable balance between signal preservation and noise removal throughout the section.

A New Upward and Downward Wavefield Continuation for Two-way Wave Equation Migration
Author: Dr. Jianhua Pan
October, 2015
Presented at SEG 2015
New Orleans, LA, USA
Summary: Dr. Jianhua Pan describes a new two-way wave equation migration that combines the efficiency of one-way wave equation migration with the imaging capability of reverse time migration. This approach extrapolates the wavefield in the frequency-wavenumber domain along the depth axis.

5D Interpolation of Seismic Data Using a Hybrid MWNI and POCS Algorithm
Author: Dr. Jianhua Pan
May 7, 2013
Presented at Integration 2013 – CSPG CSEG CWLS Joint Annual GeoConvention
Calgary, AB, Canada
Summary: The 5D interpolation of seismic data is becoming an important tool in seismic processing since data is seldom acquired with a spatial sampling that is optimal for processing. Two popular interpolation techniques currently used in the industry are MWNI (Minimum Weighted Norm Interpolation) and POCS (Projection onto a Convex Set). Both methods have their own advantages and disadvantages. In this poster, we propose an algorithm which combines these two techniques. The computational cost of this algorithm is cheaper than the usual POCS method and it retains the advantage of MWNI which has the ability to interpolate sparse datasets.

Bin-Share Stacking for 3D Converted Wave Processing
Authors: Dr. Alex A. Falkovskiy, Rob Tilson, Gerry Schlosser and Elvis Floreani
May 14, 2012
Presented at Vision 2012 – CSPG CSEG CWLS Joint Annual GeoConvention
Calgary, AB, Canada
Summary: A Bin-Share Stacking method is proposed for maintaining an optimum bin size for 3D converted wave stacking. This Bin-Sharing method for stacking converted waves allows for keeping the same grid and bin sizes as used for stacking P-P data, with the P-S data stacking radius equivalent to a larger bin size. One advantage of this is that the stacked P-S data is output on the same grid as the P-P data. A second advantage is to optimally vary the stacking bin radius with time which is important for shallow depths as the optimum bin size is larger than that of deeper horizons.

Kirchhoff Prestack Time Migration with Angle Domain Common Image Gathers
Authors: Dr. Jianhua Pan, Rob Tilson, Gerry Schlosser and Elvis Floreani
May 14, 2012
Presented at Vision 2012 – CSPG CSEG CWLS Joint Annual GeoConvention
Calgary, AB, Canada
Summary: This poster shows one method to construct angle gathers during prestack Kirchhoff time migration and another method to convert migrated offset gathers to angle gathers. The first method extracts angle gathers at each image point through gradients of travel time from the source and the receiver to the reflector. The second method calculates the angle at each image point with a certain offset for a given background velocity and a local dip, thus creating angle gathers.

Unraveling Cardium Tight Sand Paleo-depositional Trends and Subtle Structural Features using Seismic Reservoir Characterization
Authors: Valentina Baranova, Azer Mustaqeem, Elvis Floreani , Mike Gervais and Brendan Smith
May 9, 2011
Presented at Integration 2013 – CSPG CSEG CWLS Joint Annual GeoConvention
Calgary, AB, Canada
Summary: High resolution sequence stratigraphy associated with seismic attribute analysis can help distinguish paleo‐geographic features and natural sediment lineaments within Cardium formation. Moreover, the areas with different lithology and fluid types can be recognized using interval analysis. Seismic reservoir characterization tools allow better development drilling and if followed in conjunction with other data may result in better application of fracture simulation and eventually better yield of oil from tight oil sand package. We conclude in this study that using seismic reservoir characterization along with high‐quality 3D data and target oriented processing can make a huge difference in understanding the geology when it comes to development drilling and locating the areas of maximum yield in tight oil play.

Application of FX Singular Spectrum Analysis on Structural Data
Authors: Dr. Alex A. Falkovskiy, Gerry Schlosser and Elvis Floreani
May 9, 2011
Presented at Recovery 2011 – CSPG CSEG CWLS Joint Annual Convention
Calgary, AB, Canada
Summary: The application of the Singular Spectrum Analysis (SSA) method on seismic data has been extensively studied by researchers over the past number of years. Ulrych et al (1988) initially applied eigenimage filtering to seismic data. Trickett furthered this work by using frequency slices and extending eigenimage filtering to 3D data (Trickett, 2003, 2009). This poster studies the results of the SSA method when applied to noisy structural data. On both synthetic and real data, we show that the FX SSA filter (Cadzow filtering) preserves faults much better than the standard FX prediction filter (Canales, 1984). This poster discusses how the discontinuity in a plane wave would affect the rank of the trajectory matrix in SSA.

FX Cadzow / SSA Random Noise Filter: Frequency Extension
Authors: Dr. Alex A. Falkovskiy, Gerry Schlosser and Elvis Floreani
May 9, 2011
Presented at Recovery 2011 – CSPG CSEG CWLS Joint Annual Convention
Calgary, AB, Canada
Summary: The application of FX Singular Spectrum Analysis (SSA) or Cadzow filtering approach for random noise attenuation on seismic data started from the works of Ulrych et al (1988) on eigenimage filtering of seismic data. Trickett furthered this work by applying eigenimage filtering to 3D data frequency slices and later extended FX Cadzow filtering by forming a larger Hankel matrix of Hankel matrices in multiple spatial dimensions (Trickett, 2003, 2009). We propose to add another dimension for creating extended Hankel matrices. Instead of using a single frequency slice for composing the extended matrix, we pro-pose to use a range of frequency slices. This additional dimension of the matrix increases our statistics which improves the filter quality. The synthetic examples illustrate the filter quality improvement com-pared to the conventional FX Cadzow filter. Application of Frequency Extension (FE) filter in combination with FX Cadzow filter on real data showed better noise reduction compared to only FX Cadzow filtering.

A Practical One Way Scalar Wavefield Extrapolation: A Step Forward in True Amplitude Processing
Author: Dr. Zhengsheng Yao
May 10, 2010
Presented at GeoCanada 2010 – CSPG CSEG CWLS Joint Annual Convention
Calgary, AB, Canada
Summary: A new Phase-shift method for wavefield downward continuation is presented. Unlike conventional Phase-shift which is based on the one way scalar wave equation that is factorized from homogenous media, this method is derived by directly solving the full scalar wave equation to obtain one way wave propagation in an inhomogeneous media.

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