System and method for seismic trace analysis
AssigneeChevron U.S.A. Inc.
InventorLeonard Lin Zhang
Life of this patent
Estimating the term…
Abstract
Seismic data are processed to reduce or eliminate aliasing due, for example to sparse or irregular sampling. An iterative method includes an inhibiting function used in conjunction with a function evaluating a magnitude of Fourier coefficients that together act to reduce the effects of aliased energies and preferentially select true energies. Computational steps are conducted primarily in k-space, without returning to x-space, thereby reducing computational costs.
Claims13
A method of processing a sampled seismic trace representing information relating to a subsurface region, comprising:
- estimating Fourier coefficients of the seismic trace using a discrete Fourier transform;
- selecting from the estimated Fourier coefficients by applying a coherence criterion to the estimated Fourier coefficients to reduce an amount of aliased energy represented by the Fourier coefficients, wherein the coherence criterion is a measure of coherence to a line segment that crosses the origin in ω-k space;
- re-orthogonalizing, using a processor, in k-space, the selected coefficients;
- and
- using the re-orthogonalized coefficients to produce a seismic image of the subsurface region.
A method of imaging a subsurface feature, comprising:
- receiving a sampled seismic trace including information relating to the subsurface feature;
- estimating Fourier coefficients of the seismic trace using a discrete Fourier transform;
- selecting from the estimated Fourier coefficients by applying a coherence criterion to the estimated Fourier coefficients to reduce an amount of aliased energy represented by the Fourier coefficients, wherein the coherence criterion is a measure of coherence to a line segment that crosses the origin in ω-k space;
- re-orthogonalizing, using a processor, in k-space, the selected coefficients;
- and
- applying an inverse Fourier transform to the re-orthogonalized coefficients to produce regularized seismic data.
A system for imaging seismic data relating to a subsurface feature, comprising:
- a data storage device having computer readable data including data relating to a sampled seismic trace including information relating to the subsurface feature;
- a processor, configured and arranged to execute machine executable instructions stored in a processor accessible memory for performing a method comprising:
- estimating Fourier coefficients of the seismic trace using a discrete Fourier transform;
- selecting from the estimated Fourier coefficients by applying a coherence criterion to the estimated Fourier coefficients to reduce an amount of aliased energy represented by the Fourier coefficients, wherein said coherence criterion is a measure of coherence to a line segment that crosses the origin in ω-k space;
- re-orthogonalizing, in k-space, the selected coefficients;
- and
- applying an inverse Fourier transform to the re-orthogonalized coefficients to produce regularized seismic data.
Dependencies are inferred from the claim text.