Processing steps with alternative implementations
Seismic processing is
characterized by a sequence of processing steps, that is more or less fixed or
standardized; however, for each of these steps there are number of alternative
ways for their implementation. The choice of the most appropriate way depends on
geophysical considerations; therefore the processing geophysicist should have a
thorough understanding of the geophysical principles that underly these
processes.
An overview of the processing steps with, for each step a number
of alternative implementations, is given below:
-
Editing
- spike removal
- noise burst removal
-
Statics
- field statics, elevation corrections
- first arrival picking
- modelling of the near surface - long wavelength statics
- reflection signal picking
- residual statics calculation - short wavelength statics
- stackpower optimization (e.g. simulated annealing)
- wave equation redatuming
-
Stacking velocity analysis
- moveout behaviour and stacking velocity
- velocity analysis - velocity spectra - semblance analysis
- normal incidence times and normal incidence wavefront curvature
- common reflection surface (CRS) attributes
- velocity model building
- relationship of stacking velocity with dmo and time migration velocity
-
Signal-to-noise enhancement
- straight stack, weighted stack, diversity stack
- velocity stack
- median filter based methods
- ground roll filtering and swell noise filtering
- Wiener filter, matched filter, output energy filter
- Karhunen Loeve transform
- f,x-domain prediction filtering
- trace interpolation and survey regularization
-
Deconvolution
- spectrum estimation
- wavelet estimation
- attenuation and absorption
- estimation of the earth response
- vibroseis processing
- data adaptive deconvolution
- deterministic deconvolution
- partly deterministic partly adaptive (PDPA) deconvolution
- deconvolution methods:
- least-squares Wiener filters
- maximum-, minimum entropy or parsimonious deconvolution
- homomorphic deconvolution
- ARMA model deconvolution
-
Multiple elimination
- predictive deconvolution
- differential moveout methods:
- (weighted) stack
- k,f-domain
- linear or parabolic Radon transform
- convolution methods (SRME: (free) surface related multiples elimination)
- dereverberation with wave equation redatuming
- image processing techniques
-
DMO
- dmo and velocity analysis
- dmo and pre-stack imaging (PSI)
- 2D and 3D Kirchhoff implementation
-
Migration
- time migration - velocity analysis
- depth migration - velocity model building
- migration algorithms:
- finite difference algorithms
- Fourier domain;e.g. phase-shift, phase-shift plus interpolation
- Kirchhoff- or summation- or (weighted) diffraction stack migration
- Gaussian beam migration
- reverse time migration (RTM)
-
Velocity model building
- Coherency inversion or model based stack
- Map migration
- Dynamic map migration (DMM) or curvature inversion
- Stereotomography
- Traveltime inversion in the data domain (TTI)
- Traveltime inversion in the migrated domain (TTIMD)
- Common focus panel (CFP) analysis
- Tomographic velocity model building or CIG flattening
- Depth focusing analysis (DFA)
- Extended imaging conditions and wave equation migration velocity analysis (WEMVA)
- Differential semblance optimization (DSO)
- Full waveform inversion (FWI)
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