Slide 1

Basic Seismic Processing INPUT FILTER CMP Gather NMO STACK MIGRATE DISPLAY GEOM VEL ANAL STATICS MUTE Slide 2 More Seismic Processing INPUT BP FILTER CMP Gather NMO STACK MIGRATE DISPLAY GEOM VEL ANAL STATICS DEMUX VIB CORR FK FILTER DECON DMO/ MIGRATE SAVE DECON FK FILTER MUTE GAIN RCVR COHERENCY ENHANCE COHERENCY ENHANCE TIME TO DEPTH EDIT Slide 3 Pre-Processing IN OUT DEMULTIPLEXING VIBROSEIS CORRELATION PtPt Corr S t Raw S t PtPt X= Issues: Demultiplex skew Issues: DeSpike B4 Corr Filtered Pilot Raw S -t PtPt * = Yilmaz, 2001 Slide 4 Vibroseis Correlation Yilmaz, 2001 Slide 5 Gain Recovery Options: Automatic Gain Control (AGC) Gain info lost Spherical Divergence (Need V t ) Exponential Gain Correction Programmed Gain Control (PGC) Trace to Trace Gain Balance Amplitude Statics Yilmaz, 2001 Slide 6 Gain Recovery Original with Spherical Gain Correction Yilmaz, 2001 Slide 7 Gain Recovery: AGC = window length AGC shadow Yilmaz, 2001 Slide 8 Editing Slide 9 Band Pass Filter stst t s t t Input Output SfSf f f f S f RfRf rtrt Filter X= * = Time domain Frequency domain Slide 10 Bandwidth/Filter Length Filter length Bandwidth = f 2 /f 1 50/2535/5 Slide 11 Filter Shape Slide 12 Band Pass Filter: Resolution Increasing frequency Increasing Bandwidth model Slide 13 Bandpass Filter Test TVF = Time Varying Filter Slide 14 FK (2D) Filtering t f x k Slide 15 FK Filtering Slide 16 Spatial Aliasing Slide 17 FK Filtering Slide 18 FK Spectra before after B4 After Slide 19 Convolutional Model * W t = Slide 20 Deconvolution conv decon Poor decon Slide 21 Deconvolution Slide 22 Deconvolution Before Decon After Decon