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Seismic Interferometry. Instead of using just primary arrivals, you also use the multiples for a wider & more complete view. Gerard Schuster University of Utah. Overview of Seismic Interferomtery Short Course. Primary reflections. Multiple reflections. Small vs Huge Illumination.
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Seismic Interferometry Instead of using just primary arrivals, you also use the multiples for a wider & more complete view Gerard Schuster University of Utah
Overview of Seismic Interferomtery Short Course Primary reflections Multiple reflections Small vs Huge Illumination Instead of using just primary arrivals, you also use the multiples for a wider vision
Overview of Seismic Interferomtery Short Course Local VSP migration Redatum sources below overburden Instead of using just primary arrivals, you also use the multiples for a wider vision clearer
Overview of Seismic Interferomtery Short Course Data Extrapolation Instead of using just primary arrivals, you also use the multiples for a wider vision clearer
Overview of Seismic Interferomtery Short Course Hydrofrac location Monitoring 4D Instead of using just primary arrivals, you also use the multiples for a wider vision clearer
Goal:Learn Principles and Algorithms in Seismic Interferometry Format Mornings: Lecture 50 minutes, followed by exercise or MATLAB lab. Format Afternoon: MATLAB labs+discussion. Topics: Deterministic interferometry, stochastic interferometry, 3x3 classification matrix, reciprocity theorems, applications to VSP, SSP, OBS, and Xwell data.
Point Source Response with src at B and rec at B G(B|x) G(B|x) = iwt xB e B B iw(t ) reflection direct xB e A G(A|B) iw( ) t + t + t + t e Bz zB Bz zB z Phase of Common Raypath Cancels x Answer: Correlation and summation of trace pairs and stacking the result for different shot positions What is Seismic Interferometry? * = G(B|B) VSP => SSP Assume a VSP experiment
Point Source Response with src at A and rec at B G(B|x) G(B|x) = * x iwt xB e B iw(t ) reflection direct xB e A G(A|B) iw( ) t + t + t + t e Bz zB Bz zB z x Answer: Correlation and summation of trace pairs and stacking the result for different shot positions What is Seismic Interferometry? - * = G(B|B) VSP => SSP B Phase of Common Raypath Cancels x
Point Source Response with src at A and rec at B G(B|x) G(B|x) = x iwt xB e B iw(t ) reflection direct xB e A G(A|B) iw( ) t + t + t + t e Bz zB Bz zB z x Answer: Correlation and summation of trace pairs and stacking the result for different shot positions What is Seismic Interferometry? * = G(B|B) VSP => SSP B Phase of Common Raypath Cancels Do Not Need to Know Source Location! No Need to know Source Initiation Time! x
! G(x|B)* G(x|A) = G(A|B) = [dG(A|x)G(x|B)* - G(A|x)dG(x|B)*]dx = Im[G(B|A)] k Im(G(A|B) x dn dn well SSP VSP VSP A A B B A x x Old Multiples Become New Primaries! Reciprocity Correlation Equation 2D Reflection Data k Phase of Common Raypath Cancels
stellar interferometry, a team of French astronomers has captured one of the sharpest color images ever made. They observed the star T Leporis with the European Southern Observatory's Very Large Telescope Interferometer (VLTI; Cerro Paranal, Chile), which emulates a virtual telescope about 100 meters across, and which revealed a spherical molecular shell around the aged star. Stellar Interferometry An astronomical interferometer is an array of telescopes or mirror segments acting together to probe structures with higher resolution.
Standard VSP vs Interferometric VSP Imaging Standard VSP Imaging Interferometric VSP Imaging Primary reflections Multiple reflections Small vs Huge Illumination Instead of using just primary arrivals, you also use the multiples for a wider vision
Interferometry Applications 1. VSP -> SSP : Small vs Huge Illumination 2. VSP -> SWP : Redatum sources below overburden Local VSP migration
5. Source estimation Interferometry Applications 3. SSP -> SSP : Interpolation 4. OBS-> OBS : Extrapolation
Interferometry Applications 6. Passive Imaging: Monitoring 4D 7. Source Location Monitoring EOR
1968 Claerbout V(z)+passive G(A|x)* G(B|x) ~ G(A|B) Cole+Claerbout V(,x,y,z)+passive? 1980s x Scherbaum earthquake V(z)+passive 1990s 1999 Rickett+Claerbout V(z) Helioseismolgy , passive Daylight Imaging Utah Stationary Phase Theory, SSP, and VSP 2001 Seismic Interferomtery, deterministic Wapenaar Recip. Thm. Correlation Type 2003-04 Snieder Stationary Phase Redatuming Gestoft + others Surface Wave Interferometry SELECTIVE HISTORY SEISMIC INTERFEROMETRY ! Shell Virtual Sources