Seismic Interferometry Gerard Schuster University of Utah Instead

Seismic Interferometry Gerard Schuster University of Utah

Instead of using just primary arrivals, you also use the multiples for a wider view

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 Redatum sources below overburden Local VSP migration Instead of using just primary clearer arrivals, you also use the multiples for a wider vision

Overview of Seismic Interferomtery Short Course Data Extrapolation Instead of using just primary clearer arrivals, you also use the multiples for a wider vision

Overview of Seismic Interferomtery Short Course Hydrofrac location Monitoring 4 D Instead of using just primary clearer arrivals, you also use the multiples for a wider vision

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, 3 x 3 classification matrix, reciprocity theorems, applications to VSP, SSP, OBS, and Xwell data.

What is Seismic Interferometry? Answer: Correlation and summation of trace pairs and stacking the result for different shot positions iwtx. B e G(B|x)* iw(tx. B+ t. B+z tz)B e G(B|x) = iw( t. B+z tz. B ) = e G(B|B) Point Source Response with src at B and rec at B VSP => SSP B B direct z reflection A x G(A|B) Phase of Common Raypath Cancels Assume a VSP experiment

What is Seismic Interferometry? Answer: Correlation and summation of trace pairs and stacking the result for different shot positions - iwtx. B x e G(B|x)** iw(tx. B+ t. B+z tz)B e G(B|x) = iw( t. B+z tz. B ) = e G(B|B) Point Source Response with src at A and rec at B VSP => SSP B B direct z x x reflection G(A|B) A Phase of Common Raypath Cancels

What is Seismic Interferometry? Answer: Correlation and summation of trace pairs and stacking the result for different shot positions iwtx. B x e G(B|x)* iw(tx. B+ t. B+z tz)B e G(B|x) = iw( t. B+z tz. B ) = e G(B|B) Point Source Response with src at A and rec at B VSP => SSP B B direct z x x reflection G(A|B) A Phase of Common Raypath Cancels Do Not Need to Know Source Location! No Need to know Source Initiation Time!

Reciprocity Correlation Equation 2 D Reflection Data x k A) = G(x|B)* G(x| SSP VSP B G(A|B) B A A x x A Old Multiples Become New Primaries! Phase of Common Raypath Cancels

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

Interferometry Applications 3. SSP -> SSP : Interpolation 4. OBS-> OBS : Extrapolation 5. Source estimation

Interferometry Applications 6. Passive Imaging: Monitoring 4 D 7. Source Location Monitoring EOR