Seismic Interferometry and 3x3 Classification Matrix ..

Predicting Multiples & Primaries 1. Turn Primaries into Multiples, then Subtract * 2. Turn Multiples into Primaries, then Migrate Key Point: Every Bounce Pt on Surface Acts a New Virtual Source

Predicting Multiples from Primaries 2 Predicting Multiples from Primaries Turn Multiples into Primaries, then Migrate B x A x A A B G(B|x) G(A|x) S x * = G(A|B) Key Point #1: Common Raypath Cancels Key Point #2: Every Bounce Pt on Surface Acts a New Virtual Source Key Point #3: Summation over Sources Picks out Specular Contribution

Correlation Redatuming 2D Reflection Data ! k x = G(A|B) G(A|x)* G(B|x) B A x B A x B A x Key Point #5: Kills Source Statics and no need to know src location or excitation time Key Point #6: Huge increase in Illumination Area

Correlation Redatuming VSP ->SSP ! k x = G(A|B) G(A|x)* G(B|x) Standard VSP Primary VSP -> SSP

VSP Multiple (12 receivers 13 kft @ 30 ft spacing; 500 shots) 5000 Depth (ft) 13000 X (ft) 56000 TLE, Jiang et al., 2005

TLE, Jiang et al., 2005 Surface Seismic Depth (ft) X (ft) 5000 13000 X (ft) 56000 TLE, Jiang et al., 2005

VSP Multiple (12 receivers 13 kft @ 30 ft spacing; 500 shots) 5000 Depth (ft) 13000 X (ft) 56000 TLE, Jiang et al., 2005

3D SEG Salt Model Test (He, 2006)

VSP Multiples Migration Stack of 6 receiver gathers ( Courtesy of P/GSI: ~¼ million traces, ~3 GB memory, ~4 hours on a PC ) (He, 2006)

Interferometry Summary ! k x = G(A|B) G(A|x)* G(B|x) B A x B A x B A x Key Point #1: Common Raypath Cancels Key Point #2: Every Bounce Pt on Surface Acts a New Virtual Source Key Point #3: Summation over Sources Picks out Specular Contribution Key Point #4: Kills Source Statics and no need to know src location or excitation time Key Point #5: Huge increase in Illumination Area

Outline SSP VSP SWP SSP SSP SSP SSP VSP SSP SWP VSP VSP SSP VSP VSP Output Data SSP VSP SWP SSP SSP SSP SSP VSP SSP SWP VSP VSP SSP VSP VSP VSP SWP SSP SWP SWP SWP VSP SWP SWP Input Data