Velocity Analysis Using Surface-Seismic Primaries-Only Data Obtained Without Removing Multiples E. Dokter, G.A. Meles, A. Curtis, K. Wapenaar MSCA-ITN-2014-ETN – GA N° 641943

Overview extraction of primaries-only data Convolutional interferometry Marchenko redatuming velocity analysis and migration

Extracting primaries-only data convolutional interferometry & Marchenko redatuming

Extracting primaries-only data convolutional interferometry & Marchenko redatuming

Extracting primaries-only data convolutional interferometry & Marchenko redatuming

Extracting primaries-only data convolutional interferometry & Marchenko redatuming

Extracting primaries-only data convolutional interferometry & Marchenko redatuming

Extracting primaries-only data convolutional interferometry & Marchenko redatuming ! Meles et al. (2016)

Extracting primaries-only data convolutional interferometry & Marchenko redatuming ! Meles et al. (2016)

Extracting primaries-only data convolutional interferometry & Marchenko redatuming ?

Extracting primaries-only data convolutional interferometry & Marchenko redatuming

Extracting primaries-only data convolutional interferometry & Marchenko redatuming

Extracting primaries-only data convolutional interferometry & Marchenko redatuming

Extracting primaries-only data convolutional interferometry & Marchenko redatuming 𝐺 𝑃1 𝑥 2 , 𝑥 1 ≈ 𝑆 1 2𝑖ω 𝑐(𝑥)ρ(𝑥) 𝐺 𝐹 − 𝑥, 𝑥 2 𝐺 𝐷 + 𝑥, 𝑥 1 + 𝐺 𝐷 + 𝑥, 𝑥 2 𝐺 𝐹 − 𝑥, 𝑥 1 𝑑 𝑆 1

Extracting primaries-only data convolutional interferometry & Marchenko redatuming 𝐺 𝑃2 𝑥 2 , 𝑥 1 ≈ 𝑆 2 2𝑖ω 𝑐(𝑥)ρ(𝑥) 𝐺 𝐹 − 𝑥, 𝑥 2 𝐺 𝐷 + 𝑥, 𝑥 1 + 𝐺 𝐷 + 𝑥, 𝑥 2 𝐺 𝐹 − 𝑥, 𝑥 1 𝑑 𝑆 2 𝐺 𝑃 𝑥 2 , 𝑥 1 ≈ 𝑘 𝑆 𝑘 2𝑖ω 𝑐(𝑥)ρ(𝑥) 𝐺 𝐹 − 𝑥, 𝑥 2 𝐺 𝐷 + 𝑥, 𝑥 1 + 𝐺 𝐷 + 𝑥, 𝑥 2 𝐺 𝐹 − 𝑥, 𝑥 1 𝑑 𝑆 𝑘

Extracting primaries-only data 1000 m/s

Velocity analysis and migration offset offset t offset t

Velocity analysis and migration 1000 m/s

Velocity analysis and migration 1000 m/s

Velocity analysis and migration 1000 m/s

Velocity analysis and migration 1000 m/s

Velocity analysis and migration 1000 m/s

Velocity analysis and migration 1000 m/s

Velocity analysis and migration 1000 m/s

Conclusion Synthetic example for generating primaries-only data → works even with wrong velocity model No artefacts (multiples), but long offset information may be missing Used data for semblance velocity analysis to build velocity model Reverse Time Migration of primaries-only data recovers all reflectors well and without artefacts