Overview of Geophysical Research Research Who: 7 PhDs 3 Post Docs 1 Res. Scientist 1 Visit. Prof. GTS What: Develop Improved Seismic Imaging Algorithms, Solve Practical Problems

Ideal Seismic Section c Given: d(x,y,t) = Lc Find: c = L-1 d Depth velocity Given: d(x,y,t) = Lc Find: c = L-1 d c 2 1 Time Depth

5 oil+processing companies Geophysical Research Science Earthquake CSIM Consortium 5 oil+processing companies Engineering Exploration

Geophysical Research Productivity 7 PhDs awarded since 2009 2017: 6 internships in USA and Aramco 5 KAUSTAramco employee CSIM Consoritum: Aramco, Chevron, TGS, CGG, TOTAL Number Papers Published In early years, through the joint project with CSIM on 3D Full Waveform Inversion (FWI) and the software it produced, Aramco has built the foundation for software development on FWI. Through constant communications and discussions with CSIM on industrial challenging problems, Aramco gained great benefits of generating innovative ideas and algorithms.   Dr. Tong Fei (senior Aramco scientist) Year Abdullah AlTheyab: Best Student Presentation SEG FWI Workshop Bejing 2015 Sherif Hanafy: 2017 SEG Honorary Lecturer for Middle East & Africa GTS: 2013 SEG Distinguished Lecturer & 2010 Kauffman Gold Medal

Our FWI Contributions Summarized 2017 Volume editor Yonghe Sun wrote: “The book is a comprehensive and up-to-date volume on geophysical inverse problems with applications to seismic imaging, migration velocity analysis, and full-waveform inversion….is a pioneer in many of the topics covered, including least-squares migration, migration deconvolution, traveltime-guided waveform inversion, and image-domain waveform inversion. The readers will benefit from the unique perspective of the author as both an outstanding researcher and educator.

3D Multiscale Phase Inversion of Seismic Data Lei Fu 4 km Given: d = Lc Find: c = L-1 d

Seismic Inverse Problem 4 km 6 km Given: dobs = Lc Find: c 2 + w2c-2 )d = F ( Soln: min || Lc-dobs|| 2 Dd 1000x1000x500 FD model 10,000 traces/shot 50,000 simulations/iteration 20-50 iterations 100s terrabytes input data  c(k+1) = c(k) + a[LTL]-1LT Dd

3D SEG/EAGE Overthrust Model a) True Model b) Initial Model nz=61; ny=401; nx=401; dx=10; Receiver #: 10000; Shot #: 1600; 25 Hz Ricker c) FWI Tomogram d) MPI Tomogram

Vovle 3D OBC Data a) Initial Model b) FWI Tomogram c) MPI Tomogram d) RTM Image Based on a) e) RTM Image Based on b) f) RTM Image Based on c) Cable 2 Cable 2 Cable 2

Vovle 3D OBC Data RTM Image for Cable2 a) Initial b) FWI c) MPI 2 4 6 Depth (km) 2 4 6 12 6 12 6 12 X (km) X (km) X (km)

Vovle 3D OBC Data Magnified Views of RTM Image for Cable2 Zoom View of Box A Zoom View of Box B 2.4 2.2 2.8 Depth (km) Depth (km) 2.6 3.2 3.0 5 6 5 6 5 6 8 9 8 9 8 9 X (km) X (km)

Two-anomaly Model a) True Model b) Initial Model c) FWI Tomogram nz=41; ny=81; nx=81; dx=10; Receiver #: 1600; Shot #: 400; 15 Hz Ricker c) FWI Tomogram d) MPI Tomogram

Problem: Local minima + Cycle Skipping in FWI Motivation Problem: Local minima + Cycle Skipping in FWI Inaccurate initial velocity model; Inaccurate amplitude modeling, attenuation medium (Q); Elastic effects; Noise; Solution: Multiscale phase inversion (MPI), less initial model and amplitude dependent, less affected by elastic effects, robust.

Vovle 3D OBC Data Survey Geometry Cable Location Shot Location Y (km) 6 # 12 400 m Shot Location Y (km) 3 # 2 # 1 6 12 X (km)