### Table of Contents

# Spring 2020 GP280 - 3D Seismic Imaging

### Course Facts

Lectures: | MWF 1:30-2:20 PM, via Zoom | |

Instructor: | Biondo Biondi | |

Teaching Assistant: | Rahul Sarkar | |

TA Office Hours: | T-Th: 4:00 pm - 6:00 pm (via Zoom). Please email Rahul in advance: rsarkar at stanford dot edu | |

3 units with labs, 2 units without; Grade only S/NC. | ||

5 computer-based homework assignments | ||

Schedule: | schedule.pdf | |

On the right: | Stack (after migration) of a 3-D data volume acquired over a salt body. |

### Course Description

Principles of imaging complex structures in the Earth subsurface by use of 3-D reflection seismology. The emphasis is on processing methodologies and algorithms, with examples of applications to field data. Topics include: acquisition geometries of land and marine 3-D seismic surveys, time vs. depth imaging, prestack Kirchhoff migration, dip moveout, zero-offset and prestack downward continuation, full separation and splitting, migration velocity analysis, velocity model building, imaging irregularly sampled and aliased data. Computational labs involve some programming.

##### Labs

The labs will be distributed through Canvas.

You will be given 5 hands-on homework assignments throughout the quarter. Although you are not expected to be an expert programmer, most of the labs require modification of Fortran90 code. If you run into trouble, refer to this list of Fortran90 tutorial.

Go to GP280 labs (older years)

##### Lectures

Date | Topic | Notes |

4/6 | Introduction | |

4/8 | 3D Geometries | (Chapter1) |

4/10 | Sep3D software | (Appendix A) |

4/13 | Kirchhoff prestack migration | (Chapter 2) |

4/15 | Kirchhoff prestack migration (isotropy vs anisotropy) | (Chapter 2 + Notes) |

4/17 | NMO+DMO+AMO and prestack partial migration | (Chapter 3) |

4/20 | Wavefield-continuation migration | (Chapter 4) |

4/22 | Common image gathers in offsets and angles | (Chapter 6) |

4/24 | Common image gathers in offsets and angles | (Chapter 6) |

4/27 | Numerical methods for wavefield-continuation – two-way wave equation | (Notes) |

4/29 | Numerical methods for wavefield continuation - one way wave equation | (Chapter 5) |

5/1 | Definition of waveform inversion – migration as adjoint of linearized modeling | (Notes) |

5/4 | Linearized waveform inversion – phase encoding in migration and inversion | (Notes) |

5/6 | Imaging and aliasing | (Chapter 8) |

5/8 | Imaging and irregular geometries | (Chapter 9) |

5/11 | Imaging and irregular illumination + linearized Inversion | (Chapter 9 + Notes) |

5/13 | Stacking velocity, Dix inversion, and traveltime tomography | (Chapter 10) |

5/15 | Inversion of stacking velocities (Chapter 10) and time migration velocity analysis | (Chapter 11) |

5/18 | Vertical and tomographic velocity updating | (Chapter 11) |

5/20 | Tomographic velocity updating | (Chapter 11) |

5/22 | Tomographic velocity updating | (Chapter 11) |

5/25 | Memorial Day, No class | |

5/27 | Full waveform inversion (FWI) | (Notes) |

5/29 | Full waveform inversion (FWI) | (Notes) |

6/1 | Migration velocity analysis by wavefield-continuation | (Notes) |

6/3 | Migration velocity analysis by wavefield-continuation | (Notes) |

6/5 | Tomographic Full waveform inversion (TFWI) | (Notes) |

6/8 | Full waveform inversion with Model Extension (FWIME) | (Notes) |

6/10 | Reviews and Q&A |

##### Additional notes

lloydBB.pdf | Lloyd's algorithm to choose optimal reference velocities for wave-equation migration |

Full-wave-2011.pdf | Solving the wave-equation using time domain finite-differences |

adjstate.pdf | Migration as the adjoint of linearized modeling |

WaveTomo-Combo.pdf | Full waveform inversion and wave-equation tomography |