Seismic Processing Velocities - Geophysics
Introduction to 3D Seismic Velocities for Seismic Processing
What you will learn
The attendee will come to more fully understand the simplicities – and complexities – of seismic velocities.
Why are velocities so critical in the seismic processing method? How are velocities used in time migration compared to depth migration?
What are tomography and full waveform inversion? How do I understand this from a big-picture view? What is anisotropy? How can 5D interpolation be part of this?
These a non-mathematical presentations, showing the basics. Concepts are shown so that the viewer will better understand how and what these velocity terms mean.
This will help 3D seismic interpreters, geologists, geophysicists and seismic processors.
How are nmo velocities picked? What are flat gathers? How can accurate or inaccurate velocities image my depth structure?
Why take this course?
This course is about seismic velocities, especially as related to seismic processing and 3D seismic exploration. Each presentation contains hand-created graphics, illustrated to explain the concepts. The presentations are separated into 9 individual presentations. The users will better understand the importance of proper seismic velocities and how doing it wrong can severely harm your interpretation. But how using the right velocities, in the right procedures, can greatly help image the subsurface as well as find horizontal layering and vertical fractures.
Parts 1 & 2: Introduction to standard NMO velocities and multiples. How are velocities picked and how to avoid multiples.
Parts 3-5: Fundamental differences between time migration velocities and depth migration velocities. Why depth migration is required for areas with lateral velocity variations. How migrated gathers are affected. What are velocity sags and pull-ups? How to build a traditional sub-salt velocity model.
Parts 6 & 7: Tomography and Full Waveform Inversion. How they are used in depth migration to improve psdm velocity fields. How are gathers affected before and after tomo and fwi? Simple graphics explain each concept.
Parts 8 & 9: Anisotropy. VTI, HTI. Anisotropy can be used to help find horizontal rock layering and vertical fracturing. How does anisotropy look on seismic data?
Bonus - Part 10: merging multiple volumes
Additional Bonus! I narrate a real 2D land seismic project. You will see the geological motivation behind the project, the seismic acquisition and equipment, the key steps in the seismic processing and images of the final migration. You will understand why most areas of the results are terrific while a small portion is poorly imaged. The project is located in an area of sparse seismic activity - South Dakota in USA.