Posted on August 26, 2022
I hope that this note finds you very well. For your possible interest, please find in the link below an extended version of the Keynote address to be presented at the 2022 SEG Convention Workshop on “ FWI/FWM and new concepts for Imaging” on September 1, 2022, at the George R. Brown Convention Center in Houston, Texas, USA.
I am hugely grateful to Mariana Gherasim and the co-organizers of this Workshop, for the invitation to participate and the honor and privilege of presenting the Keynote address.
Warmest and very best wishes,
Below, please find some comments and observations , and several additional links that provide background, references and seismic physics derivations behind the topics presented in this talk. I hope that you find the video in the above link to be informative, interesting, and worthwhile.
Primaries and Multiples
A few additional comments- that relate to the objectives of this Workshop and the Keynote address. The title of the Keynote address is ‘A perspective on the role of primaries and multiples in seismic data processing’ and that covers all seismic methods. We then place the particular interest in using primaries and multiples for FWI/FWM within that broader context. Please see the one slide attachment that provides an overview of the presentation.
The starting point of a research project
One of the points we communicate is that for a research program to be relevant and useful, the starting point needs to begin with what is the current collective toolbox capability, and what is missing within the toolbox that the proposed research is seeking to address. What new seismic capability would be added to the toolbox if the new research would be successful?
The high-water mark of seismic imaging accommodation and capability
Within the area of seismic migration , the current high-water mark of imaging capability, is what we call Stolt- Claerbout III migration in a heterogeneous or discontinuous medium. That imaging method can automatically accommodate specular and non-specular reflectors, with planar, curved and pinch-out reflectors, to determine structure and to perform amplitude analysis.
Full Wave Imaging
We are hearing about Full Wave Imaging, that takes a derivative of a smooth velocity model, hoping for some shallow non-smooth variation- enough to call the derivative of velocity a reflector( reflectivity?). What about the frequent reflectors that are changes in density but not velocity. What about differentiating the density as a function of depth? And taking the derivative of a smooth velocity model , “Full Wave Imaging” is being offered as replacing ( and avoiding) the need to migrate?!! Is that differentiating a velocity model going to match or supersede a Stolt- Claerbout III imaging for planar, curved and pinch-out structural determination and subsequent amplitude analysis? In some real sense, FW Imaging looks like a giant step backward in concept, theory and intrinsic capability within the overall migration and imaging history and current migration toolbox.
Too big to fail
There is a real sense that the huge investment and marketing and overselling in FWI has produced something that ‘is too big to fail’ . And there is a scrabbling to go from its original claim as ‘the final and ultimate seismic method, that will deliver all subsurface information’ to now anxiously hoping to deliver anything. From promising everything to hoping for anything. Please understand that the model-matching method called FWI is not the issue. FWI doesn’t have an ego and ambition, and it did not oversell and market itself , and it never asked for ever bigger investments and bigger computers to provide a dividend .
Once again, I am deeply grateful and honored for the invitation to participate and to present this Keynote address . I look forward to an interesting, informative, and worthwhile ‘FWI and New Imaging Concepts’ Workshop.
Below please find links and a few references relevant to the Workshop and the Keynote Address