Arthur B. Weglein , Research and Publications: Update and Plans, Summer 2024

Posted on June 07, 2024

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Dear Colleagues and Friends, I hope that this note finds you very well. All is well on this end: very busy and very happy.

This note is an update on “Research, Objectives and Plans: ( Summer(2024))” and begins below.

A first draft is completed of, “Seismic Imaging and Inversion: Application of Direct Non-Linear Inverse Theory” ( Weglein, A.B. and Stolt, R.H.) for Cambridge University Press

The second volume of a two-volume set co- authored with Bob Stolt for Cambridge University Press entitled’ Seismic Imaging and Inversion: Application of Direct Non-Linear Inverse Theory’ has a first draft written, with 450 pages. We will keep you posted as it progresses, is edited, and published. The first volume ‘ Seismic Imaging and Inversion: Application of Linear Inverse Theory’ was published in 2012. Volume two provides a comprehensive framework that accommodates both volumes and allows the removal of assumptions in Volume 1. The methods in Volume II reduce to the methods in Volume I when the assumptions of Volume I are satisfied. The Seismic Physics Methods of Volume I derive from the classic Mathematical Methods in Physics as found in, for example, Morse and Feshbach, (1953) and Courant and Hilbert (1924)- the new superseding Seismic Physics in Volume II required (and derive from) a newly developed Mathematical Methods in Physics , that Volume II provides in the text and in Appendices.

A guide is provided for each seismic processing step describing the circumstances where any seismic processing option would be a cost-effective choice within the seismic toolbox.

The order of the chapters in Volume II follows the steps that seismic data takes in the seismic processing sequence. Please see the attachment where the title and preface of this volume can be found.

Removing the need for subsurface and near surface information for onshore and OBS exploration

A message from us, about a year ago, described one of the research topics currently being pursued that (as always in our history) starts by identifying and then addressing a prioritized seismic processing challenge, which in this case is a serious impediment to onshore and ocean bottom seismic exploration.

As with velocity estimation methods for depth imaging in marine and onshore exploration, there has also been much effort (but little real progress) in the past thirty-five years for near surface information for all conventional seismic imaging and inversion techniques.

The Inverse Scattering Series communicates ( via isolated task subseries) that all processing objectives are achievable directly and without knowing, estimating, or determining subsurface properties. That includes multiple removal, Q compensation, depth imaging and target identification- and now will be extended to not needing to know, estimate or determine near surface information.

The advance in removing multiples at all offsets without: adaptive subtraction, interpretive intervention, and without needing to know, estimate or determine subsurface properties (these benefits are only provided by the isolated task sub-series of the inverse scattering series) and are a direct response to that longstanding conceptual and practical problem. Please see the ( attached) recent overview paper on multiple removal co-authored with John Etgen of BP and Fred Melo and Jing Wu of Schlumberger Western/Geco.

Removing the need to know low and zero frequency data.

The recent paper on Q compensation ( without knowing, estimating, or determining Q) in JSE , with Yanglei Zou ( also please see the attachment) that in addition demonstrates that a new theory can achieve that goal without needing low or zero frequency data. The latter has positive implications and enormous practical consequences for other processing objectives and algorithms that currently require low frequency data.

A New and Recently Added Research Project: Medical Imaging

A new and recently added project within our research program is medical imaging- where current major challenges will be identified and then addressed. As with our history in seismic processing we plan to communicate with those who use medical imaging methods (e.g., physicians and surgeons ) to understand and identify the actual strengths and limitations, and under what circumstances current leading edge medical imaging capability is effective and when it fails.

In our experience, researchers are not the best source for identifying open issues and prioritized pressing challenges.

Contemporaneous with listening to the ‘customer’, i.e., physicians and surgeons, we read a selection of medical imaging literature, to match the circumstances where current capability fails with the limiting assumptions within current leading edge medical imaging capability- and the failure of those assumptions to be satisfied.

In general, methods are effective when their assumptions are satisfied and ineffective and fail when assumptions are violated. Once those violated assumptions are defined, the response can be to improve and satisfy the delivery of assumptions , and thereby to remove the violation, or to develop a fundamentally new capability and method that doesn’t make those assumptions- that is, removing the violation of assumptions by removing the assumptions.

We support either of these two responses for different assumptions and requirements. For example, for the former, we provide more effective methods to de-ghost data, and , and for the latter, we provide new methods for multiple removal, Q compensation, imaging, and inversion- without needing or determining subsurface information.

A clear, accurate and forthright identification of the challenges and obstacles being faced in medical imaging: that’s where a relevant research program begins – a program whose objective is to increase the overall capability of the medical imaging toolbox.

One area of our current interest is in early detection of cancer.

Recent Keynote addresses and the new messages they contain.

Below, please find several recent Keynote Addresses- one at the 2022 SEG International Conference Workshop on ‘FWI/FWM and New Imaging Concepts and Capability’ September 1, 2022 at the George R. Brown Convention Center in Houston, Texas USA, and one November 28-30 in 2023, at the SEG/KOC Workshop “ On-shore and Shallow Water Exploration Challenges” in Kuwait City , Kuwait and an extended and comprehensive version of the latter Keynote in 2024.

The extended version of the 2023 SEG/KOC Workshop Keynote presentation “A Perspective on Advances and Challenges in Seismic Exploration: 2024” can be found in the link below.

The link above also contains the slides of these two video recordings and the papers cited therein. The longer presentation provides “A Big Picture” with a more detailed and comprehensive seismic perspective.

Topics within this Keynote include:

Why all (direct and indirect)seismic processing methods require multiples to be removed at some point either initially or eventually ( of course that includes FWI).

That seismic waves are ubiquitous and have no illumination issues- but processing with intrinsic high frequency approximation/ ray theory methods such as Kirchhoff or RTM squeeze the recorded wave field back, into the subsurface along rays ( and rays are not ubiquitous) and therefore RTM migration produces illumination issues.

The new Stolt Claerbout III (SC III ) migration for smooth or discontinuous heterogeneous media is the only migration method that doesn’t make high frequency/ ray theory approximations in both the imaging principle and the propagation model. It is the only migration method that can automatically image and invert planar, curved or pinch-out reflectors. SCIII has higher resolution capability compared to Kirchhoff and RTM.

The inverse scattering series methods for attenuating and eliminating internal multiples are the only internal multiple removal methods that: contains a water speed SCIII migration and operates without knowing, estimating, or determining subsurface information.

No other internal multiple removal algorithm (e.g., Radon, Feed-back, Marchenko, Jakubowicz) satisfies one of those properties- let alone both.

A response to several prioritized onshore and shallow water open issues and challenges is presented.

In 1985, migration was conceptually and practically more advanced than multiple removal- now that situation is reversed. We hope that( in the near future) migration can catch up to multiple removal. Details are provided in the video presentations.

For your possible interest, please find the Keynote address presented at the 2022 SEG International Conference Workshop on ‘FWI/FWM and New Imaging Concepts and Capability’ September 1, 2022, at the George R. Brown Convention Center in Houston, Texas USA.

I hope that you find these presentations and publications to be informative, interesting, and worthwhile. I look forward to staying in touch.

In summary

In science and in research there are no closed subjects and ultimate solutions- it’s always a work in progress- and all scientific methods make assumptions and are provisional. Today’s reasonable assumption is tomorrow’s impediment to effectiveness and increased capability.

This two-volume set communicates both recent advances and open issues ( please see the KOC/SEG 2024 ( extended) Keynote Address in the second e mail of this update) . Thank you.

I look forward to staying in touch. Warmest and very best wishes, Art
























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Dr. Arthur Benjamin Weglein

Hugh Roy and Lillie Cranz Cullen Distinguished University Chair in Physics

Director, Mission-Oriented Seismic Research Program

Physics Department

University of Houston

Science and Research Building Room 617 

Houston, Texas, 77204-5005 

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