Posted on May 21, 2019
It’s been another good year at M-OSRP, with significant progress to report. Please see the link below for documentation and news items that describe overall program goals and strategies, and, within that framework, individual project objectives, progress and plans.
A recent invited presentation for Ecopetrol in Colombia
News and update from M-OSRP: May, 2019.
Below please find a succinct list and summary of the projects within M-OSRP:
PREPROCESSING FOR ONSHORE, OBS, and TOWED STREAMER ACQUISTION Developing and delivering new and more effective methods for the essential preprocessing steps that in addition to their intrinsic value are necessary prerequisites for the new high-end and most effective methods that eliminating free surface and internal multiples , and that subsequently depth image and invert primaries. Those prerequisites include: removing ground roll and preserving reflection data at all offsets, and source and receiver de-ghosting for towed streamer, on-shore and ocean bottom acquisition, accommodating both flat horizontal and non-flat acquisition surfaces.
MULTIPLE ELIMINATION FOR SURGICALLY REMOVING MULTIPLES THAT INTERFERE WITH TARGET AND RESERVOIR PRIMARIES Developing and delivering the next generation of urgently needed multiple removal capability, with the elimination of free surface and internal multiples, without depending on energy minimization adaptive subtraction and thereby accurately predicting and surgically removing a multiple that interferes with a target or reservoir primary, and with the unique ability to not damage the target or reservoir primary. The latter interference between a multiple and target primary can very frequently occur on shore and very often off-shore, as well. That next generation of capability will only be delivered by M-OSRP and for many sponsors that project and delivery is the business driver and ROI.
MORE EFFECTIVE MIGRATION AND DIRECT INVERSION VELOCITY ANALYSIS Progressing and delivering the first migration method for heterogeneous media that is equally effective at all frequencies at the target and reservoir. It provides improved structural resolution, illumination and amplitude analysis, compared to all current migration methods including RTM. This new and more effective migration will require a velocity model and we will progress a direct non-linear inverse scattering series method for velocity analysis as an alternative to all current indirect velocity analysis methods, for example, CIG flatness and FWI.
GAME CHANGING MIGRATION, DIRECT AND WITHOUT A VELOCITY MODEL
The direct inverse scattering series ( ISS) depth imaging without a velocity model will be progressed and delivered as a tool box option. In contrast to other new approaches to migration , for example, Interferometry and Marchenko imaging , that require a velocity model, the ISS direct imaging method is the only imaging method that is direct and doesn’t require a macro-velocity model or any other subsurface information.
The ISS direct depth imaging ( without a velocity )subseries derives from the same exact set of equations ,the inverse scattering series, that earlier derived, e.g. , the distinct ISS free surface and internal multiple subseries, and the subseries that performs Q compensation without knowing or needing to estimate Q. The ISS depth imaging subseries will once again have the same GAME-CHANGING delivery and impact and will play the same role, on processing primaries for structural determination and amplitude analysis , as ISS free surface and internal multiple removal has already delivered for effectively eliminating multiples. M-OSRP has the potential and opportunity to deliver that game changing next generation imaging effectiveness and capability- providing a new tool box option for the most complex, inaccessible and daunting imaging challenges- arranging for currently inaccessible targets and reservoirs to become accessible and delivered.
We will identify outstanding issues, and take the initial steps needed to take us from the current ISS direct depth imaging algorithm (without a velocity model )having passed an initial viability test on field data, to take its place as a tool box option.
ISS Q COMPENSATION WITHOUT KNOWING, ESTIMATING OR DETERMINING Q AND WITHOUT USING OR NEEDING LOW AND ZERO FREQUENCY DATA
YANGLEI ZOU and ARTHUR B. WEGLEIN
M-OSRP, Physics Department, University of Houston, Houston, TX 77204, U.S.A.
(Received June 2, 2018; revised version accepted October 12, 2018)
Zou, Y. and Weglein, A.B., 2018. ISS Q compensation without knowing, estimating or
determining Q and without using or needing low and zero frequency data. Journal of
Seismic Exploration, 27: 593-608.
MODELING AND DIRECT AND INDIRECT INVERSION: How only a direct inversion method can communicate whether our chosen ‘problem of interest’ is ‘ the problem we need to be interested in’.
Direct inverse methods assure that we have solved the problem of interest, and in addition they communicate whether the problem of interest is the problem that we (the seismic industry) need to be interested in. When a direct solution doesn’t result in an improved drill success rate, we know that the problem we have chosen to solve is not the right problem —- since the solution is direct and cannot be the issue. On the other hand with an indirect method, if the result is not an improved drill success rate, then the issue can be either the chosen problem, or the particular choice within the plethora of indirect solution methods, or both. The inverse scattering series (ISS) is the only direct inversion method for a multidimensional subsurface. Solving a forward problem in an inverse sense is not equivalent to a direct inverse solution. All current methods for parameter estimation, e.g., AVO and FWI, are solving a forward problem in an inverse sense and are indirect inversion methods. The direct ISS method for determining earth material properties, defines both the precise data required and the algorithms that directly output earth mechanical properties. For a 3D elastic earth model of the subsurface the required data is a 3x3 matrix of multi-component data, PP, PSH, PSV,SH SH… and a complete set of shot records, with only primaries. Each mechanical earth property is a distinct series, order by order in that 3x3 data matrix of primaries. With indirect methods any data can be matched and updated: one trace, one or several shot records, one component, multi-component, with primaries only or primaries and multiples. Added to that are the innumerable choices of cost functions, generalized inverses, and local and global search engines. Direct and indirect parameter inversion are compared. For a simple normal incident plane wave on a single horizontal reflector, and an acoustic model, the direct ISS method has more rapid convergence and a broader region of convergence. The difference in effectiveness increases as subsurface circumstances become more realistic and complex and in particular with band-limited noisy data.
I thought that it might be useful and timely to share one of the SEG Abstracts that we submitted last week, on multi-D internal multiple elimination without subsurface information.
In the second column of the first page there is mention of a new and very recent advance within M-OSRP that completely removes the need for near-surface information ( including at and immediately below the measurement surface , for example, at the earth’s surface or at and immediately below the ocean floor) for on-shore conventional and unconventional plays, and offshore OBS acquisition and processing- for example, for predicting the reference wave including ground roll, de-ghosted reflection data ( without damaging either the ground roll of the reflection data) and free surface and internal multiple elimination, depth imaging and amplitude analysis. That is in addition to ( and beyond) the current methods not needing subsurface information, starting at some distance below the measurement surface , which is no problem for the marine towed streamer but a major problem and obstacle at the earth’s surface for on-shore and OBS. Specifically that new advance in addition removes the need for any information whatsoever, beginning at the measurement surface ,and immediately below for example, at the earth’s surface and at the near surface and in addition to our previous deliveries not needing information in the subsurface. For marine towed streamer processing the goal is to utilize dual sensor acquisition , and broad band acquisition to predict reflection data and the direct wave without damaging either, and to bring a new level of efficiency to match the effectiveness of the ISS internal multiple eliminator.
This year’s M-OSRP Annual Technical Review will consist of video -taping presentations in early July 2019 ( that you will receive via a link)that review our program and all projects, goals and progress- and the schedule for proprietary well documented effective and efficient code deliveries for 2019 and 2020. After receiving the link with presentations, we will follow-up with individual company on-site and skype meetings with sponsors. We will return to our long-term traditional on-site UH M-OSRP Annual Technical Review in 2020.
These are busy and exciting times, we appreciate ( and thank you for) your constant encouragement and strong support. And we look forward to staying in touch.
Warmest best regards,
For your possible interest , the two links immediately below provide:(1) the presentations with synced slides of the 2018 M-OSRP Annual Technical review, with a menu to choose and select projects and topics of interest, and (2) an Executive Summary video presentation that starts with the simple and accessible solution for the wave-field in a homogeneous whole space due to an isolated point source and then derives all of the Green’s theorem and isolated task Inverse Scattering subseries methods that M-OSRP has pioneered, developed and delivered. 2018 M-OSRP Annual Technical Review Video and Synced Slides
Executive Summary – a single accessible derivation of all M-OSRP ISS and Green’s theorem methods
and a recent invited presentation for Ecopetrol in Colombia
News and update from M-OSRP: May, 2019.
Dr. Arthur Benjamin Weglein
Hugh Roy and Lillie Cranz Cullen Distinguished University Chair in Physics
Director, Mission-Oriented Seismic Research Program
Professor, Dept. of Physics, and Professor, Dept. of Earth and Atmospheric Sciences
Physics Department , SR1 617
University of Houston
Houston, Texas 77204-5005
Office phone 713-743-3848
Cell phone 832-858-9292
News and update from M-OSRP: May, 2019.
Arthur Weglein selected as Co-Editor-in-Chief of the Journal of Seismic Exploration
American Physical Society ”Thought leader” Interview with Arthur B. Weglein