DUG has released the latest results from its elastic multi-parameter full waveform inversion (MP-FWI) imaging technology via major industry publications worldwide — First Break, The Leading Edge, GeoExpro and Oil Review Middle East.

DUG Elastic MP-FWI Imaging is not only a complete replacement for the traditional processing and imaging workflows, it also replaces the subsequent inversion workflow for elastic rock properties. It is a unique approach to seismic processing and imaging which turns the traditional paradigm on its head.

In 2022 DUG launched its revolutionary MP-FWI  imaging solution. Over 70 successful projects from all over the world have since been completed. The industry is now at the dawn of a new, even more exciting era — an era where elastic least-squares imaging is a reality!

The traditional processing workflow involves the testing and application of dozens of steps such as deghosting, designature, demultiple and regularisation, which are all designed to overcome the limitations of conventional imaging. These workflows are complex, subjective, and very time-consuming due to their serial nature and they rely on many assumptions and simplifications. All of these issues impact the output data quality. The resulting, primary-only data then undergoes a similarly complex model-building workflow to derive an estimate of the subsurface velocity, which is used for depth imaging. Post-migration processing is performed before the pre-stack reflectivity undergoes another workflow to derive rock properties that feed into interpretation, also relying on simplifications of the actual physics. As a result of these workflows projects can take many months to years to complete.

“Elastic MP-FWI Imaging accounts for both compressional and shear waves, handling variations in seismic wave dynamics as a function of incidence angle, including in the presence of high impedance contrasts and onshore near-surface geological complexity,” said Tom Rayment, DUG Chief Geophysicist. “Multiples and converted waves are now treated as valuable additional signal, increasing sampling, resolution and constraining the inverted parameters.”

Comparison of the reflectivity derived with DUG Elastic MP-FWI Imaging using raw field data, versus a conventional LS-RTM workflow using extensively pre-processed input. This legacy dataset was acquired in 2006 on the Australian North West Shelf. This region contains rapidly changing shallow velocity variations due to localised channel features and carbonates. The MP-FWI imaging results demonstrate an increase in spatial resolution – the channel features, reservoir flat spot, and complex faulting are sharper and more clearly delineated.

In the figure above, three equivalent crossplots of elastic rock properties are compared. The ellipses indicate the expected distribution of the labelled lithology and fluid combinations from statistical rock physics analyses of well log data. Quantitative interpretation requires true amplitudes and high signal-to-noise ratio. Less scatter translates to less uncertainty. DUG Elastic MP-FWI Imaging eliminates the need for a conventional pre-processing and imaging workflows, and a post imaging AVA inversion workflow, along with their assumptions/workarounds that ultimately affect the AVA compliance of the data. Ultimately, more certain predictions can be realised.

Here we compare the elastic rock property well ties from DUG Elastic MP-FWI Imaging (the blue curves on the left) to a conventional processing, imaging and AVA inversion workflow (the red curves on the right). It is obvious that the DUG Elastic MP-FWI Imaging results are a better match to the well.

DUG Managing Director, Dr Matthew Lamont, added: “We have invested over a decade of R&D to be the first to realise this opportunity. Our new Elastic MP-FWI Imaging technology is the product of a multi-year, significant and ongoing R&D effort, which has seen the continuous integration of complete-physics FWI imaging including viscoelasticity, anisotropy and multi-parameter updates. When using the full wavefield for simultaneous velocity model building, rock property inversion and true-amplitude imaging, a multi-parameter solution is a necessity.”

As well as three-component reflectivity and velocity, DUG Elastic MP-FWI Imaging enables the estimation of fundamental rock properties like P-impedance, density and Vp/Vs from field data, without the need for a secondary amplitude variation with angle (AVA) inversion step. DUG Elastic MP-FWI Imaging simultaneously resolves not only subsurface structural features but also quantitative rock property information while avoiding the need for extensive data pre-processing and (post-imaging!) AVA-inversion workflows.

In this land example, significantly better illumination and event continuity is obvious when comparing the sections, thanks to DUG Elastic MP-FWI Imaging of the full wavefield — that includes interbed multiples. Incredible near-surface detail has been resolved, as can be seen on the shallow depth-slices to the right. Subtle structural and stratigraphic features that were simply not imaged with a conventional processing and imaging workflow have now been resolved.

“The fact that DUG MP-FWI Imaging is delivering material imaging uplifts using field-data input is very powerful, but to couple this with high-resolution elastic rock property outputs for quantitative interpretation is even more exciting, providing immediate opportunities for new surveys and maximising the value of legacy datasets,” said Martin Stupel, Geophysical Manager, Geophysical Pursuit Inc.

These are very exciting times — welcome to the future of seismic processing and imaging!

Download your own copy of DUG’s latest elastic showcase here.