Seismic Diffraction – Modeling, Imaging and Applications
The application of seismic diffraction imaging (DI) in the E&P industry has rapidly accelerated in recent years and is now positioned to make a major impact as a routine method combined with PSTM and PSDM. This is because the uplift in resolution and detectability of small scale features offered through the imaging of the diffracted wavefield is fundamentally superior to attributes derived from post-processing of the reflection image. Applications cover a very wide range of objectives such as faults, fractures, karsts, stratigraphic edges, channels, fluid escape pipes, volcanic pipes, injectites. This course covers both the forward and inverse problem of seismic diffraction. The coverage of the forward problem extends from the discovery of the phenomenon of diffraction and the basic formulations of Fresnel and Kirchhoff to the evolution of modern seismic diffraction modeling. Diffraction imaging will be covered from the early works in the 1970s up to the present state of the art. Case studies will be presented covering examples for both structural and stratigraphic targets. The course will put emphasis on key components for successful DI case studies: • full integration of all available data, such as well data, legacy seismic, prior interpretation • optimal focusing during pre-processing, model building and migration • calibration of DI by Fresnel zone sampling to identify different components of the wavefield offering different interpretation perspectives • validation of DI by forward modeling exercises at various scales (elementary conceptual models, bespoke models, full-detail scenarios) • customization to interpretation throughout the workflow
Upon completion of this course, the participants will: • Have a detailed and up-to-date understanding of the physics of diffraction, diffraction modeling and imaging • Be able to effectively communicate the key aspects of diffraction technology with other professionals • Have a good understanding of the added value that seismic diffraction brings to current exploration and production projects
First day (4 hrs) 1. Introduction • Motivation, basic ideas and concepts • Reflection versus diffraction • Applications of diffraction analysis and imaging • Interpretation value 2. History • Discovery and founding years (1650-1820): Grimaldi, Huygens, Newton, Young, Fresnel, Poisson, Arago • Scalar diffraction: mathematical foundation — 19th century: Green, Helmholtz, Kirchhoff, Sommerfeld • Towards Geometrical Theory of Diffraction — early 20th century: Maggi, Rubinowicz, Keller • Towards Modern Theory: Trorey, Klem-Musatov 3. Diffraction Modeling • Motivation, definitions, objectives • Physical modeling • Numerical modeling: integral methods, boundary layer methods, surface and caustic diffraction, finite differences, time-lapse, scattering methods Second day (4 hrs) 4. Imaging • Motivation, definitions, objectives • Anatomy of diffraction • Diffraction and standard processing • Detection of diffracted waves • Separation of diffracted waves • Inversion of diffracted waves • Imaging • Common Reflection Surface/Multifocusing • Focusing and velocity estimation • Fracture detection • Model-based diffraction imaging • Illumination: edge and tip diffraction imaging • Resolution and super-resolution • Image processing and diffraction imaging Third day (4 hrs) 5. Applications/case studies • Carbonate Shales, Carbonate Ridges • Faults And Fractures, Fault Detection, Reservoir Fault Interpretation, Fractured reservoirs, Basement Fractures • Fluid Escape Features, Volcanic Pipes, Vertically Aligned Objects • Channels • Ground-Penetrating Radar Case Study
The course is designed for a general audience of geophysicists, geologists and reservoir engineers.
Prerequisites are a basic knowledge of seismic processing and imaging and a very elementary mathematical background. Recommended reading Klem-Musatov K., Hoeber H.C., Moser T.J. and Pelissier M.A. (editors) 2016. Classical and Modern Diffraction Theory, Geophysical Reprint Series Nr 29, SEG. Klem-Musatov K., Hoeber H.C., Moser T.J. and Pelissier M.A. (editors) 2016. Seismic Diffraction, Geophysical Reprint Series Nr 30, SEG.
About the Instructor
Tijmen Jan Moser has a PhD from Utrecht University and has worked as a geophysical consultant for a number of companies and institutes (Amoco, Institut Français du Pétrole, Karlsruhe University, Bergen University, Statoil/Hydro, Geophysical Insitute of Israel, Fugro-Jason, Horizon Energy Partners). Since 2005, he has been working as an independent consultant, associated with Z-Terra, SGS-Horizon and others. His main interests include seismic imaging, asymptotic methods, seismic reservoir characterization and diffraction. Since a few years he is also involved in geothermal exploration and microseismic monitoring. He has authored many influential papers on ray theory and ray methods, Born inversion and modeling, macro-model independent imaging, and diffraction imaging, several of which have received Best Paper awards. He has co-chaired Special Sessions devoted to Diffraction at the EAGE conferences of 2010, 2011 and 2012 and the Workshop on Seismic Diffraction Methods for Fault and Fracture Detection at the SEG conference in 2012, co-presented the EAGE Short Course on Seismic Diffraction (2011) and is co-editor of the SEG reprint volumes on Diffraction (2016). He co-organizes the APSLIM-IWSA woskhops taking place in the Czech Republic (2015, 2022). He is Editor-in-Chief of Geophysical Prospecting, has served on SEG’s “Geoscientists Without Borders®” and is serving on SEG’s Publication Committee and EAGE’s Oil, Gas and Geoscience Division Committee and Research Committee. He is a member of SEG and MAA, and honorary member of EAGE.