Instructor | Dr Tijmen Jan Moser (Moser Geophysical Services, The Netherlands) |
Date | 17-18 October 2021 |
Disciplines | Geophysics - Integrated Geophysics |
Level | Foundation |
Language | English |
EurGeol | 5 CPD points |
Keywords |
Course description
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.
Course Objectives
Upon completion of this course, the participants will:
Course Outline
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
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
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
Prerequisites
Participants' profile
The course is designed for a general audience of geophysicists, geologists and reservoir engineers.
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.