Seismic images are the basis of crucial exploration, development, and production decisions. Optimal use of these images requires a full understanding of the seismic imaging processes that create them, from data acquisition to the final migration.
The primary objective of this course is to provide a broad and intuitive understanding of seismic imaging concepts and methods that enables geoscientists to make the appropriate decisions during acquisition, processing, imaging, and interpretation projects. Another objective is to expose the audience to current trends in imaging research and empower them to adopt new technologies quickly.
The course is organized in four lectures. The first lecture introduces the fundamental concepts of seismic imaging. The remaining lectures focus on the solutions to three crucial problems encountered in practical application of 3D seismic data: 1) choice of the most effective migration algorithm, 2) estimation of the velocity model, and 3) poor image quality caused by irregular and inadequate data spatial sampling and incomplete subsurface illumination.
1. Introduction to 3-D seismic imaging
· Commonly used data-acquisition geometries and their impact on imaging
· Seismic imaging as a data focusing process and Kirchhoff migration methods
· Partial prestack migration and other approximations to full prestack migration
· Principles of wavefield-continuation equation migration
· The relationship between seismic velocity and migration
2. A user’s guide to the migration toolbox
· Time vs. depth migration
· Kirchhoff depth migration
· Depth migration by wavefield-continuation
· Anisotropic migration
· Current trends in depth migration (beam, plane-wave, and reverse-time migration)
3. The never-ending quest for the perfect velocity model
· Basic methods for velocity estimation (velocity spectra, Dix equation)
· Velocity estimation and complex structure
· Principles of reflection traveltime tomography
· Migration Velocity Analysis (MVA)
· Introducing geological knowledge in the MVA process
· Current trends in MVA (velocity scans, residual migration, wave-equation MVA)
4. Imaging, aliasing, and incomplete subsurface illumination
· Spatial aliasing and imaging artifacts caused by inadequate spatial sampling
· Avoiding aliasing in Kirchhoff migration and wavefield-continuation migration
· Imaging artifacts caused by irregular data geometry and incomplete illumination
· Illumination maps: how to use and not abuse them.
· Application of approximate regularized inversion to imaging enhancements
· Data-domain methods (data geometry regularization)
· Model-domain methods (imaging by least-squares migration)
Who should attend
All geoscience professionals who use or process seismic data will benefit from attending this course. The course emphasizes conceptual and graphical understanding and minimizes the use of mathematical developments. Therefore the course does not require a theoretical background in seismology and can be taken by a broad section of working geoscientists, including seismic interpreters, processors, and imagers as well as petroleum geologists and reservoir engineers.
Biondo Biondi is Associate Professor (Research) of Geophysics at Stanford University. Biondo graduated from Politecnico di Milano in 1984 and received an M.S. (1988) and a Ph.D. (1990) in geophysics from Stanford. He is co-director of the Stanford Exploration Project (SEP) and leads its efforts in 3D seismic imaging. SEP is an academic consortium whose mission is to develop innovative seismic imaging methodologies and to educate the next generation of leaders in exploration seismology. SEP's activities are supported by approximately 25 companies involved in oil & gas exploration and production.
Biondi has made contributions on several aspects of seismic imaging, ranging from velocity estimation to parallel algorithms for seismic migration. Since the early 1990s he has been at the forefront of the development of wave-equation 3D prestack migration methods. In 2004 the Society of Exploration Geophysicists (SEG) honored Biondi with the Reginald Fessenden Award for his "development of azimuthal moveout (AMO), ... AMO has contributed to many other developments in the areas of migration, multiple attenuation, and regularization of seismic data."
Biondi has recently written a book, 3D Seismic Imaging, that will be the first book to introduce the theory of seismic imaging from the 3D perspective. The book will be published by SEG in the Investigations in Geophysics series by the end of 2006.
Biondi is in close contact with the practical applications of seismic imaging by his involvement with 3DGeo Development that he co-founded in 1994. 3DGeo Development is a growing seismic services company that brings innovative technologies to the exploration industry such as wave-equation imaging and Internet-based seismic processing.