Geoscience Professional Development Centre
Department of Geoscience, University of Calgary
Calgary, Alberta T2N 1N4
403-220-6445 (voice) | 403-284-0074 (fax)
gpdc@ucalgary.ca 

Winter 2009

A Practical Understanding of Poststack Migration (Course 34081)
and
A Practical Understanding of Prestack Migration (Course 34082)

Instructor: Dr. John Bancroft
Time: 0830 to 1630 hrs
Maximum class size: 20
Location: Earth Science Building, Room ES 254
Course # 34081 January 5 - 7, 2009
     Cost: 1,050.00 + GST
Course # 34082 January 8 - 9, 2009
     Cost: 700.00 + GST

Registration Form   (.pdf form)

Course information

These two courses present the basic methods of migration in a simple manner and uses diagrams and figures to illustrate principles.  The first course is three days and covers the basic algorithms of poststack migration, then discusses issues related to migration such as topography, frequency content, or parameters, to build a foundation for the following prestack course.  The second two day course deals with the prestack nature of migration and its superior capability of imaging the subsurface.  

A feature of these courses is the nature in which the material is presented.  Most pages in the notes contain a text page on the left with accompanying figures on the right.  The concepts are presented in an intuitive graphical manner without detailed mathematics that can obscure the fundamental concepts.  Some mathematics are included to illustrate the simplicity of the algorithms.  Numerous geometrical constructions are included in the notes to illustrate the simplicity of migration algorithms.   

This version of the course will include laboratory exercises that will evaluate modelling and migration programs. 

Poststack Course Description (3 days)

Zero offset seismic modelling is introduced first because of it’s simplicity as it represents a forward process.  These modelling concepts will later become part of the migration process itself.

A review of the Fourier Transform, aliasing, interpolation, velocity concepts, and the difference between time and depth migration are then presented. The various migration algorithms are introduced as the inverse process of modelling.  Practical methods for evaluating the migration algorithms are presented. 

Various topics that affect the migration qualities are examined, especially the problems associated with rugged topography.  

Prestack Course Description (2 days)

Prestack modelling with variable source receiver offsets are studied along with some prestack models.

Dip moveout is evaluated, especially the conditions under which it is a useful process.

Intended participants:

The course is designed for all geophysicists, independent of their background.  Each participant will have an understanding of the basic algorithms and should be able to communicate freely between processing specialists and seismic interpreters.  Those with computer skills will be able to write their own migration programs.

Instructor: John C. Bancroft, Ph.D., P. Eng., P.Geoph.

John Bancroft graduated from the University of Calgary with a B.Sc. in 1970 and an M.Sc. in 1972, both in Electrical Engineering.  He received his Ph.D. in Electrical Engineering from Brigham Young University in 1976.  After completing his degrees, he worked with the National Technical Institute for the Deaf / Rochester Institute of Technology as a Research Scientist quantifying speech parameters and as team member developing a cochlea implant.  In 1980 he changed his career to geophysics and moved back to Calgary to work at Geo-X Systems Ltd. as director of research, and then with Veritas Seismic from 1988 till 1990 as director of research.  In 1990, he started his consulting business, and in 1994 joined the CREWES project and Department of Geology and Geophysics (now the Department of Geoscience) at the University of Calgary.

During these years he developed extensive software for seismic processing including a complete 3-D processing system, along with surface consistent analysis for scaling, deconvolution, and statics.  He also developed a suite of migrations for 2-D and 3-D, pre and poststack, with FK, Kirchhoff and downward continuation algorithms. His new algorithm for prestack time and depth migration is recognized for its accuracy and speed and incorporate advanced features such as anisotropy.  Along with his interest in migration, he has written an extensive set of course notes on the practical aspects of migration, which are published by the SEG, and has taught courses in many international locations.   

Current research interests include pursuing the development of prestack migration and incorporating it into a seismic package that resolves statics and velocities independent of the CMP approach.  Additional extensions to the method include P-SV converted wave processing, anisotropy, and migration from rugged surfaces. 

Dr. Bancroft has served on numerous technical committees for the CSEG and SEG, and won the Best Paper award at the 1995 CSEG national convention, honourable mention in he 1994 International SEG Convention, a Best Paper at 1996 CGU, a best paper award at the 2001 ASEG national convention, and a runner-up best paper award in the 2003 CSEG national convention. 

In 2005, he was elected an “Honorary Member” of the CSEG.