Lunchbox Geophysics

Explicit Depth Migration: Tips, Tricks, and Techniques

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Chad Hogan
CREWES/POTSI, University of Calgary

Friday, March 30th, 2007 – 12:00 PM
Aquitaine Auditorium, +15 level of 540 - 5 Avenue SW

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LunchBox Geophysics is free! Simply bring your own lunch (refreshments provided) and enjoy.

Abstract

As imaging problems become more complex and reservoirs become more difficult to find, we are motivated to spend a little more time to get the best image possible. In many cases, wave equation (wavefield extrapolation) migration can deliver exceptional high-quality images. The challenge is to make these migration algorithms feasible in terms of computational cost vs. quality of result. Our research is designed to provide better overall performance in wave equation prestack depth migration (PSDM).

My talk will focus on two major topics. First, I will introduce GPSPI wavefield extrapolation and place it in context with other major wavefield extrapolation techniques such as Gazdag's phase shift, Phase-Shift-Plus-Interpolation, split-step Fourier migration, and phase/pseudo-screen methods. I will describe how GPSPI is actually a general formulation that includes each of these methods as particular special cases. Second, I will describe some tips and tricks that we have developed in order to improve the performance of GPSPI-based algorithms, both in terms of computational efficiency and image quality. These tips and tricks apply to some or all of the special-case methods involved, and so can immediately be applied to current industrial PSDM processing.

Biography

Chad Hogan is originally from Red Deer, Alberta and has lived in Vancouver and Victoria for several years. He holds a B.Sc. in Physics and Mathematics (Coop) from the University of Victoria. During his co- op terms he worked in a wide variety of settings, including TRIUMF (the particle accelerator at the University of British Columbia), PanCanadian Petroleum, the Joint Astronomy Centre in Hawaii, and the Dominion Astrophysical Observatory in Victoria. After finishing his Bachelor's degree, he worked from 2000-2003 in information security management for various high-tech companies in Vancouver, and then as a research assistant at the University of Calgary in 2004. In 2005, he began graduate research with the CREWES project and the POTSI collaboration, supported by an SEG Foundation award and an NSERC postgraduate scholarship. He continues to pursue a Ph.D. degree with Dr. Gary Margrave and Dr. Michael Lamoureux. His research interests include imaging and migration, scattering theory, and applied mathematics.