Speaker Abstracts
February 3, 2010
PBGS Monthly Luncheon
Wave Equation Prestack Depth Migration for Improved Land Seismic Exploration
Morgan Brown, CEO of Wave Imaging Technology Inc., Houston
Abstract
Prestack depth migration (PSDM) is widely viewed as a technology which only applies under Gulf of Mexico salt or in extremely complicated geology. To the contrary, nearly every basin exhibits lateral velocity variations, causing time sags and other focusing effects which challenge the assumptions behind time migration (PSTM).
In theory, PSDM should always "beat" PSTM, but traditionally, PSDM has over-promised and under-delivered. We argue that the gap between theory and practice is proportional to the effort put into depth velocity estimation. In this talk, we demonstrate that by running multiple iterations of wave equation migration (WEM) focusing analysis at every shotpoint, radical imaging improvements can be made.
Typically, the industry uses Kirchhoff PSDM algorithms on land. A big reason is convenience--common-offset Kirchhoff PSDM provides offset and/or azimuth "gathers" for free. These gathers may be analyzed for AVO, velocity, or anisotropy effects. WEM algorithms can more naturally handle the amplitude variations due to velocity focusing effects but until recently, it was not known how to efficiently decompose WEM images into angle gathers.
The presented technology is applied to several onshore field data examples from the Gulf Coast and Mid-Continent.
Biography
Morgan Brown is CEO of Wave Imaging Technology Inc., a Houston-headquartered specialty seismic processing company focused on developing and applying innovative "wave equation" imaging tools to solve tough imaging problems the world over.
Brown has worked in R&D positions for Hess and 3DGeo and holds a B.A. in applied math from Rice University and a Ph.D. in geophysics from Stanford University.
