Geophysics - Surface Imaging

The Principles of Quantitative Acoustical Imaging

 

Instructor

  Prof. Dr Dries Gisolf (Delft Inversion, Netherlands)

Duration

  2 days

Disciplines

  Geophysics – Surface Imaging

Level

  Advanced

Language

  English

EurGeol

  10 CPD points

Keywords

 
 AMPLITUDE   EXTRAPOLATION   FOURIER   INVERSION   MIGRATION   RADON TRANSFORM   REFLECTION   WAVE EQUATION   WAVE PROPAGATION 

 

Course description

This course presents a systematic approach to imaging of acoustic reflection data and the extraction of media property information from the image amplitudes, based on wave theory. Although the approach is valid for a wide range of acoustical frequencies and applications, there is a bias towards seismic imaging.

The theory of acoustic wave propagation is presented, from the constituent equations Hooke and Newton, to the acoustic wave equation, to wavefield extrapolation and eventually to extraction of image amplitudes. This last process is treated as an inversion problem, where downward projected wavefields are directly inverted for the media properties. A feature of the course is the careful analysis of every step in these processes in terms of the linearity of the wavefields in the media property representation they are inverted for. During the course, live demonstrations will be given that show practical implementations of the theory presented.

 

Course objectives

After attending the course, participants will have acquired a good understanding of the fundamental assumptions and limitations of state-of-the-art seismic migration. They will have been made familiar with the steps needed to extract quantitative property information from seismic data.

 

Course outline

  • Short recap on complex transforms (Fourier, Laplace, Radon)
  • Derivation of the acoustic wave equation
  • Derivation of wavefield extrapolation equations, forward and backward in space and time
  • The imaging condition and derivation of expressions for image amplitudes
  • Inversion of image amplitudes for media properties

 

Participants' profile

Geophysicists from oil & gas (service) companies, or geophysicists from academia, involved in R&D.

 

Prerequisites

Participants should have a basic understanding of the seismic method as well as familiarity with mathematical tools like complex numbers and integrals.

 

About the instructor

Prof. Dr Dries Gisolf

Prof. Dr Dries Gisolf graduated from the Delft University of Technology in 1971 and obtained his PhD at the University of Utrecht in 1975. In 1976 he joined Shell International Research Co. in Rijswijk, The Netherlands, as a seismic data processing geophysicist. Between 1980-2000 he held various positions for Shell in Oman, The Netherlands, Australia, Malaysia and Nigeria. Throughout his career with Shell he was involved in acquisition, processing and interpretation of seismic data, with an emphasis on quantitative prediction of reservoir properties. In September 2000 he was nominated as Professor of Acoustical Imaging and Sound Control at the Faculty of Applied Sciences at the Delft University of Technology. After retiring from TU Delft in 2010, he co-founded Delft Inversion in 2012, a service company providing high-resolution reservoir oriented inversion services to the oil and gas industry.

 

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