GEOL 757 - Seismic Imaging

Course Outline Call #84301 Instructor: J. Louie, 217 LME, x4219 Fall, 2001
Learning Objectives: This course ``provides a coherent overview of the whole field of data processing as it is used in petroleum exploration,'' (Claerbout, 1985) and is the basic course in seismic exploration at the University of Nevada. The course goes beyond the text by including introductions to tomography and finite-difference modeling developed by Profs. Robert W. Clayton and John E. Vidale, and material on Kirchhoff migration from Prof. John Louie. Further objectives from Claerbout (1985):
``As it happens, waves are marvelously geometrical objects, and much can be learned with little mathematical analysis. But you should begin the book having previous familiarity with calculus, complex exponentials, and Fourier transformation.
``Your knowledge won't be complete if you don't know some opinions as well as the facts. You will be getting opinions as well as facts when I explain the discrepancies between theory and industrial practice, and when I explain what should work but doesn't seem to.
``Prospecting for oil begins with seismic soundings. The echoes are processed by computer into images that reveal much geological history. Worldwide, echo sounding and image making constitute about a four-billion-dollar-per-year activity.
``... the skills developed in this book, computer implementations of concepts from physics, will always be of general utility.''

Schedule: 11:00-12:15 Tuesdays and Thursdays in LME 426. Please contact John Louie (784-4219) or come to 217 LME (one floor below Quad level) to work out schedule conflicts. First meeting is at 11:00 AM on Tuesday August 28.

Lectures: Two 75-minute lectures each week. See also the tentative schedule below.

Text: Jon Claerbout, 1985, Imaging the Earth's Interior, Blackwell, ISBN #0-86542-304-0, $50. Out of print; instructor has copies; read it on-line at Stanford; or download your own copy in PDF format, in parts through pages: 50; 100; 150; 200; 250; 300; 350; 400 (up to 1.7 Mb each). A copy will also be available at the reserve desk of the DeLaMare Mines/Engineering Library.

Call number: 84301

URL: http://www.seismo.unr.edu/ftp/pub/louie/class/757-syll.html

Grading: Labs and Discussions 40%; Midterm 20%; Project 40%
I encourage any student needing to request accommodations for a specific disability to please meet with me at your earliest convenience to ensure timely and appropriate accommodations.

  • Introduction

  • Zero-Offset Methods
    • Multiplicity and stacking
    • Exploding reflector model
    • Extrapolation and imaging
    • Migration
      • Impulse response and superposition
      • Hand migration
      • Dispersion relation for acoustic WE
      • Downward continuation
      • 2-d Fourier transforms
      • Phase-shift (Gazdag) migration
      • F-K (Stolt) migration
      • Lab 2: 2-d FFTs and migration
    • Physical and geological factors
      • Accuracy of seismic experiments
      • Property variation and the acoustic WE
      • Evanescent energy
    • Paraxial wave equation
      • Fourier derivation
      • Planewave derivation
      • Parabolic WE
      • 15, 45, and 60 degree extrapolators
      • Retarded coordinates
      • Thin lens term, time & depth migrations
    • Finite differencing
      • Explicit methods
      • Implicit methods
      • Tridiagonal systems
      • Stability
      • Lab 3: Finite differencing
      • Time-domain extrapolation
      • Absorbing boundaries
    • Perspective on extrapolation
    • Lab 4: Monochrome wave extrapolation
    • Dip filters
    • Splitting and full separation
      • 3-d migration
      • Thin-lens term
    • Lab 5: Time-domain downward continuation
    • MIDTERM

  • Multi-Offset Methods
    Multi-Offset (continued)
    • Survey sinking
      • Reciprocity
      • Dip and wavenumber
      • Double square root (DSR) equation
      • Imaging condition
      • F-K multi-offset migration
    • Separation of the DSR equation
      • Normal moveout (NMO)
      • Dip moveout (DMO)
      • Velocity analysis
    • Prestack partial migration
      • NMO as a dip filter
      • Fourier representation of DMO
      • DMO algorithm
    • Slant stack (p-tau or array phasing)
      • Impulse response
      • Radon transform
      • Inverse slant stack
      • Refraction velocity inversion
    • 3-d Kirchhoff migration
    • Signal/noise separation and enhancement
      • Coherence
      • Multi-dimensional linear transforms
      • Bayesian signal enhancement

  • Lateral Velocity Variation (as time permits)
    • Statics & ray coverage
    • Transmission tomography
      • Applications
      • Radon transform
      • Tomographic approximation
      • Linearization, velocity variation
      • Back projection
    • Traveltime Optimization
      • Nevada methods (not Monte-Carlo)
      • First arrivals
      • Reflection times
      • Reflection coherency
    • Diffraction tomography
      • Born approximation
      • WKBJ & far-field approximations
      • Inversion by back projection
      • Iteration
      • Approximations to elastic WE
    • Velocity-structure tradeoff
    • Finite-difference modeling
      • Acoustic and SH
      • Elastic
      • Boundary conditions
      • Source imposition
      • Stochastic media
    • Wide-angle experiments
      • Multiphase recording
      • Shallow effects
      • Frequency vs offset
      • Amplitude vs offset
      • Poisson's ratio and lithology

Fall 2001 Schedule

 Geol 757 meets each Tues. and Thurs. 9:30-10:45 in LMR 355 except as noted below:
DayDateSchedule Change
TuesdayAugust 28First lecture, 11-12:30, LME 426
Thursday30David Simpson lecture, 1:30-2:30, LME 322d
ThursdaySeptember 20Finish Lab 1
Tuesday25No Class, SCEC Meeting
Friday28Make-up Lecture, 11:00-12:30, LMR 355
ThursdayOctober 4Lab 2 DUE, in class
Tuesday9No Class, PASSCAL Meeting
Friday12Make-up Lecture, 11:00-12:30, LMR 355
Friday12Lab 3 DUE, in class
Thursday18No Class, UTEP Meeting
Friday19Make-up Lecture, 11:00-12:30, LMR 355
Thursday25Lab 4 DUE, in class
ThursdayNovember 1Lab 5 DUE, in class
Monday5Make-up Lecture, 1:30-2:45, LMR 253
Tuesday6No Class, Walnut Creek demo
Thursday8Project title DUE, in class
Tuesday13MIDTERM, in class
Monday15Project outline DUE, in class
Thursday22Thanksgiving Day, no class
FridayDecember 7Make-up Lecture, 1:30-2:45, LMR 355
Friday7Last class, evaluation at 1:30, lecture at 1:40
Tuesday11AGU Meeting, no class
Tuesday18PROJECTS DUE 5:00 PM in LME 217

Reference List to Inspire Projects