Chapter 9
Migration Summary

This chapter briefly summarizes the information about migration presented in previous chapters.

 

Introduction

Target audience

Overview

 

Seismic Modeling

 

Primary Concerns

Three Earth Models

Seismic Acquisition: The Basic Idea

Why Model?

Waves and Wavefields

The Scalar Wave Equations

Stress-Strain Equations

Algorithms

Variational Formulation and Finite Elements

Finite Differences

Model Boundaries

Fourier Based Methods

A Word About Sources

Huygens Principle and Integral Methods

Raytracing

Raytrace Modeling

Zero Offset Modeling

History

Data Acquisition

Zero Offset Hand Migration

Shot Profile Hand Migration in Two Dimensions

Curved Rays

Shot Profile Hand Migration in Three Dimensions

Remarks about Migration

Redundant Data

Swing Arms

Non-Zero Offsets

Stacking and DMO

Historical Summary

 

Zero Offset Migration Algorithms

The Migration Algorithm Hierarchy

Migration in Depth

Migration in Time

Migration Summary

 

Exploding Reflector Examples

Canadian Glauconitic Channel Play

Gulf of Mexico Salt Model

Granitic Overthrust

 

Prestack Migration

Wavefield and Wave-Motion Hierarchies

Shot Profile Prestack Migration

Partial Prestack Migratio–Azimuth Moveout (AMO)

Velocity Independent Prestack Time Imaging

Double Downward Continuation—Common Azimuth Migration

Common Offset Kirchhoff Ray-Based Methods

Beam and Plane Wave Migrations

Algorithmic Differences

 

Prestack Migration Examples

Common Azimuth on the SEG/EAGE C3-NA Synthetic

Kirchhoff versus One-Way on a Gulf of Mexico 2D Salt Synthetic

A North Sea Sill Synthetic

Marmousi Case Study

An Imaging Note and the BP 2.5 Dimensional Data

BP 2.5 D Data

BP 2004 Salt Structure Data

SEG AA' Data Set

Migration from Topography

The SMAART JV Sigsbee Model

SMAART JV Pluto Data Set

SEG/EAGE C3-NA Data Imaging

Anisotropic Earth Models

 

Data Acquisition

Array Effects

Aperture

Aliasing

Modern Acquisition Geometries

Data Acquisition Summary

 

Migration Summary

Computational Complexity

Velocity Sensitivity

Amplitudes

Conclusions

 

Isotropic Velocity Analysis

Migration Velocity Analysis Geometry

Constant Velocity Migration Velocity Analysis

Velocity Independent Migration Velocity Analysis

Migrated Common Image Gathers

Semblance-Based Isotropic MVA on CIGs, CAGs, and SMIGs

Painless (No Horizons) Velocity Model Construction

Horizon-Based Velocity Analysis

Residual Tomography

SEG AA' Case Study

Marmousi Case Study

 

Anisotropic Velocity Analysis

Anisotropic Earth Models

The Anisotropic Earth

Anisotropic Normal Moveout

Depthing

A VTI example

 

Case Studies

Salt Flood and Body Insert

Amplitude Preservation

Which One Should I Use?

Land Data PSTM Versus PSDM Comparison

Autopicking PSTM

Tomography

South Texas Fault Shadow

Blessing Texas Case Study

Data Mapping through AMO on the Blessing data

 

Course Summary