Industry Insights | Least-Squares Migration

Least-squares migration offers a powerful approach to a variety of problems encountered in seismic imaging. In this edition of Industry Insights, Andrew Long, Chief Scientist & Technology Analyst at PGS explains how it works, explores current thinking and uses of LSM, and predicts some of the interesting opportunities it presents to geophysicists.

 

Least-Squares Migration (LSM) treats seismic imaging as an inverse problem and can be implemented in a diverse range of ways. The common elements are that the output aims to provide an improved prestack depth migration (PSDM), and the velocity model is not updated during the process. When implemented using finite difference operators in an iterative workflow, LSM can be extended to imaging the full seismic wavefield.

In addition to improving the amplitude and spatial wavenumber content of seismic images, LSM is now being explored as a solution to compensate for different acquisition geometries and/or shooting directions in 4D projects, or as a possible solution to deliberately reduce the acquisition cost and effort.

Andrew presents the material in four sections:

  • Reasons to consider Least-Squares Migration
  • How Least-Squares Migration works
  • Industry trends
  • What’s next

Read the article in the PGS Technical Publications Library

A modern FWI velocity model (depth slice) example: The optimum platform for Least-Squares Migration (LSM)
This modern FWI velocity model (depth slice) example provides the optimum platform for Least-Squares Migration (LSM)