Least-Squares Migrations have been well studied for the last few decades and are essentially known for their good properties in improving the signal-to-noise ratio, increasing the resolution and giving more accurate and better-balanced amplitudes. We focus on Least-Square Reverse Time Migration for its ability to handle complex velocity fields with sharp velocity contrasts. In this paper we present a short list of issues faced on real data cases. We propose solutions to overcome them but mainly detail the problems coming from the limitations of Born modelling in such cases. We describe an innovative solution based on the use of an adaptive subtraction algorithm to deal with strong velocity contrasts in the background model. The efficiency of this method is proven on a simple synthetic example. Subsequent application on a real field will exhibit the potential of our approach for producing images with fewer artefacts and better reflectivity updates.


Article metrics loading...

Loading full text...

Full text loading...


  1. Agut, C., Duprat, V., BergouniouxE., BainaR.
    , 2017, Pre-Stack Least-Squares Reverse Time Migration: a Case Study From Deep Offshore West Africa, 79th EAGE Conference and Exhibition.
    [Google Scholar]
  2. Claerbout, J. F.
    , 1971, Toward a unified theory of reflector mapping: Geophysics, 36, 467–481.
    [Google Scholar]
  3. Duprat, V. and R.Baina
    , 2016, An efficient least-squares reverse-time migration using true-amplitude imaging condition as an optimal preconditioner: 78th EAGE Conference and Exhibition.
    [Google Scholar]
  4. Dutta, G., GiboliM., AgutC., WilliamsonP.
    , 2016, Least-Squares Reverse Time Migration with Radon preconditioning, SEG Technical Program Expanded Abstracts 2016: 4198–4203.
    [Google Scholar]
  5. Nemeth, T. and Wu, C. and Schuster, G. T.
    , 1999, Least-squares migration of incomplete reflection data: Geophysics, 64, 208–221.
    [Google Scholar]
  6. Schuster, G.
    , 1993, Least-squares crosswell migration: SEG Expanded Abstracts, 12, 25–28.
    [Google Scholar]
  7. Wong, M.
    , 2013, Handling salt reflection in Least-squares RTM, SEG Expanded Abstracts, 3921–3925.
    [Google Scholar]

Data & Media loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error