INVERSE SCATTERING SERIES DIRECT DEPTH IMAGING WITHOUT THE VELOCITY MODEL: FIRST FIELD DATA EXAMPLES

摘要

In Weglein et al. (2010) an update and status report were provided on the progress on the inverse scattering series (ISS) direct depth imaging without the velocity model. In that article, results on synthetics with sufficient realism indicated that field data tests were warranted. This paper documents those first field data tests. These first early tests are encouraging and indicate that ISS direct depth imaging on field data is possible. Each member of a set of three distinct data or algorithmic conditions and requirements are identified and shown to be necessary for inverse scattering direct depth imaging, without a velocity model, to be effective and to produce the accurate structural configuration of reflectors and interfaces in the subsurface. Taken together, that set represents both necessary and sufficient conditions. In addition, for ISS imaging, the CIG flatness condition is a necessary and sufficient indication that an accurate depth image has been reached. The latter property is in contrast to conventional velocity dependent imaging methods where common image gather (CIG) flatness is a necessary but not a sufficient condition that a correct depth image has been achieved. The next steps, and open issues, on the road between viable and providing relevant and differential added value to the seismic tool-box are described and discussed.