Redatuming Directly to Angle Gathers, for the Purpose of Target Oriented Quantitative Interpretation
A. Gisolf, P.R. Haffinger and P. Doulgeris
Event name: 77th EAGE Conference and Exhibition 2015
Session: AVO - Theory for Imaging & Reflectivity
Publication date: 01 June 2015
Info: Extended abstract, PDF ( 1.98Mb )
Price: € 20
A new method is presented that redatums surface recorded data directly to angle(horizontal slowness) gathers at a target boundary, without the need to associate angles with offsets by ray-tracing. The new method is fully wave-based and produces angle gathers at the target level of much higher signal-to-noise ratio than converntional migration followed by conversion of offsets to angles. This is because the wave-based method uses all input data to produce individual ouput angle traces. Also, the method is strictly true amplitude. The only assumption that is made is that the reflections over the target interval are azimuth independent. This is the same assumption that is made in any quantitative interpretation algorithm based on migrated data. The method is first illustrated with the help of a synthetic example that proves the true amplitude character of the redatuming procedure. The method is aso applied to real, deep North Sea data, where indeed the new direct angle redatuming procedure produces ouput of significantly higher signal to noise ratio than the conventional PSDM result, converted from offset to angle (horizontal slowness).