The Vp/Vs Inversion Procedure: A Methodology for Shallow Water Flow (SWF) Prediction from Seismic Analysis of Multicomponent Data.

摘要

The petrophysical properties characteristic of the sandsrnprone to shallow water flow (SWF) make themrnidentifiable due to their abnormally high Vp/Vs ratiosrncompared to the adjacent rocks. The Vp/Vs inversionrnprocedure identifies anomalies that could be related tornSWF sands and it is based on seismic inversion ofrnmulticomponent seismic data. The new approach forrnestimating the Vp/Vs ratio from multicomponent seismicrndata was evaluated on synthetic logs where thernestimated Vp/Vs ratios matched very well the realrnvalues. For real ocean bottom cable data (OBC) fromrnGOM, the Vp/Vs inversion procedure was used tornestimate Vp/Vs sections that showed clear anomaliesrnthat could be related to sand bodies responsible forrnSWF. These sections are useful for identifying highrnVp/Vs ratio zones and could be used to plan a drillingrnprogram to prevent SWF during perforation. Preliminaryrnanalyses indicate that the methodology has the potentialrnof being a direct hydrocarbon indicator (DHI) as well.