Simultaneous determination of Q and AVO from surface seismic data

Knowledge of the interval quality factor value, Q, is of great interest in seismic exploration. Interval Q values can be used as a lithology and pore fluid discriminator as well as in processing of seismic data to restore high frequencies to deep reflectors. Q values are generally obtained from VSP data which has a spatial coverage limited to borehole locations therefore a method to derive Q from surface seismic data is desirable due to the much larger spatial coverage of the derived Q values. Pre-Stack Q Inversion is a method whereby not only is interval Q calculated from pre-stack data but as a by product attenuation-free AVO is produced. Here we introduce updates and extensions to the PSQI algorithm including an s-tau -p transform designed to overcome aliasing problems in tau-p domain data as well as inversion for powerlaw frequency dependent Q. The inversion intercepts are also analyzed with a view to deriving estimates of the p-wave, s-wave and density of the region surrounding and including the interval of interest. It is found that it is possible to constrain the highest interval velocity surrounding the region of interest through a Monte Carlo simulation.