Gas saturation estimation from seismic data: What is the accuracy of our prediction and how can we improve it?

Seismic inversion can be viewed as a process in which one estimates the parameters governing the propagation of seismic waves in the subsurface. Seismic inversion technology can provides estimates of P-impedance, S-impedance, and density using prestack seismic data. AVO analysis (Castanga, 1993) based on Zeoppritz equations (or subsequent approximations) is the most popular tool with which to derive subsurface elastic attributes from seismic data. We note that other techniques such as waveform inversion (Malick, 1995) have been also used to derive the subsurface elastic attributes.