Lithology and Gas Detection by AVO Crossplot Polarization and Intercept Inversion

P039 LITHOLOGY AND GAS DETECTION BY AVO CROSSPLOT POLARIZATION AND INTERCEPT INVERSION Abstract 1 In this paper we try to study the causes of amplitude anomalies observed on true amplitude stacked seismic data in two southern Algerian gas fields using AVO crossplot analysis and acoustic impedance contrast estimation from AVO intercept. We present two examples associated with gas sandstones: Carboniferous gas sandstones in Sbaa basin and Ordovician gas sandstones in Ahnet basin. The two factors that strongly determine the AVO behavior of sandstones reflections are the normal incidence reflection R(0) called the intercept and the relative change in amplitude with