An AVO Indicator Based on the Impedance Concept

In the last two decades, many approximations for the PP reflection coefficient have been proposed in the literature. Basically, all of them are derived from the classical approximation of Aki & Richards, using additional assumptions on the medium parameters. The aim of constructing such approximations is to establish reliable attributes that can be capable to indicate the presence of oil or gas. In this work we review some well known approximations and their respective attributes. We also introduce a new indicator<br>based on a impedance-type of approximation for the reflection coefficient. Numerical examples are also provided.