AVO examples of long-offset 2-D data in the Gulf of Mexico

For more than 17 years, AVO has been a primary tool for predicting a reservoir's rock type and pore-fluid content. However, the success of an AVO interpretation (recognition and validation of an anomaly) is constrained by the rock properties of the reservoir and its surrounding media. Class 3 and 4 anomalies are recognized as amplitude bright spots on stack data, and pore-fluid prediction is routinely accomplished by anomaly/background amplitude analyses. For Class 2 anomalies, AVO interpretation of prestack data is often needed just to recognize potential reservoirs. Finally, AVO interpretation in Class 1 environments is difficult because hydrocarbons don't yield bright spots or amplitude brightening with source-receiver offset. In short, success in recognizing an anomaly and validating its composition is best for Class 3 and 4 environments and poorest for Class 1.