Chapter 8: A Subtle AVO Anomaly
In this example, AVO analysis successfully identified a gas effect in a subtle, poorly defined amplitude anomaly on a line with acquisition difficulties. AVO analysis correctly predicts the contents of several wells on the seismic line.
AVO can be successful in distinguishing pay sands from wet rocks.
Iterative surface-consistent amplitude balancing revealed an AVO anomaly not apparent after one pass of balancing.
Figures & Tables
A cursory look at the contents of the book might lead the reader to belive that AVO is not a successful hydrocarbon indicator, as we show many examples of AVO predictions gone awry, and dry holes drilled based on AVO anomalies. However, a closer look at the pages will give the reader the message we are trying to convey: used properly and cautiously, AVO can be a valuable tool for direct detection. The preponderance of unhappy endings in the book is unavoidable, as the goal of this book is to provide information that may prevent other dry holes being drilled. Inevitably, the best lessons are learned from mistakes, a statement that applies to life in general as well as to seismic interpretation.