Application of Frequency Division AVO Technique in Gas Bearing Analysis in A Structure of Deep Water Area in South China Sea

In this paper it is founded out that applying AVO theory to field data leads to a great difference with real geological strata, the main reason for difference lies on the fact that the thin layer tuning effect modified the seismic AVO changing rule. The main target sandbody in A gas bearing structure shows strong amplitude anomaly and low P impedance in seismic data, but with no obvious AVO anomaly and inconsistence problem in AVO type between well and seismic data, So there is great multiple solutions in applying AVO technique to detect hydrocarbon. In order to avoid pitfall in application of AVO technique in this area, the seismic amplitude difference which caused by absorption and attenuation for difference frequency range were analyzed, the studies on frequency division AVO attribute for different frequency bands were conducted for A structure. The results show that frequency division AVO technique can effectively resolve the inconsistence problem for the reservoir AVO well-to-seismic responses, and then technique was applied in predicting favorite geological objects, and finally the correct prediction results were obtained.