Instantaneous spectral difference anomaly extraction on prestack multi-angle gathers and its application
Chen Xuehua1,2, He Zhenhua1,2, Zhao Yan2, Zhong Wenli3
1. State Key Laboratory of Oil & Gas Reservoir Geology and Exploitation,Chengdu University of Technology,Chengdu,Sichuan 610059,China;
2. College of Geophysics,Chengdu University of Technology,Chengdu,Sichuan 610059,China;
3. College of Earth Sciences,Chengdu University of Technology,Chengdu,Sichuan 610059,China
Abstract：Since seismic reflection amplitude(or energy) and its low frequency components of the fluid-filled reservoirs on different angle stack gathers vary significantly,this paper presents a new fluid identification method using seismic low frequency components on prestack different angle stack gathers.The method first carries out instantaneous spectral decomposition of both near-angle and far-angle stack gathers,and then introduces an instantaneous spectral difference extraction formula by the low frequency spectral components.Finally a fluid identification section is obtained.Applications of the method on both offshore and onshore seismic data are given respectively in the paper.The results show that the detected hydrocarbon anomaly is consistent with the actual drilling.
