基于短时傅里叶变换的频谱比法提取吸收系数及应用

The Absorption Coefficient Extracted Based on Spectral Ratio and Its Application

地震波的衰减是指地震波在地层介质中传播时部分能量不可逆地转化为热的过程。地震波衰减信息是从纵波反射地震资料中提取的一个十分重要的物性信息,因为它对地层岩性及含油气性的灵敏度远远高于速度、密度等物性参数。结合实际地震资料,利用基于短时傅里叶变换的频谱比法对目标区的吸收系数进行提取,通过分析发现,含气层的吸收系数要强于周边地层,再结合钻井、地质、测井等资料综合分析,可以较好地预测含气层。

Seismic wave attenuation was an irreversible process of seismic-wave energy partially transformed into heat during its propagation in the medium.The information of seismic attenuation was an important property picked up from P-wave reflection materials,it was considered as far more sensitive to formation lithology and hydrocarbon than other parameters,such as velocity and density.In current seismic exploration,with the development of directly hydrocarbon detection and exploration,more and more attention was paid on seismic attenuation.To detect reliable magnitude of attenuation was an important theme of both practical and theoretical exploration,in combination with practical seismic data,absorption coefficient in target area is attracted by using frequency spectrum.It is found out in analysis that the absorption coefficient of gas-bearing horizon is higher than peripheral layer,and then in combination with data of geology and well logging,a preferable oil prediction can be obtained.