薄层陷频法

Discussion on notches-in-thin-bed

近来出现的谱分解法实际上就是已知的薄层陷频法。对砂泥岩薄互层段 ,用短时窗对地震道做傅里叶分析 ,可以显示薄层振幅谱和相位谱的周期性。对三维数据体目的层段做谱分析后 ,可以形成 (x ,y ,f)薄层振幅谱或相位谱数据体。非洲岸外的一个例子说明 ,在合适频率上做频率振幅切片有可能显示古河道。墨西哥湾的一个例子证明 ,做频率相位切片可以比党规三维振幅切片更清晰地显示断层。薄层谱还可用来估算薄层厚度及弹性参数。

The spectral decomposition emerged in recent years is actually the notches-in-thin-bed.For a thin interbed of sand and shale,the periodicity of its amplitude or phase spectrum can be unveiled with Fourier analysis in a narrow window.The data volume of amplitude or phase spectrum of a thin bed is generated for the targeted intervals with spectrum analysis.Amplitude slice at a particular frequency can depict possible palaeochannels as show in the example from offshore Africa.Faults are much clearer in phase slice than in conventional 3-D amplitude slice.An example that supports the claim is presented in the paper.Spectra are also used to estimate the thickness and elastic parameters of thin beds.Both the theory and application of notches-in-thin-bed are discussed in the paper.